The peer-reviewed International Journal of Engineering Inventions (IJEI) is started with a mission to encourage contribution to research in Science and Technology. Encourage and motivate researchers in challenging areas of Sciences and Technology.
International Journal of Computational Engineering Research (IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Power quality conditioners are devices used in smart grids to improve the quality of power delivered to loads. They ensure efficient power transfer, isolate grids from disturbances, convert DC to AC, and integrate with energy storage. Common types include distribution static compensators (DSTATCOMs), active power filters, and unified power quality conditioners (UPQCs). DSTATCOMs regulate voltage and compensate for reactive power. Active power filters compensate for harmonics and reactive power. UPQCs combine series and shunt filters to compensate for both voltage and current issues. Power quality conditioners are important for integrating renewable energy and ensuring loads function properly in smart grids.
A Voltage Controlled Dstatcom for Power Quality Improvementiosrjce
Due to increasing complexity in the power system, voltage sag is becoming one of the most significant
power quality problems. Voltage sag is a short reduction voltage from nominal voltage, occurs in a short time.
If the voltage sags exceed two to three cycles, then manufacturing systems making use of sensitive electronic
equipments are likely to be affected leading to major problems. It ultimately leads to wastage of resources (both
material and human) as well as financial losses. This is possible only by ensuring that uninterrupted flow of
power is maintained at proper voltage levels. This project tends look at the solving the sag problems by using
custom power devices such as Distribution Static compensator (D-STATCOM).Proposed scheme follows a new
algorithm to generate reference voltage for a distribution static compensator (DSTATCOM) operating in
voltage-control mode. The proposed scheme ensures that unity power factor (UPF) is achieved at the load
terminal during nominal operation, which is not possible in the traditional method. Also, the compensator
injects lower currents therefore, reduces losses in the feeder and voltage-source inverter. Further, a saving in
the rating of DSTATCOM is achieved which increases its capacity to mitigate voltage sag. Nearly UPF is
maintained, while regulating voltage at the load terminal, during load change. The state-space model of
DSTATCOM is incorporated with the deadbeat predictive controller for fast load voltage regulation during
voltage disturbances. With these features, this scheme allows DSTATCOM to tackle power-quality issues by
providing power factor correction, harmonic elimination, load balancing, and voltage regulation based on the
load requirement.
Detection and analysis of power quality disturbances under faulty conditions ...IAEME Publication
This document discusses power quality disturbances in electrical power systems. It begins with an introduction that defines power quality and common power quality disturbances. It then discusses how power quality disturbances can be detected and analyzed under faulty conditions in a simulated four bus power system model in MATLAB/Simulink. Various types of faults are created at the load bus, and power quality disturbances are detected at the generator bus. The document provides classification of different types of power quality disturbances based on standards and considers causes and impacts of disturbances on power systems.
IRJET- Study on Power Quality Problem and its Mitigation Techniques in Electr...IRJET Journal
This document discusses power quality problems in electrical power systems and techniques to mitigate them. It begins by defining power quality and listing some common power quality issues like voltage sags, swells, interruptions, harmonics, and waveform distortions. Potential causes of these issues are also provided. The document then discusses various techniques that can be used to improve power quality, including surge protection devices, UPS systems, filters, custom devices like DVRs, STATCOMs and UPQC. It concludes by stating that power quality must be maintained as power needs increase and sensitive loads become more common, and discusses the need for mitigation techniques to address issues like voltage sags and harmonics.
This document summarizes a seminar presentation on transmission line maintenance techniques in India. It provides an overview of extra high voltage alternating current (EHVAC) transmission line maintenance in India, including methods such as predictive maintenance using thermography and insulator testing, as well as preventive maintenance techniques including cold line maintenance (with the line de-energized) and live line maintenance (with the line energized). It describes some of the specific maintenance works that can be done using live line techniques, and discusses the advantages of live line maintenance.
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...Pradeep Avanigadda
Renewable energy resources (RES) are being increasingly connected in distribution systems utilizing power electronic converters.
This project presents a novel control strategy for achieving maximum benefits from these grid-interfacing inverters when installed in 3-phase 4-wire distribution systems.
The inverter can thus be utilized as:
1) power converter to inject power generated from RES to the grid &
2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current.
International Journal of Computational Engineering Research (IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Power quality conditioners are devices used in smart grids to improve the quality of power delivered to loads. They ensure efficient power transfer, isolate grids from disturbances, convert DC to AC, and integrate with energy storage. Common types include distribution static compensators (DSTATCOMs), active power filters, and unified power quality conditioners (UPQCs). DSTATCOMs regulate voltage and compensate for reactive power. Active power filters compensate for harmonics and reactive power. UPQCs combine series and shunt filters to compensate for both voltage and current issues. Power quality conditioners are important for integrating renewable energy and ensuring loads function properly in smart grids.
A Voltage Controlled Dstatcom for Power Quality Improvementiosrjce
Due to increasing complexity in the power system, voltage sag is becoming one of the most significant
power quality problems. Voltage sag is a short reduction voltage from nominal voltage, occurs in a short time.
If the voltage sags exceed two to three cycles, then manufacturing systems making use of sensitive electronic
equipments are likely to be affected leading to major problems. It ultimately leads to wastage of resources (both
material and human) as well as financial losses. This is possible only by ensuring that uninterrupted flow of
power is maintained at proper voltage levels. This project tends look at the solving the sag problems by using
custom power devices such as Distribution Static compensator (D-STATCOM).Proposed scheme follows a new
algorithm to generate reference voltage for a distribution static compensator (DSTATCOM) operating in
voltage-control mode. The proposed scheme ensures that unity power factor (UPF) is achieved at the load
terminal during nominal operation, which is not possible in the traditional method. Also, the compensator
injects lower currents therefore, reduces losses in the feeder and voltage-source inverter. Further, a saving in
the rating of DSTATCOM is achieved which increases its capacity to mitigate voltage sag. Nearly UPF is
maintained, while regulating voltage at the load terminal, during load change. The state-space model of
DSTATCOM is incorporated with the deadbeat predictive controller for fast load voltage regulation during
voltage disturbances. With these features, this scheme allows DSTATCOM to tackle power-quality issues by
providing power factor correction, harmonic elimination, load balancing, and voltage regulation based on the
load requirement.
