This presentation provides an overview of power quality, including definitions of power quality, common power quality disturbances like sags, swells, harmonics and interruptions. It discusses the increased sensitivity of modern electronic equipment to power quality issues. Real-time power quality monitoring systems are described that can identify issues, locate their sources, and help utilities and customers mitigate problems to reduce costs and equipment damage. The benefits of power quality monitoring include improved reliability, preventative maintenance, and identification of sensitive equipment needing protection.
this is useful for peoples interested in power quality problems and their mitigation. it provides causes, effects of voltage sag and their mitigation techniques.
A power quality monitoring system gathers and analyzes electricity measurement data to provide useful information. It allows plants to perform energy management, preventive maintenance, quality control, and save money. Power quality monitoring equipment includes digital fault recorders, smart relays, voltage recorders, in-plant power monitors, and special-purpose power quality equipment. These devices monitor voltage, current, and other measurements to detect issues like harmonics, sags, disturbances and optimize power quality and performance.
This document discusses power quality monitoring. It defines power quality as the properties of the power supply delivered to users. Power quality can be affected by various steady state variations and events that cause deviations from the ideal voltage waveform. The document describes different types of power quality disturbances and how automatic classifiers are used to classify disturbances. It discusses power quality monitoring objectives and the types of commercially available power quality monitors used to identify and analyze power quality problems.
The document discusses power quality issues caused by harmonics from non-linear loads. It provides background on the increasing use of non-linear loads and effects of harmonics. Specific sources of harmonics are outlined along with their impact on power quality including overheating, failures, and interference. Mitigation techniques are reviewed such as passive and active filtering. Active power filters are highlighted as an effective solution, with shunt active power filters discussed in detail for compensating harmonic currents and reactive power. The document concludes that active power filtering is still developing and more research is needed on techniques like controls and artificial intelligence to further improve power quality.
Loading Capability Limits of Transmission LinesRaja Adapa
This document discusses the four main loading capability limits of transmission lines: thermal, voltage, dielectric, and stability limits. The thermal limit depends on ambient temperature, wind conditions, conductor size and is usually the main limiting factor. Voltage limits require the transmission voltage to be maintained within a specified range, like plus/minus 5% of nominal. The dielectric limit concerns insulation and allows for some increase in normal operating voltage. Stability limits involve ensuring the power system remains stable after the loss of a single element to prevent cascading outages. FACTS technology can help utilize more of the thermal limits and improve stability.
This document discusses power quality issues such as voltage sags, interruptions, spikes, swells, and harmonics. It explains the causes and consequences of each issue. Solutions discussed include improving the electric grid, using distributed energy resources like generators and energy storage, following standards, installing enhanced interface devices, and making equipment less sensitive. The key is preventing power quality problems through various measures to avoid losses.
Power System Transient - Introduction.pptxssuser6453eb
This document provides an introduction to power system transients. It discusses the sources of transients, both internal like capacitor switching and external like lightning. It classifies transients into three categories based on speed: ultrafast surges, medium-fast short-circuit phenomena, and slow transient stability issues. The effects of transients are outlined, such as damage to insulation, semiconductors, and contacts. The importance of studying transients for insulation design is emphasized to prevent breakdown under overvoltage conditions.
this is useful for peoples interested in power quality problems and their mitigation. it provides causes, effects of voltage sag and their mitigation techniques.
A power quality monitoring system gathers and analyzes electricity measurement data to provide useful information. It allows plants to perform energy management, preventive maintenance, quality control, and save money. Power quality monitoring equipment includes digital fault recorders, smart relays, voltage recorders, in-plant power monitors, and special-purpose power quality equipment. These devices monitor voltage, current, and other measurements to detect issues like harmonics, sags, disturbances and optimize power quality and performance.
This document discusses power quality monitoring. It defines power quality as the properties of the power supply delivered to users. Power quality can be affected by various steady state variations and events that cause deviations from the ideal voltage waveform. The document describes different types of power quality disturbances and how automatic classifiers are used to classify disturbances. It discusses power quality monitoring objectives and the types of commercially available power quality monitors used to identify and analyze power quality problems.
The document discusses power quality issues caused by harmonics from non-linear loads. It provides background on the increasing use of non-linear loads and effects of harmonics. Specific sources of harmonics are outlined along with their impact on power quality including overheating, failures, and interference. Mitigation techniques are reviewed such as passive and active filtering. Active power filters are highlighted as an effective solution, with shunt active power filters discussed in detail for compensating harmonic currents and reactive power. The document concludes that active power filtering is still developing and more research is needed on techniques like controls and artificial intelligence to further improve power quality.
Loading Capability Limits of Transmission LinesRaja Adapa
This document discusses the four main loading capability limits of transmission lines: thermal, voltage, dielectric, and stability limits. The thermal limit depends on ambient temperature, wind conditions, conductor size and is usually the main limiting factor. Voltage limits require the transmission voltage to be maintained within a specified range, like plus/minus 5% of nominal. The dielectric limit concerns insulation and allows for some increase in normal operating voltage. Stability limits involve ensuring the power system remains stable after the loss of a single element to prevent cascading outages. FACTS technology can help utilize more of the thermal limits and improve stability.
This document discusses power quality issues such as voltage sags, interruptions, spikes, swells, and harmonics. It explains the causes and consequences of each issue. Solutions discussed include improving the electric grid, using distributed energy resources like generators and energy storage, following standards, installing enhanced interface devices, and making equipment less sensitive. The key is preventing power quality problems through various measures to avoid losses.
Power System Transient - Introduction.pptxssuser6453eb
This document provides an introduction to power system transients. It discusses the sources of transients, both internal like capacitor switching and external like lightning. It classifies transients into three categories based on speed: ultrafast surges, medium-fast short-circuit phenomena, and slow transient stability issues. The effects of transients are outlined, such as damage to insulation, semiconductors, and contacts. The importance of studying transients for insulation design is emphasized to prevent breakdown under overvoltage conditions.
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 concept of FACTS (Flexible Alternating Current Transmission System) refers to a family of power electronics-based devices able to enhance AC system controllability and stability and to increase power transfer capability.
