The purpose of this study is to develop a method to determine spare transformer number and location. Using Markov Chain method, state transition model and steady state probability was used on each 500-kV substation in order to analyze the effect of spare number and location variation with the reliability changes. To give an actual result of the case study, calculation of spare transformer number and location on 500/150 kV transformers in Java Bali System was analyzed. The steady state probability results will vary depending on the number of spare transformer, these results can then be used to assess the spare transformer needed. The variation of spare transformer location can be used to analyze the best possible location of the spare in order to satisfy the reliability required. The methodology presented shows an integrated calculation for determining the spare transformer number and location.
Generator Assessment of Hydro Power Station Adequacy after Reconstruction fro...IJECEIAES
Reliability analysis of substations and generator assessment of power plant stations are very important elements in a design and maintenance process. This paper presents a generator adequacy assessment of a classical “H” scheme for an open conventional substation, which is often used, and a new HIS - High Integrated Switchgear with SF6 gas isolation. Generator adequacy indices of both types of classical and HIS switchgear were compared and the results showed a high level of reliability and availability of the HIS presented substation. The input data were the annual reports of Croatian TSO-Transmission System Operator (HOPS) and statistics of operation events of Croatian National Electricity (HEP Inc.). For the HIS substation, the input reliability data were used from relevant international literature since only few of HIS substations are installed in Croatia. The generator is modelled with a three-state Markov state space model and Monte Carlo simulations were used for the generator assessment analysis. Adequacy indices LOLP and EDNS were obtained using DIgSILENT software.
ENHANCING RELIABILITY BY RECONFIGURATION OF POWER DISTRIBUTION SYSTEMS CONSID...Suganthi Thangaraj
The paper describes an effective method to reconfigure a power distribution system using optimization techniques. Here genetic algorithm is used for the reconfiguration to enhance reliability and to reduce losses. The reliability at the load points is evaluated using probabilistic reliability approach. For finding minimal cut sets and losses different algorithms are used. To maximise the reliability and to reduce the losses, the status of the switch is controlled using genetic algorithm. The effectiveness of the system is tested in 33 bus distribution system.
The document summarizes research on using a genetic algorithm to optimize the location and parameters of Flexible AC Transmission System (FACTS) devices in a power system. It first introduces FACTS devices and their ability to control power flow. It then describes using a genetic algorithm to simultaneously determine the optimal type, location, and rating of FACTS devices with the objectives of minimizing generation costs and power losses/voltage deviations. The methodology is tested on the IEEE 30-bus system with different FACTS device types. The results indicate the genetic algorithm approach can effectively determine the configuration of FACTS devices that increase system loadability.
Disturbance observer-based controller for inverted pendulum with uncertaintie...IJECEIAES
A new approach based on linear matrix inequality (LMI) technique for stabilizing the inverted pendulum is developed in this article. The unknown states are estimated as well as the system is stabilized simultaneously by employing the observer-based controller. In addition, the impacts of the uncertainties are taken into consideration in this paper. Unlike the previous studies, the uncertainties in this study are unnecessary to satisfy the bounded constraints. These uncertainties will be converted into the unknown input disturbances, and then a disturbance observer-based controller will be synthesized to estimate the information of the unknown states, eliminate completely the effects of the uncertainties, and stabilize inverted pendulum system. With the support of lyapunov methodology, the conditions for constructing the observer and controller under the framework of linear matrix inequalities (LMIs) are derived in main theorems. Finally, the simulations for system with and without uncertainties are exhibited to show the merit and effectiveness of the proposed methods.
Robust Evolutionary Approach to Mitigate Low Frequency Oscillation in a Multi...IDES Editor
This paper proposes a new optimization algorithm
known as Modified Shuffled Frog Leaping Algorithm (MSFLA)
for optimal designing of PSSs controller. The design problem
of the proposed controller is formulated as an optimization
problem and MSFLA is employed to search for optimal
controller parameters. An eigenvalue based objective function
reflecting the combination of damping factor and damping
ratio is optimized for different operating conditions. The
proposed approach is applied to optimal design of multimachine
power system stabilizers. Three different power
systems, A Single Machine Infinite Bus (SMIB), four-machine
of Kundur and ten-machine New England systems are
considered. The obtained results are evaluated and compared
with other results obtained by Genetic Algorithm (GA).
Eigenvalue analysis and nonlinear system simulations assure
the effectiveness and robustness of the proposed controller in
providing good damping characteristic to system oscillations
and enhancing the system dynamic stability under different
operating conditions and disturbances.
Estimation of Weekly Reference Evapotranspiration using Linear Regression and...IDES Editor
The study investigates the applicability of linear
regression and ANN models for estimating weekly reference
evapotranspiration (ET0) at Tirupati, Nellore, Rajahmundry,
Anakapalli and Rajendranagar regions of Andhra Pradesh.
The climatic parameters influencing ET0 were identified
through multiple and partial correlation analysis. The
sunshine, temperature, wind velocity and relative humidity
mostly influenced the study area in the weekly ET0 estimation.
Linear regression models in terms of the climatic parameters
influencing the regions and, optimal neural network
architectures considering these climatic parameters as inputs
were developed. The models’ performance was evaluated with
respect to ET0 estimated by FAO-56 Penman-Monteith method.
The linear regression models showed a satisfactory
performance in the weekly ET0 estimation in the regions
selected for the present study. The ANN (4,4,1) models,
however, consistently showed a slightly improved performance
over linear regression models.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Power System State Estimation - A ReviewIDES Editor
This document provides a review of power system state estimation techniques. It discusses both static and dynamic state estimation algorithms. For static state estimation, it covers weighted least squares, decoupled, and robust estimation methods. Weighted least squares is commonly used but can have numerical instability issues. Decoupled state estimation approximates the gain matrix for faster computation. Robust estimation uses M-estimators and other techniques to handle outliers and bad data. Dynamic state estimation applies Kalman filtering, leapfrog algorithms, and other methods to continuously monitor system states over time.
Generator Assessment of Hydro Power Station Adequacy after Reconstruction fro...IJECEIAES
Reliability analysis of substations and generator assessment of power plant stations are very important elements in a design and maintenance process. This paper presents a generator adequacy assessment of a classical “H” scheme for an open conventional substation, which is often used, and a new HIS - High Integrated Switchgear with SF6 gas isolation. Generator adequacy indices of both types of classical and HIS switchgear were compared and the results showed a high level of reliability and availability of the HIS presented substation. The input data were the annual reports of Croatian TSO-Transmission System Operator (HOPS) and statistics of operation events of Croatian National Electricity (HEP Inc.). For the HIS substation, the input reliability data were used from relevant international literature since only few of HIS substations are installed in Croatia. The generator is modelled with a three-state Markov state space model and Monte Carlo simulations were used for the generator assessment analysis. Adequacy indices LOLP and EDNS were obtained using DIgSILENT software.
ENHANCING RELIABILITY BY RECONFIGURATION OF POWER DISTRIBUTION SYSTEMS CONSID...Suganthi Thangaraj
The paper describes an effective method to reconfigure a power distribution system using optimization techniques. Here genetic algorithm is used for the reconfiguration to enhance reliability and to reduce losses. The reliability at the load points is evaluated using probabilistic reliability approach. For finding minimal cut sets and losses different algorithms are used. To maximise the reliability and to reduce the losses, the status of the switch is controlled using genetic algorithm. The effectiveness of the system is tested in 33 bus distribution system.
The document summarizes research on using a genetic algorithm to optimize the location and parameters of Flexible AC Transmission System (FACTS) devices in a power system. It first introduces FACTS devices and their ability to control power flow. It then describes using a genetic algorithm to simultaneously determine the optimal type, location, and rating of FACTS devices with the objectives of minimizing generation costs and power losses/voltage deviations. The methodology is tested on the IEEE 30-bus system with different FACTS device types. The results indicate the genetic algorithm approach can effectively determine the configuration of FACTS devices that increase system loadability.
Disturbance observer-based controller for inverted pendulum with uncertaintie...IJECEIAES
A new approach based on linear matrix inequality (LMI) technique for stabilizing the inverted pendulum is developed in this article. The unknown states are estimated as well as the system is stabilized simultaneously by employing the observer-based controller. In addition, the impacts of the uncertainties are taken into consideration in this paper. Unlike the previous studies, the uncertainties in this study are unnecessary to satisfy the bounded constraints. These uncertainties will be converted into the unknown input disturbances, and then a disturbance observer-based controller will be synthesized to estimate the information of the unknown states, eliminate completely the effects of the uncertainties, and stabilize inverted pendulum system. With the support of lyapunov methodology, the conditions for constructing the observer and controller under the framework of linear matrix inequalities (LMIs) are derived in main theorems. Finally, the simulations for system with and without uncertainties are exhibited to show the merit and effectiveness of the proposed methods.
Robust Evolutionary Approach to Mitigate Low Frequency Oscillation in a Multi...IDES Editor
This paper proposes a new optimization algorithm
known as Modified Shuffled Frog Leaping Algorithm (MSFLA)
for optimal designing of PSSs controller. The design problem
of the proposed controller is formulated as an optimization
problem and MSFLA is employed to search for optimal
controller parameters. An eigenvalue based objective function
reflecting the combination of damping factor and damping
ratio is optimized for different operating conditions. The
proposed approach is applied to optimal design of multimachine
power system stabilizers. Three different power
systems, A Single Machine Infinite Bus (SMIB), four-machine
of Kundur and ten-machine New England systems are
considered. The obtained results are evaluated and compared
with other results obtained by Genetic Algorithm (GA).
Eigenvalue analysis and nonlinear system simulations assure
the effectiveness and robustness of the proposed controller in
providing good damping characteristic to system oscillations
and enhancing the system dynamic stability under different
operating conditions and disturbances.
Estimation of Weekly Reference Evapotranspiration using Linear Regression and...IDES Editor
The study investigates the applicability of linear
regression and ANN models for estimating weekly reference
evapotranspiration (ET0) at Tirupati, Nellore, Rajahmundry,
Anakapalli and Rajendranagar regions of Andhra Pradesh.
The climatic parameters influencing ET0 were identified
through multiple and partial correlation analysis. The
sunshine, temperature, wind velocity and relative humidity
mostly influenced the study area in the weekly ET0 estimation.
Linear regression models in terms of the climatic parameters
influencing the regions and, optimal neural network
architectures considering these climatic parameters as inputs
were developed. The models’ performance was evaluated with
respect to ET0 estimated by FAO-56 Penman-Monteith method.
