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
The quality of power supply is very important in any power network particularly to electricity consumers. Power quality encompasses availability of supply, frequency and voltage magnitude as well as waveform characteristics of the power supply.
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.
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.
This document provides an introduction to power quality, including definitions, concepts, and classifications of various power quality disturbances. It defines power quality as the characteristics of voltage and current in a power system that allow equipment to function properly. Power quality issues are deviations from the ideal voltage and current sine waves, including transients, sags, swells, interruptions, harmonics, and voltage imbalance. These issues are characterized and classified based on duration, magnitude, frequency content, and causes. International standards for measuring and monitoring power quality are also mentioned.
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.
A Novel Multi Level Converter Unified Power – Quality (MC-UPQC) Conditioning ...IRJET Journal
This document discusses a novel multi-level converter unified power quality conditioning system (MC-UPQC) capable of simultaneously compensating for voltage and current in multi-bus/multi-feeder systems. The proposed MC-UPQC topology includes one shunt voltage-source converter and two or more series VSCs, allowing power to be transferred between feeders to compensate for sags, swells, and interruptions. Simulation results show the MC-UPQC can significantly reduce power losses, mitigate under voltages, and enhance voltage stability in distribution networks compared to other designs. The MC-UPQC provides a more efficient solution for under voltage mitigation in multi-feeder systems.
Grid Connected PV System with Power Quality Improvement Using Intelligent Con...IJMTST Journal
The depletion of the fossil fuel resources and the global warming effects has led the world to think
seriously of other alternative sources of energy. So renewable energy resources (RES) are being connected to
the distribution systems, mostly done by using power electronic converters. But use of power electronic
converters and non-linear loads like at distribution level injects harmonics, which intern cause power quality
problems. Distribution static compensator (DSTATCOM) is very popular in compensating power problems for
nonlinear and unbalanced loads. Any change in the load affects the DC-link voltage (DCLV) directly.
Conventionally, a PI controller is used to maintain the DCLV to the reference value, but its transient response
is poor. So, fuzzy logic controller is proposed which shows better dynamic response. To trigger inverter HCC
is used. The proposed inverter with the control when connected to wind energy, helps the 3-phase 4-wire
linear/non-linear unbalanced load at point of common coupling appear as balanced linear load to the grid.
With MATLAB/Simulink simulation studies, the proposed control technique is demonstrated and evaluated
here.
The quality of power supply is very important in any power network particularly to electricity consumers. Power quality encompasses availability of supply, frequency and voltage magnitude as well as waveform characteristics of the power supply.
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.
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.
This document provides an introduction to power quality, including definitions, concepts, and classifications of various power quality disturbances. It defines power quality as the characteristics of voltage and current in a power system that allow equipment to function properly. Power quality issues are deviations from the ideal voltage and current sine waves, including transients, sags, swells, interruptions, harmonics, and voltage imbalance. These issues are characterized and classified based on duration, magnitude, frequency content, and causes. International standards for measuring and monitoring power quality are also mentioned.
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.
A Novel Multi Level Converter Unified Power – Quality (MC-UPQC) Conditioning ...IRJET Journal
This document discusses a novel multi-level converter unified power quality conditioning system (MC-UPQC) capable of simultaneously compensating for voltage and current in multi-bus/multi-feeder systems. The proposed MC-UPQC topology includes one shunt voltage-source converter and two or more series VSCs, allowing power to be transferred between feeders to compensate for sags, swells, and interruptions. Simulation results show the MC-UPQC can significantly reduce power losses, mitigate under voltages, and enhance voltage stability in distribution networks compared to other designs. The MC-UPQC provides a more efficient solution for under voltage mitigation in multi-feeder systems.
Grid Connected PV System with Power Quality Improvement Using Intelligent Con...IJMTST Journal
The depletion of the fossil fuel resources and the global warming effects has led the world to think
seriously of other alternative sources of energy. So renewable energy resources (RES) are being connected to
the distribution systems, mostly done by using power electronic converters. But use of power electronic
converters and non-linear loads like at distribution level injects harmonics, which intern cause power quality
problems. Distribution static compensator (DSTATCOM) is very popular in compensating power problems for
nonlinear and unbalanced loads. Any change in the load affects the DC-link voltage (DCLV) directly.
Conventionally, a PI controller is used to maintain the DCLV to the reference value, but its transient response
is poor. So, fuzzy logic controller is proposed which shows better dynamic response. To trigger inverter HCC
is used. The proposed inverter with the control when connected to wind energy, helps the 3-phase 4-wire
linear/non-linear unbalanced load at point of common coupling appear as balanced linear load to the grid.
With MATLAB/Simulink simulation studies, the proposed control technique is demonstrated and evaluated
here.
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 document summarizes a paper about different types of power problems. It begins by introducing the topic and defining key power quality issues like transients, interruptions, sag/swell, and waveform distortion. It then describes the causes and effects of different types of transients, including impulsive transients from lightning and oscillatory transients from switching operations. Standards for defining and measuring power problems are also discussed. The document provides examples and diagrams to illustrate power quality events. In summary, it provides an overview of common power problems, their characteristics, causes, and potential impacts.
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...ijtsrd
Traditional power production has become challenging for utilities due to the depletion of fossil fuels, coal, and oil. This must be done in a less expensive and more efficient manner. To meet the consumers power needs, a new source is needed. The alternative source should be sustainable and capable of fulfilling the needs of the customer. The incorporation of renewable energy into the grid is a helpful method of meeting demand. The integration of renewable energy has three main challenges frequency fluctuation, power quality issues, and power system instability. The following issues were critical in nature. An expert system based on an analytic hierarchy method is used to detect and classify power quality issues. Previously, it could detect sag, swell, transients, harmonics, interruptions, and flickers. A method for categorizing events that is error free has been proposed. The streamlined process provides for more accurate identification and classification of power quality issues. an examination of power quality issues and their mitigation via the use of unified power quality conditioners UPQC To reduce different power quality problems, an Adaptive Neuro Fuzzy Inference System ANFIS is employed. Using renewable energy sources effectively reduces environmental impact. The proposed technique corrects voltage imbalances and reduces overall harmonic distortion at the point of common connection PCC . The installation of an ANFIS controlled DVR is utilized to minimize voltage fluctuations induced by the integration of renewable energy sources and transmission line failures. With the aim of using renewable energy, a fake fault was introduced to power quality events. The ANFIS controlled DVR plan is in place to mitigate the negative impacts of power quality events. ANFIS controlled DVR is compared to a conventional surveillance method. Nonlinear loads generate voltage flickers and total harmonic distortion, therefore a distributed static compensator D STATCOM is employed to avoid these. It is recommended that D STATCOM use three control methods instantaneous power theory, synchronous vector PI control, and harmonic elimination. The D efficacy of STATCOMs is tested under severe load conditions. Various control methods will be used to evaluate and debate the proposed expert system and customized power devices. Rahul Gokhle | Pramod Kumar Rathore "Analysis and Implementation of Power Quality Enhancement Techniques Using Custom Power Devices" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-6 , October 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46380.pdf Paper URL : https://www.ijtsrd.com/engineering/electrical-engineering/46380/analysis-and-implementation-of-power-quality-enhancement-techniques-using-custom-power-devices/rahul-gokhle
IRJET- Investigation of Various Power Quality Issues & its Solution in Gr...IRJET Journal
This document discusses various power quality issues that can occur in grid-connected distributed power systems and their potential solutions. It defines power quality and lists several common power quality issues including voltage sags, swells, fluctuations, interruptions, harmonics, flicker, and unbalances. For each issue, it provides a definition and description of the potential causes and impacts. The goal of the paper is to investigate these power quality problems and discuss their possible solutions to help suppliers, distributors and consumers of electricity maintain a clean and stable power supply.