Simplified analysis of graetz circuit copy - copyVert Wheeler
The document summarizes the analysis of a Graetz circuit, which is used in HVDC transmission, under two scenarios: without overlap and with overlap between thyristor valves. In the without overlap scenario, the analysis assumes valves switch on and off instantaneously with no two valves on at once. This allows simplifying the circuit to determine voltage and current waveforms. When overlap is considered and two valves can be on simultaneously, the analysis is more complex with different operation modes identified depending on the overlap angle. Key aspects of voltage, current, power factor and harmonics are derived.
The document discusses harmonics in power systems. Harmonics are caused by non-linear loads that draw current in pulses rather than smoothly. Common sources are electronic devices, variable speed drives, and UPS systems. Harmonics can overheat equipment, increase power costs, and distort voltages and currents. They are managed by measuring harmonic levels and installing filters if problems are detected.
Unit 04 Protection of generators and transformers PremanandDesai
The document discusses faults and protection methods for alternators and transformers. For alternators, common faults include failure of the prime mover, field failure, overcurrent, overspeed, overvoltage, and unbalanced or stator winding faults. Differential and inter-turn protection are described. For transformers, faults include open circuits, overheating, and winding short-circuits. Buchholz devices, earth fault relays, overcurrent relays, and differential systems provide protection. Earth fault protection for transformers uses a core-balance leakage scheme.
This document discusses power quality and power quality disturbances. It defines power quality as the set of parameters defining the properties of power supply in normal operating conditions. Common power quality disturbances include steady-state variations like voltage fluctuations, harmonics, and high frequency noise as well as events like interruptions, sags, swells, and transients. Solutions to power quality problems include distributed generation, energy storage systems, codes and standards, interface devices, and making equipment less sensitive.
In microgrid, if fault occurs or any other contingency happens, then the problems would be created which are related to power flow, also there are various protection schemes are used for minimize or eliminate these problems.
Voltage control is used for reactive power balance and P-f control is used for active power control.
Various protection schemes such as, over current protection, differential protection scheme, zoning of network in adaptive protection scheme are used in microgrid system .
This document discusses power system protection settings and provides information on calculating protection settings. It covers the functions of protective relays and equipment protection, the required information for setting calculations such as line parameters and fault studies, and the process of calculating, checking, and implementing protection settings. The goal is to set protections to operate dependably, securely, and selectively during faults while meeting clearance time requirements.
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.
This document discusses power quality and defines it as the ability of a power system to supply voltage continuously within tolerances. It outlines various power quality events like sags, swells, interruptions, harmonics, and their causes and effects. It then describes various techniques to mitigate power quality issues, including dynamic voltage restorers, harmonic filters, static VAR compensators, and unified power quality conditioners. Maintaining high power quality improves system efficiency and equipment lifespan while eliminating problems like voltage fluctuations, harmonics, and reactive power issues.
POWER SYSTEM PROTECTION
Protection Devices and the Lightning,. protection,
Lightning protection, Introduction
Air Break Switches
Disconnect switches
Grounding switches
Current limiting reactors
Grounding transformers
Co-ordination of protective devices
Grounding of electrical installations
Electric shock
Lightning protection
Lightning Arrestor
EHV (extra high voltage) AC transmission refers to equipment designed for voltages greater than 345 kV. Higher transmission voltages increase efficiency by reducing transmission losses and current, decrease infrastructure costs, and increase transmission capacity. However, they also present safety and interference risks. New technologies like FACTS (flexible AC transmission systems) help maximize the benefits of EHV transmission by enabling voltage control and power flow management. There is growing support for expanding national EHV transmission grids to facilitate large-scale renewable energy integration and inter-regional power sharing.
three phase fault analysis with auto reset for temporary fault and trip for p...Vikram Rawani
The project was aimed to prevent failures due to some faults which can be temporary or permanent in 3-phase power supply .
The purpose of our project was to develop an automatic tripping mechanism for the three phase supply system. The project output resets automatically after a brief interruption in the event temporary fault while it remains in tripped condition in case of permanent fault.
It is based on current transformer description
It's working and applications are present in it ,it also includes videos of it's windings and it's inrush ability of transformer, and also about instrument transformer and it's working with applications.Current transformers are used-in measuring high currents and connected with it in parallel to it
Protection against overvoltage
overvoltage
causes of overvoltage
lightning
types of lightning strokes
harmful effect of lightning
protection against lightning
Power quality monitoring involves gathering raw measurement data from equipment like digital fault recorders, smart relays, and power quality monitors. This data is then analyzed to provide useful information about disturbances, harmonics, sags, and other power quality issues. When setting up a monitoring system, key considerations include determining what to monitor, choosing monitoring locations, setting thresholds, and the duration of monitoring. A variety of equipment can be used for permanent power quality monitoring including devices that already monitor voltage and current as well as specialized power quality monitors.
This case study describes the key components of an electric transmission substation. It discusses transformers that change voltage levels, conductors that transmit electricity, insulators that prevent arcing, isolators for safety during maintenance, busbars for distributing power, lightning arresters for overvoltage protection, and circuit breakers for interrupting faults. The document provides details on the working principles and applications of these various substation equipment.
The document discusses power system transients. It defines transients as pulses of very short duration but high intensity. Transients can be classified as ultra-fast, medium-fast, or slow depending on their speed. Causes of transients include lightning, switching operations, faults, and resonance. When a transmission line is energized, voltages build up gradually along it via traveling waves. The velocity and behavior of these waves are determined by the line's inductance and capacitance per unit length.
Power quality issues arise from disturbances in the electric power supply that can negatively impact equipment. Common issues include voltage sags, swells, interruptions, harmonics, and spikes. Around 80% of problems originate from within industrial facilities due to large loads or improper wiring, while 20% come from external utility issues like weather events. Poor power quality can increase energy costs and cause equipment failures. Monitoring power quality helps identify disturbances and their sources to improve reliability and reduce costs. Various devices like filters, regulators, and compensators can help mitigate different power quality issues. Maintaining high power quality supports the economic operation of power systems and equipment.