The linear regression models showed a satisfactory
performance in the weekly ET0 estimation in the regions
selected for the present study. The ANN (4,4,1) models,
however, consistently showed a slightly improved performance
over linear regression models.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Power System State Estimation - A ReviewIDES Editor
This document provides a review of power system state estimation techniques. It discusses both static and dynamic state estimation algorithms. For static state estimation, it covers weighted least squares, decoupled, and robust estimation methods. Weighted least squares is commonly used but can have numerical instability issues. Decoupled state estimation approximates the gain matrix for faster computation. Robust estimation uses M-estimators and other techniques to handle outliers and bad data. Dynamic state estimation applies Kalman filtering, leapfrog algorithms, and other methods to continuously monitor system states over time.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Switched DC Sources Based Novel Multilevel InverterIRJET Journal
This document summarizes a research paper on a novel multilevel inverter topology that uses switched DC sources. The proposed topology connects alternate DC sources in opposite polarities through power switches, significantly reducing the number of switches compared to existing topologies. The operating principle of a single-phase five-level inverter using two DC sources is demonstrated. Mathematical equations are provided to describe the output voltage, source currents, voltage stresses on switches, and number of output levels for the generalized topology. Losses associated with the power switches are also discussed.
In this paper, a detail design and description of a predictive current control scheme are adopted for three-phase grid-connected two-level inverter and its application in wind energy conversion systems. Despite its advantages, the predictive current controller is very sensitive to parameter variations which could eventually affected on system stability. To solve this problem, an estimation technique proposed to identify the value of harmonic filter parameter based on Model reference adaptive system (MRAS). Lyapunov stability theory is selected to guarantee a robust adaptation and stable response over large system parameter variation. The simulation results shows the efficiency of the proposed techniques to improve the current tracking performance.
Improvement the voltage stability margin of Iraqi power system using the opti...IJECEIAES
The detection of potential voltage collapse in power systems is essential to maintain the voltage stability in heavy load demand. This paper proposes a method to detect weak buses in power systems using two stability indices: the voltage stability margin factor (dS/dY) and the voltage collapse prediction index (VCPI). Hence, the paper aims to improve the voltage stability of Iraqi transmission grid by allocating FACTS devices in the optimal locations and optimal sizes. Two types of FACTS are used in this paper which are Thyristor controlled series compensator (TCSC) and static var compensator (SVC). The objective function of the problem is fitted using particle swarm optimization (PSO). The proposed method is verified using simulation test on Diyala-132 kV network which is a part of the Iraqi power system. The results observed that improvement the voltage stability margin, the voltage profile of Diyala-132 kV is increased and the power losses is decreased.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
This document summarizes a research paper that proposes using artificial intelligence techniques and FACTS controllers for reactive power planning in real-time power transmission systems. The paper formulates the reactive power planning problem and incorporates flexible AC transmission system (FACTS) devices like static VAR compensators (SVC), thyristor controlled series capacitors (TCSC), and unified power flow controllers (UPFC). Evolutionary algorithms like evolutionary programming (EP) and differential evolution (DE) are applied to find the optimal locations and settings of the FACTS controllers to minimize losses and costs. Simulation results on IEEE 30-bus and 72-bus Indian test systems show that UPFC performs best in reducing losses compared to SVC and TCSC.
Power system transient stability margin estimation using artificial neural ne...elelijjournal
This paper presents a methodology for estimating the normalized transient stability margin by using the multilayered perceptron (MLP) neural network. The complex relationship between the input variables and output variables is established by using the neural networks. The nonlinear mapping relation between the normalized transient stability margin and the operating conditions of the power system is established by using the MLP neural network. To obtain the training set of the neural network the potential energy boundary surface (PEBS) method along with time domain simulation method is used. The proposed method is applied on IEEE 9 bus system and the results shows that the proposed method provides fast and accurate tool to assess online transient stability.
The effect of load modelling on phase balancing in distribution networks usin...IJECEIAES
Due to the unequal loads in phases and different customer consumption, the distribution network is unbalanced. Unbalancing in the distribution network, in addition to increasing power losses, causes unbalancing in voltages and increases operating costs. To reduce this unbalancing, various methods and algorithms have been presented. In most studies and even practical projects due to lack of information about the network loads, load models such as constant power model, constant current or constant impedance are used to model the loads. Due to the changing and nonlinear behaviours of today's loads, these models cannot show results in accordance with reality. This paper while introducing an optimal phase-balancing method, discusses the effect of load modelling on phase balancing studies. In this process the re-phasing method for balancing the network and the harmony search algorithm for optimizing the phase displacement process have been used. The simulation was carried out on an unbalanced distribution network of 25 buses. The results show well the effect of this comprehensive modelling on phase balancing studies. It also shows that in the re-phasing method for balancing the network and in the absence of a real load model, the use of which model offers the closest answer to optimal solutions.
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
Cross-layer Design of an Asymmetric Loadpower Control Protocol in Ad hoc Netw...IDES Editor
Cross-layer design is important in wireless ad hoc
network and the power control methods. Power control is the
intelligent selection of transmit power in a communication to
achieve the better performance within the system. Cross-layer
is used to sharing the information between the layers. CLD
using LOADPOWER (LOADPOW) control protocol is reduce
the overall end-end delay in transmission power. So many
power control schemes are dealt in network layer but this
work Power control protocol was done in MAC layer and it
plays a vital role. A MAC approach to power control only does
a local optimization whereas network layer is capable of a
global optimization. Simulation was done in NS-2 simulator
with the performance metrics as throughput, and energy
consumption and end-end delay. The key concept is to improve
the throughput, saves energy by sending all the packets with
optimal transmit power according to the network load,
transmission power was given, when the network load is low,
higher transmission power gives lower end-end delay and viceversa.
A Novel Approach for Allocation of Optimal Capacitor and Distributed Generati...paperpublications3
This document presents two algorithms for optimally allocating capacitors and distributed generation on radial distribution systems. The algorithms predict reactive power and real power requirements that can be supplied by capacitor banks and distributed generation units. This arrangement reduces transmission losses and improves voltage stability. The algorithms were implemented on the IEEE 69-node and 52-node test systems. Load flow analysis was performed using a forward/backward sweep method to calculate node voltages, branch currents, and power losses. The results show reductions in losses and improvements to voltage profiles with the addition of capacitors and distributed generation.
FUZZY NUMBERS BASED ON ENERGY INDICATORS OF RELIABILITY POWER SYSTEMelelijjournal
This paper presents the approach of fuzzy numbers for reliability calculation of electrical energy indices
and compared to an analytical method. In this paper, the fuzzy numbers which are represented by
triangular fuzzy numbers are used to evaluate the load duration curve and the probabilities capacity
generators that are in services, in term of the expected energy not supplied (EENS), loss of energy
expectation (LOEE) and the energy index of the reliability (EIR). A case study based on the Malaysia
distribution network (DISCO-Net) is carried out.The proposed method shows a simple implementation and
the results seem to be a good approximation to the analytical approach.
Optimal SVC allocation via symbiotic organisms search for voltage security im...TELKOMNIKA JOURNAL
It is desirable that a power system operation is in a normal operating condition. However, the increase of load demand in a power system has forced the system to operate near to its stability limit whereby an increase in load poses a threat to the power system security. In solving this issue, optimal reactive power support via SVC allocation in a power system has been proposed. In this paper, Symbiotic Organisms Search (SOS) algorithm is implemented to solve for optimal allocation of SVC in the power system. IEEE 26 Bus Reliability Test System is used as the test system. Comparative studies are also conducted concerning Particle Swarm Optimization (PSO) and Evolutionary Programming (EP) techniques based on several case studies. Based on the result, SOS has proven its superiority by producing higher quality solutions compared to PSO and EP. The results of this study can benefit the power system operators in planning for optimal power system operations.
Abstract: In this paper three phase load flow analysis on four bus system using Mi Power software is reformed. As power system never operates under steady state condition therefore single phase load flow analysis doesn’t provide accurate results. Hence three phase load flow analysis which can be performed under different contingencies, provide data when system is unbalanced. The system is analysing on the basis of parameter values in MW & MVAR for transmission line and generator buses. Harmonic values of resistance, reactance, and susceptance can predict the condition of small and large kind of system network. This type of analysis is useful for solving the power flow problem in different power systems which will useful to calculate the unknown parameter.
Decentralised PI controller design based on dynamic interaction decoupling in...IJECEIAES
An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closedloop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.
Passivity Based Control for PV Applications by Using a Buck Power Converter
The use of power converters for everyday applications is becoming more and more important. Current technological applications simultaneously demand a high level of precision and performance, so DC-DC converters have a very important role in systems requiring energy level conversion and adaptation. As part of the work of this paper, we are interested in an analysis of modeling and control law synthesis approaches to ensure stability and a certain level of performance in the entire operating domain. The objective of our research work is therefore to propose a control law whose synthesis is based on a formalized (modeling & control) approach with a view to obtaining a control law adapted to the operating point. The principles used are based on the control and observation by the theory of passivity for the synthesis of control law of buck power converter for PV Applications.
This document summarizes a research paper that proposes using a genetic algorithm-optimized fuzzy controller to improve power quality issues like voltage sags and total harmonic distortion using a static synchronous compensator (STATCOM). The paper describes how a genetic algorithm can be used to optimize the parameters of a fuzzy logic controller for the STATCOM in order to minimize voltage sag and total harmonic distortion more effectively than conventional controllers. Simulation results demonstrate that the proposed genetic algorithm technique improves sag compensation and reduces harmonic distortion in distribution systems during fault conditions.
Power transformer faults diagnosis using undestructive methods and ann for dg...Mellah Hacene
Power transformer faults diagnosis using undestructive methods (Roger and IEC) and artificial neural network for dissolved gas analysis applied on the functional transformer in the Algerian north-eastern: a comparative study
Bouchaoui Lahcene, Kamel Eddine Hemsas, Hacene Mellah, saad eddine benlahneche
Nowadays, power transformer aging and failures are viewed with great attention in power transmission industry. Dissolved gas analysis (DGA) is classified among the biggest widely used methods used within the context of asset management policy to detect the incipient faults in their earlier stage in power transformers. Up to now, several procedures have been employed for the lecture of DGA results. Among these useful means, we find Key Gases, Rogers Ratios, IEC Ratios, the historical technique less used today Doernenburg Ratios, the two types of Duval Pentagons methods, several versions of the Duval Triangles method and Logarithmic Nomograph. Problem. DGA data extracted from different units in service served to verify the ability and reliability of these methods in assessing the state of health of the power transformer. Aim. An improving the quality of diagnostics of electrical power transformer by artificial neural network tools based on two conventional methods in the case of a functional power transformer at Sétif province in East North of Algeria. Methodology. Design an inelegant tool for power transformer diagnosis using neural networks based on traditional methods IEC and Rogers, which allows to early detection faults, to increase the reliability, of the entire electrical energy system from transport to consumers and improve a continuity and quality of service. Results. The solution of the problem was carried out by using feed-forward back-propagation neural networks implemented in MATLAB-Simulink environment. Four real power transformers working under different environment and climate conditions such as: desert, humid, cold were taken into account. The practical results of the diagnosis of these power transformers by the DGA are presented. Practical value.....
