IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
This document discusses harmonic mitigation techniques for AC-DC converters used in induction motor drives. It examines 12-pulse and 18-pulse AC-DC converters that use autotransformers to reduce harmonics compared to a standard 6-pulse rectifier. The document analyzes the performance of these converters under different load and voltage imbalance conditions using simulations and experimental results. It finds that 12-pulse converters can achieve 10-12% total harmonic distortion at full load but performance decreases at light loads or with voltage imbalance. Proper transformer and circuit design is needed to ensure current sharing between bridge rectifiers for optimal harmonic cancellation.
Operational Cost Avoidance through Harmonic Mitigation in Industrial Environm...Schneider Electric
Industrial sites suffer from margin erosion because operations and equipment costs are not efficiently controlled. Such costs can be avoided if the proper harmonic mitigation solution is implemented. This paper reviews several approaches to harmonic mitigation and identifies best practices.
Power Factor Correction Methods
Fixed Capcitors
Synchronous Condensors
Phase Advancers
Switch Capacitors
Static Var Compensator(SVC)
Static Synchronous Compensator(STATCOM)
Modulated power filter capacitor compensator
Economics of power factor improvement
Economical comparison of increasing the power supply
Power factor is a ratio between actual power and apparent power in a circuit. A low power factor is caused by inductive loads like motors and transformers which draw lagging current. Improving power factor through devices like capacitors reduces line losses, improves voltage regulation, lowers electricity bills, and allows for more load to be served. Properly locating power factor correction equipment such as installing capacitor banks at substations instead of individual loads provides the benefits of power factor improvement in a cost effective manner.
Application of Capacitors to Distribution System and Voltage RegulationAmeen San
Application of Capacitors to
Distribution System and Voltage
Regulation
POWER FACTOR IMPROVEMENT,
System Harmonics
Voltage Regulation
Methods of Voltage Control
LCL Filter for Grid Connected VSC Converter
Comprehensive analysis and modeling of the three-phase LCL filter for VSC converters, suitable for wind energy or photovoltaic applications.
report of Improvement of the Electric Power Quality Using Series Active and S...Vikram Rawani
The increase of nonlinear loads due to the proliferation of electronic equipment causes power quality in the power system to deteriorate. Harmonic current drawn from a supply by the nonlinear load results in the distortion of the supply voltage waveform at the point of common coupling (PCC) due to the source impedance. Both distorted current and voltage may cause end-user equipment to malfunction, conductors to overheat and may reduce the efficiency and life expectancy of the equipment connected at the PCC.
This document discusses power quality issues related to harmonics. It covers:
- The causes of harmonics from non-linear loads like switched mode power supplies, electronic ballasts, variable speed drives, and UPS units.
- The effects of harmonic currents within electrical systems, including neutral conductor overheating, transformer overheating, circuit breaker tripping, and capacitor stress.
- Harmonic voltages can also cause problems like voltage distortion, issues with induction motors, and zero-crossing noise.
- Harmonic currents on the supply system can also cause problems that require separate solutions from those used within an installation.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
This document discusses harmonic mitigation techniques for AC-DC converters used in induction motor drives. It examines 12-pulse and 18-pulse AC-DC converters that use autotransformers to reduce harmonics compared to a standard 6-pulse rectifier. The document analyzes the performance of these converters under different load and voltage imbalance conditions using simulations and experimental results. It finds that 12-pulse converters can achieve 10-12% total harmonic distortion at full load but performance decreases at light loads or with voltage imbalance. Proper transformer and circuit design is needed to ensure current sharing between bridge rectifiers for optimal harmonic cancellation.
Operational Cost Avoidance through Harmonic Mitigation in Industrial Environm...Schneider Electric
Industrial sites suffer from margin erosion because operations and equipment costs are not efficiently controlled. Such costs can be avoided if the proper harmonic mitigation solution is implemented. This paper reviews several approaches to harmonic mitigation and identifies best practices.
Power Factor Correction Methods
Fixed Capcitors
Synchronous Condensors
Phase Advancers
Switch Capacitors
Static Var Compensator(SVC)
Static Synchronous Compensator(STATCOM)
Modulated power filter capacitor compensator
Economics of power factor improvement
Economical comparison of increasing the power supply
Power factor is a ratio between actual power and apparent power in a circuit. A low power factor is caused by inductive loads like motors and transformers which draw lagging current. Improving power factor through devices like capacitors reduces line losses, improves voltage regulation, lowers electricity bills, and allows for more load to be served. Properly locating power factor correction equipment such as installing capacitor banks at substations instead of individual loads provides the benefits of power factor improvement in a cost effective manner.