BREAKDOWN MECHANISM OF GASEOUS , VACUUM, LIQUID & SOLID DIELECTRICSSwaminathan P
1. The document discusses breakdown mechanisms in gaseous, liquid, and solid dielectric materials. It explains that gases are good insulators at normal conditions but can break down through ionization processes under high electric fields.
2. It introduces Townsend's first ionization coefficient which describes the number of electrons produced per unit length through collisions. Cathode processes and secondary effects are also discussed.
3. Breakdown in liquid dielectrics can occur through electronic breakdown, suspended particles, cavitation, and electroconvection. Various insulating materials and their applications in different temperature classes are reviewed.
4. Insulation used in power transformers, circuit breakers, and applications of gases in power systems are summarized. Common
Power quality-disturbances and monitoring SeminarSurabhi Vasudev
The document provides an overview of power quality monitoring and automatic power quality disturbance classification. It defines power quality and discusses increased interest in power quality. It describes various power quality disturbances like voltage fluctuations, harmonics, sags, and swells. It then discusses automatic power quality disturbance classifiers which use techniques like segmentation, feature extraction, and classification to identify different disturbance types. Neural networks and expert systems are presented as methods for automatic classification. The document emphasizes the importance of power quality monitoring and classification systems.
seminar report on power quality monitoring khemraj298
The document discusses power quality monitoring and its importance for sustainable energy systems like solar power in India. It provides context on increased sensitivity of modern equipment to power quality issues and defines different types of steady state variations and events that impact power quality. Monitoring objectives include proactive and reactive approaches to characterize system performance and identify specific problems. The development of an intelligent power quality monitoring system using LabVIEW and sensors is described to efficiently monitor power quality in sustainable energy systems.
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 concept of FACTS (Flexible Alternating Current Transmission System) refers to a family of power electronics-based devices able to enhance AC system controllability and stability and to increase power transfer capability.
Simplified analysis of graetz circuit copy - copyVert Wheeler
The document summarizes the analysis of a Graetz circuit, which is used in HVDC transmission, under two scenarios: without overlap and with overlap between thyristor valves. In the without overlap scenario, the analysis assumes valves switch on and off instantaneously with no two valves on at once. This allows simplifying the circuit to determine voltage and current waveforms. When overlap is considered and two valves can be on simultaneously, the analysis is more complex with different operation modes identified depending on the overlap angle. Key aspects of voltage, current, power factor and harmonics are derived.
The document discusses harmonics in power systems. Harmonics are caused by non-linear loads that draw current in pulses rather than smoothly. Common sources are electronic devices, variable speed drives, and UPS systems. Harmonics can overheat equipment, increase power costs, and distort voltages and currents. They are managed by measuring harmonic levels and installing filters if problems are detected.
Unit 04 Protection of generators and transformers PremanandDesai
The document discusses faults and protection methods for alternators and transformers. For alternators, common faults include failure of the prime mover, field failure, overcurrent, overspeed, overvoltage, and unbalanced or stator winding faults. Differential and inter-turn protection are described. For transformers, faults include open circuits, overheating, and winding short-circuits. Buchholz devices, earth fault relays, overcurrent relays, and differential systems provide protection. Earth fault protection for transformers uses a core-balance leakage scheme.
This document discusses power quality and power quality disturbances. It defines power quality as the set of parameters defining the properties of power supply in normal operating conditions. Common power quality disturbances include steady-state variations like voltage fluctuations, harmonics, and high frequency noise as well as events like interruptions, sags, swells, and transients. Solutions to power quality problems include distributed generation, energy storage systems, codes and standards, interface devices, and making equipment less sensitive.
In microgrid, if fault occurs or any other contingency happens, then the problems would be created which are related to power flow, also there are various protection schemes are used for minimize or eliminate these problems.
Voltage control is used for reactive power balance and P-f control is used for active power control.
Various protection schemes such as, over current protection, differential protection scheme, zoning of network in adaptive protection scheme are used in microgrid system .
This document discusses power system protection settings and provides information on calculating protection settings. It covers the functions of protective relays and equipment protection, the required information for setting calculations such as line parameters and fault studies, and the process of calculating, checking, and implementing protection settings. The goal is to set protections to operate dependably, securely, and selectively during faults while meeting clearance time requirements.
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.
This document discusses power quality and defines it as the ability of a power system to supply voltage continuously within tolerances. It outlines various power quality events like sags, swells, interruptions, harmonics, and their causes and effects. It then describes various techniques to mitigate power quality issues, including dynamic voltage restorers, harmonic filters, static VAR compensators, and unified power quality conditioners. Maintaining high power quality improves system efficiency and equipment lifespan while eliminating problems like voltage fluctuations, harmonics, and reactive power issues.
POWER SYSTEM PROTECTION
Protection Devices and the Lightning,. protection,
Lightning protection, Introduction
Air Break Switches
Disconnect switches
Grounding switches
Current limiting reactors
Grounding transformers
Co-ordination of protective devices
Grounding of electrical installations
Electric shock
Lightning protection
Lightning Arrestor
EHV (extra high voltage) AC transmission refers to equipment designed for voltages greater than 345 kV. Higher transmission voltages increase efficiency by reducing transmission losses and current, decrease infrastructure costs, and increase transmission capacity. However, they also present safety and interference risks. New technologies like FACTS (flexible AC transmission systems) help maximize the benefits of EHV transmission by enabling voltage control and power flow management. There is growing support for expanding national EHV transmission grids to facilitate large-scale renewable energy integration and inter-regional power sharing.
three phase fault analysis with auto reset for temporary fault and trip for p...Vikram Rawani
The project was aimed to prevent failures due to some faults which can be temporary or permanent in 3-phase power supply .
The purpose of our project was to develop an automatic tripping mechanism for the three phase supply system. The project output resets automatically after a brief interruption in the event temporary fault while it remains in tripped condition in case of permanent fault.