Single Hard Fault Detection in Linear Analog Circuits Based On Simulation bef...IJERD Editor
This document presents a method for detecting single hard faults in linear analog circuits using a simulation before testing approach. The method generates test vectors for nominal and tolerance-bound component values to form a fault dictionary. The circuit under test is then simulated with injected faults. Fault variables are derived by comparing nominal and faulty responses. The component with the lowest relative standard deviation of its fault variable is identified as faulty. The method was tested on benchmark circuits like a linear voltage divider and correctly identified injected short and open faults in components. The technique addresses tolerance challenges in analog circuit testing.
Optimal Location of FACTS Device for Power System Security Improvement using ...IRJET Journal
This paper proposes using a hybrid genetic algorithm-ant colony optimization (GA-ACO) approach to determine the optimal location and capacity of a static synchronous compensator (STATCOM) to improve power system security and voltage stability. The GA-ACO is applied to a 30-bus test system to identify the optimal placement of STATCOM devices. The results show that installing STATCOMs at buses 26 and 29 enhances system voltages and security compared to the base case without STATCOMs. Simulations under varying load conditions from 60% to 90% demonstrate that the identified optimal STATCOM locations and capacities change to continue improving voltages. The hybrid GA-ACO approach effectively determines STATCOM settings to enhance power system performance and security.
AN IMPROVED METHOD FOR IDENTIFYING WELL-TEST INTERPRETATION MODEL BASED ON AG...IAEME Publication
This paper presents an approach based on applying an aggregated predictor formed by multiple versions of a multilayer neural network with a back-propagation optimization algorithm for helping the engineer to get a list of the most appropriate well-test interpretation models for a given set of pressure/ production data. The proposed method consists of three stages: (1) data decorrelation through principal component analysis to reduce the covariance between the variables and the dimension of the input layer in the artificial neural network, (2) bootstrap replicates of the learning set where the data is repeatedly sampled with a random split of the data into train sets and using these as new learning sets, and (3) automatic reservoir model identification through aggregated predictor formed by a plurality vote when predicting a new class. This method is described in detail to ensure successful replication of results. The required training and test dataset were generated by using analytical solution models. In our case, there were used 600 samples: 300 for training, 100 for cross-validation, and 200 for testing. Different network structures were tested during this study to arrive at optimum network design. We notice that the single net methodology always brings about confusion in selecting the correct model even though the training results for the constructed networks are close to 1. We notice also that the principal component analysis is an effective strategy in reducing the number of input features, simplifying the network structure, and lowering the training time of the ANN. The results obtained show that the proposed model provides better performance when predicting new data with a coefficient of correlation approximately equal to 95% Compared to a previous approach 80%, the combination of the PCA and ANN is more stable and determine the more accurate results with lesser computational complexity than was feasible previously. Clearly, the aggregated predictor is more stable and shows less bad classes compared to the previous approach.
FAULT DETECTION IN FIVE BUS SYSTEM USING MATLAB & SIMULINK (DISCRETE WAVELET ...IRJET Journal
This document describes a study that uses discrete wavelet transform (DWT) to detect and classify faults in a five-bus power transmission system simulated in MATLAB/Simulink. Twelve different fault types with varying durations are introduced at different transmission line locations in the five-bus system. The current signals at the receiving end of lines undergoing faults are analyzed using DWT to extract wavelet coefficients. These coefficients are then used to identify the specific fault type, location, and duration. The results demonstrate that DWT with the db8 mother wavelet can accurately detect and classify faults with mean error of -0.34% under different system conditions.
A Multilevel Inverter with MPPT Control for Drifting Analysis and Improved Po...IRJET Journal
This document presents a voltage sensor-based maximum power point tracking (MPPT) control algorithm for a multilevel inverter photovoltaic system. The MPPT algorithm uses only the output voltage measurement to track the maximum power point and regulates the battery charge. Simulation results show that the algorithm achieves fast tracking of changes in solar irradiance and load variations. The paper also analyzes the steady-state behavior and drift phenomenon of the MPPT algorithm to evaluate tracking efficiency. A 15-level asymmetric cascaded H-bridge multilevel inverter topology is proposed to reduce output voltage harmonics and improve the voltage range from the PV array.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Switched DC Sources Based Novel Multilevel InverterIRJET Journal
This document summarizes a research paper on a novel multilevel inverter topology that uses switched DC sources. The proposed topology connects alternate DC sources in opposite polarities through power switches, significantly reducing the number of switches compared to existing topologies. The operating principle of a single-phase five-level inverter using two DC sources is demonstrated. Mathematical equations are provided to describe the output voltage, source currents, voltage stresses on switches, and number of output levels for the generalized topology. Losses associated with the power switches are also discussed.
In this paper, a detail design and description of a predictive current control scheme are adopted for three-phase grid-connected two-level inverter and its application in wind energy conversion systems. Despite its advantages, the predictive current controller is very sensitive to parameter variations which could eventually affected on system stability. To solve this problem, an estimation technique proposed to identify the value of harmonic filter parameter based on Model reference adaptive system (MRAS). Lyapunov stability theory is selected to guarantee a robust adaptation and stable response over large system parameter variation. The simulation results shows the efficiency of the proposed techniques to improve the current tracking performance.
Improvement the voltage stability margin of Iraqi power system using the opti...IJECEIAES
The detection of potential voltage collapse in power systems is essential to maintain the voltage stability in heavy load demand. This paper proposes a method to detect weak buses in power systems using two stability indices: the voltage stability margin factor (dS/dY) and the voltage collapse prediction index (VCPI). Hence, the paper aims to improve the voltage stability of Iraqi transmission grid by allocating FACTS devices in the optimal locations and optimal sizes. Two types of FACTS are used in this paper which are Thyristor controlled series compensator (TCSC) and static var compensator (SVC). The objective function of the problem is fitted using particle swarm optimization (PSO). The proposed method is verified using simulation test on Diyala-132 kV network which is a part of the Iraqi power system. The results observed that improvement the voltage stability margin, the voltage profile of Diyala-132 kV is increased and the power losses is decreased.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
This document summarizes a research paper that proposes using artificial intelligence techniques and FACTS controllers for reactive power planning in real-time power transmission systems. The paper formulates the reactive power planning problem and incorporates flexible AC transmission system (FACTS) devices like static VAR compensators (SVC), thyristor controlled series capacitors (TCSC), and unified power flow controllers (UPFC). Evolutionary algorithms like evolutionary programming (EP) and differential evolution (DE) are applied to find the optimal locations and settings of the FACTS controllers to minimize losses and costs. Simulation results on IEEE 30-bus and 72-bus Indian test systems show that UPFC performs best in reducing losses compared to SVC and TCSC.
Power system transient stability margin estimation using artificial neural ne...elelijjournal
This paper presents a methodology for estimating the normalized transient stability margin by using the multilayered perceptron (MLP) neural network. The complex relationship between the input variables and output variables is established by using the neural networks. The nonlinear mapping relation between the normalized transient stability margin and the operating conditions of the power system is established by using the MLP neural network. To obtain the training set of the neural network the potential energy boundary surface (PEBS) method along with time domain simulation method is used. The proposed method is applied on IEEE 9 bus system and the results shows that the proposed method provides fast and accurate tool to assess online transient stability.
The effect of load modelling on phase balancing in distribution networks usin...IJECEIAES
Due to the unequal loads in phases and different customer consumption, the distribution network is unbalanced. Unbalancing in the distribution network, in addition to increasing power losses, causes unbalancing in voltages and increases operating costs. To reduce this unbalancing, various methods and algorithms have been presented. In most studies and even practical projects due to lack of information about the network loads, load models such as constant power model, constant current or constant impedance are used to model the loads. Due to the changing and nonlinear behaviours of today's loads, these models cannot show results in accordance with reality. This paper while introducing an optimal phase-balancing method, discusses the effect of load modelling on phase balancing studies. In this process the re-phasing method for balancing the network and the harmony search algorithm for optimizing the phase displacement process have been used. The simulation was carried out on an unbalanced distribution network of 25 buses. The results show well the effect of this comprehensive modelling on phase balancing studies. It also shows that in the re-phasing method for balancing the network and in the absence of a real load model, the use of which model offers the closest answer to optimal solutions.
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
Cross-layer Design of an Asymmetric Loadpower Control Protocol in Ad hoc Netw...IDES Editor
Cross-layer design is important in wireless ad hoc
network and the power control methods. Power control is the
intelligent selection of transmit power in a communication to
achieve the better performance within the system. Cross-layer
is used to sharing the information between the layers. CLD
using LOADPOWER (LOADPOW) control protocol is reduce
the overall end-end delay in transmission power. So many
power control schemes are dealt in network layer but this
work Power control protocol was done in MAC layer and it
plays a vital role. A MAC approach to power control only does
a local optimization whereas network layer is capable of a
global optimization. Simulation was done in NS-2 simulator
with the performance metrics as throughput, and energy
consumption and end-end delay. The key concept is to improve
the throughput, saves energy by sending all the packets with
optimal transmit power according to the network load,
transmission power was given, when the network load is low,
higher transmission power gives lower end-end delay and viceversa.
A Novel Approach for Allocation of Optimal Capacitor and Distributed Generati...paperpublications3
This document presents two algorithms for optimally allocating capacitors and distributed generation on radial distribution systems. The algorithms predict reactive power and real power requirements that can be supplied by capacitor banks and distributed generation units. This arrangement reduces transmission losses and improves voltage stability. The algorithms were implemented on the IEEE 69-node and 52-node test systems. Load flow analysis was performed using a forward/backward sweep method to calculate node voltages, branch currents, and power losses. The results show reductions in losses and improvements to voltage profiles with the addition of capacitors and distributed generation.
FUZZY NUMBERS BASED ON ENERGY INDICATORS OF RELIABILITY POWER SYSTEMelelijjournal
This paper presents the approach of fuzzy numbers for reliability calculation of electrical energy indices
and compared to an analytical method. In this paper, the fuzzy numbers which are represented by
triangular fuzzy numbers are used to evaluate the load duration curve and the probabilities capacity
generators that are in services, in term of the expected energy not supplied (EENS), loss of energy
expectation (LOEE) and the energy index of the reliability (EIR). A case study based on the Malaysia
distribution network (DISCO-Net) is carried out.The proposed method shows a simple implementation and
the results seem to be a good approximation to the analytical approach.
Optimal SVC allocation via symbiotic organisms search for voltage security im...TELKOMNIKA JOURNAL
It is desirable that a power system operation is in a normal operating condition. However, the increase of load demand in a power system has forced the system to operate near to its stability limit whereby an increase in load poses a threat to the power system security. In solving this issue, optimal reactive power support via SVC allocation in a power system has been proposed. In this paper, Symbiotic Organisms Search (SOS) algorithm is implemented to solve for optimal allocation of SVC in the power system. IEEE 26 Bus Reliability Test System is used as the test system. Comparative studies are also conducted concerning Particle Swarm Optimization (PSO) and Evolutionary Programming (EP) techniques based on several case studies. Based on the result, SOS has proven its superiority by producing higher quality solutions compared to PSO and EP. The results of this study can benefit the power system operators in planning for optimal power system operations.