Application of Capacitors to Distribution System and Voltage RegulationAmeen San
Application of Capacitors to
Distribution System and Voltage
Regulation
POWER FACTOR IMPROVEMENT,
System Harmonics
Voltage Regulation
Methods of Voltage Control
LCL Filter for Grid Connected VSC Converter
Comprehensive analysis and modeling of the three-phase LCL filter for VSC converters, suitable for wind energy or photovoltaic applications.
report of Improvement of the Electric Power Quality Using Series Active and S...Vikram Rawani
The increase of nonlinear loads due to the proliferation of electronic equipment causes power quality in the power system to deteriorate. Harmonic current drawn from a supply by the nonlinear load results in the distortion of the supply voltage waveform at the point of common coupling (PCC) due to the source impedance. Both distorted current and voltage may cause end-user equipment to malfunction, conductors to overheat and may reduce the efficiency and life expectancy of the equipment connected at the PCC.
This document discusses power quality issues related to harmonics. It covers:
- The causes of harmonics from non-linear loads like switched mode power supplies, electronic ballasts, variable speed drives, and UPS units.
- The effects of harmonic currents within electrical systems, including neutral conductor overheating, transformer overheating, circuit breaker tripping, and capacitor stress.
- Harmonic voltages can also cause problems like voltage distortion, issues with induction motors, and zero-crossing noise.
- Harmonic currents on the supply system can also cause problems that require separate solutions from those used within an installation.
Highly efficient Active Front End enables trouble free operation of low harmo...Schneider Electric
NEW 3 level Active Front End (AFE) technology from Schneider Electric allows trouble free operation, both for mains supply side and motor side.
This technology allows exceptional low harmonics impact on the main side, which helps to protect other assets while saving energy. It also solves the major issue existing with 2 level AFE which can create premature wear on motors' bearings. By suppressing the common mode voltage, the 3 level AFE technology ensures the motor is running without potential issue, extending the motor’s lifetime and saving maintenance costs.
This document provides an overview of power factor, including basics, causes of low power factor, disadvantages, correction methods, and advantages of correction. It defines power factor as the ratio of true power to apparent power. Induction motors, transformers, and other inductive loads cause low power factors. Correcting power factor reduces equipment sizes and losses, improves voltage regulation, and avoids penalties under power factor tariffs. Static capacitors and synchronous condensers are common correction methods.
This document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factors are caused by inductive loads and non-linear loads. APFC systems use capacitors in automatic steps controlled by a microprocessor to maintain a high power factor under varying loads without manual intervention or risk of overvoltage. This improves efficiency and reduces utility penalties and equipment loading and sizes. The document provides specifications for capacitor selection and switching equipment for APFC systems.
This document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factors are caused by inductive loads and non-linear loads. APFC systems use capacitors in automatic steps controlled by a microprocessor to maintain a high power factor under varying loads without manual intervention or risk of overvoltage. This improves efficiency and reduces utility penalties and equipment loading and sizes. The document provides specifications for capacitor selection and switching equipment for APFC systems.
The document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factor causes inefficient energy use and other issues. APFC systems automatically switch capacitor banks to maintain a high power factor under varying loads without manual intervention. This prevents issues like overvoltage and penalties compared to fixed capacitor compensation. The document provides details on components, control, and benefits of APFC systems.
A High Performance PWM Voltage Source Inverter Used for VAR Compensation and ...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
power quality and reduction of drive harmonics using filters in source side.pptSathishCharles1
1) AC drives can negatively impact power quality through poor power factor, voltage sags during motor starting, and current harmonic distortion. Modern drives use techniques like active front ends and soft starters to mitigate these issues.
2) Current harmonics from non-linear loads like drives can overheat transformers and interfere with other equipment if they exceed recommended IEEE limits. Common harmonic-producing loads and their harmonic profiles are discussed.
3) Various techniques can be used to attenuate harmonics, including passive and active filters, line reactors, isolation transformers, and multi-pulse drive rectifier designs. Higher pulse rectifiers provide better harmonic performance but at increased cost.
In electrical engineering, a synchronous condenser (sometimes synchronous capacitor or synchronous compensator) is a device identical to a synchronous motor, whose shaft is not connected to anything but spins freely.
This document presents an overview of reactive power compensation. It defines reactive power compensation as managing reactive power to improve AC system performance. There are two main aspects: load compensation to increase power factor and voltage regulation, and voltage support to decrease voltage fluctuations. Several methods of reactive power compensation are discussed, including shunt compensation using capacitors and reactors, series compensation, static VAR compensators (SVCs), static compensators (STATCOMs), and synchronous condensers. SVC and STATCOM technologies are compared, with STATCOMs having advantages of smaller components, better control, and transient response.