It is based on current transformer description
It's working and applications are present in it ,it also includes videos of it's windings and it's inrush ability of transformer, and also about instrument transformer and it's working with applications.Current transformers are used-in measuring high currents and connected with it in parallel to it
Protection against overvoltage
overvoltage
causes of overvoltage
lightning
types of lightning strokes
harmful effect of lightning
protection against lightning
Power quality monitoring involves gathering raw measurement data from equipment like digital fault recorders, smart relays, and power quality monitors. This data is then analyzed to provide useful information about disturbances, harmonics, sags, and other power quality issues. When setting up a monitoring system, key considerations include determining what to monitor, choosing monitoring locations, setting thresholds, and the duration of monitoring. A variety of equipment can be used for permanent power quality monitoring including devices that already monitor voltage and current as well as specialized power quality monitors.
This case study describes the key components of an electric transmission substation. It discusses transformers that change voltage levels, conductors that transmit electricity, insulators that prevent arcing, isolators for safety during maintenance, busbars for distributing power, lightning arresters for overvoltage protection, and circuit breakers for interrupting faults. The document provides details on the working principles and applications of these various substation equipment.
The document discusses power system transients. It defines transients as pulses of very short duration but high intensity. Transients can be classified as ultra-fast, medium-fast, or slow depending on their speed. Causes of transients include lightning, switching operations, faults, and resonance. When a transmission line is energized, voltages build up gradually along it via traveling waves. The velocity and behavior of these waves are determined by the line's inductance and capacitance per unit length.
Power quality issues arise from disturbances in the electric power supply that can negatively impact equipment. Common issues include voltage sags, swells, interruptions, harmonics, and spikes. Around 80% of problems originate from within industrial facilities due to large loads or improper wiring, while 20% come from external utility issues like weather events. Poor power quality can increase energy costs and cause equipment failures. Monitoring power quality helps identify disturbances and their sources to improve reliability and reduce costs. Various devices like filters, regulators, and compensators can help mitigate different power quality issues. Maintaining high power quality supports the economic operation of power systems and equipment.
BREAKDOWN MECHANISM OF GASEOUS , VACUUM, LIQUID & SOLID DIELECTRICSSwaminathan P
1. The document discusses breakdown mechanisms in gaseous, liquid, and solid dielectric materials. It explains that gases are good insulators at normal conditions but can break down through ionization processes under high electric fields.
2. It introduces Townsend's first ionization coefficient which describes the number of electrons produced per unit length through collisions. Cathode processes and secondary effects are also discussed.
3. Breakdown in liquid dielectrics can occur through electronic breakdown, suspended particles, cavitation, and electroconvection. Various insulating materials and their applications in different temperature classes are reviewed.
4. Insulation used in power transformers, circuit breakers, and applications of gases in power systems are summarized. Common
Power quality-disturbances and monitoring SeminarSurabhi Vasudev
The document provides an overview of power quality monitoring and automatic power quality disturbance classification. It defines power quality and discusses increased interest in power quality. It describes various power quality disturbances like voltage fluctuations, harmonics, sags, and swells. It then discusses automatic power quality disturbance classifiers which use techniques like segmentation, feature extraction, and classification to identify different disturbance types. Neural networks and expert systems are presented as methods for automatic classification. The document emphasizes the importance of power quality monitoring and classification systems.
seminar report on power quality monitoring khemraj298
The document discusses power quality monitoring and its importance for sustainable energy systems like solar power in India. It provides context on increased sensitivity of modern equipment to power quality issues and defines different types of steady state variations and events that impact power quality. Monitoring objectives include proactive and reactive approaches to characterize system performance and identify specific problems. The development of an intelligent power quality monitoring system using LabVIEW and sensors is described to efficiently monitor power quality in sustainable energy systems.
Power Quality Monitoring by Disturbance Detection using Hilbert Phase Shiftingidescitation
This paper presents an innovative approach for the analysis of the Power Quality
Disturbances both qualitatively and quantitatively. The proposed method employs the phase
shifting property of Hilbert Transform for the accurate detection and computation of the
characteristic magnitudes of the power quality disturbances along with the time of their
occurrence. This facilitates for the real time detection and characterization of various
disturbances such as voltage swells, voltage sags, voltage fluctuation, harmonics and
transient oscillation accurately. The various disturbances have been simulated on the
LabVIEW platform and the phase shifting property of Hilbert Transform has given
satisfactory results. Real Time Signals were generated and digitalized by the aid of Data
Acquisition (DAQ) card, which were processed in the LabVIEW environment, to yield
immaculate results indicating the characteristic magnitudes and time of occurrence of
disturbances.
Case study - Instruments remote monitoringIskraEurope
Iskra helped global foundry company to get better insight into energy consumption by installation of Iskra electrical measuring instruments at strategic big energy consumption locations (electric furnaces, robots, cranes) and in the central transformer station.
Regulatory Guidelines to set up Voltage Quality MonitoringLeonardo ENERGY
This session is part of the Clean Energy Regulators Initiative Webinar Programme.
Theme 2 - Pressure Points
Module 2: Voltage Quality Regulation
Voltage quality, sometimes called power quality or technical quality, covers a variety of disturbances in an electrical power system. It is mainly determined by the quality of the voltage waveform and it is an important aspect of the electricity service.
Customers are becoming increasingly sensitive to disturbances in voltage quality. This issue is particularly important taking into account the new regulatory frameworks which put strong emphasis on cost reduction, thereby potentially jeopardizing quality. When setting up a quality regulation framework, there are a number of basic issues that need to be considered first. This understanding is crucial in order to make the right choices in order to arrive at an effective voltage quality regulatory system. It is important to clearly define voltage quality and develop suitable indicators.
This presentation assesses the issue of what regulators need to consider whenever establishing a voltage quality regulatory framework for distribution networks (i.e. up to 35 kV). It presents a general set of guidelines that regulators could consider in introducing and developing voltage quality regulation. Regulation of five important voltage quality dimensions is considered: short-interruptions, voltage dips, flicker, supply voltage variation and harmonic distortion.