Detection and analysis of power quality disturbances under faulty conditions ...IAEME Publication
This document discusses power quality disturbances in electrical power systems. It begins with an introduction that defines power quality and common power quality disturbances. It then discusses how power quality disturbances can be detected and analyzed under faulty conditions in a simulated four bus power system model in MATLAB/Simulink. Various types of faults are created at the load bus, and power quality disturbances are detected at the generator bus. The document provides classification of different types of power quality disturbances based on standards and considers causes and impacts of disturbances on power systems.
IRJET- Study on Power Quality Problem and its Mitigation Techniques in Electr...IRJET Journal
This document discusses power quality problems in electrical power systems and techniques to mitigate them. It begins by defining power quality and listing some common power quality issues like voltage sags, swells, interruptions, harmonics, and waveform distortions. Potential causes of these issues are also provided. The document then discusses various techniques that can be used to improve power quality, including surge protection devices, UPS systems, filters, custom devices like DVRs, STATCOMs and UPQC. It concludes by stating that power quality must be maintained as power needs increase and sensitive loads become more common, and discusses the need for mitigation techniques to address issues like voltage sags and harmonics.
This document summarizes a seminar presentation on transmission line maintenance techniques in India. It provides an overview of extra high voltage alternating current (EHVAC) transmission line maintenance in India, including methods such as predictive maintenance using thermography and insulator testing, as well as preventive maintenance techniques including cold line maintenance (with the line de-energized) and live line maintenance (with the line energized). It describes some of the specific maintenance works that can be done using live line techniques, and discusses the advantages of live line maintenance.
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...Pradeep Avanigadda
Renewable energy resources (RES) are being increasingly connected in distribution systems utilizing power electronic converters.
This project presents a novel control strategy for achieving maximum benefits from these grid-interfacing inverters when installed in 3-phase 4-wire distribution systems.
The inverter can thus be utilized as:
1) power converter to inject power generated from RES to the grid &
2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a research paper about using a STATCOM to improve power quality for a grid-connected wind energy system supplying both balanced and unbalanced nonlinear loads. The paper introduces power quality issues caused by wind generation systems and describes how a STATCOM connected to a battery energy storage system can mitigate these issues. Simulation results using MATLAB/Simulink show that the STATCOM is able to regulate voltage and current waveforms at the point of common coupling and maintain unity power factor for both types of loads.
A Svc Light Based Technique for Power Quality Improvement for Grid Connected ...IOSR Journals
This document presents a SVC light based technique for improving power quality in a grid-connected wind energy system. The technique uses a STATCOM device called SVC light connected at the point of common coupling to address various power quality issues caused by the connection of wind turbines to the grid, including voltage fluctuations, harmonics, reactive power absorption, and fault ride-through capability. The proposed control scheme aims to maintain unity power factor at the source, provide reactive power support from the SVC light, and reduce harmonic distortion. Simulation results show the SVC light is able to regulate the grid voltage, compensate reactive power demand, and cancel harmonic currents, improving the overall power quality when integrated with the wind and load.
Variable renewable energy sources like solar and wind power are growing rapidly worldwide, with investments in renewable power exceeding those in non-renewable sources in recent years. As the share of variable renewable energy increases in many power systems, grid codes are playing an important role in facilitating their integration while maintaining reliability, security, and quality of supply. Grid codes set technical requirements for generators connecting to the grid. They aim to address challenges from the variability and uncertainty of renewable energy sources while allowing for sustainable growth. Requirements in grid codes need to be tailored to each country's power system characteristics and adapted over time as the system evolves.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes a paper that proposes a Green Power Zone (GPZ) concept to provide high quality electrical power. A GPZ would use custom power devices like a DVR, DSTATCOM, and UPQC to regulate voltage and power quality. It would receive power from two independent substations through solid state transfer switches to improve reliability. The GPZ center would monitor power quality and control devices to maintain a stable voltage supply closer to ideal levels, despite faults or interruptions from utilities. Simulation results demonstrated the GPZ's ability to compensate for issues like sags, swells, harmonics and imbalance.
These slides present the maximum power point tracking (MPPT ) algorithms for solar (PV) systems. Later of the class we will discuss on MPPT control of wind generators.
This document provides a review of Dynamic Voltage Restorer (DVR) systems used for compensating voltage sags in power distribution systems. It discusses that voltage sags are a serious power quality problem and DVR is an efficient custom power device to mitigate this issue. The document reviews the components, configurations, operating modes and control strategies of DVR systems. It describes that DVR injects voltage into the distribution system using a voltage source converter to regulate the load voltage during sags or disturbances.
IRJET - Power Quality Improvement using Statcom in PV Grid Connected SystemIRJET Journal
This document discusses power quality issues that can arise when integrating photovoltaic (PV) systems into electric grids. It proposes using a static synchronous compensator (STATCOM) connected at the point of common coupling to mitigate these issues. Power quality problems from renewable energy sources like PV systems include voltage variations, flicker, and harmonics. The STATCOM uses power electronics to regulate voltage and correct power factors in order to improve power quality delivered to customers from the grid-connected PV system.