This document discusses power quality and issues that can arise such as voltage variations, frequency variations, and waveform distortions. It defines key power quality terms like sags, swells, flicker, harmonics, and describes how loads and generation sources can impact power quality. Active power filters are presented as a solution to power quality problems in electric rail systems by compensating for unbalance, harmonic distortion, and low power factor. Compression algorithms are also discussed to efficiently store and analyze large power quality data sets.
Come join the area's leading power quality experts as we demonstrate and replicate common power quality issues, problems and solutions in today's industrial and commercial electrical environments.
sachu technologies team provides comprehensive power quality analysis and can implement measures to bring power quality to acceptable standards. Improving power quality can bring significant financial benefits.
Poor power quality can damage sensitive equipment.
Poor power quality can lower productivity and also drive up energy costs.
Poor power quality can cause increased expenditure on electrical assets when plant or building expansion is necessary.
Poor power quality can impair the safety of electrical installations.
This document provides an overview of a presentation on fundamentals of power quality. It discusses topics that will be covered including power quality fundamentals, voltage sags and interruptions, transients, and harmonics. It defines power quality issues and explains why power quality is important due to increased use of sensitive electronic equipment. Power quality engineering investigates equipment malfunctions to determine if they are caused by power quality problems and how to mitigate the issues. Power electronics are discussed as an important factor in power quality due to causing harmonic distortion and being vulnerable to power quality variations, and their increasing prevalence.
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.
This document provides an overview of power quality issues and solutions. It defines common power quality problems like sags, swells, interruptions, harmonics and more. For each problem it describes the typical duration, voltage change, frequency of occurrence and symptoms. It then reviews potential solutions and compares their effectiveness, efficiency and costs. A example case study calculates the payback period of different solutions for addressing voltage sags. Key takeaways are to properly define power quality problems and costs, evaluate solution performance and operating costs, and select the most cost-effective option to meet needs.
Introduction
Power Quality Problems
Power Quality Measurement Devices
Power Quality Terminology
Power Quality Standards
Unbundled Power Quality Services
Power Quality Monitoring
Benefits of Power Quality
Conclusion
References
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.
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.
Mitigation of Power Quality Problems Using Custom Power Devices: A Reviewijeei-iaes
Electrical power quality (EPQ) in distribution systems is a critical issue for commercial, industrial and residential applications. The new concept of advanced power electronic based Custom Power Devices (CPDs) mainly distributed static synchronous compensator (D-STATCOM), dynamic voltage restorer (DVR) and unified power quality conditioner (UPQC) have been developed due to lacking the performance of traditional compensating devices to minimize power quality disturbances. This paper presents a comprehensive review on D-STATCOM, DVR and UPQC to solve the electrical power quality problems of the distribution networks. This is intended to present a broad overview of the various possible DSTATCOM, DVR and UPQC configurations for single-phase (two wire) and three-phase (three-wire and four-wire) networks and control strategies for the compensation of various power quality disturbances. Apart from this, comprehensive explanation, comparison, and discussion on D-STATCOM, DVR, and UPQC are presented. This paper is aimed to explore a broad prospective on the status of D-STATCOMs, DVRs, and UPQCs to researchers, engineers and the community dealing with the power quality enhancement. A classified list of some latest research publications on the topic is also appended for a quick reference.
Matlab Implementation of Power Quality Improvement Based on Fast Dynamic Controlijtsrd
This document summarizes a research paper on implementing power quality improvement using a fast dynamic control method in MATLAB. It proposes a transformer-less unified power quality conditioner (TL-UPQC) using four switching devices to form two half-bridge voltage-source inverters, one connected in parallel with the load and one in series with the AC mains sharing the same DC link. The paper presents simulation results in MATLAB showing the TL-UPQC can mitigate voltage sags/swells and current harmonics under nonlinear loads. It concludes the TL-UPQC provides improved power quality compared to other single-phase UPQC configurations.
Power quality refers to maintaining a steady supply of electric power that operates equipment properly without damage or stress. Deviations from the normal voltage can cause issues like brief power interruptions or dimming lights. Poor power quality costs US companies billions annually and negatively impacts energy efficiency. Common power quality issues include voltage variations, frequency variations, harmonic distortions, and low power factor, all of which increase energy consumption and equipment wear.
System operators face a proliferation of power electronics
interfaced devices such as HVDC transmission lines,
wind and solar generation in their grids. Depending on
the jurisdiction, the instantaneous share of electrical
energy produced from renewable energy sources
occasionally reaches 150%. However, to operate a power
system with sustained high levels of renewable energy,
several operational challenges need to be addressed. The
goal of this survey paper, which is one of the products
of CIGRE joint working group C2/B4.38, is to identify
such challenges. To this extend, extensive literature
review and survey among and discussions with system
operators throughout the world were performed.
This paper identified several operational challenges that
were validated by system operators. These challenges
are grouped in the following three categories: (i) new
behavior of the power system, (ii) new operation of the
power system and (iii) lack of voltage and frequency
support. For each of the identified challenge, a
description, practical examples and relevant references
are provided.
Introduction to Power Quality: Terms and definitions of transients,
Long Duration Voltage Variations: under Voltage, Under Voltage and Sustained Interruptions
; Short Duration Voltage Variations: interruption, Sag, Swell; Voltage Imbalance; Notching D C offset,; waveform distortion; voltage fluctuation; power frequency variations
- This study presents the evaluation and
parametric modeling of voltage drop in power distribution
networks. The issues of voltage drop in power distribution
networks has become a recurrent decimal in power distribution
sector, which has avert effects on electronics appliances, which
result in incessant fire out in offices and residential buildings.
Benin Electricity Distribution Company (BEDC) injection
substation both in Ekpoma and Benin City were investigated for
a period of three months (1ST February to 30TH April, 2014). Data
were obtained from both technical staff and prospect power
consumers in that area with the help of questionnaires. Causes of
various voltages drop in six power distribution injection
substation sectors were obtained from both residential and
industrial areas with the corresponding time (hour).
Mathematical modeling was developed for voltage drop. Firstly,
it was observed from BEDC power system that there were no
technical reports recorded on voltage drop cases and due to lack
of technical record, this aspect has witnessed a low response time
from the technical sector to eradicate. It is observed that voltage
drop occurrences and response time before repairs has similar
exponential pattern, which justify the neglect of voltage drop.
Voltage drop in both residential and industrial areas were
considered
This document discusses power quality issues in electricity distribution systems and solutions using power electronics. It defines power quality as dealing with voltage magnitude disturbances and waveform distortions. Common power quality issues include transients, voltage variations, waveform distortions, and frequency variations. International standards like IEEE 519-1992 establish limits for harmonic distortions. Power electronic solutions for improving power quality include shunt controllers like static VAR compensators (D-SVC) and distribution static synchronous compensators (D-STATCOM), and series controllers like dynamic voltage restorers. D-SVC and D-STATCOM are discussed in further detail regarding their operation and advantages.