Power quality, its problem and power quality monitoringIAEME Publication
This document discusses power quality, issues related to power quality, and power quality monitoring. It defines power quality as the consistency of voltage, current, and frequency. Poor power quality can be caused by variations such as sags, swells, interruptions, transients, overvoltage, undervoltage, and harmonics. Monitoring power quality is important to characterize disturbances, identify sensitivity of equipment, and take remedial actions. The objectives of power quality monitoring are to quantify power quality, provide early warnings, and suggest improvements.
Unit-V
Measurement and Solving of Power Quality Problems: Power quality measurement devices- Harmonic Analyzer , Transient Disturbance Analyzer, wiring and grounding tester, Flicker Meter, Oscilloscope, multi-meter etc. Introduction to Custom Power Devices-Network Reconfiguration devices; Load compensation and voltage regulation using DSTATCOM; protecting sensitive loads using DVR; Unified power Quality Conditioner. (UPQC)
This document provides information about lightning protection. It discusses what lightning is and why it occurs, including the different types of lightning strikes. It also covers important factors to consider in designing a lightning protection system, such as types of losses and risk assessment. The document describes different types of lightning protection methods, including air termination techniques and ground conductor methods. It discusses lightning detection systems that use ground-based antennas, mobile antennas, and space-based satellites. The document concludes by listing some references for further information.
This document discusses reactive power compensation in power systems. It defines reactive power as power that is temporarily stored and returned to the source due to inductive loads. Reactive power compensation is needed to improve power factor, reduce losses, improve voltage regulation and stability. The main compensation techniques discussed are synchronous condensers, shunt compensation using capacitors connected in parallel, and series compensation using capacitors connected in series to reduce line inductive reactance. The document provides examples of transmission lines with shunt and series compensation and concludes that reactive power compensation is important for improving AC system performance.
This document discusses the future of power electronics for wind turbine systems. It outlines how wind turbine technology has advanced from 4-8 kW units in the 1980s to today's 4.5-8 MW units, and how control systems are now necessary to regulate frequency and voltage. It describes how wind power can be generated using doubly-fed induction generators or synchronous generators, and compares the advantages and disadvantages of each. Finally, it discusses technology challenges around cost, stability, and reliability, and how further advances in generators, power electronics, and power devices could help wind power match or exceed conventional energy sources.
This document describes a project to build a third harmonic distortion meter using a PIC18F2550 microcontroller. It explains that non-linear components can cause harmonics in AC power systems, with the third harmonic being particularly impactful. The project involves using a microcontroller and discrete Fourier transform calculations to measure the amplitude of the fundamental frequency and third harmonic from a rectified input signal. This allows the third harmonic distortion to be displayed as a percentage. The document provides details of the circuit design and software used to implement this third harmonic distortion meter.
This document discusses using a STATCOM to improve power quality in a grid-connected wind energy system. A STATCOM is a voltage-source converter that can compensate for voltage fluctuations on AC transmission lines. The document examines power quality issues like voltage variations and harmonics in wind energy systems. It presents test results showing that a STATCOM maintains the source voltage and current in-phase to support the reactive power demand of the wind generator and load. The STATCOM fulfills power quality standards and can eliminate or reduce voltage fluctuations at the plant input.
improved reactive power capability of grid connected doubly fed induction gen...vinay kumar mali
The document discusses issues related to doubly fed induction generators (DFIGs) used in wind turbines remaining connected to the power grid during faults. It notes that grid codes now require renewable generators to provide ancillary services like reactive power during faults to support voltage and frequency. While DFIGs are sensitive to voltage dips, various protection methods like crowbar circuits, energy storage, and dynamic voltage restorers can help DFIGs ride through faults by limiting current surges. The document examines different control strategies and protection devices that allow DFIG wind turbines to meet grid code low voltage ride-through requirements.
Power quality issues can cause equipment failures and financial losses for businesses. Common power quality disturbances include transients, sags, swells, and harmonics. Proper power quality monitoring using portable or permanently installed devices can help identify issues, their causes, and reduce downtime.
This report gives an overview of patenting activity around Doubly-fed Induction Generators (DFIG) used in the horizontal axis wind turbines for efficient power generation. Patents were categorized as per key DFIG technologies and analyzed for generating different trends within PatSeer Project.
1. The document discusses power quality and its importance in reliable power supply as the sensitivity of equipment has increased. It defines power quality as the set of parameters defining the properties of power supply during normal operation in terms of voltage continuity and characteristics.
2. Power quality problems can have internal causes like equipment start/stop or external causes like weather or utility issues. Disturbances are categorized as steady state variations like voltage fluctuations or events which are sudden deviations. Common steady state variations discussed are voltage/current unbalance and harmonic distortion.
3. Power quality monitoring is important to identify causes of problems before interruptions and helps improve power quality with suitable solutions. It is a critical step in ensuring reliability of sustainable energy sources and reducing
Modeling and simulation of dynamic voltage restorer for voltage sag mitigatio...IJRRR
Abstract- Power quality deals with utilization of electric energy from the distribution system successfully without interference or interruption. Various factors like interruption in power supply, under voltage, over voltage, unbalanced voltage or current, harmonic distortion, flickering voltage, voltage fluctuation voltage sag etc. result in poor power quality. These power quality related problems can be solved with the help of various custom power devices. Voltage sags are considered to be the most common type of disturbances in the field based on current power disturbances studies. Their impact on sensitive loads is rigorous. The impact ranges from load disruptions to financial losses. In spite of the technical advances in electronics, there are some pieces of equipment that are so sensitive that they are unable to withstand voltage sags. There are many varies methods to mitigate voltage sags, but a Custom Power Supply device is considered to be the most efficient method. This dissertation is the study of Dynamic Voltage Restorer (DVR) which is the most efficient and effective device to protect sensitive equipment against voltage sags. It has low cost, smaller size and it has dynamic response to the disturbance.
Keywords- Voltage sag, DVR, power system, mitigation
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.
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.
1) The document discusses various power quality problems faced in power systems such as voltage sags, interruptions, flicker, surges, spikes, and harmonics.