Implementation of Fuzzy Controlled Photo Voltaic Fed Dynamic Voltage Restorer...ijfls
Power Quality(PQ) has become an area of concern in the electrical distribution system. Dynamic Voltage
Restorer(DVR) restores load voltage to a nominal balanced sinusoidal voltage, when the source voltage
has harmonic distortions, sag, swell and unbalances. In this paper a Photo Voltaic(PV) fed DVR is
proposed to mitigate PQ problems. The PV system can supply the maximum power to the load at a
particular operating point known as Maximum Power Point (MPP), at which the entire PV system operates
with maximum efficiency. A Fuzzy Controller based MPPT is implemented to generate the optimal voltage
from the photovoltaic system by modulating the duty cycle applied to the boost converter. The DVR is
implemented using a Fuzzy Logic Controller based voltage source inverter with Photovoltaic system. The
test system has been simulated and the efficacy of the proposed PV based Fuzzy controlled DVR is
compared with Proportional Integral (PI) controlled DVR.
Control of parallel dc dc converters in a dc microgridSushil Aggarwal
This document discusses controlling parallel DC-DC converters in a DC microgrid using a virtual output impedance method. It begins with introductions to power converters and DC converters. It then discusses types of DC converters, their performance parameters, output impedance, and how output impedance mismatch can cause circulating currents. It proposes using a virtual output impedance control loop to compensate for differences in converter output voltages and reduce circulating currents. Simulation results show this method can decrease circulating currents to near zero while maintaining voltage regulation within allowed deviations.
IRJET-Simulation and Modeling of Dynamic Voltage Restorer for Compensation Of...IRJET Journal
The document describes the simulation and modeling of a dynamic voltage restorer (DVR) for mitigating voltage sags and swells in a power distribution system. A DVR is a custom power device that injects voltage in series with the distribution line to regulate the voltage at a load. The simulation model includes a DVR connected between a power source and sensitive load. Simulation results show that during a 50% voltage sag or 25% voltage swell, the DVR is able to quickly inject the appropriate compensating voltage to keep the load voltage at its nominal level. The DVR utilizes a control scheme based on dq0 transformation to identify voltage disturbances and determine the offset voltage required for compensation.
Performance of DVR under various Fault conditions in Electrical Distribution ...IOSR Journals
1) The document describes the performance of a Dynamic Voltage Restorer (DVR) under various fault conditions in an electrical distribution system.
2) A DVR is connected in series with the distribution network to inject voltage and compensate for voltage sags and swells, maintaining the load voltage at its nominal value.
3) Simulation results using MATLAB/Simulink show that the DVR is able to effectively compensate for voltage disturbances caused by single line-to-ground faults, double line-to-ground faults, line-to-line faults, and three-phase faults, keeping the load voltage stable at its desired level.
The document proposes a matrix converter-based dynamic voltage restorer (DVR) system for power quality enhancement. The DVR uses a single matrix converter instead of a conventional AC/DC/AC converter. It is connected between the distribution feeder and load to mitigate voltage sags. The control system is based on dqo modeling of the matrix converter. It injects power from an energy storage device like a flywheel to restore the load voltage during sags. Simulation results show the DVR is able to effectively reduce sags and regulate the supply voltage, improving power quality.
A brief and basic presentation of interconnections of pwer system,it covers all the basic aspects of power system interconnection that how systems can be built with interconnections
Power quality enhancement by improving voltage stability using dstatcomeSAT Publishing House
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
Power Quality Improvement using DVR (Dynamic Voltage Restorer) Under Various ...IRJET Journal
1) The document discusses a Dynamic Voltage Restorer (DVR) which is used to improve power quality by mitigating voltage sags and swells.
2) A DVR injects voltage into the distribution system through a series transformer to keep the load voltage constant during faults.
3) It describes the components of a DVR including an energy storage device, voltage source inverter, series injection transformer, and control unit with PI controller for PWM switching of the inverter.
4) The paper presents simulation results of a DVR's performance under different fault conditions to demonstrate its effectiveness in improving voltage quality.
Photo Voltaic Cell Integrated DVR for Power Quality ImprovementIJMTST Journal
The document discusses integrating photovoltaic cells and ultracapacitors with a dynamic voltage restorer (DVR) to improve power quality. A DVR injects voltage in phase with the grid voltage to compensate for voltage sags and swells. Ultracapacitors provide the energy storage and a bidirectional DC-DC converter maintains the voltage level as the ultracapacitor charges and discharges. Average current mode control is used to regulate the converter voltage and determine the direction of power flow to and from the ultracapacitor bank. Simulation results demonstrate the integrated system can effectively compensate for voltage disturbances.
This document examines using a Static Synchronous Compensator (STATCOM) for reactive power compensation in Nigeria's electricity grid. It develops power flow equations to model the grid's 28-bus, 330kV system with and without STATCOM. Simulations using MATLAB show that with STATCOM, voltage magnitudes at 5 buses rise to within limits of 0.95-1.05 p.u. and total system power loss reduces by 5.88% from 98.21MW to 92.44MW. The results indicate STATCOM can stabilize voltages and reduce losses in the Nigeria grid.
This document discusses power quality issues related to wind power integration. It begins with an abstract noting how increasing electricity demand is leading to more renewable energy sources like wind power, but wind farm integration can negatively impact the grid's power quality. The document then covers international power quality standards, defines power quality issues, and lists various causes of power quality problems like power imbalances, voltage variations, harmonics, and flickers that can result from wind power integration. Finally, it discusses challenges wind power poses to grid stability and provides mitigation strategies like improved energy storage, forecasting, and grid reinforcement.
This document discusses power quality issues related to wind power integration. It begins with an abstract noting how increasing electricity demand is leading to more renewable energy sources like wind power, but wind integration can negatively impact the grid's power quality. The document then covers international power quality standards, defines power quality, and lists various power quality issues caused by wind power like power imbalances, voltage variations, harmonics, and flickers. Challenges of wind power integration to power system stability are also discussed. Finally, the document presents some mitigation strategies for integrating wind energy conversion systems onto the grid.