Abstract: In this paper three phase load flow analysis on four bus system using Mi Power software is reformed. As power system never operates under steady state condition therefore single phase load flow analysis doesn’t provide accurate results. Hence three phase load flow analysis which can be performed under different contingencies, provide data when system is unbalanced. The system is analysing on the basis of parameter values in MW & MVAR for transmission line and generator buses. Harmonic values of resistance, reactance, and susceptance can predict the condition of small and large kind of system network. This type of analysis is useful for solving the power flow problem in different power systems which will useful to calculate the unknown parameter.
Decentralised PI controller design based on dynamic interaction decoupling in...IJECEIAES
An enhanced method for design of decenralised proportional integral (PI) controllers to control various variables of flotation columns is proposed. These columns are multivariable processes characterised by multiple interacting manipulated and controlled variables. The control of more than one variable is not an easy problem to solve as a change in a specific manipulated variable affects more than one controlled variable. Paper proposes an improved method for design of decentralized PI controllers through the introduction of decoupling of the interconnected model of the process. Decoupling the system model has proven to be an effective strategy to reduce the influence of the interactions in the closed-loop control and consistently to keep the system stable. The mathematical derivations and the algorithm of the design procedure are described in detail. The behaviour and performance of the closed-loop systems without and with the application of the decoupling method was investigated and compared through simulations in MATLAB/Simulink. The results show that the decouplers - based closedloop system has better performance than the closed-loop system without decouplers. The highest improvement (2 to 50 times) is in the steady-state error and 1.2 to 7 times in the settling and rising time. Controllers can easily be implemented.
Passivity Based Control for PV Applications by Using a Buck Power Converter
The use of power converters for everyday applications is becoming more and more important. Current technological applications simultaneously demand a high level of precision and performance, so DC-DC converters have a very important role in systems requiring energy level conversion and adaptation. As part of the work of this paper, we are interested in an analysis of modeling and control law synthesis approaches to ensure stability and a certain level of performance in the entire operating domain. The objective of our research work is therefore to propose a control law whose synthesis is based on a formalized (modeling & control) approach with a view to obtaining a control law adapted to the operating point. The principles used are based on the control and observation by the theory of passivity for the synthesis of control law of buck power converter for PV Applications.
This document summarizes a research paper that proposes using a genetic algorithm-optimized fuzzy controller to improve power quality issues like voltage sags and total harmonic distortion using a static synchronous compensator (STATCOM). The paper describes how a genetic algorithm can be used to optimize the parameters of a fuzzy logic controller for the STATCOM in order to minimize voltage sag and total harmonic distortion more effectively than conventional controllers. Simulation results demonstrate that the proposed genetic algorithm technique improves sag compensation and reduces harmonic distortion in distribution systems during fault conditions.
Power transformer faults diagnosis using undestructive methods and ann for dg...Mellah Hacene
Power transformer faults diagnosis using undestructive methods (Roger and IEC) and artificial neural network for dissolved gas analysis applied on the functional transformer in the Algerian north-eastern: a comparative study
Bouchaoui Lahcene, Kamel Eddine Hemsas, Hacene Mellah, saad eddine benlahneche
Nowadays, power transformer aging and failures are viewed with great attention in power transmission industry. Dissolved gas analysis (DGA) is classified among the biggest widely used methods used within the context of asset management policy to detect the incipient faults in their earlier stage in power transformers. Up to now, several procedures have been employed for the lecture of DGA results. Among these useful means, we find Key Gases, Rogers Ratios, IEC Ratios, the historical technique less used today Doernenburg Ratios, the two types of Duval Pentagons methods, several versions of the Duval Triangles method and Logarithmic Nomograph. Problem. DGA data extracted from different units in service served to verify the ability and reliability of these methods in assessing the state of health of the power transformer. Aim. An improving the quality of diagnostics of electrical power transformer by artificial neural network tools based on two conventional methods in the case of a functional power transformer at Sétif province in East North of Algeria. Methodology. Design an inelegant tool for power transformer diagnosis using neural networks based on traditional methods IEC and Rogers, which allows to early detection faults, to increase the reliability, of the entire electrical energy system from transport to consumers and improve a continuity and quality of service. Results. The solution of the problem was carried out by using feed-forward back-propagation neural networks implemented in MATLAB-Simulink environment. Four real power transformers working under different environment and climate conditions such as: desert, humid, cold were taken into account. The practical results of the diagnosis of these power transformers by the DGA are presented. Practical value.....
Single Hard Fault Detection in Linear Analog Circuits Based On Simulation bef...IJERD Editor
This document presents a method for detecting single hard faults in linear analog circuits using a simulation before testing approach. The method generates test vectors for nominal and tolerance-bound component values to form a fault dictionary. The circuit under test is then simulated with injected faults. Fault variables are derived by comparing nominal and faulty responses. The component with the lowest relative standard deviation of its fault variable is identified as faulty. The method was tested on benchmark circuits like a linear voltage divider and correctly identified injected short and open faults in components. The technique addresses tolerance challenges in analog circuit testing.
Optimal Location of FACTS Device for Power System Security Improvement using ...IRJET Journal
This paper proposes using a hybrid genetic algorithm-ant colony optimization (GA-ACO) approach to determine the optimal location and capacity of a static synchronous compensator (STATCOM) to improve power system security and voltage stability. The GA-ACO is applied to a 30-bus test system to identify the optimal placement of STATCOM devices. The results show that installing STATCOMs at buses 26 and 29 enhances system voltages and security compared to the base case without STATCOMs. Simulations under varying load conditions from 60% to 90% demonstrate that the identified optimal STATCOM locations and capacities change to continue improving voltages. The hybrid GA-ACO approach effectively determines STATCOM settings to enhance power system performance and security.
AN IMPROVED METHOD FOR IDENTIFYING WELL-TEST INTERPRETATION MODEL BASED ON AG...IAEME Publication
This paper presents an approach based on applying an aggregated predictor formed by multiple versions of a multilayer neural network with a back-propagation optimization algorithm for helping the engineer to get a list of the most appropriate well-test interpretation models for a given set of pressure/ production data. The proposed method consists of three stages: (1) data decorrelation through principal component analysis to reduce the covariance between the variables and the dimension of the input layer in the artificial neural network, (2) bootstrap replicates of the learning set where the data is repeatedly sampled with a random split of the data into train sets and using these as new learning sets, and (3) automatic reservoir model identification through aggregated predictor formed by a plurality vote when predicting a new class. This method is described in detail to ensure successful replication of results. The required training and test dataset were generated by using analytical solution models. In our case, there were used 600 samples: 300 for training, 100 for cross-validation, and 200 for testing. Different network structures were tested during this study to arrive at optimum network design. We notice that the single net methodology always brings about confusion in selecting the correct model even though the training results for the constructed networks are close to 1. We notice also that the principal component analysis is an effective strategy in reducing the number of input features, simplifying the network structure, and lowering the training time of the ANN. The results obtained show that the proposed model provides better performance when predicting new data with a coefficient of correlation approximately equal to 95% Compared to a previous approach 80%, the combination of the PCA and ANN is more stable and determine the more accurate results with lesser computational complexity than was feasible previously. Clearly, the aggregated predictor is more stable and shows less bad classes compared to the previous approach.
FAULT DETECTION IN FIVE BUS SYSTEM USING MATLAB & SIMULINK (DISCRETE WAVELET ...IRJET Journal
This document describes a study that uses discrete wavelet transform (DWT) to detect and classify faults in a five-bus power transmission system simulated in MATLAB/Simulink. Twelve different fault types with varying durations are introduced at different transmission line locations in the five-bus system. The current signals at the receiving end of lines undergoing faults are analyzed using DWT to extract wavelet coefficients. These coefficients are then used to identify the specific fault type, location, and duration. The results demonstrate that DWT with the db8 mother wavelet can accurately detect and classify faults with mean error of -0.34% under different system conditions.
A Multilevel Inverter with MPPT Control for Drifting Analysis and Improved Po...IRJET Journal
This document presents a voltage sensor-based maximum power point tracking (MPPT) control algorithm for a multilevel inverter photovoltaic system. The MPPT algorithm uses only the output voltage measurement to track the maximum power point and regulates the battery charge. Simulation results show that the algorithm achieves fast tracking of changes in solar irradiance and load variations. The paper also analyzes the steady-state behavior and drift phenomenon of the MPPT algorithm to evaluate tracking efficiency. A 15-level asymmetric cascaded H-bridge multilevel inverter topology is proposed to reduce output voltage harmonics and improve the voltage range from the PV array.
Enhanced MPPT Technique For DC-DC Luo Converter Using Model Predictive Contro...IJERD Editor
The present study explored an enhanced maximum power point tracking technique which ensures fast tracking in PV systems. This system represents a Model Predictive Control (MPC) MPPT technique. Extracting the maximum power from PV systems has been widely investigated. The main benefaction of this article is an improvement of the Perturb and Observe (P&O) method through a fixed step predictive control under measured fast solar radiation. The preferred predictive control to achieve Maximum Power Point (MPP) speeds up the control loop since it predicts error before the switching signal is applied to the DC-DC Luo converter. Comparing the improved technique to the conventional P&O method indicates significant improvement in PV system performance. The proposed MPC-MPPT technique for a Luo converter is implemented using the MAT LAB SIMULINK
Selective localization of capacitor banks considering stability aspects in po...IAEME Publication
The issue of voltage stability has become predominant in larger power systems, since the
system is operated close to its capabilities in recent years. Addressing this concern considering the
economic constraints is a challenge .This draws attention towards the localization of the reactive
components that can improve the overall voltage profile in the system. This paper discusses a
methodology for suitable selection of position (bus) for the placement of capacitor bank wherein the
injection of fixed amount of reactive power is made to depict a picture of the overall improved
voltage in the system considering the stability aspect for respective injection at that bus. The reduced
jacobian is used to determine the impact of reactive power injection in the form of system voltage
improvement.
Oscillatory Stability Prediction Using PSO Based Synchronizing and Damping To...journalBEEI
This paper presents the assessment of stability domains for the angle stability condition of the power system using Particle Swarm Optimization (PSO) technique. An efficient optimization method using PSO for synchronizing torque coefficients Ksand damping torque coefficients Kd to identify the angle stability condition on multi-machine system. In order to accelerate the determination of angle stability, PSO is proposed to be implemented in this study. The application of the proposed algorithm has been justified as the most accurate with lower computation time as compared to other optimization techniques such as Evolutionary Programming (EP) and Artificial Immune System (AIS). Validation with respect to eigenvalues determination, Least Square (LS) method and minimum damping ratio ξmin confirmed that the proposed technique is feasible to solve the angle stability problems.