2) It describes different types of active power filters that can be used to solve power quality issues, including shunt active filters that inject compensating current, and series active filters that inject compensating voltage.
3) The unified power quality conditioner is introduced, which uses both series and shunt active filters to improve both voltage and current quality by controlling series injected voltage and shunt injected current.
This document discusses power quality and defines it as any deviation from the normal sinusoidal voltage or current waveform. It covers various power quality issues like voltage sags, swells, fluctuations, harmonics, interruptions and more. It explains the causes and impacts of different power quality problems. The document also discusses classification of issues, measurement and evaluation of power quality as well as relevant standards from organizations like IEEE.
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 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-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 Review on Basic Concepts and Important Standards of Power Quality in Power ...Editor IJCATR
This paper deals with the basic of Power quality in power system. In addition basic definition and important concepts was
discussed in simple way. This paper also covers the important power quality standards. In addition IEEE, IEC, SEMI and UIE Power
quality standards are listed. This paper would be helpful for the UG and PG students to study about the basics of Power quality in
electrical engineering.
A Review on Basic Concepts and Important Standards of Power Quality in Power ...Editor IJCATR
This paper deals with the basic of Power quality in power system. In addition basic definition and important concepts was discussed in simple way. This paper also covers the important power quality standards. In addition IEEE, IEC, SEMI and UIE Power quality standards are listed. This paper would be helpful for the UG and PG students to study about the basics of Power quality in electrical engineering.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
IRJET- Improvement of Power Quality using Active FiltersIRJET Journal
This document discusses improving power quality using active filters. It provides an overview of various power quality issues caused by harmonic pollution and reactive power in distribution systems. Active filters are presented as an effective solution to power quality problems. The document describes different types of active filters, including shunt and series active filters, and their applications in compensating for issues like harmonics, reactive power, voltage fluctuations, and unbalanced currents. Control strategies for active filters are also discussed. The document aims to give researchers and engineers an understanding of active filter technology and its role in addressing common power quality problems.
Voltage Flicker Analysis and its Mitigation by STATCOM for Power Quality Impr...IJMTST Journal
Voltage flicker is considered as one of the most severe power quality problems (especially in loads like electrical arc furnaces) and much attention has been paid to it lately. The reason for this disturbance is mainly due to the large nonlinear loads such as electric arc furnaces. Due to the latest achievements in the semiconductors industry and consequently the emergence of the compensators based on voltage source converters, FACTS devices have been gradually noticed to be used for voltage flicker compensation. This paper covers the contrasting approaches; dealing with the voltage flicker mitigation in three stages and assessing the related results in details. Initially, the voltage flicker mitigation, using FCTCR (Fixed Capacitor Thyristor Controlled Reactor), was simulated. Secondly, the compensation for the Static Synchronous Compensator (STATCOM) has been performed. The voltage flicker compensation by 8– pulse as well as 12 – pulse static synchronous compensator (STATCOM) has been performed. This paper deals with the voltage flicker mitigation and reduction in total harmonic distortion (THD) and compared the results in detail. The obtained results show that STATCOM is very efficient and effective for the compensation and mitigation of voltage flicker and harmonics all the simulation results have been performed on the MATLAB Software.
This document summarizes a research paper that models the performance of different types of Dynamic Voltage Restorers (DVRs) in mitigating balanced and unbalanced voltage sags on distribution systems. The paper presents modeling aspects of several DVR configurations and analyzes their effectiveness in compensating for various voltage sag scenarios through detailed simulation results. It also discusses the capability of DVRs to regulate voltage quality at load terminals during power quality issues like sags, swells and harmonics.
This presentation on Power Quality Improvement Techniques: A Review presented by Sahid Raja Khan student of B. Tech. Electrical Engineering of Compucom Institute of Technology and Management Jaipur. It describes the improvement technique of Power Quality at GSS and other Substations including Generating Stations.
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.
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.
1 power quality-issues-problems-standards-their-effects-in-industry-with-corr...abuaadil2510
This document summarizes power quality issues, standards, and corrective methods. It discusses common power quality problems like harmonics, voltage sags, and interruptions. International standards for current and voltage harmonics like IEEE 519 and IEC 61000 set limits to protect equipment and utility systems. Effects of power quality issues vary by equipment but can cause failures. Correction methods aim to make power sources meet standards and reduce problems at all levels of power delivery systems through redundancy.
This is an overview of my current metallic design and engineering knowledge base built up over my professional career and two MSc degrees : - MSc in Advanced Manufacturing Technology University of Portsmouth graduated 1st May 1998, and MSc in Aircraft Engineering Cranfield University graduated 8th June 2007.
We have designed & manufacture the Lubi Valves LBF series type of Butterfly Valves for General Utility Water applications as well as for HVAC applications.
Covid Management System Project Report.pdfKamal Acharya
CoVID-19 sprang up in Wuhan China in November 2019 and was declared a pandemic by the in January 2020 World Health Organization (WHO). Like the Spanish flu of 1918 that claimed millions of lives, the COVID-19 has caused the demise of thousands with China, Italy, Spain, USA and India having the highest statistics on infection and mortality rates. Regardless of existing sophisticated technologies and medical science, the spread has continued to surge high. With this COVID-19 Management System, organizations can respond virtually to the COVID-19 pandemic and protect, educate and care for citizens in the community in a quick and effective manner. This comprehensive solution not only helps in containing the virus but also proactively empowers both citizens and care providers to minimize the spread of the virus through targeted strategies and education.
Data Communication and Computer Networks Management System Project Report.pdfKamal Acharya
Networking is a telecommunications network that allows computers to exchange data. In
computer networks, networked computing devices pass data to each other along data
connections. Data is transferred in the form of packets. The connections between nodes are
established using either cable media or wireless media.
2. CONTENTS
1. INTRODUCTION
2. INCREASED INTEREST IN POWER QUALITY
3. POWER QUALITY DEFINITION
4. CAUSES OF POWER QUALITY PROBLEMS
5. POWER QUALITY DISTURBANCES
6. IMPACT OF POOR POWER QUALITY
7. POWER QUALITY MONITORING
8. REAL TIME MONITORING SYSTEM
9. BENEFITS OF POWER QUALITY MONITORING
10. CONCLUSION
11. REFERENCES
2
3. INTRODUCTION
The aim of the power system has always been to supply electrical energy to
customers.