IRJET- A Review Paper on Power Quality Issues and Monitoring TechniquesIRJET Journal
This document summarizes a research paper on power quality issues and monitoring techniques. It discusses various power quality issues like voltage sag, interruptions, harmonics, and monitoring methods including portable monitors, permanent monitors, and real-time monitoring systems. Power quality monitoring is important to identify issues, maintain reliability, and prevent equipment damage. Different analysis techniques are used to classify disturbances and identify their causes in order to select appropriate mitigation methods.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a research paper about using a STATCOM to improve power quality for a grid-connected wind energy system supplying both balanced and unbalanced nonlinear loads. The paper introduces power quality issues caused by wind generation systems and describes how a STATCOM connected to a battery energy storage system can mitigate these issues. Simulation results using MATLAB/Simulink show that the STATCOM is able to regulate voltage and current waveforms at the point of common coupling and maintain unity power factor for both types of loads.
A Svc Light Based Technique for Power Quality Improvement for Grid Connected ...IOSR Journals
This document presents a SVC light based technique for improving power quality in a grid-connected wind energy system. The technique uses a STATCOM device called SVC light connected at the point of common coupling to address various power quality issues caused by the connection of wind turbines to the grid, including voltage fluctuations, harmonics, reactive power absorption, and fault ride-through capability. The proposed control scheme aims to maintain unity power factor at the source, provide reactive power support from the SVC light, and reduce harmonic distortion. Simulation results show the SVC light is able to regulate the grid voltage, compensate reactive power demand, and cancel harmonic currents, improving the overall power quality when integrated with the wind and load.
Variable renewable energy sources like solar and wind power are growing rapidly worldwide, with investments in renewable power exceeding those in non-renewable sources in recent years. As the share of variable renewable energy increases in many power systems, grid codes are playing an important role in facilitating their integration while maintaining reliability, security, and quality of supply. Grid codes set technical requirements for generators connecting to the grid. They aim to address challenges from the variability and uncertainty of renewable energy sources while allowing for sustainable growth. Requirements in grid codes need to be tailored to each country's power system characteristics and adapted over time as the system evolves.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes a paper that proposes a Green Power Zone (GPZ) concept to provide high quality electrical power. A GPZ would use custom power devices like a DVR, DSTATCOM, and UPQC to regulate voltage and power quality. It would receive power from two independent substations through solid state transfer switches to improve reliability. The GPZ center would monitor power quality and control devices to maintain a stable voltage supply closer to ideal levels, despite faults or interruptions from utilities. Simulation results demonstrated the GPZ's ability to compensate for issues like sags, swells, harmonics and imbalance.
These slides present the maximum power point tracking (MPPT ) algorithms for solar (PV) systems. Later of the class we will discuss on MPPT control of wind generators.
This document provides a review of Dynamic Voltage Restorer (DVR) systems used for compensating voltage sags in power distribution systems. It discusses that voltage sags are a serious power quality problem and DVR is an efficient custom power device to mitigate this issue. The document reviews the components, configurations, operating modes and control strategies of DVR systems. It describes that DVR injects voltage into the distribution system using a voltage source converter to regulate the load voltage during sags or disturbances.
IRJET - Power Quality Improvement using Statcom in PV Grid Connected SystemIRJET Journal
This document discusses power quality issues that can arise when integrating photovoltaic (PV) systems into electric grids. It proposes using a static synchronous compensator (STATCOM) connected at the point of common coupling to mitigate these issues. Power quality problems from renewable energy sources like PV systems include voltage variations, flicker, and harmonics. The STATCOM uses power electronics to regulate voltage and correct power factors in order to improve power quality delivered to customers from the grid-connected PV system.
Implementation of Fuzzy Controlled Photo Voltaic Fed Dynamic Voltage Restorer...ijfls
Power Quality(PQ) has become an area of concern in the electrical distribution system. Dynamic Voltage
Restorer(DVR) restores load voltage to a nominal balanced sinusoidal voltage, when the source voltage
has harmonic distortions, sag, swell and unbalances. In this paper a Photo Voltaic(PV) fed DVR is
proposed to mitigate PQ problems. The PV system can supply the maximum power to the load at a
particular operating point known as Maximum Power Point (MPP), at which the entire PV system operates
with maximum efficiency. A Fuzzy Controller based MPPT is implemented to generate the optimal voltage
from the photovoltaic system by modulating the duty cycle applied to the boost converter. The DVR is
implemented using a Fuzzy Logic Controller based voltage source inverter with Photovoltaic system. The
test system has been simulated and the efficacy of the proposed PV based Fuzzy controlled DVR is
compared with Proportional Integral (PI) controlled DVR.
Control of parallel dc dc converters in a dc microgridSushil Aggarwal
This document discusses controlling parallel DC-DC converters in a DC microgrid using a virtual output impedance method. It begins with introductions to power converters and DC converters. It then discusses types of DC converters, their performance parameters, output impedance, and how output impedance mismatch can cause circulating currents. It proposes using a virtual output impedance control loop to compensate for differences in converter output voltages and reduce circulating currents. Simulation results show this method can decrease circulating currents to near zero while maintaining voltage regulation within allowed deviations.
IRJET-Simulation and Modeling of Dynamic Voltage Restorer for Compensation Of...IRJET Journal
The document describes the simulation and modeling of a dynamic voltage restorer (DVR) for mitigating voltage sags and swells in a power distribution system. A DVR is a custom power device that injects voltage in series with the distribution line to regulate the voltage at a load. The simulation model includes a DVR connected between a power source and sensitive load. Simulation results show that during a 50% voltage sag or 25% voltage swell, the DVR is able to quickly inject the appropriate compensating voltage to keep the load voltage at its nominal level. The DVR utilizes a control scheme based on dq0 transformation to identify voltage disturbances and determine the offset voltage required for compensation.
Performance of DVR under various Fault conditions in Electrical Distribution ...IOSR Journals
1) The document describes the performance of a Dynamic Voltage Restorer (DVR) under various fault conditions in an electrical distribution system.