Maximum Power Point Tracking Using Adaptive Fuzzy Logic control for Photovolt...IJERA Editor
This work presents an intelligent approach to the improvement and optimization of control performance of a photovoltaic system with maximum power point tracking based on fuzzy logic control. This control was compared with the conventional control based on Perturb &Observe algorithm. The results obtained in Matlab/Simulink under different conditions show a marked improvement in the performance of fuzzy control MPPT of the PV system.
Reliability Analysis of a 3-Machine Power Station Using State Space ApproachIJERA Editor
With the advent of high-integrity fault-tolerant systems, the ability to account for repairs of partially failed (but still operational) systems become increasingly important. This paper presents a systemic method of determining the reliability of a 3-machine electric power station, taking into consideration the failure rates and repair rates of the individual component (machine) that make up the system. A state-space transition process for a 3-machine with 23 states was developed and consequently, steady state equations were generated based on Markov mathematical modeling of the power station. Important reliability components were deduced from this analysis. This research simulation was achieved with codes written in Excel®-VBA programming environment. System reliability using state space approach proofs to be a viable and efficient technique of reliability prediction as it is able to predict the state of the system under consideration. For the purpose of neatness and easy entry of data, Graphic User Interface (GUI) was designed.
IRJET- Voltage Stability, Loadability and Contingency Analysis with Optimal I...IRJET Journal
This document discusses contingency analysis and optimal placement of renewable distributed generators (RDGs) using continuation power flow analysis to improve voltage stability and loadability. It presents a methodology to determine the optimal location and mix of different RDG technologies (solar, wind, fuel cells) on the IEEE 9-bus test system using the Power System Analysis Toolbox (PSAT). Reactive power performance indices are calculated for different line contingencies to identify critical buses. The results show that optimally placing RDGs can enhance voltage stability and increase the maximum loadability point compared to the base case without RDGs.
PHOTOVOLTAIC BASED ELECTRIC VEHICLE USING MAXIMUM POWER POINT TRACKINGIRJET Journal
The document describes a photovoltaic (PV) system for charging electric vehicles (EVs) using maximum power point tracking (MPPT) with model predictive control (MPC). It proposes using an MPC-based MPPT technique to track the global maximum power point of the PV panel with zero oscillations. This provides optimal PV power tracking with high efficiency. A hybrid energy storage system using an ultracapacitor and battery supplies power from the PV system to a BLDC motor that drives the EV. Simulation results in MATLAB/Simulink show that the MPC technique effectively tracks solar power under varying weather conditions.
Model Order Reduction of an ISLANDED MICROGRID using Single Perturbation, Dir...IRJET Journal
This document discusses using model order reduction techniques to simplify the model of an islanded microgrid system from 6th order to lower order approximations. It evaluates three methods: single perturbation, direct truncation, and particle swarm optimization. Single perturbation and direct truncation are used to reduce the model to 4th order, while particle swarm optimization further reduces it to 2nd order. The responses of the reduced models are compared to the original 6th order model, showing that even the 2nd order model reduced using particle swarm optimization provides an improved response.
Determination of Fault Location and Type in Distribution Systems using Clark ...IJAPEJOURNAL
In this paper, an accurate method for determination of fault location and fault type in power distribution systems by neural network is proposed. This method uses neural network to classify and locate normal and composite types of faults as phase to earth, two phases to earth, phase to phase. Also this method can distinguish three phase short circuit from normal network position. In the presented method, neural network is trained by αβ space vector parameters. These parameters are obtained using clarke transformation. Simulation results are presented in the MATLAB software. Two neural networks (MLP and RBF) are investigated and their results are compared with each other. The accuracy and benefit of the proposed method for determination of fault type and location in distribution power systems has been shown in simulation results.
Exploiting 2-Dimensional Source Correlation in Channel Decoding with Paramete...IJECEIAES
The document describes a proposed joint source-channel coding (JSCC) system that exploits 2-dimensional source correlation in channel decoding with parameter estimation. The system uses a modified Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm at the decoder to exploit source correlation on rows and columns of a 2D source. A parameter estimation technique based on the Baum-Welch algorithm is used jointly with the decoder to estimate source correlation parameters at the receiver since these parameters are not always known in practice. Simulation results show that the proposed coding scheme that performs joint decoding and parameter estimation performs very close to an ideal 2D JSCC system with perfect knowledge of source correlation parameters.
IRJET- A Review on Solar based Multilevel Inverter with Three Phase Grid SupplyIRJET Journal
- The document discusses solar-powered multilevel inverters that can supply three-phase grid power. Multilevel inverters have advantages over single-level inverters like lower harmonic distortion, reduced electromagnetic interference, and the ability to operate at several voltage levels.
- The literature review covers prior research on different multilevel inverter topologies for photovoltaic systems, including the flying capacitor, neutral point clamped, and cascaded H-bridge inverters. It also discusses control methods like maximum power point tracking and modulation techniques.
- The goal is to develop a multilevel inverter powered by PV panels that can supply three-phase grid power with minimum harmonic distortion and reduced component requirements compared to
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IRJET- Control of Induction Motor using Neural NetworkIRJET Journal
This document describes research into using neural networks to control induction motors. It begins by introducing the topic and noting limitations of traditional PI controllers for induction motor control. It then provides details on the experimental setup, which uses an artificial neural network (ANN) to mimic a PI controller for speed control of an induction motor drive system. Simulation results are presented comparing the performance of the ANN controller to a traditional PI controller under different dynamic operating conditions. The document concludes that the ANN mapping controller provides superior performance to the PI controller.
Transient Stability Assessment and Enhancement in Power SystemIJMER
This document discusses transient stability assessment and enhancement in power systems. It first introduces transient stability and its importance. It then describes using PSAT software to analyze the IEEE 39-bus test system and calculate critical clearing times (CCTs) for different faults to assess stability. An artificial neural network is trained to predict CCTs at different operating points. Finally, particle swarm optimization is used to find the optimal placement of a thyristor controlled series capacitor to enhance stability by minimizing real power losses, increasing several CCTs above 0.1 seconds.
Fuzzy-Logic-Controller-Based Fault Isolation in PWM VSI for Vector Controlled...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document summarizes a research paper that proposes a two-level control system to improve maximum power point tracking (MPPT) in photovoltaic systems. The first level uses ripple correlation control to calculate the duty cycle for maximum power output. The second level uses model reference adaptive control to eliminate transient oscillations in output voltage caused by duty cycle changes. Simulation results showed the system converges rapidly to the maximum power point with minimal output voltage oscillation under changing environmental conditions.
Predicting Post Outage Transmission Line Flows using Linear Distribution FactorsDr. Amarjeet Singh
In order to design and implement preventive
and remedial actions, a continuous performance of fast
security analysis is imperative amid outages of system
components. Following the contingency of a system
component, State estimation and Load flow techniques
are the two popular techniques used to determine
system state variables leading to estimation of flows,
losses and violations in nodal voltages and transmission
line flows. But the dynamic state and complexity of the
system requires faster means of estimations which can
be achieved by linear distribution factors. The use of
Distribution factors in form of Power Transfer
Distribution Factors (PTDF) and Line Outage
Distribution Factors (LODF) which are transmission
line sensitivities with respect to active power exchanges
between buses and transmission line outages offer an
alternative to these two techniques being linear,
quicker, and non-iterative. Following the estimation of
the linear distribution factors from a reference
operating point (base case) and contingency cases
involving line outage, generator output variation and
outage of a Six bus network using Matlab programs,
the results show that by means of Linear Distribution
factors quick estimates of post outage line flows can be
made which match flow results obtained from DC load
flow analysis.
IRJET- Monitoring Against Voltage Instabilities using Line Voltage Stability ...IRJET Journal
This document summarizes methods for monitoring voltage stability in power systems using line voltage stability indices. It analyzes the IEEE 14 bus and IEEE 30 bus test systems to identify weak lines using four indices: line stability index (LMN), fast voltage stability index (FVSI), line stability factor (LQP), and voltage collapse point indicators (VCPI). The results are used to determine which lines are most prone to voltage instability under heavy loading conditions in order to rectify issues by implementing FACTS devices on those lines.
Similar to The use of Markov Chain method to determine spare transformer number and location (20)
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Neural network optimizer of proportional-integral-differential controller par...IJECEIAES
Wide application of proportional-integral-differential (PID)-regulator in industry requires constant improvement of methods of its parameters adjustment. The paper deals with the issues of optimization of PID-regulator parameters with the use of neural network technology methods. A methodology for choosing the architecture (structure) of neural network optimizer is proposed, which consists in determining the number of layers, the number of neurons in each layer, as well as the form and type of activation function. Algorithms of neural network training based on the application of the method of minimizing the mismatch between the regulated value and the target value are developed. The method of back propagation of gradients is proposed to select the optimal training rate of neurons of the neural network. The neural network optimizer, which is a superstructure of the linear PID controller, allows increasing the regulation accuracy from 0.23 to 0.09, thus reducing the power consumption from 65% to 53%. The results of the conducted experiments allow us to conclude that the created neural superstructure may well become a prototype of an automatic voltage regulator (AVR)-type industrial controller for tuning the parameters of the PID controller.
An improved modulation technique suitable for a three level flying capacitor ...IJECEIAES
This research paper introduces an innovative modulation technique for controlling a 3-level flying capacitor multilevel inverter (FCMLI), aiming to streamline the modulation process in contrast to conventional methods. The proposed
simplified modulation technique paves the way for more straightforward and
efficient control of multilevel inverters, enabling their widespread adoption and
integration into modern power electronic systems. Through the amalgamation of
sinusoidal pulse width modulation (SPWM) with a high-frequency square wave
pulse, this controlling technique attains energy equilibrium across the coupling
capacitor. The modulation scheme incorporates a simplified switching pattern
and a decreased count of voltage references, thereby simplifying the control
algorithm.
A review on features and methods of potential fishing zoneIJECEIAES
This review focuses on the importance of identifying potential fishing zones in seawater for sustainable fishing practices. It explores features like sea surface temperature (SST) and sea surface height (SSH), along with classification methods such as classifiers. The features like SST, SSH, and different classifiers used to classify the data, have been figured out in this review study. This study underscores the importance of examining potential fishing zones using advanced analytical techniques. It thoroughly explores the methodologies employed by researchers, covering both past and current approaches. The examination centers on data characteristics and the application of classification algorithms for classification of potential fishing zones. Furthermore, the prediction of potential fishing zones relies significantly on the effectiveness of classification algorithms. Previous research has assessed the performance of models like support vector machines, naïve Bayes, and artificial neural networks (ANN). In the previous result, the results of support vector machine (SVM) were 97.6% more accurate than naive Bayes's 94.2% to classify test data for fisheries classification. By considering the recent works in this area, several recommendations for future works are presented to further improve the performance of the potential fishing zone models, which is important to the fisheries community.