Today electric power is viewed as a product with certain characteristics which
can be measured, predicted, guaranteed, improved etc. Moreover it has
become an integral part of our life. The term ‘power quality’ emerged as a
result of the new emphasis placed on the customer utility relationship.
Power quality has always been important. However, for many years the
equation defining power quality was very simple:
POWER QUALITY = RELIABILITY
Understanding the problems associated with power quality variations is the
first step towards developing standards and the optimum approach to
solutions.
This presentation represents an overviews of electric power quality with
special emphasis on power quality problems.
The adverse impact on utility of customers and their mitigation techniques.
3
4. INCREASED INTEREST IN
POWER QUALITY
Customer loads were linear in nature. When a sinusoidal voltage was
supplied to them, they drew a sinusoidal current. They typically fell
into the categories of lighting, heating and motors. In general, they
were not very sensitive to momentary variations in the supply voltage.
Two major changes in the characteristics of customer loads and systems
have completely changed the nature of the power quality equation:
1. The first is the sensitivity of the loads themselves.
2. Interconnected loads in extensive networks and
automated processes.
4
5. 1. The sensitivity of the loads: The devices and equipment being
applied in industrial and commercial facilities are more sensitive to
power quality variations than equipment applied in the past. New
equipment includes microprocessor-based controls and power
electronics devices that are sensitive to many types of disturbances
besides actual interruptions. Controls can be affected by
momentary voltage sags or relatively minor transient voltages,
resulting in nuisance tripping or misoperation of an important
process.
2. The fact that these sensitive loads are interconnected in extensive
networks and automated processes. This makes the whole system
as sensitive as the most sensitive device and increases the problem
by requiring a good zero potential ground reference for the entire
system.
5
6. POWER QUALITY DEFINITION
6
The definition of power quality given in the IEEE dictionary is as follows:
“Power quality is the set of parameters defining the properties of the power
supply as delivered to the user in normal operating conditions in terms of
the continuity of voltage and voltage characteristics”.
Modern electronic and power electronic devices are not only sensitive to
voltage disturbances; it also causes disturbances for other customers. These
devices become the source and victims of power quality problems. As such
the term power quality is used to define the interaction of electronic
equipments within the electrical environment.
7. Different parameters of power quality are:-
Voltage quality :Voltage quality concerns with the deviation of the voltage
from the ideal characteristics. The ideal voltage is a single frequency sine
wave of constant frequency and constant magnitude.
Current quality: Current quality concerns with the deviation of the current
from the ideal characteristics. The ideal current is again a single frequency
sine wave of constant magnitude and frequency. An additional requirement
is that the sine wave should be in phase with the supply voltage.
Power quality : Power quality is the combination of voltage quality and
current quality. Thus power quality is concerned with the deviations of
voltage and/or current from the ideal characteristics.
Thus Power Quality is the set of parameters defining the properties of the
power supply as delivered to the user in normal operating conditions, in
terms of the continuity of voltage and voltage characteristics.
7
8. CAUSES OF POWER QUALITY
PROBLEMS
Difficult to point an exact cause for a specific problem.
Broadly divided into 2 categories:
1.Internal causes
i) About 80% of Power Quality problems originate within a business
facility.
ii) Due to large equipments start or shut down, improper wiring and
grounding, overloaded circuits or harmonics.
2.External causes
i)About 20% of Power Quality problems originate within the utility
transmission and distribution system.
ii)Due to lightning strikes, equipments failure, weather conditions etc.
8
9. POWER QUALITY DISTURBANCES
Power Quality disturbances can be divided into 2 basic categories:
1.Steady-state variations:-Small deviations from the desired voltage or current
values.
i) Voltage fluctuations
ii) Voltage and current unbalance
iii) Harmonic distortion
2.Events:-Significant sudden deviations of voltage or current from the nominal
or ideal wave shape.
i) Interruptions
ii) Voltage sag
iii) Voltage swell
iv) Transients
9
10. VOLTAGE FLUCTUATION
Fast changes or swings in the steady state voltage magnitude.
Due to variations of total load of a distribution system, action of
transformer tap changers, switching of capacitor banks etc.
If the variations are large enough or in a certain critical frequency range, it
can affect the performance of the equipment.
10
Figure 1. Voltage waveform showing Variations
11. VOLTAGE AND CURRENT UNBALANCE
Voltage unbalance is marked by a difference in the phase voltages, or when
the phase separation is not 120 degrees.
Current unbalance is similar, except the values are for current, instead of
voltage.
Causes of voltage and current unbalance:-
i) Large or unequal distribution of single phase load.
ii) Equipments which simply require single phase but at line to
line voltage(a 415 V welder).
iii) Unbalanced 3 phase loads.
11
12. HARMONIC DISTORTION
Deviation of voltage and current
waveforms from the ideal pure
sinusoidal waveforms of
fundamental frequency.
Non-fundamental frequency
components are called harmonics.
Due to non linear loads and
devices in the power system.
12
Figure 2. Voltage waveform showing Harmonics
13. INTERRUPTIONS
Supply interruption occurs when voltage at supply terminals is
close to zero.
Normally initiated by faults which subsequently trigger protection
measures.
Based on the duration, interruptions are subdivided into:
1) Sustained interruptions, which are terminated through manual
restoration or replacement.
2) Temporary interruptions, which last less than 2 minutes and
terminated through automatic restoration.
3) Momentary interruptions, which are terminated through self
restoration.
13
Figure 3. Voltage waveform showing interruption
14. VOLTAGE SAG
Decrease in the RMS value of the voltage, ranging from a half cycle to few
seconds(less than 1 minute).
Causes:
1) Faults on the transmission or distribution networks.
2) Connection of heavy loads.
Consequences:
1) Malfunction of microprocessor based control systems.