2) A DVR is connected in series with the distribution network to inject voltage and compensate for voltage sags and swells, maintaining the load voltage at its nominal value.
3) Simulation results using MATLAB/Simulink show that the DVR is able to effectively compensate for voltage disturbances caused by single line-to-ground faults, double line-to-ground faults, line-to-line faults, and three-phase faults, keeping the load voltage stable at its desired level.
The document proposes a matrix converter-based dynamic voltage restorer (DVR) system for power quality enhancement. The DVR uses a single matrix converter instead of a conventional AC/DC/AC converter. It is connected between the distribution feeder and load to mitigate voltage sags. The control system is based on dqo modeling of the matrix converter. It injects power from an energy storage device like a flywheel to restore the load voltage during sags. Simulation results show the DVR is able to effectively reduce sags and regulate the supply voltage, improving power quality.
A brief and basic presentation of interconnections of pwer system,it covers all the basic aspects of power system interconnection that how systems can be built with interconnections
Power quality enhancement by improving voltage stability using dstatcomeSAT Publishing House
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
Power Quality Improvement using DVR (Dynamic Voltage Restorer) Under Various ...IRJET Journal
1) The document discusses a Dynamic Voltage Restorer (DVR) which is used to improve power quality by mitigating voltage sags and swells.
2) A DVR injects voltage into the distribution system through a series transformer to keep the load voltage constant during faults.
3) It describes the components of a DVR including an energy storage device, voltage source inverter, series injection transformer, and control unit with PI controller for PWM switching of the inverter.
4) The paper presents simulation results of a DVR's performance under different fault conditions to demonstrate its effectiveness in improving voltage quality.
Photo Voltaic Cell Integrated DVR for Power Quality ImprovementIJMTST Journal
The document discusses integrating photovoltaic cells and ultracapacitors with a dynamic voltage restorer (DVR) to improve power quality. A DVR injects voltage in phase with the grid voltage to compensate for voltage sags and swells. Ultracapacitors provide the energy storage and a bidirectional DC-DC converter maintains the voltage level as the ultracapacitor charges and discharges. Average current mode control is used to regulate the converter voltage and determine the direction of power flow to and from the ultracapacitor bank. Simulation results demonstrate the integrated system can effectively compensate for voltage disturbances.
This document examines using a Static Synchronous Compensator (STATCOM) for reactive power compensation in Nigeria's electricity grid. It develops power flow equations to model the grid's 28-bus, 330kV system with and without STATCOM. Simulations using MATLAB show that with STATCOM, voltage magnitudes at 5 buses rise to within limits of 0.95-1.05 p.u. and total system power loss reduces by 5.88% from 98.21MW to 92.44MW. The results indicate STATCOM can stabilize voltages and reduce losses in the Nigeria grid.
This document discusses power quality issues related to wind power integration. It begins with an abstract noting how increasing electricity demand is leading to more renewable energy sources like wind power, but wind farm integration can negatively impact the grid's power quality. The document then covers international power quality standards, defines power quality issues, and lists various causes of power quality problems like power imbalances, voltage variations, harmonics, and flickers that can result from wind power integration. Finally, it discusses challenges wind power poses to grid stability and provides mitigation strategies like improved energy storage, forecasting, and grid reinforcement.
This document discusses power quality issues related to wind power integration. It begins with an abstract noting how increasing electricity demand is leading to more renewable energy sources like wind power, but wind integration can negatively impact the grid's power quality. The document then covers international power quality standards, defines power quality, and lists various power quality issues caused by wind power like power imbalances, voltage variations, harmonics, and flickers. Challenges of wind power integration to power system stability are also discussed. Finally, the document presents some mitigation strategies for integrating wind energy conversion systems onto the grid.
IRJET- A Review Paper on Power Quality Issues and Monitoring TechniquesIRJET Journal
This document summarizes a research paper on power quality issues and monitoring techniques. It discusses various power quality issues like voltage sag, interruptions, harmonics, and monitoring methods including portable monitors, permanent monitors, and real-time monitoring systems. Power quality monitoring is important to identify issues, maintain reliability, and prevent equipment damage. Different analysis techniques are used to classify disturbances and identify their causes in order to select appropriate mitigation methods.
Power Quality Improvement by UPQC based on Voltage Source ConvertersIJRST Journal
In modern power system consists of wide range of electrical, electronic and power electronic equipment in commercial and industrial applications. Since most of the electronic equipment’s are nonlinear in nature these will induce harmonics in the system, which affect the sensitive loads to be fed from the system. These problems are partially solved with the help of LC passive filters. However, this kind of filter cannot solve random variation in the load current wave form and voltage wave form. Active filters can resolve this problem. However, the cost of active filters is high. They are difficult to implement in large scale. Additionally, they also present lower efficiency than shunt passive filters. One of the many solutions is the use of a combined system of shunt and active series filters like Unified Power Quality Conditioner (UPQC) which aims at achieving a low cost under highly effective control. The UPQC device combines a shunt active filter together with a series active filter in a back-to-back configuration, to simultaneously compensate the supply voltage and the load current or to mitigate any type of voltage and current fluctuations and power factor correction in a power distribution network, such that improved power quality can be made available at the point of common coupling. The control strategies are modeled using MATLAB/SIMULINK. The performance is also observed under influence of utility side disturbances such as harmonics and voltage sags. The simulation results are compared without and with UPQC for the verification of results.
This document provides a summary of a project presentation on improving power quality in a distribution system using a Dynamic Voltage Restorer (DVR). The presentation was given by 5 students and covered the background, problem statement, objectives, methodology, and work schedule of the project. The document discusses various power quality issues like voltage sags, swells, harmonics, and transients. It describes how a DVR works to inject voltage and regulate the load voltage during disturbances. The methodology section explains the basic components and operating mode of a DVR. The work schedule outlines a 16 week plan for the project simulation, testing, and reporting.