Electrical signal interference minimization using appropriate core material f...IJECEIAES
As demand for smaller, quicker, and more powerful devices rises, Moore's law is strictly followed. The industry has worked hard to make little devices that boost productivity. The goal is to optimize device density. Scientists are reducing connection delays to improve circuit performance. This helped them understand three-dimensional integrated circuit (3D IC) concepts, which stack active devices and create vertical connections to diminish latency and lower interconnects. Electrical involvement is a big worry with 3D integrates circuits. Researchers have developed and tested through silicon via (TSV) and substrates to decrease electrical wave involvement. This study illustrates a novel noise coupling reduction method using several electrical involvement models. A 22% drop in electrical involvement from wave-carrying to victim TSVs introduces this new paradigm and improves system performance even at higher THz frequencies.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Bibliometric analysis highlighting the role of women in addressing climate ch...IJECEIAES
Fossil fuel consumption increased quickly, contributing to climate change
that is evident in unusual flooding and draughts, and global warming. Over
the past ten years, women's involvement in society has grown dramatically,
and they succeeded in playing a noticeable role in reducing climate change.
A bibliometric analysis of data from the last ten years has been carried out to
examine the role of women in addressing the climate change. The analysis's
findings discussed the relevant to the sustainable development goals (SDGs),
particularly SDG 7 and SDG 13. The results considered contributions made
by women in the various sectors while taking geographic dispersion into
account. The bibliometric analysis delves into topics including women's
leadership in environmental groups, their involvement in policymaking, their
contributions to sustainable development projects, and the influence of
gender diversity on attempts to mitigate climate change. This study's results
highlight how women have influenced policies and actions related to climate
change, point out areas of research deficiency and recommendations on how
to increase role of the women in addressing the climate change and
achieving sustainability. To achieve more successful results, this initiative
aims to highlight the significance of gender equality and encourage
inclusivity in climate change decision-making processes.
Voltage and frequency control of microgrid in presence of micro-turbine inter...IJECEIAES
The active and reactive load changes have a significant impact on voltage
and frequency. In this paper, in order to stabilize the microgrid (MG) against
load variations in islanding mode, the active and reactive power of all
distributed generators (DGs), including energy storage (battery), diesel
generator, and micro-turbine, are controlled. The micro-turbine generator is
connected to MG through a three-phase to three-phase matrix converter, and
the droop control method is applied for controlling the voltage and
frequency of MG. In addition, a method is introduced for voltage and
frequency control of micro-turbines in the transition state from gridconnected mode to islanding mode. A novel switching strategy of the matrix
converter is used for converting the high-frequency output voltage of the
micro-turbine to the grid-side frequency of the utility system. Moreover,
using the switching strategy, the low-order harmonics in the output current
and voltage are not produced, and consequently, the size of the output filter
would be reduced. In fact, the suggested control strategy is load-independent
and has no frequency conversion restrictions. The proposed approach for
voltage and frequency regulation demonstrates exceptional performance and
favorable response across various load alteration scenarios. The suggested
strategy is examined in several scenarios in the MG test systems, and the
simulation results are addressed.
Enhancing battery system identification: nonlinear autoregressive modeling fo...IJECEIAES
Precisely characterizing Li-ion batteries is essential for optimizing their
performance, enhancing safety, and prolonging their lifespan across various
applications, such as electric vehicles and renewable energy systems. This
article introduces an innovative nonlinear methodology for system
identification of a Li-ion battery, employing a nonlinear autoregressive with
exogenous inputs (NARX) model. The proposed approach integrates the
benefits of nonlinear modeling with the adaptability of the NARX structure,
facilitating a more comprehensive representation of the intricate
electrochemical processes within the battery. Experimental data collected
from a Li-ion battery operating under diverse scenarios are employed to
validate the effectiveness of the proposed methodology. The identified
NARX model exhibits superior accuracy in predicting the battery's behavior
compared to traditional linear models. This study underscores the
importance of accounting for nonlinearities in battery modeling, providing
insights into the intricate relationships between state-of-charge, voltage, and
current under dynamic conditions.
Smart grid deployment: from a bibliometric analysis to a surveyIJECEIAES
Smart grids are one of the last decades' innovations in electrical energy.
They bring relevant advantages compared to the traditional grid and
significant interest from the research community. Assessing the field's
evolution is essential to propose guidelines for facing new and future smart
grid challenges. In addition, knowing the main technologies involved in the
deployment of smart grids (SGs) is important to highlight possible
shortcomings that can be mitigated by developing new tools. This paper
contributes to the research trends mentioned above by focusing on two
objectives. First, a bibliometric analysis is presented to give an overview of
the current research level about smart grid deployment. Second, a survey of
the main technological approaches used for smart grid implementation and
their contributions are highlighted. To that effect, we searched the Web of
Science (WoS), and the Scopus databases. We obtained 5,663 documents
from WoS and 7,215 from Scopus on smart grid implementation or
deployment. With the extraction limitation in the Scopus database, 5,872 of
the 7,215 documents were extracted using a multi-step process. These two
datasets have been analyzed using a bibliometric tool called bibliometrix.
The main outputs are presented with some recommendations for future
research.
Use of analytical hierarchy process for selecting and prioritizing islanding ...IJECEIAES
One of the problems that are associated to power systems is islanding
condition, which must be rapidly and properly detected to prevent any
negative consequences on the system's protection, stability, and security.
This paper offers a thorough overview of several islanding detection
strategies, which are divided into two categories: classic approaches,
including local and remote approaches, and modern techniques, including
techniques based on signal processing and computational intelligence.
Additionally, each approach is compared and assessed based on several
factors, including implementation costs, non-detected zones, declining
power quality, and response times using the analytical hierarchy process
(AHP). The multi-criteria decision-making analysis shows that the overall
weight of passive methods (24.7%), active methods (7.8%), hybrid methods
(5.6%), remote methods (14.5%), signal processing-based methods (26.6%),
and computational intelligent-based methods (20.8%) based on the
comparison of all criteria together. Thus, it can be seen from the total weight
that hybrid approaches are the least suitable to be chosen, while signal
processing-based methods are the most appropriate islanding detection
method to be selected and implemented in power system with respect to the
aforementioned factors. Using Expert Choice software, the proposed
hierarchy model is studied and examined.
Enhancing of single-stage grid-connected photovoltaic system using fuzzy logi...IJECEIAES
The power generated by photovoltaic (PV) systems is influenced by
environmental factors. This variability hampers the control and utilization of
solar cells' peak output. In this study, a single-stage grid-connected PV
system is designed to enhance power quality. Our approach employs fuzzy
logic in the direct power control (DPC) of a three-phase voltage source
inverter (VSI), enabling seamless integration of the PV connected to the
grid. Additionally, a fuzzy logic-based maximum power point tracking
(MPPT) controller is adopted, which outperforms traditional methods like
incremental conductance (INC) in enhancing solar cell efficiency and
minimizing the response time. Moreover, the inverter's real-time active and
reactive power is directly managed to achieve a unity power factor (UPF).
The system's performance is assessed through MATLAB/Simulink
implementation, showing marked improvement over conventional methods,
particularly in steady-state and varying weather conditions. For solar
irradiances of 500 and 1,000 W/m2
, the results show that the proposed
method reduces the total harmonic distortion (THD) of the injected current
to the grid by approximately 46% and 38% compared to conventional
methods, respectively. Furthermore, we compare the simulation results with
IEEE standards to evaluate the system's grid compatibility.
Enhancing photovoltaic system maximum power point tracking with fuzzy logic-b...IJECEIAES
Photovoltaic systems have emerged as a promising energy resource that
caters to the future needs of society, owing to their renewable, inexhaustible,
and cost-free nature. The power output of these systems relies on solar cell
radiation and temperature. In order to mitigate the dependence on
atmospheric conditions and enhance power tracking, a conventional
approach has been improved by integrating various methods. To optimize
the generation of electricity from solar systems, the maximum power point
tracking (MPPT) technique is employed. To overcome limitations such as
steady-state voltage oscillations and improve transient response, two
traditional MPPT methods, namely fuzzy logic controller (FLC) and perturb
and observe (P&O), have been modified. This research paper aims to
simulate and validate the step size of the proposed modified P&O and FLC
techniques within the MPPT algorithm using MATLAB/Simulink for
efficient power tracking in photovoltaic systems.
Adaptive synchronous sliding control for a robot manipulator based on neural ...IJECEIAES
Robot manipulators have become important equipment in production lines, medical fields, and transportation. Improving the quality of trajectory tracking for
robot hands is always an attractive topic in the research community. This is a
challenging problem because robot manipulators are complex nonlinear systems
and are often subject to fluctuations in loads and external disturbances. This
article proposes an adaptive synchronous sliding control scheme to improve trajectory tracking performance for a robot manipulator. The proposed controller
ensures that the positions of the joints track the desired trajectory, synchronize
the errors, and significantly reduces chattering. First, the synchronous tracking
errors and synchronous sliding surfaces are presented. Second, the synchronous
tracking error dynamics are determined. Third, a robust adaptive control law is
designed,the unknown components of the model are estimated online by the neural network, and the parameters of the switching elements are selected by fuzzy
logic. The built algorithm ensures that the tracking and approximation errors
are ultimately uniformly bounded (UUB). Finally, the effectiveness of the constructed algorithm is demonstrated through simulation and experimental results.
Simulation and experimental results show that the proposed controller is effective with small synchronous tracking errors, and the chattering phenomenon is
significantly reduced.
Remote field-programmable gate array laboratory for signal acquisition and de...IJECEIAES
A remote laboratory utilizing field-programmable gate array (FPGA) technologies enhances students’ learning experience anywhere and anytime in embedded system design. Existing remote laboratories prioritize hardware access and visual feedback for observing board behavior after programming, neglecting comprehensive debugging tools to resolve errors that require internal signal acquisition. This paper proposes a novel remote embeddedsystem design approach targeting FPGA technologies that are fully interactive via a web-based platform. Our solution provides FPGA board access and debugging capabilities beyond the visual feedback provided by existing remote laboratories. We implemented a lab module that allows users to seamlessly incorporate into their FPGA design. The module minimizes hardware resource utilization while enabling the acquisition of a large number of data samples from the signal during the experiments by adaptively compressing the signal prior to data transmission. The results demonstrate an average compression ratio of 2.90 across three benchmark signals, indicating efficient signal acquisition and effective debugging and analysis. This method allows users to acquire more data samples than conventional methods. The proposed lab allows students to remotely test and debug their designs, bridging the gap between theory and practice in embedded system design.