This document summarizes the trend of leveraging creative capital through partnerships with creative individuals and organizations. It discusses how underutilized and unusual assets are being repurposed by creative groups to create innovation and design precincts. Several case studies of these types of developments are provided, including The Sheds in Auckland, New Zealand and The Old Biscuit Mill in Cape Town, South Africa. Larger, purpose-built developments focusing on creativity are also mentioned, such as the Tea Building in London and Industry City in Brooklyn. The benefits of these types of developments in attracting tourism, businesses and vibrancy are highlighted.
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 document summarizes a paper about different types of power problems. It begins by introducing the topic and defining key power quality issues like transients, interruptions, sag/swell, and waveform distortion. It then describes the causes and effects of different types of transients, including impulsive transients from lightning and oscillatory transients from switching operations. Standards for defining and measuring power problems are also discussed. The document provides examples and diagrams to illustrate power quality events. In summary, it provides an overview of common power problems, their characteristics, causes, and potential impacts.
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...ijtsrd
Traditional power production has become challenging for utilities due to the depletion of fossil fuels, coal, and oil. This must be done in a less expensive and more efficient manner. To meet the consumers power needs, a new source is needed. The alternative source should be sustainable and capable of fulfilling the needs of the customer. The incorporation of renewable energy into the grid is a helpful method of meeting demand. The integration of renewable energy has three main challenges frequency fluctuation, power quality issues, and power system instability. The following issues were critical in nature. An expert system based on an analytic hierarchy method is used to detect and classify power quality issues. Previously, it could detect sag, swell, transients, harmonics, interruptions, and flickers. A method for categorizing events that is error free has been proposed. The streamlined process provides for more accurate identification and classification of power quality issues. an examination of power quality issues and their mitigation via the use of unified power quality conditioners UPQC To reduce different power quality problems, an Adaptive Neuro Fuzzy Inference System ANFIS is employed. Using renewable energy sources effectively reduces environmental impact. The proposed technique corrects voltage imbalances and reduces overall harmonic distortion at the point of common connection PCC . The installation of an ANFIS controlled DVR is utilized to minimize voltage fluctuations induced by the integration of renewable energy sources and transmission line failures. With the aim of using renewable energy, a fake fault was introduced to power quality events. The ANFIS controlled DVR plan is in place to mitigate the negative impacts of power quality events. ANFIS controlled DVR is compared to a conventional surveillance method. Nonlinear loads generate voltage flickers and total harmonic distortion, therefore a distributed static compensator D STATCOM is employed to avoid these. It is recommended that D STATCOM use three control methods instantaneous power theory, synchronous vector PI control, and harmonic elimination. The D efficacy of STATCOMs is tested under severe load conditions. Various control methods will be used to evaluate and debate the proposed expert system and customized power devices. Rahul Gokhle | Pramod Kumar Rathore "Analysis and Implementation of Power Quality Enhancement Techniques Using Custom Power Devices" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-6 , October 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46380.pdf Paper URL : https://www.ijtsrd.com/engineering/electrical-engineering/46380/analysis-and-implementation-of-power-quality-enhancement-techniques-using-custom-power-devices/rahul-gokhle
IRJET- Investigation of Various Power Quality Issues & its Solution in Gr...IRJET Journal
This document discusses various power quality issues that can occur in grid-connected distributed power systems and their potential solutions. It defines power quality and lists several common power quality issues including voltage sags, swells, fluctuations, interruptions, harmonics, flicker, and unbalances. For each issue, it provides a definition and description of the potential causes and impacts. The goal of the paper is to investigate these power quality problems and discuss their possible solutions to help suppliers, distributors and consumers of electricity maintain a clean and stable power supply.
This document discusses power quality and issues that can arise such as voltage variations, frequency variations, and waveform distortions. It defines key power quality terms like sags, swells, flicker, harmonics, and describes how loads and generation sources can impact power quality. Active power filters are presented as a solution to power quality problems in electric rail systems by compensating for unbalance, harmonic distortion, and low power factor. Compression algorithms are also discussed to efficiently store and analyze large power quality data sets.
Come join the area's leading power quality experts as we demonstrate and replicate common power quality issues, problems and solutions in today's industrial and commercial electrical environments.
sachu technologies team provides comprehensive power quality analysis and can implement measures to bring power quality to acceptable standards. Improving power quality can bring significant financial benefits.
Poor power quality can damage sensitive equipment.
Poor power quality can lower productivity and also drive up energy costs.
Poor power quality can cause increased expenditure on electrical assets when plant or building expansion is necessary.
Poor power quality can impair the safety of electrical installations.
This document provides an overview of a presentation on fundamentals of power quality. It discusses topics that will be covered including power quality fundamentals, voltage sags and interruptions, transients, and harmonics. It defines power quality issues and explains why power quality is important due to increased use of sensitive electronic equipment. Power quality engineering investigates equipment malfunctions to determine if they are caused by power quality problems and how to mitigate the issues. Power electronics are discussed as an important factor in power quality due to causing harmonic distortion and being vulnerable to power quality variations, and their increasing prevalence.
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.
This document provides an overview of power quality issues and solutions. It defines common power quality problems like sags, swells, interruptions, harmonics and more. For each problem it describes the typical duration, voltage change, frequency of occurrence and symptoms. It then reviews potential solutions and compares their effectiveness, efficiency and costs. A example case study calculates the payback period of different solutions for addressing voltage sags. Key takeaways are to properly define power quality problems and costs, evaluate solution performance and operating costs, and select the most cost-effective option to meet needs.
Introduction
Power Quality Problems
Power Quality Measurement Devices
Power Quality Terminology
Power Quality Standards
Unbundled Power Quality Services
Power Quality Monitoring
Benefits of Power Quality
Conclusion
References
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.
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.
Mitigation of Power Quality Problems Using Custom Power Devices: A Reviewijeei-iaes
Electrical power quality (EPQ) in distribution systems is a critical issue for commercial, industrial and residential applications. The new concept of advanced power electronic based Custom Power Devices (CPDs) mainly distributed static synchronous compensator (D-STATCOM), dynamic voltage restorer (DVR) and unified power quality conditioner (UPQC) have been developed due to lacking the performance of traditional compensating devices to minimize power quality disturbances. This paper presents a comprehensive review on D-STATCOM, DVR and UPQC to solve the electrical power quality problems of the distribution networks. This is intended to present a broad overview of the various possible DSTATCOM, DVR and UPQC configurations for single-phase (two wire) and three-phase (three-wire and four-wire) networks and control strategies for the compensation of various power quality disturbances. Apart from this, comprehensive explanation, comparison, and discussion on D-STATCOM, DVR, and UPQC are presented. This paper is aimed to explore a broad prospective on the status of D-STATCOMs, DVRs, and UPQCs to researchers, engineers and the community dealing with the power quality enhancement. A classified list of some latest research publications on the topic is also appended for a quick reference.
Matlab Implementation of Power Quality Improvement Based on Fast Dynamic Controlijtsrd
This document summarizes a research paper on implementing power quality improvement using a fast dynamic control method in MATLAB. It proposes a transformer-less unified power quality conditioner (TL-UPQC) using four switching devices to form two half-bridge voltage-source inverters, one connected in parallel with the load and one in series with the AC mains sharing the same DC link. The paper presents simulation results in MATLAB showing the TL-UPQC can mitigate voltage sags/swells and current harmonics under nonlinear loads. It concludes the TL-UPQC provides improved power quality compared to other single-phase UPQC configurations.