IRJET-Review on Power Quality Enhancement in weak Power Grids by Integration ...IRJET Journal
Prathmesh Mayekar, Mahesh Wagh, Nilkanth Shinde "Review on Power Quality Enhancement in weak Power Grids by Integration of Renewable Energy Technologies", International Research Journal of Engineering and Technology (IRJET), Volume2,issue-01 April 2015.e-ISSN:2395-0056, p-ISSN:2395-0072. www.irjet.net
Abstract
During Last decade power quality problems has become more complex at all level of power system. With the increased use of sophisticated electronics, high efficiency variable speed drive, power electronic controllers and also more & more non-linear loads, Power Quality has become an increasing concern to utilities and customers. The modern sensitive, Non-linear and sophisticated load affects the power quality. This paper deals with the issues of low power quality in weak power grids. Initially the various power quality issues are discussed with their definition or occurrence and then finally the solution to mitigate this power quality issues are discussed. The innovative solutions like integration of renewable energy systems along with energy storage to enhance power quality by interfacing with custom power devices are explained in detail. Nearly all sorts of solution for mitigating power quality issue require some sort of DC source for providing active power, which can be supplied by renewable energy source. Also the various energy storage systems are studied.
A High-Performance SPWM Controller for Three-Phase UPS Systems Operating Unde...ijiert bestjournal
The increased use of rectifiers in critical loads employed by the information technologies,and medical and military equipment mandate the design of uninterruptible power supplies (UPS) with high- quality outputs. The highly nonlinear currents drawn especially by high-power single-phase rectifier loads greatly distort the uninterruptible power supplies (UPS) outputs. The distorted uninterruptible power supplies (UPS) voltages cause generation of low dc voltage at the output of the rectifier loads,which causes high current flow,increased power losses,and possibly the malfunction of the critical load or the uninterruptible power supplies (UPS). As a result,different harmonics mitigating techniques have gained a lot of attention. The main objective of this project is to develop simulation of a high-performance Pulse Width Modulation (PWM) technique based AC-DC converter system operating under highly nonlinear loads using MATLAB/SIMULINK. Here,controlled Insulated-gate bipolar transistor (IGBT) based AC-DC converter is used to supply the load instead of Diode or Thyristor Bridge. The pulse width modulation method is quite effective in controlling the root mean square (RMS) magnitude of the AC-DC converter output voltages and shape of input current. This enables automatic harmonic compensation by Rectifier itself.
This document presents a study on using a Distribution Static Compensator (DSTATCOM) to improve power quality issues like voltage sags and swells. It begins with an introduction to power quality problems such as voltage sags, swells, harmonics and transients. It then discusses different custom power devices that can be used as solutions, focusing on DSTATCOM. The document presents the configuration, modelling and control of a DSTATCOM. It proposes a control scheme for DSTATCOM and presents simulation results demonstrating its ability to regulate voltage during sags and improve power factor. The conclusion states that the proposed DSTATCOM scheme can effectively mitigate various power quality issues related to voltage and current.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IRJET- Mitigation Techniques of Power Quality Issues in Electrical Power SystemIRJET Journal
1. The document discusses various power quality issues such as voltage sags, swells, harmonics, transients, and their causes and consequences. It also describes different mitigation techniques for these issues including static VAR compensator (SVC), distribution static compensator (DSTATCOM), passive harmonic filters, and surge arresters.
2. The main objectives are to investigate suitable mitigation techniques, analyze mitigation using Mi Power software, and observe the effectiveness of SVC, DSTATCOM, harmonic filters, and surge arresters.
3. Among the mitigation methods, FACTS devices like DSTATCOM are most effective at overcoming voltage unbalance problems while requiring fewer electronic switches than other options like D
Introduction: Definition & Reasons of Occurrence of following Voltage Dip, Brief voltage increases, Brief voltage interruption, Transients, Voltage Notches, Flickers, Distortion, Un-balance. Power Quality Indices,Limits of Harmonic Distortion according to IEEE, IEC, EN and NORSOK limits.Brief Introduction of Power quality Standards: IEC 61000-2-5,IEC 61000-2-1, IEC 1159 ( Categories of Power quality variation according to IEEE 1159 standard with their relevant Spectral content, Duration of occurrence & Magnitude)
The document summarizes power quality issues including defects like under voltage, over voltage, dips, surges, blackouts, harmonics, and transients. It discusses who is responsible for ensuring power quality and some typical problems caused by defects. Solutions mentioned include surge protection, UPS systems, generators, filters, proper wiring, and load zoning. Assuring high quality power is challenging as electricity must flow continuously from generators to consumers via a shared infrastructure.
Power Quality is a combination of Voltage profile, Frequency profile, Harmonics contain and reliability of power supply.
The Power Quality is defined as the degree to which the power supply approaches the ideal case of stable, uninterrupted, zero distortion and disturbance free supply.
POWER QUALITY PROBLEMS & SOLUTIONS- POWER SYSTEMAnandYadav207
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IRJET- Voltage Stability Improvement and Reactive Power Compensation using ST...IRJET Journal
1) The document discusses improving voltage stability and reactive power compensation in a transmission line using STATCOM (Static Synchronous Compensator) in MATLAB.
2) It simulates a three phase transmission line in MATLAB and observes the voltage drop when an additional load is added.
3) To mitigate this voltage drop, a STATCOM is used to dynamically inject reactive power and regulate the transmission voltage. The MATLAB model and results showing improved voltage stability with STATCOM are presented and analyzed.
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The document discusses various power quality problems such as harmonic distortion, voltage sags, swells, and interruptions. It then discusses solutions for power quality problems including maintaining grid adequacy, using distributed resources like distributed generation and energy storage, and implementing enhanced interface devices. The document also describes the operation of the Merus A-series Active Filter, which can be used to compensate for harmonics and reactive power in an electrical system.