Detecting and resolving feature envy through automated machine learning and m...IJECEIAES
Efficiently identifying and resolving code smells enhances software project quality. This paper presents a novel solution, utilizing automated machine learning (AutoML) techniques, to detect code smells and apply move method refactoring. By evaluating code metrics before and after refactoring, we assessed its impact on coupling, complexity, and cohesion. Key contributions of this research include a unique dataset for code smell classification and the development of models using AutoGluon for optimal performance. Furthermore, the study identifies the top 20 influential features in classifying feature envy, a well-known code smell, stemming from excessive reliance on external classes. We also explored how move method refactoring addresses feature envy, revealing reduced coupling and complexity, and improved cohesion, ultimately enhancing code quality. In summary, this research offers an empirical, data-driven approach, integrating AutoML and move method refactoring to optimize software project quality. Insights gained shed light on the benefits of refactoring on code quality and the significance of specific features in detecting feature envy. Future research can expand to explore additional refactoring techniques and a broader range of code metrics, advancing software engineering practices and standards.
Smart monitoring technique for solar cell systems using internet of things ba...IJECEIAES
Rapidly and remotely monitoring and receiving the solar cell systems status parameters, solar irradiance, temperature, and humidity, are critical issues in enhancement their efficiency. Hence, in the present article an improved smart prototype of internet of things (IoT) technique based on embedded system through NodeMCU ESP8266 (ESP-12E) was carried out experimentally. Three different regions at Egypt; Luxor, Cairo, and El-Beheira cities were chosen to study their solar irradiance profile, temperature, and humidity by the proposed IoT system. The monitoring data of solar irradiance, temperature, and humidity were live visualized directly by Ubidots through hypertext transfer protocol (HTTP) protocol. The measured solar power radiation in Luxor, Cairo, and El-Beheira ranged between 216-1000, 245-958, and 187-692 W/m 2 respectively during the solar day. The accuracy and rapidity of obtaining monitoring results using the proposed IoT system made it a strong candidate for application in monitoring solar cell systems. On the other hand, the obtained solar power radiation results of the three considered regions strongly candidate Luxor and Cairo as suitable places to build up a solar cells system station rather than El-Beheira.
An efficient security framework for intrusion detection and prevention in int...IJECEIAES
Over the past few years, the internet of things (IoT) has advanced to connect billions of smart devices to improve quality of life. However, anomalies or malicious intrusions pose several security loopholes, leading to performance degradation and threat to data security in IoT operations. Thereby, IoT security systems must keep an eye on and restrict unwanted events from occurring in the IoT network. Recently, various technical solutions based on machine learning (ML) models have been derived towards identifying and restricting unwanted events in IoT. However, most ML-based approaches are prone to miss-classification due to inappropriate feature selection. Additionally, most ML approaches applied to intrusion detection and prevention consider supervised learning, which requires a large amount of labeled data to be trained. Consequently, such complex datasets are impossible to source in a large network like IoT. To address this problem, this proposed study introduces an efficient learning mechanism to strengthen the IoT security aspects. The proposed algorithm incorporates supervised and unsupervised approaches to improve the learning models for intrusion detection and mitigation. Compared with the related works, the experimental outcome shows that the model performs well in a benchmark dataset. It accomplishes an improved detection accuracy of approximately 99.21%.
Impartiality as per ISO /IEC 17025:2017 StandardMuhammadJazib15
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Better Builder Magazine brings together premium product manufactures and leading builders to create better differentiated homes and buildings that use less energy, save water and reduce our impact on the environment. The magazine is published four times a year.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
This study Examines the Effectiveness of Talent Procurement through the Imple...DharmaBanothu
In the world with high technology and fast
forward mindset recruiters are walking/showing interest
towards E-Recruitment. Present most of the HRs of
many companies are choosing E-Recruitment as the best
choice for recruitment. E-Recruitment is being done
through many online platforms like Linkedin, Naukri,
Instagram , Facebook etc. Now with high technology E-
Recruitment has gone through next level by using
Artificial Intelligence too.
Key Words : Talent Management, Talent Acquisition , E-
Recruitment , Artificial Intelligence Introduction
Effectiveness of Talent Acquisition through E-
Recruitment in this topic we will discuss about 4important
and interlinked topics which are
Sachpazis_Consolidation Settlement Calculation Program-The Python Code and th...Dr.Costas Sachpazis
Consolidation Settlement Calculation Program-The Python Code
By Professor Dr. Costas Sachpazis, Civil Engineer & Geologist
This program calculates the consolidation settlement for a foundation based on soil layer properties and foundation data. It allows users to input multiple soil layers and foundation characteristics to determine the total settlement.
2. ISSN: 2088-8708
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2
2. RESEARCH METHOD
The main framework used in this research is Markov Chain Method. Based on the Markov Chain
Model [9], [10], the definition of system reliability is the steady probability group of normal condition states
(success states). The first step in Markov Chain Model is by making a state transition model. This research
will use one spare transition state model, as shown on the Figure 1.
Figure 1. Transition state model of one spare transformer
Based on the Figure 1 and referring to the actual condition, the probability group of system
reliability will be the steady state probability in state 1 and state 2. while other states are defining an
abnormal operation, the definition of each states are:
a. State 1 is normal condition with 1 spare available and without any system failure.
b. State 2 is normal condition with no spare available and without any system failure.
c. State 3 is N-1 condition with 1 spare available and with system failure.
d. State 4 is N-1 condition with no spare available and with system failure.
e. State 5 is N-2 condition with 1 spare available and with 2 transformer disturbance (system failure).
f. State 6 is N-2 condition with no spare available and with 2 transformer disturbance (system failure).
Based on the Figure 1, there are three rates that will affect the calculation result which are failure
rate (λ), procurement rate (µ), and transport rate (ρ). The failure rate (λ) value is derived from A-B-C
classification concept. The procurement rate (µ) is a constant value where there are no constrain in spare
procurement. The transport rate (ρ) is derived with spare location variation value.
The failure rate calculation uses A-B-C Classification (Pareto Law Concept) [11]. All of the assets
must be classified into ‘models’. The disturbance data which affected the failure rate are only those
disturbances occurred on the A component based on the A-B-C classifications. For asset classification, the
method used is inventory management. Inventory Management is an activity of monitoring and controlling
the business and production processes of a company, from the beginning of the booking, storage, using the
components, until the production process. This method has been used to classify different ‘models’ of any
assets. The reason why these classification is necessary is because in this research, each ‘model’ defines the
reliability in every 500-kV substations. Each ‘model’ has its own failure rate, therefore to calculate this
failure rate, the disturbance data needs to be classified by using Pareto Law. The Pareto principle, also known
as the 80/20 rule, is a theory which says that 80 percent of the output from any given situation or system is
determined by 20 percent of the input.
The next step is determining the µ value and ρ value. Based on an ideal repair and preventive
maintenance [12], [13] concept, these values have uniform probability density based on the following
formula,
𝑓 = 1/𝑇 (𝑒 ) (1)
3. Int J Elec & Comp Eng ISSN: 2088-8708
The use of markov chain method to determine spare transformer number and ...(Musa Partahi Marbun)
3
The difference is, the µ value will be constant for every variation but the ρ value will have variation
value based on the spare transformer location. The one spare transition state has six possibilities of states;
therefore, the calculation of the transition matrix is as shown in Figure 2.
Figure 2. One Spare Matrix Transition
By definition, this research calculates the steady state probability. Mathematically, steady state
probability is a condition where any initial state when multiplied with the transition matrix will have the
same output as the initial state.
[Intial State] x [Transition Matrix] = [Initial State] (2)
Calculating the above formula by using the principle of matrix calculation will give the steady state
probability results. The required output is the probability group values of all states which has normal
conditions. Based on the above simple example, the output is the sum of steady state probability of state
1 and state 2.
3. METHODOLOGIES
This paper will determine the spare transformer number and location by reliability of each 500-kV
substation. The main framework used is Markov Chain Model therefore the reliability is the steady state
probability of Markov Chain Calculations.
3.1. General description of the proposed model
In order to have comprehensive effect, every 500-kV substation have its state transition model,
therefore it have its own failure rate based on the disturbance data of each substation and different
transportation rate based on the location variation.
3.2. Location variation
The idea of transportation rate variation is based on the different range between 500-kV substation.
This assumption regarding the spare transformer, is located in the 500-kV substation, not in a special spare
warehouse. The visualization of location variation based on Table 1.
Table 1. Substation Range Table
To
A B C
From
A 0 2 6
B 2 0 3
C 6 3 0
In order to utilize the reliability value of each 500-kV substation, every substation has its own
Markov Chain model and its own calculation results, while every model is linked to each other by the
installation rate (ρ). Based on this definition, the location determination is the effect of component reliability
when the installation rate (ρ) changes. This installation rate value changes based on the distance changes
between substations. The mathematical formula of the ideal rate [12], [13] is,
𝑓 = 1/𝑇 (𝑒 ) (3)
1 2 3 4 5 6
1 1-λ 0 λ 0 0 0
2 μ 1-μ-λ 0 λ 0 0
3 0 ρ 1-ρ-λ 0 λ 0
4 0 0 μ 1-μ-λ 0 λ
5 0 0 0 ρ 1-ρ 0
6 0 0 0 0 μ 1-μ
TO
TRANSITION MATRIX
FROM
4. ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 9, No. 1, February 2019 : 1 - 13
4
Therefore, the distance calculated from Table 1 will be converted into period (TM) by rough
assumption of a distance per time constant factor. These assumptions were based on several actual spare
transformer transportations between the substations. The installation rate will be different for every
component’s reliability even though each substation will have the same Markov Chain model but different
installation rate and different failure rate.
3.3. Value of lost load
The Markov Chain calculation will produce the probability steady state of success states or
reliability. Based on the results, the economical calculation should give exact number and location based on
the cost/benefit analysis of spare provision. The cost component is spare price or cost, but the benefit instead
of production cost or tariff, this research uses value of lost load. The first step of coming up with the benefit
component is calculating the outage cost,
Outage Cost=(1-reliability) x capacity x LF x VoLLxtime (4)
And the Value of Lost Load calculation is:
𝑉𝑜𝐿𝐿 = 𝑥 (5)
VoLL calculation assume that any electricity outages will affect the economic condition [14].
4. RESULTS & DISCUSSION
500/150 kV transformer of Java Bali System was used as case study. These transformers had several
conditions that needed to be classified in order to have logical calculations of spare amount number and
location:
1. Classification
a. 1 phase per banks or 3 phase per bank.
b. 2 kinds of impedance.
c. Locations throughout Java
2. Failure rate calculation
Inventory management was used to classify the above conditions into several “models”. These
models had their own failure rates, which would be derived from Pareto Law–ABC Classifications.
The next step was steady state probability calculation for every failure rates and each variation of spare
location.
4.1. Java Bali 500/150 kV transformer model
500/150 kV Transformer or Inter Bus Transformer (IBT) in Java Bali System has two types, which
are the single phase per bank transformer and the 3 phase per bank transformer. The majority of the IBT in
Java Bali system are single phase per banks transformer. The advantages of single phase per banks
transformers are the flexibility of the spare transformer, where if there is a failure in one of the transformer,
the spare will replace only one unit instead of all three. Moreover, it is lighter than 3 phase per bank
transformer, where the advantage will be on transportation method aspect. The type of the transformer used
for this calculation is shown in the transformer type graphical recap in Figure 3.