Power quality refers to maintaining a steady supply of electric power that operates equipment properly without damage or stress. Deviations from the normal voltage can cause issues like brief power interruptions or dimming lights. Poor power quality costs US companies billions annually and negatively impacts energy efficiency. Common power quality issues include voltage variations, frequency variations, harmonic distortions, and low power factor, all of which increase energy consumption and equipment wear.
System operators face a proliferation of power electronics
interfaced devices such as HVDC transmission lines,
wind and solar generation in their grids. Depending on
the jurisdiction, the instantaneous share of electrical
energy produced from renewable energy sources
occasionally reaches 150%. However, to operate a power
system with sustained high levels of renewable energy,
several operational challenges need to be addressed. The
goal of this survey paper, which is one of the products
of CIGRE joint working group C2/B4.38, is to identify
such challenges. To this extend, extensive literature
review and survey among and discussions with system
operators throughout the world were performed.
This paper identified several operational challenges that
were validated by system operators. These challenges
are grouped in the following three categories: (i) new
behavior of the power system, (ii) new operation of the
power system and (iii) lack of voltage and frequency
support. For each of the identified challenge, a
description, practical examples and relevant references
are provided.
Introduction to Power Quality: Terms and definitions of transients,
Long Duration Voltage Variations: under Voltage, Under Voltage and Sustained Interruptions
; Short Duration Voltage Variations: interruption, Sag, Swell; Voltage Imbalance; Notching D C offset,; waveform distortion; voltage fluctuation; power frequency variations
- This study presents the evaluation and
parametric modeling of voltage drop in power distribution
networks. The issues of voltage drop in power distribution
networks has become a recurrent decimal in power distribution
sector, which has avert effects on electronics appliances, which
result in incessant fire out in offices and residential buildings.
Benin Electricity Distribution Company (BEDC) injection
substation both in Ekpoma and Benin City were investigated for
a period of three months (1ST February to 30TH April, 2014). Data
were obtained from both technical staff and prospect power
consumers in that area with the help of questionnaires. Causes of
various voltages drop in six power distribution injection
substation sectors were obtained from both residential and
industrial areas with the corresponding time (hour).
Mathematical modeling was developed for voltage drop. Firstly,
it was observed from BEDC power system that there were no
technical reports recorded on voltage drop cases and due to lack
of technical record, this aspect has witnessed a low response time
from the technical sector to eradicate. It is observed that voltage
drop occurrences and response time before repairs has similar
exponential pattern, which justify the neglect of voltage drop.
Voltage drop in both residential and industrial areas were
considered
This document discusses power quality issues in electricity distribution systems and solutions using power electronics. It defines power quality as dealing with voltage magnitude disturbances and waveform distortions. Common power quality issues include transients, voltage variations, waveform distortions, and frequency variations. International standards like IEEE 519-1992 establish limits for harmonic distortions. Power electronic solutions for improving power quality include shunt controllers like static VAR compensators (D-SVC) and distribution static synchronous compensators (D-STATCOM), and series controllers like dynamic voltage restorers. D-SVC and D-STATCOM are discussed in further detail regarding their operation and advantages.
This document summarizes the trend of leveraging creative capital through partnerships with creative individuals and organizations. It discusses how underutilized and unusual assets are being repurposed by creative groups to create innovation and design precincts. Several case studies of these types of developments are provided, including The Sheds in Auckland, New Zealand and The Old Biscuit Mill in Cape Town, South Africa. Larger, purpose-built developments focusing on creativity are also mentioned, such as the Tea Building in London and Industry City in Brooklyn. The benefits of these types of developments in attracting tourism, businesses and vibrancy are highlighted.
The document summarizes a science outreach program in Abu Dhabi called Lema? that aims to inspire scientific curiosity in students with special needs. The program held hands-on workshops on topics like robotics and anatomy for deaf and hearing-impaired students. One workshop used humor and props to teach students about human anatomy. The program seeks to make science more accessible and fun to complement classroom learning. It has reached over 50,000 students total and hopes to involve more special needs centers in e-learning initiatives.
Fabutech is a recruitment solutions company that offers personalized recruitment strategies, candidate screening and skills assessments, and workforce development consulting. They maintain a database of candidate profiles and work with clients in a variety of sectors such as banking, healthcare, and IT. Fabutech aims to find the perfect candidate match for each job profile and provide clients with a well-groomed talent pool along with replacement options when needed.
The document discusses findings from research on the Customer Attraction Score (CAS), which measures the overall attractiveness of shopping and travel destinations. The research was based on an online survey of over 1600 Australian shoppers and travellers. It found that the benefits of a destination have a much greater influence on its attractiveness than the costs. For both shopping and travel destinations, the strongest benefit factor is social interaction. Marketing efforts should focus on promoting these experiential benefits rather than reduced costs alone.
The document provides an overview of evolving learning space typologies in education, workplaces and other emerging contexts. It discusses three key areas:
1) Educational spaces - Examines how educational institutions are facilitating learning through new pedagogical approaches like project-based learning, rescheduling learning periods, and widening teaching methods. Case studies of innovative schools are provided.
2) Workspaces - Explores how workplaces are designing learning spaces to support continual learning, collaboration, and knowledge sharing. Examples of co-working spaces that foster learning among solopreneurs and startups are discussed.
3) Emerging contexts - Briefly mentions unconventional learning spaces emerging outside of traditional institutions, like makers
- In the late 1980s, Japan's economy grew rapidly but then experienced a "lost decade" of stagnation in the 1990s due to an asset bubble fueled by easy credit policies.
- The Bank of Japan attempted to stimulate the economy through low interest rates, but this helped create a real estate and stock market bubble that burst in the early 1990s.
- The bursting of the bubble devastated bank balance sheets through non-performing loans and led households and firms to focus on reducing debt rather than spending, exacerbating the economic downturn.
This document discusses trends in increasing density in urban areas through deliberate design solutions. It describes how local governments, organizations, and businesses are working to improve public spaces, reduce car traffic, and encourage smaller retail, housing, and accommodations. Multiple studies have shown that increased walkability boosts retail sales and property values. Examples highlighted include Paris installing traffic lights along the Seine river and closing a highway to create a beach area, and New York shutting roads on weekends to promote walking and cycling. Target also launched a smaller "CityTarget" store format for dense urban areas.
This document provides a summary of Darren Johnson's experience and qualifications. It outlines his objective to obtain a challenging position applying skills in areas like infrastructure, cloud solutions, datacenter management, IT architecture, networking, virtualization, storage, security and information management. It then details his experience over 16+ years in roles managing servers, storage, virtualization technologies, backups, security, networking and more for various organizations. It lists technical skills and exposure to platforms like Windows, Unix, Linux, VMware, Azure, Office 365 and security/monitoring tools.
The Place Report identifies 10 global trends that are redefining how people shop, live, work and play. One of these trends is "Retail Convenience", which involves integrating intuitive technologies into retail settings to enhance the customer experience. For both traditional retailers and online providers, convenience focuses on either leveraging the experiential qualities of physical stores or delivering a streamlined online buying experience. An example of this trend is Dutch retailer Bilder & De Clercq, which has created a retail food experience that is highly convenient for time-poor customers by allowing them to order products online and pick them up without waiting in line.