The document discusses the operation of power systems and control centers. It provides background on how electricity is generated and transmitted on a large scale to power grids. Control centers use SCADA systems and digital computers to monitor the entire power system in real time, control generation and transmission equipment, and ensure reliable and economic operation of the grid. Key functions of control centers include automatic generation control, economic dispatch, system security, and load forecasting. Critical data is acquired from sensors every 2 seconds to track the state of the power system.
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Power Quality Improvement using AC To AC PWM converter for distribution line
1. International Journal of Engineering Inventions
e-ISSN: 2278-7461, p-ISSN: 2319-6491
Volume 2, Issue 11 (July 2013) PP: 60-66
www.ijeijournal.com Page | 60
Power Quality Improvement using AC To AC PWM converter
for distribution line
Shalini Bajpai
Jabalpur Engineering Collage Jabalpur Madhya Pradesh
Abstract: In this paper, a new voltage sag compensator for critical loads in electrical distribution system
discussed. The proposed scheme employs a Pulse width modulation ac-ac convertor along with an auto
transformer. During a disturbance such as voltage sag, the proposed scheme supplies the missing voltage and
helps in maintaining rated voltage at the terminals of the critical load. Under normal condition the approach
works in bypass mode and delivering utility power directly to load. A four step switching technique ti drive the
ac-ac convertor is employed to realize snubber less operation. A design is presented for 440v, 50 hz, system.
Keywords: Power Quality, Voltage Sag, PWM Ac-Ac Converter
I. Introduction: Power Quality
POWER QUALITY is a term that mean different to different people. Institute of Electrical and
electrical engineers (IEEE) standard IEEE 1100 defines power quality “as the concept of powering and
grounding sensitive electronic equipment in a manner suitable for the equipment”. In a simpler words PQ is a set
of electrical boundaries that allows a part of equipment to work in a intended manner without loss of
performance or life expectancy.
In recent years power engineers are increasingly concerned over PQ due to following reasons:
II. Reasons For Increased Concern Regarding Power Quality
The most responsible reason is the newer-generation load equipment with microprocessor-based
controls and power electronic devices such loads are more sensitive to power quality variations than was
equipment used in the past.
The another reason is the increased use of power electronics devices such as electrical drives ,fact
devices, static relays etc due to the increased emphasis on improving overall power system efficiency . This is
resulting in increasing harmonic levels on power systems and has many people oncerned about the future impact
on system capabilities.Increased awareness of power quality issues among the end users.Most of the systems are
now interconnected in a network. Hence the processes are integrated in which the failure of anycomponent can
results into important consequences.The globalization of industries has increased the awareness about
deficiencies in power quality around the world.
The economic value of power quality is also one important reason for its increased concern. There is a
big money associated with these power quality disturbances. Many efforts have been taken by the utilities to
meet the consumer’s PQ requirements. Hence FACT devices and various other custom power devices are
introduced in the electrical system to improve the PQ of the electrical power.
III. Types Of Power Quality Problems
1.Voltage sag (or dip)
It is a dip of .1 to .9 p.u. in rms voltage or current at the power frequency, for interval of 0,5 cycle to 1
minute.
Causes: Whenever a load end draws a heavy current suddenly. That’s why it is associated with faults on the
transmission or distribution network, faults in consumer’s installation , sudden connection of heavy loads and
start-up of large motors.
Consequences: Malfunction of microprocessor-based control systems (PCs, PLCs, ASDs, etc), that may cause
false tripping of contactors and electromechanical relays. Maloperation of electric rotating machines.
Fig.1-Voltage sag
2. Power Quality Improvement using AC To AC PWM converter for distribution line
www.ijeijournal.com Page | 61
2. Very short interruptions
It is a total interruption or decrease of supply voltage or load current to less than .1 p.u. for few
milliseconds to one or two seconds.
Causes: It occurs due to failure of protecting devices, insulation failure, control malfunction. Also due to
delayed reclosing of the protecting devices.
Consequences: False tripping of protection devices, loss of information results in malfunction of data
processing equipment. Sensitive equipment stops working.
Fig.2- Very short interruptions
3. Long interruptions
Total interruption of electrical supply for duration greater than 1 to 2 seconds
Causes: Equipment failure in the power system network, storms and objects (trees, cars, etc) striking lines or
poles, fire, human error, bad coordination or failure of protection devices.
Consequences: Stoppage of all equipment.
Fig.3- Long interruptions
4. Voltage spike
It is the very fast variation of the voltage for durations from a several microseconds to few
milliseconds. These variations may reach thousands of volts, even in low voltage.
Causes: Lightning which is a natural cause , switching of lines or power factor correction capacitors ,sudden
removal of heavy loads.
Consequences: Damage of components (particularly electronic components) and of insulation materials, data
processing errors , electromagnetic interference or information loss.
Fig.4- Voltage Spike
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5. Voltage swell
Momentary increase of the voltage, at the power frequency, outside the normal tolerances, with
duration of more than one cycle and typically less than a few seconds.
Causes: Start/stop of heavy loads, badly dimensioned power sources, badly regulated transformers (mainly
during off-peak hours).
Consequences: Data loss, flickering of lighting and screens, stoppage or damage of sensitive equipment,
if the voltage values are too high.
Fig.5- Voltage swell
6. Harmonic distortion
These are periodically distorted voltage or current waveform . The waveform corresponds to the sum of
different sine-waves with different magnitude and phase, having frequencies that are multiples of power-system
frequency.
Causes: Arc furnances electric machines working above the magnetic saturation, welding machines, rectifiers,
and DC brush motors. All non-linear loads, such as power electronics equipment including ASDs, switched
mode power supplies, high efficiency lighting, data processing equipments.
Consequences: Probability of occurrence severe resonance increases, neutral overloading in 3-phase systems,
overheating of all cables and equipment, loss of efficiency in electric machines, electromagnetic interference
with communication systems, errors in measures when using average reading meters, nuisance tripping of
thermal protections ,can induce visual flicker in arc lighting.