Looking at Figure 3, the single phase per bank transformer has two type of impedance. For this
study the impedance difference will be neglected. The effect will be the loading differences, therefore in
order to have good results of spare number and location, the loading differences when there is different
impedance will be neglected.
The next logical way to classify the IBT was dividing substation location in Java-Bali System by its
provinces. This logic is based on the transportation constrain in order to have spare location and economical
calculations. There are 7 provinces in Java Bali System but only 5 provinces have the 500 kV Substation.
The IBT data by provinces is shown in Figure 4.
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Figure 3. 500/150 kV Transformer Type Figure 4. 500/150 kV Transformer by Provinces
Next step is determining the transformer failure classification, in order to have failure rate of each
‘models’. Classification of disturbances type was recorded and compiled by maintenance engineer on Extra
High Voltage Substation. The data type of this failure was taken from disturbance data from 2008 up to 2013.
In order to get the failure rate, the disturbance data needs to be defined into major disturbance and minor
disturbance. Pareto Law-ABC classification [11] has become a commonly used method, where the
classification of A only has 20% volume of the total equipment but have the interference effect of 80%. In a
transformer, this principle means, the small component of a whole equipment, could disturb the whole
transformer.
Based on A-B-C classification method, the transformer failure data was divided into
failure/disturbance on component A, component B, and component C of the whole transformer. A-B-C
classification analysis simplified the component disturbance data based on the Pareto Law where the
definition of component A in this study is a component where its disturbance has major effect on the entire
transformer and this component is unique. Component B is defined as components that has a high investment
value but does not affect the entire transformer in maintenance or replacements phase. Component C is
defined as supporting components. Based on the definition of the classification of A-B-C above, it can be
summarized that:
1. Disturbance of component A were Bushing & Insulators, and OLTC, by 19 %.
2. Interference Protection System of Component B by 31 %.
3. Impaired Support Tools of Component C which, Outer Party, and system conditions, by 49 %.
Due to data limitations and monitoring equipment, Figure 5 is showing the different classification
types of disturbance per IBT 500/150 kV components in Java-Bali system for major disturbance. According
to Pareto Law–A-B-C Classification, the Component A failure will have major effect to the entire
transformer and also to the entire power system. Based on the classification of location and impedance, the
failure rate from the disturbance data has been simplified into its average number. The failure rate calculation
was using three units of transformer as one. This condition occurred because Java Bali System uses 1 phase
per bank transformer, therefore one disturbance in one unit will fail all of the three units.
Figure 5. Component Disturbance & A-B-C Classifications
Component Name A-B-C Classifications
Bucholz Relay C
Bushing A
PowerSupply C
Current Transformer B
Insulator A
PowerCable C
Trip Control C
Marshailling Kiosk C
OLTC A
CB B
Protection System C
Reactor B
Switch C
Wiring C
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4.2. Failure rate
Based on Section III, the first step is detailing the failure rate(λ) into every 500-kV substation. The
results are shown in Figure 6 The results of the above figures were using statistical data for every IBT in Java
Bali System. The calculation of failure rates of each substation was based on A-B-C classification.
Figure 6. 500 kV Substation failure rate
4.3. Transportation rate
The next step is modeling the range data between 500 kV substations, the transportation model is
shown in the Table 2 Based on the above data assumption, there will be a significant installation rate value.
The one-spare Markov Chain model on each substation is linked to each other by the installation rate value.
Table 2. Range Between Each 500-kV Substation
4.4. Spare number and location results
The steps are putting the spare transformer at Cilegon Substation, by using the data in Table 2. The
installation rate on Markov Chain model at Cilegon Substation, and another different substation. Thus, the
steady state probability group at each Substation will be different. The second scenario and so on is done by
changing the spare transformer location. The location optimization is the steady state probability group
calculation result that changes as the installation rate changes as well. The results calculation of probability
steady state of each 500-kV substation with spare IBT location variation is shown in Table 3.
Based on the results above, each provinces should have a spare, because the significant increase of
reliability occur from 0 spare to 1 spare. Based on the reliability calculation, the spare number should be 5
(1 in every province) and the optimum locations are Cilegon, Gandul, Cibatu, Ungaran, and Krian (Green
color). The next calculation is by comparing these with the economic criteria.
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Table 3. Calculation Results
GITET 0 Spare 1 Spare 2 Spare 3 Spare 4 Spare
Suralaya - - - - -
Suralaya Baru - - - - -
Cilegon 0.4718932 0.9493701 0.9620499 0.9633226 0.9634550
Balaraja - - - - -
Kembangan 0.7015161 0.9706113 0.9776816 0.9776816 0.9776816
Cawang 0.2235391 0.8532107 0.8532107 0.8532107 0.8532107
Gandul 0.7962396 0.9860126 0.9860126 0.9860126 0.9860126
Depok - - - - -
Bekasi 0.7015161 0.9670808 0.9688456 0.9776816 0.9776816
Cibinong 0.3203320 0.8883486 0.8883486 0.8883486 0.9107184
Cibatu 0.8461596 0.9898468 0.9898468 0.9898468 0.9898468
Cirata 0.3203320 0.8663371 0.8663371 0.8663371 0.9107184
Bandung Selatan 0.7015161 0.9459764 0.9776816 0.9776816 0.9776816
Mandirancan 0.7015161 0.9233003 0.9407244 0.9776816 0.9776816
Tasikmalaya - - - - -
Pedan 0.3203320 0.8393674 0.9107184 0.9107184 0.9405737
Ungaran 0.7962396 0.9860126 0.9860126 0.9877685 0.9877685
Tanjung Jati - - - - -
Kediri - - - - -
Ngimbang - - - - -
Krian 0.8461596 0.9899606 0.9908443 0.9908670 0.9908676
Grati - - - - -
Gresik - - - - -
Paiton - - - - -
4.5. Spare number and location by economical criteria
The economic criteria are comparing the cost and benefit. The cost component is spare transformer
price, with the assumption of Rp 3.24 B (around 240.000,- USD) The benefit component is the outage cost
with value of lost load, whereas the value of lost load in each province is shown in Table 4. Based on the
above calculation results and the calculation result of spare cost, the outage cost with spare number and
location variation are calculated and analyzed. The results for 500-kV Substation in Banten in Figure 7.
Table 4. Value of Lost Load
Provinces Value of Lost Load
Banten Rp 4,247 /kwh
Jakarta Rp 8,888 /kwh
West Java Rp 4,906 /kwh
Central Java Rp 4, 481 /kwh
East Java Rp 7, 300 /kwh
Figure 7. Cilegon 500-kV substation results
Based on the above results, the spare number is 1 referring to the crosspath between spare cost and
avoided cost, and spare location in Cilegon Substation (no other 500 kV substation). The next results for
500-kV Substation in DKI Jakarta in Figures 8-12.
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Figure 11. Bekasi 500-kV substation results
Figure 12. Cibinong 500-kV substation results
Based on the above results, the spare number is 2 (corresponding to the Kembangan and Bekasi
results) and the location of each spare is in Cawang and Cibinong (corresponding to the small effect of
Bekasi and Gandul reliability on spare location variation). The Cawang and Cibinong must have a follow up
on reducing the disturbance, because its problem cannot be solved with spare provision. The next results for
500-kV Substation in West Java in Figures 13-16.
Figure 13. Cibatu 500-kV substation results
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Figure 14. Cirata 500-kV substation results
Figure 15. Bandung Selatan 500-kV substation results
Figure 16. Mandirancan 500-kV substation results
Based on the above results, the spare number is 2 (corresponding to the Mandirancan results) and
the location of each is in Mandirancan (corresponding to location variation 1), and Cirata (corresponding to
the small effect of Cibatu reliability on spare location variation). The Cirata must have a follow up on
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reducing the disturbance, because its problem cannot be solved with spare provision. The next results for
500-kV Substation in Central Java in Figures 17-18.
Based on the above results, the spare number is 2 and the location of each is in Ungaran and Pedan.
Based on the Pedan results, both spares should be located in Pedan, but the effect on Ungaran will be greater
if the location of each is in Pedan and Ungaran. The 3 spares provision will be too high and redundant. The
next results for East Java in Figure 19.
Figure 17. Pedan 500-kV substation results
Figure 18. Ungaran 500-kV substation results
Figure 19. Krian 500-kV substation results
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4.6. Discussion
These results give two major revelation regarding transformer spare, especially in Java-Bali system.
First revelation is optimal number of spare transformer number, the idea of increasing spare transformer
number will not increase significant reliability, and there are certain limit of spare transformer number.
Therefore, some investment cost could be saved if the spare transformer number is limited. Second revelation
is the effect of location variation to maintain reliability of each substation show that with the optimum way of
putting the spare transformer could maintain reliability of overall system reliability, these aspects currently
overlooked by other research.
5. CONCLUSION
Markov chain gives the best calculation to determine the number and location of spare transformer
by varying every possible combination. Markov Chain model in every 500 kV substations gives clear
reliability results based on the variation above. Most of the current studies have not clearly consider the spare
location output, on the other hand this research finds the opportunity to maintain the system reliability by
changing the installation rate. This installation rate defines the location of spare transformer. Based on the
calculation results, there are significant effect on system reliability if the spare number and location could be
determined by this method. Economic criteria give better determination of spare number and location, instead
of reliability measure standalone as the criteria.
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BIOGRAPHIES OF AUTHORS
Musa Partahi Marbun was born in Jakarta, Indonesia, in 1985. He received his Electrical
Engineering degree, Electrical Master degree, Doctoral in School of Electrical Engineering and
Informatics from Bandung Institute of Technology, Indonesia, in 2009, 2011, and 2017
respectively. He is currently working for the State-Owned Electric Utility Company in Indonesia
(PT PLN (Persero)). His research interests include probability method applied on power system.
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Ngapuli I Sinisuka was born in Medan, Indonesia, in 1950. He received his Electrical
Engineering degree from Bandung Institute of Technology, Indonesia, and Dr-Ing from
Université Paul Sabatier, Toulouse, France, in 1974 and 1980, respectively. Currently he is a
Full Professor at the School of Electrical Engineering and Informatics Bandung Institute of
Technology, Indonesia. His research interests include electrical insulation, maintenance
engineering, economic of electric energy systems, as well as statistics and optimization theory
and its applications and risk analysis.
Nanang Hariyanto was received the doctor degree in 2010 in electrical engineering from Institut
Teknologi Bandung. He is currently working as a head of electric power system laboratory and a
head of electrical power engineering study program of School of Electrical Engineering &
Informatics ITB. His main research interest includes power system stability, power system
control and power system operation, and power system reliability and economics