Reactive power compensation is used to improve the performance of AC power systems. There are various methods of reactive power compensation including shunt compensation, series compensation, static VAR compensators, and static synchronous compensators. Shunt compensation devices such as capacitors and reactors are connected in parallel to transmission lines to regulate voltage. Series compensation uses capacitors connected in series to transmission lines to increase power transfer capability. Static VAR compensators and static synchronous compensators use thyristor-based voltage sourced converters to dynamically inject or absorb reactive power and control voltage. Reactive power compensation provides benefits such as improved power factor, voltage regulation, reduced losses, and increased power transfer capacity.
IRJET- Harmonics Reduction using Harmonics Injection MethodIRJET Journal
This document discusses a current harmonic injection technique to reduce harmonics from induction motor drives used in variable frequency drives (VFDs). VFDs generate harmonics that can cause motor heating, electromagnetic interference, and instrument malfunctions. The technique injects specific harmonics from an inverter circuit into the VFD output to cancel out current harmonics and reduce total harmonic distortion. It uses three bi-directional switches in the injection circuit instead of a traditional zigzag transformer to lower costs and size. Simulation results showed the technique reduced harmonics with a minimal increase in diode power ratings.
Enhancement of Power System Dynamics Using a Novel Series Compensation SchemeIJMER
Phase imbalanced capacitive compensation is a “hybrid” series compensation scheme, where the
series capacitive compensation in one phase is created using a single-phase TCSC in series with a fixed capacitor
(Cc), and the other two phases are compensated by fixed series capacitors (C). The TCSC control is initially set
such that its equivalent compensations at the power frequency combined with the fixed capacitor yield a
resultant compensation equal to the other two phases. Thus, the phase balance is maintained at the power
frequency while at any other frequency, a phase imbalance is created. The effectiveness of the scheme in damping
power system oscillations for various network conditions, namely different system faults and tie-line power flows is
evaluated using the MATLAB/SIMULINK Software
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.
Power Quality Improvement using Passive shunt filters, TCR and TSC combinationIJERA Editor
In this thesis Power Quality Improvement is examined using Passive shunt filter, TCR and TSC combination. Today’s electric power systems are connected to many non-linear loads. The characteristics of these non-linear loads inevitably change the sinusoidal nature of the a.c. power current, resulting in the flow of harmonic current in the a.c. power system. Use of shunt passive filters in the reduction of harmonics offers the advantages of more simplicity, high reliability, high efficiency and low cost. The uncontrolled ac-dc converter suffers from operating problems of poor power factor, injection of harmonics into the ac mains, variations in dc link voltage of input ac supply, equipment overheating due to harmonic current absorption, voltage distortion due to the voltage drop caused by harmonic currents flowing through system impedances etc.The combinations of passive filters with TCR and TSC are designed and analyzed to improve the power quality at ac mains. This scheme has resulted in improved power quality with overall reduced rating of passive components used in front end ac-dc converters with R-L load.
A Shunt Active Power Filter for 12 Pulse Converter Using Source Current Detec...IAES-IJPEDS
A shunt Active Power Filter (APF) with current detection at the source side
is considered as a closed-loop system from the view of the whole power
distribution system, which is expected with better harmonics filtering
performance compared with conventional current detection methods such as
load current detection and open loop control. This paper introduces an
efficient source current detection method (direct) control scheme to mitigate
the grid current harmonics generated by the twelve pulse converter. The
proposed system uses Control Rectifier (12 –pulse converter) which
efficiently regulates the DC voltage by varying the angle of each 6 pulse
converter. Moreover, the proposed system uses three winding transformer
which eliminates the harmonics during equal angles switching at each six
pulse converter which in turn simplifies the operation of the SAPF. The
proposed system is simulated in MATLAB SIMULINK to evaluate the
performance of the proposed system.
In the modern power system the reactive power compensation is one of the main issues, the transmission of active power requires a difference in angular phase between voltages at the sending and receiving points (which is feasible within wide limits), whereas the transmission of reactive power requires a difference in magnitude of these same voltages (which is feasible only within very narrow limits). The reactive power is consumed not only by most of the network elements, but also by most of the consumer loads, so it must be supplied somewhere. If we can't transmit it very easily, then it ought to be generated where it is needed." (Reference Edited by T. J. E. Miller, Forward Page ix).Thus we need to work on the efficient methods by which VAR compensation can be applied easily and we can optimize the modern power system. VAR control technique can provides appropriate placement of compensation devices by which a desirable voltage profile can be achieved and at the same time minimizing the power losses in the system. This report discusses the transmission line requirements for reactive power compensation. In this report thyristor switched capacitor is explained which is a static VAR compensator used for reactive power management in electrical systems.