Fig.-6 Harmonic distortion
7. Voltage fluctuation
It is a series of random voltage variations or systematic variations of voltage envelop but the variation
does not exceeds the voltage ranges of 0.9 to 1.1 p.u. . Oscillation of voltage value, amplitude modulated by a
signal with frequency of 0 to 30 Hz.
Causes:Frequent start/stop of electric motors (for instance elevators), oscillating loads,arc furnances
Consequences: . The most perceptible consequence is the flickering of lighting and screens, giving the
impression of unsteadiness of visual perception and the rest effects are similar to undervoltages.
Fig.-7 Voltage fluctuation
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8. Noise
It is the Superimposing of high frequency unwanted signals on the waveform of the power-system
frequency.
Causes: Electromagnetic interferences provoked by microwaves, television diffusion, and radiation due to
welding machines, arc furnaces, and electronic equipment. Improper grounding may also be a cause.
Consequences: Disturbances on sensitive electronic equipment, usually not destructive. May cause some data
related errors .
9. Voltage Unbalance
A maximum voltage variation in a three-phase system in which the three voltage magnitudes or the
phase angle differences between them are not equal.
Causes:, Incorrect distribution of all single-phase loads by the three phases of the system (this may be also
due to a fault). Large single-phase loads (induction furnaces, traction loads)
Consequences: It mostly affects three-phase induction machines. Unbalanced systems imply the existence of a
negative sequence that is harmful to all three phase loads.
It has found that among all the PQ issues voltage sag and swell are the most occurring problems at the
distribution end [1]-[2]-[3],as shown in fig.8-
Fig.-8 Showing the occurring percentage of various PQ issues
From fig.8 we can see that the voltage sag swell issues cover almost 89% of the graph area. That
means they are the most responsible issues for decreasing power quality.
10. Proposed system configuration
The proposed device for mitigating voltage sag and swell in the system consists of a PWM switched
power electronic device connected to an autotransformer in series with the load.
Fig. 9 shows the single phase circuit configuration of the mitigating device and the control circuit logic
used in the system. It consists of a single PWM insulated gate bipolar transistor (IGBT) switch in a bridge
configuration, a thyristor bypass switch, an autotransformer, and voltage controller.
11. Principle Of Operation
To maintain the load voltage constant an IGBT is used as power electronic device to inject the error
voltage into the line. Four power diodes (D1 to D4) connected to IGBT switch (SW) controls the direction of
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power flow and connected in ac voltage controller configuration with a suitable control circuit maintains
constant rms load voltage. In this scheme sinusoidal PWM pulse technique is used. RMS value of the load
voltage VL is calculated and compared with the reference rms voltage Vref. During normal condition the power
flow is through the anti parallel thyristors. Output filters containing a main capacitor filter and a notch filter are
used at the output side to filter out the switching noise and reduce harmonics. During this normal condition, VL
= Vref and the error voltage Verr is zero. The gate pulses are blocked to IGBT. Due to sudden increase or
decrease in the load or due to faults voltage sag or swell occurs. The supply voltage VS and hence VL
decreases. When the sensing circuit detects an error voltage Verr greater than 10% of the normal voltage the
voltage controller acts immediately to switch off the thyristors. Voltage Verr applied tothe pi controller gives the
phase angle delta .The phase angle delta is dependent on the percentage of disturbance and hence controls the
magnitude of Vcontrol. This control voltage is then compared with the triangular voltage Vtri to generate the
PWM pulses VG which are applied to the IGBT to regulate the output voltage. Hence the IGBT switch operates
only during voltage sag or swells condition and regulates the output voltage according to the PWM duty-cycle.
To suppress the over voltage when the switches are turned off, RC snubber circuits are connected across the
IGBT and thyristor.
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IV. Simulation Analysis And Results
Simulation analysis is performed on a three-phase, 11KV/440V, 100 MVA, 50 Hz system to study the
performance of the PWM switched autotransformer in mitigating the voltage sag and swell disturbances. The
MATLAB/SIMULINK model of the system used for analysis is shown An RL load is considered asa sensitive
load, which is to be supplied at constant voltage. Tab. 1 shows the system parameter specifications used for
simulation. Under normal condition, the power flow is through the antiparallel SCRs and the gate pulses are
inhibitedto IGBT. The load voltage and current are same as supply voltage and current. When a disturbance
occurs, an error voltage which is the difference between the reference rms voltage and the load rms voltage is
generated.
The PI controller thus gives the angle . Control voltage at fundamental frequency (50 Hz) is generated
andcompared with the carrier frequency triangular wave of carrier frequency 1.5 kHz. The PWM pulses now
drivethe IGBT switch. The simulation modeling of PWM switched autotransformer used as mitigating device
along with its control circuit is shown The autotransformer rating in each phase is 6.35/6.35 kV (as line voltage
is 11 kV) with 1:1 turns ratio. The effective voltage available at the primary of autotransformer is such that the
load voltage is maintained at desired RMS value (6.35 kV or 1 pu).
Voltage sag is created during the simulation by sudden application of heavy load of P=10MW and
Q=50Mvar for a period of 0.1 sec(5cycles) from t1 = 0.1 sec to t2 = 0.2 sec. Shows the simulation waveforms of
the load voltage for voltage sag of 27%.
V. Conclusion
A new voltage sag compensator based on PWM switched autotransformer has been presented in this paper.
Control circuit based on rms voltage reference is discussed. The proposed technique could identify the
disturbance and capable of mitigating the disturbance by maintaining the load voltage at desired magnitude
within limits. The proposed technique is simple and only one IGBT switch per phase is required. Hence the
system is more simple and economical compared to commonly used DVR or STATCOM. Simulation analysis is
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performed for 27% voltage sag for three phase system and simulation results verify that the proposed device is
effective in compensating the voltage sag disturbances.
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