The Abu Dhabi Science Festival is expanding its reach by touring various Northern Emirates communities. The festival aims to engage students across the UAE and inspire them with hands-on activities in areas like robotics, engineering and health. In addition to its venues in Abu Dhabi, the festival will visit locations in Al Ain, Ras Al Khaimah, Fujairah, Umm Al Quwain and other Northern Emirates communities between November 14-23, hosting exhibits and workshops for both school groups and the general public. The touring component seeks to provide more youth with access to the festival's programs that aim to cultivate their scientific interests.
This document discusses the trend of culture quarters, where artistic and cultural activations are being used to revitalize unused spaces and attract people. It provides examples like Gap Filler in Christchurch, New Zealand, which activated vacant earthquake-damaged sites with creative projects. Another example is Rote Fabrik in Zurich, Switzerland, a former silk factory converted to long-term artist studios and cultural events. Developers in Hong Kong also used public art displays in a new shopping mall. Museums are finding ways to strengthen their brands by opening satellite locations, like the Louvre Museum satellite in Lens, France, which has attracted 750,000 visitors.
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.
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.
IRJET- A Comparative Study of Various Filters for Power Quality ImprovementIRJET Journal
This document discusses various filters that can be used to improve power quality by reducing harmonics and correcting power factor. It describes passive filters, shunt active power filters, and series active power filters. Shunt active power filters inject harmonic currents to cancel out load harmonics, while series active power filters generate compensating voltages. Both types of active filters require control schemes to generate the proper compensating signals. Passive filters use tuned filter branches to sink harmonic currents or block harmonic voltages. The document evaluates the compensation characteristics and control methods of different filter topologies to mitigate power quality issues like harmonics and reactive power.
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 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.
Electrical power is an intrinsic and essential part of modern life. It is generated and delivered across miles to power homes and businesses,operate a wide range of equipment and devices. We take power for granted, rarely bothering to ask “how good is the quality ofthe power I am using?”; “am I using it correctly?”; “is my equipment compatible to function with the power provided?” etc.
This document discusses a study analyzing and simulating a Dynamic Voltage Restorer (DVR) to compensate for power quality issues like voltage sags and swells. A DVR is a custom power device that injects voltage into the distribution system to regulate the load voltage. It monitors the load voltage and injects or absorbs any imbalance to maintain the load voltage within tolerance limits. The document outlines different power quality problems caused by faults and equipment, and introduces DVRs and other custom power devices as effective solutions to mitigate issues like voltage sags and harmonics.
This document discusses the use of multiresolution signal decomposition (MSD) and wavelet transform (WT) techniques to detect and localize power quality disturbances. It presents a case study analyzing power system switching transients caused by capacitor switching. The original disturbance signal is decomposed into smoothed and detailed signals at multiple scales using MSD and WT. The detailed signals contain the high frequency components and clearly indicate the occurrence of disturbances like the voltage step change from capacitor energizing. The proposed MSD and WT approach is effective for robust detection and localization of power quality issues from switching events.
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.
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.
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.
Control of Dvr with Battery Energy Storage System Using Srf TheoryIJERA Editor
One of the best solutions to improve power quality is the dynamic voltage restorer (DVR). DVR is a kind of
custom power devices that can inject active/reactive power to the power grids. This can protect loads from
disturbances such as sag and swell. Usually DVR installed between sensitive loads feeder and source in
distribution system. Its features include lower cost, smaller size, and its fast dynamic response to the
disturbance. In this project SRF technique is used for conversion of voltage from rotating vectors to the
stationary frame. SRF technique is also referred as park’s transformation. In this the reference load voltage is
estimated using the unit vectors. The real power exchanged at the DVR output ac terminal is provided by the
DVR input dc terminal by an external energy source or energy storage system. In this project three phase
parallel or series load may be used along with SRF technique to compensate voltage sag and voltage swell. And
also wind generator is also used as a load. This project presents the simulation of DVR system using
MATLAB/SIMULINK.
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.
MITIGATING ELECTRICAL DISTURBANCES WITH HYBRID DISTRIBUTION TRANSFORMERijscmcj
Hybrid transformers (HT) have the advantages of the conventional transformer, the regulatory abilities of
power electronic converters, and reduce the impact of the grid. The impacts of the existing grid are
voltage sag, voltage swell, harmonic distortion, and voltage unbalanced. The power electronic converter
has a controllable advantage such as regulating the voltage and can transfer only a fraction of the power.
The aim of the paper is to augment the conventional power distribution transformer with a partially rated
power electronic module to enhance flexibility and introduce new features to the distribution transformer.
In this paper, the proposed back-to-back converter included an active front rectifier and a modular
multilevel converter (MMC) was simulated by MATLAB/Simulink software. The proposed back-to-back
converter was used at the primary side of the distribution transformer to compensate for the voltage sag
and swell issues. The simulation results were obtained under different conditions such as various supply
voltages and various loads. Hence, the proposed system has the ability to regulate the output voltage
under various conditions with ±10%.
Electrical Engineering: An International Journal (EEIJ)ijccmsjournal
Hybrid transformers (HT) have the advantages of the conventional transformer, the regulatory abilities of
power electronic converters, and reduce the impact of the grid. The impacts of the existing grid are
voltage sag, voltage swell, harmonic distortion, and voltage unbalanced. The power electronic converter
has a controllable advantage such as regulating the voltage and can transfer only a fraction of the power.
The aim of the paper is to augment the conventional power distribution transformer with a partially rated
power electronic module to enhance flexibility and introduce new features to the distribution transformer.
In this paper, the proposed back-to-back converter included an active front rectifier and a modular
multilevel converter (MMC) was simulated by MATLAB/Simulink software. The proposed back-to-back
converter was used at the primary side of the distribution transformer to compensate for the voltage sag
and swell issues. The simulation results were obtained under different conditions such as various supply
voltages and various loads. Hence, the proposed system has the ability to regulate the output voltage
under various conditions with ±10%.
MITIGATING ELECTRICAL DISTURBANCES WITH HYBRID DISTRIBUTION TRANSFORMERijscmcj
Hybrid transformers (HT) have the advantages of the conventional transformer, the regulatory abilities of
power electronic converters, and reduce the impact of the grid. The impacts of the existing grid are
voltage sag, voltage swell, harmonic distortion, and voltage unbalanced. The power electronic converter
has a controllable advantage such as regulating the voltage and can transfer only a fraction of the power.
The aim of the paper is to augment the conventional power distribution transformer with a partially rated
power electronic module to enhance flexibility and introduce new features to the distribution transformer.
In this paper, the proposed back-to-back converter included an active front rectifier and a modular
multilevel converter (MMC) was simulated by MATLAB/Simulink software. The proposed back-to-back
converter was used at the primary side of the distribution transformer to compensate for the voltage sag
and swell issues. The simulation results were obtained under different conditions such as various supply
voltages and various loads. Hence, the proposed system has the ability to regulate the output voltage
under various conditions with ±10%
The document provides background information on power system harmonics. It discusses how the increasing use of nonlinear loads has led to power quality issues from harmonic interference. Harmonics are integer multiples of the fundamental power system frequency that distort the voltage and current waveforms. The document covers sources of harmonics, their effects, and methods for analyzing and mitigating harmonics, including harmonic indices like THD and TDD. Key concepts discussed include the representation of signals as the sum of harmonic components using Fourier analysis, definitions of different types of harmonics like triplen harmonics, and an overview of harmonic filtering techniques.