2) Loss of efficiency in electrical rotating machines.
14
Figure 4 . Voltage waveform showing voltage sag
15. VOLTAGE SWELL
Momentary increase of the voltage, at the power frequency, outside the normal
tolerances with duration of more than 1 cycle, and typically less than 1 minute.
Referred to as ‘over voltage', if continues for longer duration.
Causes:
1)Start and stop of heavy loads.
2)poorly regulated transformers
Consequences:
1)Flickering of lighting and screens.
2)Damage of sensitive equipments.
15
Figure 5. Voltage waveform showing voltage swell
16. RMS Voltage Variations
0
Sag Swell Interruption
100
-100
Figure 6. Voltage waveform showing RMS voltage variation simultaneously
16
17. TRANSIENTS
Sub cycle disturbances of very short duration that vary greatly in magnitude
are called as transients.
Mainly subdivided into:
1) Impulsive transient: where there is a large deviation of the waveform for a
very short duration in one direction, followed possibly by a couple of smaller
transients in both directions.
2) Oscillatory transient: where there is a ringing signal or oscillation
following the initial transient.
17
Figure 7. Voltage waveform showing impulsive transient and oscillatory transient
19. 19
Distribution of Power Quality Problems
Voltage
Sags
60%
Voltage
Swells
29%
Transients
8%
Interruptions
3%
Figure 9. distribution of power quality problems
20. IMPACT OF POOR POWER QUALITY
The effect of poor power quality problems has serious implication on
the utilities and customers.
Higher losses in transformers, cables.
Energy meters will give faulty readings.
Solid state protective relays may damaged .
Speed drives may shut down.
Motor will increase core and cu losses
Non sinusoidal waveforms will reduce the efficiency of motors.
Electronic computer may loss data due to voltage variation .
Domestics TV and other equipments are affected by the poor quality.
20
21. POWER QUALITY MONITORING
It is a multi-pronged approach to identifying, analyzing and correcting
power quality problems.
Helps to identify the cause of power system disturbances.
Helps to identify problem conditions before they cause interruptions or
disturbances, in some cases.
Objectives for power quality monitoring are generally classified into:
◦ Proactive approach
Intended to characterize the system performance.
Helps to understand and thus match the system performance with
customer needs.
◦ Reactive approach
Intended to characterize a specific problem.
Performs short term monitoring at specific customers or at different
loads.
21
22. POWER QUALITY MONITORS
Commercially available monitors are classified into:
1) PORTABLE MONITORS
Used for troubleshooting after an event has taken place.
Subdivided into:
I. Voltage recorders
Recorders digitize voltage and current signals by taking samples of
voltage and current over time.
Used for continuous monitoring of steady state voltage variations.
Most important factor to consider when selecting and using a voltage
recorder is the method of calculation of the RMS value of the
measured signal.
II. Disturbance analyzer
Designed to capture events affecting sensitive devices.
Thresholds are set and recording starts the moment when a threshold
value is exceeded.
22Figure 10 . A Portable Monitor
23. 2) PERMANENT MONITORS:
These monitors are permanently installed full system monitors,
strategically placed throughout the facility, letting the users know any
power quality disturbance as soon as it happened.
Characterize the full range of power quality variations.
Record both the triggered and sampled data.
Triggering depends on RMS thresholds for RMS variations and on
wave shape for transient variation.
‘Real time monitoring system’ is an example.
23
Figure 11 . PERMANENTLY INSTALLED FULL SYSTEM MONITOR
24. 24
REAL TIME MONITORING SYSTEM
Real Time Monitoring System
contains software and
communication facilities for
data collection, processing and
result presentation. The
software maintains a database
of system performance
information which can be
accessed. At the heart we have
a server computer optimized
for database management and
analysis. Both the disturbance
analyzers and voltage
recorders can be integrated
into the real time monitoring
system. The figure shown
below explains the
configuration of a real time
monitoring system.
Figure12 . Schematic view of a Real Time Monitoring System
25. This permanent monitoring system has the following
components :-
1) Measurement instruments
Involves both the voltage recorder and disturbance analyzer.
Has a trigger circuit to detect events.
Includes a data acquisition board to acquire all the triggered and
sampled data.
2) Monitoring workstation
Used to gather all information from the measuring instruments.
Periodically send information to a control workstation.
3) Control workstation
This station configures the parameters of measuring instruments.
Gathers and stores the data coming from the remote monitoring
workstations.
Does the data analysis and export.
25
26. .4) Control software
This software drives the control workstation.
Does the analysis and processing of data.
Algorithms used for processing varies according to the system
used.
Algorithms used may be based on wavelet transforms or expert
systems or some other advanced technique.
5) Database server
Database management system should provide fast and concurrent
access to many users without critical performance degradation.
Also, it should avoid any form of unauthorized access.
6) Communication channels
Selection of communication channel strongly depends on monitoring
instruments, connectivity functions and on their physical locations.
Some of the possible channels are fixed telephone channels by using a
modem and mobile communication system by using a GSM modem.
26
27. BENEFITS OF POWER QUALITY
MONITORING
Ensures power system reliability.
Identify the source and frequency of events.
Helps in the preventive and predictive maintenance.
Evaluation of incoming electrical supply and distribution to
determine if power quality disturbances are impacting.
Determine the need for mitigation equipments.
Reduction of energy expenses and risk avoidances.
Process improvements-monitoring systems allows to identify the
most sensitive equipments and install power conditioning systems
wherever necessary.
27
28. CONCLUSION
Electric power quality, which is a current interest to several power
utilities all over the world, is often severely affected by various
power quality disturbances like harmonics and transient
disturbances. Deterioration of power quality has always been a
leading cause of economic losses and damage of sensitive
equipments.
Various types of power quality disturbances are analyzed. Automatic
Power Quality Disturbance Classifiers are discussed in detail, along
with different classification approaches, with a case study. Power
Quality Monitoring systems and techniques are presented,
emphasizing the ‘real time monitoring systems'. Data analysis and
benefits of Power Quality Monitoring are also presented.
28