Seminar Topic For Electrical and Electronics Engineering (EEE)
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Soft power factor modification using staticchodachude
A good power quality at a system can optimize the efficiency of electrical energy utilization.
Comparison of active power and apparent power will produce a power factor (COS ø).Capacitors bank can
maintain optimum power factor with compensating some reactive power to the system. Static VAR
Compensator (SVC) is generally composed of a conventional capacitor bank in parallel with the load contactor
switch. This leads to a very large inrush current to the capacitor which will resulting damage to the
contactor switches and also capacitors. To reduce inrush current, thyristor is used as a replacement of
contactor switch. Switch can be set by adjusting the firing angle of thyristor. Power factor improvement consists
of a voltage sensor, current sensor, zero crossing detector, thyristor driver and the capacitor bank. The existing
load on the system consists of induction motor 125W, rectifier with load of series of incandescent lamp with
ballasts 85W and fluorescent lamp 20W.Cos phi variation of the load is 0.49 (lag), 0.99 (lag), 0.92 (lag) and 0.62
(lag) when all the loads connect to the system. Through the calculation, the value of capacitor that can
compensate the reactive power to the system is 5.12 µF, 2.71 µF, 2.41 µF and 9.55µF. The capacitor
installation obtain good response because it can increase the cos phi of system to 0.99 (lag) and the current
consumption of the system is smaller than the pre-installation of capacitors, which can reduce the line system
current up to 30% of the system current
Research Inventy : International Journal of Engineering and Scienceresearchinventy
This document summarizes a research paper about simulating a distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC) but eliminates the common DC link. It allows active power exchange between series and shunt converters through the transmission line at the third-harmonic frequency instead of through a DC link. Detailed simulations are conducted on a two-machine system to analyze the DPFC's control capabilities and effects on power transfer and system reliability. The document outlines the DPFC topology, operating principle of active power exchange without a DC link using non-sinusoidal power theory, and use of the third-harmonic frequency for this exchange due to its zero-sequence properties.
Highly efficient Active Front End enables trouble free operation of low harmo...Schneider Electric
NEW 3 level Active Front End (AFE) technology from Schneider Electric allows trouble free operation, both for mains supply side and motor side.
This technology allows exceptional low harmonics impact on the main side, which helps to protect other assets while saving energy. It also solves the major issue existing with 2 level AFE which can create premature wear on motors' bearings. By suppressing the common mode voltage, the 3 level AFE technology ensures the motor is running without potential issue, extending the motor’s lifetime and saving maintenance costs.
This document provides an overview of power factor, including basics, causes of low power factor, disadvantages, correction methods, and advantages of correction. It defines power factor as the ratio of true power to apparent power. Induction motors, transformers, and other inductive loads cause low power factors. Correcting power factor reduces equipment sizes and losses, improves voltage regulation, and avoids penalties under power factor tariffs. Static capacitors and synchronous condensers are common correction methods.
This document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factors are caused by inductive loads and non-linear loads. APFC systems use capacitors in automatic steps controlled by a microprocessor to maintain a high power factor under varying loads without manual intervention or risk of overvoltage. This improves efficiency and reduces utility penalties and equipment loading and sizes. The document provides specifications for capacitor selection and switching equipment for APFC systems.
This document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factors are caused by inductive loads and non-linear loads. APFC systems use capacitors in automatic steps controlled by a microprocessor to maintain a high power factor under varying loads without manual intervention or risk of overvoltage. This improves efficiency and reduces utility penalties and equipment loading and sizes. The document provides specifications for capacitor selection and switching equipment for APFC systems.
The document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factor causes inefficient energy use and other issues. APFC systems automatically switch capacitor banks to maintain a high power factor under varying loads without manual intervention. This prevents issues like overvoltage and penalties compared to fixed capacitor compensation. The document provides details on components, control, and benefits of APFC systems.
A High Performance PWM Voltage Source Inverter Used for VAR Compensation and ...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
power quality and reduction of drive harmonics using filters in source side.pptSathishCharles1
1) AC drives can negatively impact power quality through poor power factor, voltage sags during motor starting, and current harmonic distortion. Modern drives use techniques like active front ends and soft starters to mitigate these issues.
2) Current harmonics from non-linear loads like drives can overheat transformers and interfere with other equipment if they exceed recommended IEEE limits. Common harmonic-producing loads and their harmonic profiles are discussed.