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
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.
Modeling Analysis& Solution of Power Quality Problems Using DVR & DSTATCOMijsrd.com
A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure or a disoperation of end use equipment. Utility distribution networks, sensitive industrial loads, and critical commercial operations all suffer from various types of outages and service interruptions which can cost significant financial loss per incident based on process down-time, lost production, idle work forces, and other factors. With the restructuring of Power Systems and with shifting trend towards Distributed and Dispersed Generation, the issue of Power Quality is going to take newer dimensions. The aim therefore, in this work, is to identify the prominent concerns in the area and thereby to recommend measures that can enhance the quality of the power, keeping in mind their economic viability and technical repercussions. In this paper electromagnetic transient studies are presented for the following two custom power controllers: the distribution static compensator (DSTATCOM), and the dynamic voltage restorer (DVR). Comprehensive results are presented to assess the performance of each device as a potential custom power solution.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
IEEE Aerospace and Electronic Systems Society as a Graduate Student Member
Power Quality Report
1. 1
CHAPTER 1
INTRODUCTION
The aim of the power system has always been to supply electrical energy to customers.
Earlier the consumers of electrical energy were mere acceptors. Interruptions and other voltage
disturbances were part of the deal. But 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. So the quality of the power supply has gained much
importance. The term ‘power quality’ emerged as a result of this new emphasis placed on the
customer utility relationship.
The fact that power quality has become an issue recently does not mean that it was not
important in the past. Utilities all over the world have for decades worked on the improvement of
what is now known as power quality. In the recent years, users of electric power have detected
an increasing number of drawbacks caused by electric power quality variations. These variations
already existed on the electrical system but only recently they are causing serious problems. This
is due to the increased sensitivity of equipments and devices used by customers. These end user
equipments are more interconnected in networks and industrial processes, that the impact of a
problem with any piece of equipment is much more severe. Also power quality of power systems
affects all connected electrical and electronic equipments and is a measure of deviations in
voltage, current, frequency, temperature, force, and torque of particular supply systems and their
components.
To fulfill the demand of required supply, the world is under tremendous pressure for
alternative sources of energy and has been inclined towards sustainable energy for future source
of energy. The energy sources like solar energy, wind energy, hydroelectric power, tidal power,
geothermal power and wave power are all important types of renewable energy. However if
these energy sources are coupled with the energy efficacy it is termed as sustainable energy
sources. Sustainable Energy is the provision of energy such that it meets the needs of the future
without compromising the ability of future generations to meet their own needs. It is required to
have more efficient means of converting and utilizing these energy. This will depend on the
quality of power supplied and the impact of end user equipments on that power. But power
2. 2
electronic equipments are mostly used in sustainable and renewable energies in different stages
for acquisition and conversion or inversion into useable form. Due to increasing sensitivity of the
equipments and devices used by the customers, power qualities of sustainable energy are
affected.
Poor Power Quality results in high costs and that is gradually rising. The poorer the
Power Quality, the more would be the initiatives required from concerned parties and regulating
bodies to adopt corrective measures to ensure better Power Quality. As a consequence, the
economy of a country is largely affected with even low tech industries suffering serious financial
losses. Especially for successful sustainable energy programe, Power Quality Monitoring can
help identify the cause of power system disturbances and the underlying problem conditions on a
system before they cause interruptions and disturbances. Due to this many power utilities
perform power quality monitoring as an essential service for their main customers. Essential
capabilities of a power quality monitoring system are reduced cost and remote data transmission
capability.
With the electrical industry undergoing change, increased attention is being focused on
reliability and power quality. Power providers and users alike are concerned about reliable
power, whether the focus is on interruptions and disturbances or harmonic distortion or flicker.
One of the most critical steps in ensuring reliability is monitoring power quality. Power quality
monitoring can help to identify the cause of power system disturbances and even help to identify
problem conditions before they cause interruptions or disturbances. Hence power quality
monitoring is a multi-pronged approach to identifying, analyzing, and correcting power quality
problems. To improve power quality with adequate solutions, it is necessary to know what kinds
of disturbances occurred. A power quality monitoring system that is able to automatically detect,
characterize and classify disturbances on electrical lines is therefore required. With power
quality monitoring, power engineers can eliminate some of their troubleshooting headaches.
3. 3
CHAPTER 2
POWER QUALITY
2.1 DEFINATION
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.
2.2 CAUSES OF POWER QUALITY PROBLEMS
The causes of power quality problems can be many. It is often difficult to point an exact cause
for a specific problem. Power quality monitoring equipments comes to aid in such situations.
Most of the causes of power quality problem can be divided into two categories
Internal causes
Approximately 80% of electrical problems originate within a business facility. Potential culprits
may include large equipments start or shut down, improper wiring and grounding, overloaded
circuits or harmonics.
External causes
About 20% of power quality problems originate with the utility transmission and distribution
system .The most common cause is a lightning strike; other possibilities include equipments
failure, vehicle accidents, weather conditions, neighboring business and even normal operation
of utility equipments.
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2.3 POWER QUALITY DISTURBANCES
Power quality is concerned with the deviation of the voltage from the ideal waveform or the
deviation of the current from the ideal waveform. Such a deviation is called a power quality
phenomena or disturbances. It is important to first understand the kinds of power quality
disturbances that can cause problems with the sensitive loads. Categories of these disturbances
must be developed with a consistent set of definitions, so that the measurement equipments can
be designed in a consistent manner. Power quality phenomena can be divided into two basis
categories.
Steady state variations
A characteristic of voltage or current is never exactly equal to its nominal or desired value.
The small deviations from the desired value are called voltage or current variations. A property
of any variation is that it has value at any moment in time. Monitoring of variations thus has to
take place continuously.
Events
Occasionally, the voltage or current deviates significantly from the nominal or ideal wave
shape. These sudden deviations are called events. Monitoring of events take place by using a
triggering mechanism where recording of voltage or current starts the moment, a threshold is
exceeded.
STEADY STATE VARIATIONS
This category includes voltage and current variations which are relatively small
deviations of voltage and current characteristics around their nominal or ideal values. The two
basic characteristics are magnitude and frequency. On average voltage magnitude and voltage
frequency are equal to their nominal value but they are never exactly equal. Variations must be
measured by sampling the voltage and current over time. Information is best presented as a trend
of the quantity over time and then analyzed using statistical methods. An overview of voltage
and current variations are given below:
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Voltage fluctuation
The fast changes or swings in the steady state voltage magnitude are called voltage
fluctuation. The change in voltage magnitude can be due to variations of total load of a
distribution system, action of transformer tap changers, switching of capacitor banks. If the
variations are large enough or in a certain critical frequency range, the performance of the
equipment can be affected.
Fig. 2.1
Voltage and current unbalance
Unbalance or 3 phase unbalance is the phenomenon in a 3 phase system in which the
RMS values of voltages and phase angles between consecutive phases are not equal. The
primary source of voltage unbalance is the unbalanced load. This can be due to an uneven
spread of low voltage customers over the three phases but more commonly unbalance is due
to a large single phase load.
Harmonic voltage and current distortion
Widespread use of electronic equipment in today’s commercial and industrial
environments make harmonic distortion an important but complicated power quality issue.
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Any power supply that converts AC to DC power will have a much distorted waveform at the
supply. The current waveform is always a picture of the way a load reacts to the AC supply.
The distorted voltage created by the return current through the impedance of the cable and
switchgear can cause the voltage waveform to distort. This voltage distortion will affect
every device connected to the corrupted circuit. Harmonic distortion of voltage and current
result, from the operation of non-linear loads and devices in the power system.
Fig. 2.2 Harmonic Distortion
High frequency voltage noise
The non-periodic components in supply voltage can be called ‘noise’. Distinguishing
noise from other components is not always simple. An analysis is needed only in case where
noise leads to some problem with power system or end user equipments. Electrical noise can
be defined as the high frequency interference caused by a number of factors like arc welding
or operation of electrical motor.
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EVENTS
Events are the phenomena which happen once in a while. Power quality events are the
disturbances which can lead to the tripping of equipments, interruptions of production or plant
operation or endanger power system operation. Events are measured by a triggering mechanism.
An overview of various events is given below.
Interruptions
A supply interruption is a condition in which the voltage at supply terminals is close to
zero. Interruptions are normally initiated by faults which subsequently trigger protection
measures. Interruptions can be subdivided based on their duration, thus based on the way of
restoring the supply.
1. Sustained Interruptions: These kinds of interruptions are terminated through manual
restoration or replacement of faulted components.
2. Temporary Interruptions: This refers to interruptions lasting less than 2 minutes. This
interruption is terminated through automatic restoration of pre-event situation.
3. Momentary Interruptions: These interruptions are terminated through self-restoration.
E.g. Interruption due to transients and other self-restoring events.
Fig. 2.3
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Voltage sags / swells
A sag or swell is a decrease or increase in the RMS value of voltage ranging from a half
cycle to few seconds. The most likely kind of power quality problem is the voltage sag. Short
duration under voltages is called ‘voltage sags’ whereas, longer duration under voltages are
referred to as ‘under voltage’. Likewise over voltages of very short duration and high
magnitude are called ‘voltage swells’. Longer duration over voltage is called as ‘over
voltage’. Short duration voltage variations include variations in the fundamental frequency
voltage that lasts less than 1 minute.
Fig. 2.4
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Transients
Transients are sub cycle disturbances of very short duration that vary greatly in
magnitude. Transients are used to refer to fast changes in the system voltage or current with
duration less than .5 cycles. Transients can be measured by triggering on the abnormality
involved. When transients occur, thousands of voltage can be generated into the electrical
system causing problems for equipments down the line. Transients can be divided into 2
categories:
1. Impulsive transient: Lightning striking a distribution line is normally an impulsive
transient where there is a large deviation of the wave form for a very short duration in
one direction, followed possibly by a couple of much smaller transients in both
directions.
2. Oscillatory transient: An oscillatory transient is one where there is a ringing signal or
oscillation following the initial transient. E.g.: switching of power factor correction
capacitor is considered the most prevalent type of transient.
Fig. 2.5
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2.4 INCREASED INTEREST IN POWER QUALITY
Power quality is an increasingly important issue for all business. A recent study by IBM
showed that power quality problems cost US business more than $15 billion a year. The
increased interest in power quality has resulted in significant advances in monitoring equipments
that can be used to characterize disturbances and power quality variations. The recent increased
interest in power quality can be explained in a number of ways.
• Equipments have become more sensitive to voltage disturbances
The electronic and power electronic equipments have especially become much more
sensitive to voltage disturbances than their counterparts 10 or 20years ago.
• Equipments cause voltage disturbances
Modern electronic and power electronic equipments are not only sensitive to voltage
disturbances but also cause disturbances for other customers. E.g. Non-sinusoidal current
drawn by rectifiers and inverters.
• Technical challenge taken up by utilities
Designing a system with a high reliability of supply at a limited cost is a technical challenge
which appealed too many in the power industry and hopefully still does in the future.
• Power quality can be measured.
The availability of electronic equipments to measure and show wave forms has certainly
contributed to the interest in power quality.
2.5 IMPACTS ON GLOBAL ECONOMY
The cost of energy or a KWH not supplied because of an outage is much higher than the
cost of a KWH that is supplied when needed. The global bill for poor power quality is more than
500 billion euros per year which is 50% of the turnover of the global electricity sector. For many
business uses, the cost of poor Power Quality is higher than the electricity bill and the cost is
rising. The global average energy consumption is steeply rising.
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Fig. 2.6 Projections of Indian average energy consumption
Due to high average increase of energy demand, India needs to have sustainable energy
productions to meet the huge energy requirements. The Government of India is trying to
accelerate solar power generation. By January 2014 the installed grid connected solar power had
increased to 2,208.36 MW, and India expects to install an additional 10,000 MW by 2017 and a
total of 20,000 MW by 2022. Poor Power Quality has serious impact on Indian economy. A joint
study by the manufacturers association of information technology(MAIT) and emersion network
power(India) has thrown up the finding that network power downtime costs Indian economy
more than Rs.43000 crores annually(2008) and this has been steeply rising. Similarly, economic
cost of outages of Bangladesh amounted to 1.72% (US $778millions) of the Country GDP in
2001. Industrial losses due to poor Power Quality had been estimated as $150- $200 billion
dollars for European Union (2001). Therefore, an efficient and intelligent monitoring is essential
to avoid staggering economic losses due to poor power quality and to meet the challenges.
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CHAPTER 3
POWER QUALITY MONITORING (PQM)
3.1 SOLAR ENERGY IN INDIA AND PQ MONITORING
Solar Energy is one of the cleanest and greenest technologies. Solar electric panels
produce DC. Necessary conversion is done for AC applications. A solar electric system may be
completely independent of the grid or designed to primarily feed power into the grid. The solar
radiation in India is very much satisfactory and most parts are suitable for generating power from
Solar Energy. In such case it is essential for India to install efficient power quality monitoring
systems to maintain quality and undertake exact mitigations in time. The support extended by
Government of India by way of providing attractive incentives under Jawaharlal Nehru National
Solar Mission (JNNSM) is generating significant interest in Solar Energy. India has
Geographical advantage with excellent solar radiation across the Country. In fact Rajasthan has
been recently termed as amongst the best in the world for Solar Energy. As an alternative source
of energy efforts are made to have larger production units from solar, wind mills sources etc. But
many systems (utility/customer) are affected due to absence of an effective PQM programme.
Integration of sustainable energy with the grid and use of power electronics, power quality
problems have increased in manifold. Monitoring within an industrial, residential or domestic
unit can reveal the origin of problems and give the necessary information for their solution.
Efficient power quality monitoring will provide the information needed to validate compliance,
improve system stability, and minimize unplanned downtime. It is therefore an important issue
for the successful and efficient operation of existing as well as future energy systems. In such
conditions, monitoring of power quality is the real challenge. An intelligent power quality
monitoring system is an essential requirement of the future energy system. The PQM should be
capable to detect most (and almost all) of the power quality events and disturbances. Intelligent
PQM is the need for smart grid due to principal functionality characteristics of Smart Grids.
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3.2 OBJECTIVES OF PQ MONITORING
The objectives of a monitoring program determine the choice of measuring equipments
and triggering thresholds, the methods for collecting data, data storage and analysis requirements
and the overall level of effort needed. General classification of objectives for power quality
monitoring is explained in the following section.
Proactive approach:
This approach of monitoring is intended to characterize the system performance. A power
producer may find this objective important because this helps to understand the system
performance and then be able to match the system performance with customer needs.
Reactive approach:
This kind of monitoring is intended to characterize a specific problem. Many services
solve power quality problems by performing short term monitoring at specific customers or at
different loads.
3.3 DEVLOPMENT OF SYSTEM
The aim of this work is to develop a method that is suitable for efficient monitoring of
power qualities in sustainable energy system like solar energy etc. The emphasis is therefore on
low computational power required to perform the necessary calculations. Stress is also laid on
the possibility to detect as many categories of PQ disturbances as possible.
An intelligent power monitoring system can be developed by designing virtual
instruments using LabVIEW software and NI’s DAQ system and sensors. Along with LabVIEW,
Higher order statistics (HOS) and quadratic discriminant analysis techniques are employed to
classify and analyze the huge amount of acquired data to determine the condition of the
waveforms. The system shows fast response with accuracy in monitoring and analysis of the
desired power qualities.
Initially, the distortions have been simulated in the labs and measured with the help of the
developed virtual instruments (VIs) using graphical programming in LabVIEW. Different types
of disturbances measurements are done with front panel created on PC monitor. The huge
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amount of acquired data has been analyzed using quadratic discriminant analysis technique to
determine the quality of the supply. The quadratic function is estimated treating a sample from
the data as a training data. The data can be exported in different formats in a text file or directly
in common software products like Excel etc. The test results of the simulated and the prototype
system show the desired performance of the system and thus validate the proposed technique.
The beauty of the system is that it can be used for monitoring of power qualities in both existing
power system and sustainable energy systems with provisions for switching-over.
In this application, we generate a graphical user interface through which the user can
monitor and adjust different parameters to customize the monitoring tasks. On the other hand, a
National Instruments Data Acquisition card is chosen to interface the analog AC signal as a
second step after using step-down transformer along with voltage divider circuit for signal
conditioning. For voltage measurements, magnetic voltage transformers are used (upto 5 KHz).
However current probes and Hall Effect voltage transducers are employed to acquire voltage and
current signals for accurate sensing.
Fig. 3.1 Block diagram of power quality monitoring system
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3.4 POWER QUALITY MONITORS
The first step to troubleshooting power quality problems is to have a monitor that
accurately measures voltage and current waveforms. The role of monitor for troubleshooting
power quality problems is undeniable. Power quality monitoring devices come in a variety of
shapes and sizes. Commercially available monitors fall into two categories: 1) portable
monitors and 2) permanent monitors.
PORTABLE MONITORS
Handheld and portable instruments have made great improvements in testing capability in
recent years and are helpful in uncovering small localized problems. But these are used for
troubleshooting after an event has taken place. Installing a power quality monitor after the
occurrence of the event tells us little about the past. Portable monitors are again subdivided into
two classes:
1. Voltage recorders
These instruments record voltage and current strip chart data. Portable monitors are used for
continuous monitoring of steady state voltage variations. These recorders digitize voltage and
current signals by taking samples of voltage and current over time. The 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.
2. Disturbance analyzer
Disturbance analyzer and disturbance monitors form a category of instruments which have
been developed specifically for power quality measurements. The analyzers are designed to
capture events affecting sensitive devices. They typically can measure a wide variety of
system events from very short duration transients to long duration outages. Thresholds can
be set and the instrument is left unattended to record disturbances over a long period of
time. Recording starts the moment, a threshold value is exceeded.
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Fig. 3.2 PORTABLE MONITOR
PERMANENT MONITORS
In the past, measurement equipments were designed to handle either the events or steady
state variations. With advances in processing capability, new instruments have become available
that can characterize the full range of power quality variations. The new challenge involves
characterizing all the data in a convenient form, so that it can be used to identify and solve
problems. This highlights the features of permanent monitors.
Permanently installed full system monitors strategically placed on pieces of equipments
throughout the facility, lets the users know, what happened, where it happened as soon as it
happened. The main feature of these kinds of monitors is that they characterize full range of
power quality variations. They record both the triggered and sampled data. Triggering is based
upon the RMS thresholds for RMS variations and on wave shape for transient variation. The
simplest monitoring system could be a self-contained circuit monitor; however the real value of
monitoring is in automatic data downloading from the measuring instruments. Monitoring
system should fully utilize the networking infrastructure. A more apt term for these efficient
monitoring systems would be ‘real time monitoring systems’.
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CHAPTER 4
ANALYSIS OF POWER QUALITY MEASUREMENTS
4.1 MONITORING OBSERVATIONS OF POWER QUALITIES
A large number of readings were recorded during observations of monitoring performed
by the developed system. Fig. 4.1 show some typical distortions or disturbances captured during
monitoring of simulated disturbances in the laboratory.
Fig. 4.1 PQ disturbances monitored by the developed method.
The waveforms captured show different power quality events or disturbances, including
voltage sag, swell, interruptions, transients, harmonics etc.
The table I shows the summary report of power quality monitoring of 200 KVA UPS
Input at NIT Silchar Systems. And table II shows the summary report of power quality
monitoring of 200 KVA UPS Output at NIT Silchar System.
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The tables I and II show extract of actual recordings, which would be helpful for assessment of
power quality of the systems. UPS input has about 15% input current harmonics distortion as it
has 12 pulse rectifier at the input. Similarly it has been observed that the blower motors which
have thyristor rectifiers at input are affected due to a lot of input current harmonic distortion.
Thus this system is showing monitoring of harmonics (THD), supply voltage and current.
4.2 DATA ANALYSIS
Acquired data can be exported in different formats in a text file, HTML or directly in
common software products or evaluation software provided by National Instruments. It has been
found during investigations and analysis that the sources of disturbances can be determined by
simultaneous measurement or monitoring of voltage and current. Analysis tools for processing
measured data present the information as individual events i.e. disturbance wave forms, trends or
statistical summaries. By comparing the captured events with libraries of typical power quality
variation characteristics and correlating with system events, causes of variations can be
determined. The data analysis system should be flexible enough to handle data from a variety of
monitoring equipments and maintain a database that can be used by many different applications.
4.3 BENEFITS OF POWER QUALITY MONITORING
The benefits of power quality monitoring are many. The following section mentions some of
them.
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 where necessary.
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CHAPTER 5
CONCLUSION
Global economy has been affected due to poor PQ of the supply systems. Power qualities
of sustainable energy are also affected due to increasing sensitivity of the equipments and
devices used by the customers, and need proper monitoring and analysis for mitigation purposes.
Traditional monitoring methods are based on the RMS measurements and constrained by their
accuracies. Recently proposed approaches for automated detection and classification of power
quality disturbances are based on wavelet analysis, artificial neural networks, hidden Markov
model and bispectra. The use of such advanced techniques makes the power quality monitoring
system more accurate and the power system more reliable.
The configuration complexity of a monitoring system depends primarily upon the number
of instruments used to acquire information and the number of people who need to utilize it. The
simplest monitoring system could be a self-contained circuit monitor built into a sensitive load.
However the real value of monitoring system is in automatic data downloading from the
measuring instruments and hence today, a lot of emphasis is given on the design of ‘real time
monitoring systems’.
5.1 FUTURE OF POWER QUALITY
In 10 years’ time, it may well be that equipment has become fully compatible with the power
supply and does not cause any disturbance to the customers. However, there is no indication that
this will happen soon. So right now the emphasis is on mitigation equipments and on intelligent
power quality monitoring systems which enables the automatic classification and analysis of the
measured data.