3) Various techniques can be used to attenuate harmonics, including passive and active filters, line reactors, isolation transformers, and multi-pulse drive rectifier designs. Higher pulse rectifiers provide better harmonic performance but at increased cost.
In electrical engineering, a synchronous condenser (sometimes synchronous capacitor or synchronous compensator) is a device identical to a synchronous motor, whose shaft is not connected to anything but spins freely.
This document presents an overview of reactive power compensation. It defines reactive power compensation as managing reactive power to improve AC system performance. There are two main aspects: load compensation to increase power factor and voltage regulation, and voltage support to decrease voltage fluctuations. Several methods of reactive power compensation are discussed, including shunt compensation using capacitors and reactors, series compensation, static VAR compensators (SVCs), static compensators (STATCOMs), and synchronous condensers. SVC and STATCOM technologies are compared, with STATCOMs having advantages of smaller components, better control, and transient response.
Reactive power compensation is used to improve the performance of AC power systems. There are various methods of reactive power compensation including shunt compensation, series compensation, static VAR compensators, and static synchronous compensators. Shunt compensation devices such as capacitors and reactors are connected in parallel to transmission lines to regulate voltage. Series compensation uses capacitors connected in series to transmission lines to increase power transfer capability. Static VAR compensators and static synchronous compensators use thyristor-based voltage sourced converters to dynamically inject or absorb reactive power and control voltage. Reactive power compensation provides benefits such as improved power factor, voltage regulation, reduced losses, and increased power transfer capacity.
IRJET- Harmonics Reduction using Harmonics Injection MethodIRJET Journal
This document discusses a current harmonic injection technique to reduce harmonics from induction motor drives used in variable frequency drives (VFDs). VFDs generate harmonics that can cause motor heating, electromagnetic interference, and instrument malfunctions. The technique injects specific harmonics from an inverter circuit into the VFD output to cancel out current harmonics and reduce total harmonic distortion. It uses three bi-directional switches in the injection circuit instead of a traditional zigzag transformer to lower costs and size. Simulation results showed the technique reduced harmonics with a minimal increase in diode power ratings.
Enhancement of Power System Dynamics Using a Novel Series Compensation SchemeIJMER
Phase imbalanced capacitive compensation is a “hybrid” series compensation scheme, where the
series capacitive compensation in one phase is created using a single-phase TCSC in series with a fixed capacitor
(Cc), and the other two phases are compensated by fixed series capacitors (C). The TCSC control is initially set
such that its equivalent compensations at the power frequency combined with the fixed capacitor yield a
resultant compensation equal to the other two phases. Thus, the phase balance is maintained at the power
frequency while at any other frequency, a phase imbalance is created. The effectiveness of the scheme in damping
power system oscillations for various network conditions, namely different system faults and tie-line power flows is
evaluated using the MATLAB/SIMULINK Software
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.
Power Quality Improvement using Passive shunt filters, TCR and TSC combinationIJERA Editor
In this thesis Power Quality Improvement is examined using Passive shunt filter, TCR and TSC combination. Today’s electric power systems are connected to many non-linear loads. The characteristics of these non-linear loads inevitably change the sinusoidal nature of the a.c. power current, resulting in the flow of harmonic current in the a.c. power system. Use of shunt passive filters in the reduction of harmonics offers the advantages of more simplicity, high reliability, high efficiency and low cost. The uncontrolled ac-dc converter suffers from operating problems of poor power factor, injection of harmonics into the ac mains, variations in dc link voltage of input ac supply, equipment overheating due to harmonic current absorption, voltage distortion due to the voltage drop caused by harmonic currents flowing through system impedances etc.The combinations of passive filters with TCR and TSC are designed and analyzed to improve the power quality at ac mains. This scheme has resulted in improved power quality with overall reduced rating of passive components used in front end ac-dc converters with R-L load.
A Shunt Active Power Filter for 12 Pulse Converter Using Source Current Detec...IAES-IJPEDS
A shunt Active Power Filter (APF) with current detection at the source side
is considered as a closed-loop system from the view of the whole power
distribution system, which is expected with better harmonics filtering
performance compared with conventional current detection methods such as
load current detection and open loop control. This paper introduces an
efficient source current detection method (direct) control scheme to mitigate
the grid current harmonics generated by the twelve pulse converter. The
proposed system uses Control Rectifier (12 –pulse converter) which
efficiently regulates the DC voltage by varying the angle of each 6 pulse
converter. Moreover, the proposed system uses three winding transformer
which eliminates the harmonics during equal angles switching at each six
pulse converter which in turn simplifies the operation of the SAPF. The
proposed system is simulated in MATLAB SIMULINK to evaluate the
performance of the proposed system.
In the modern power system the reactive power compensation is one of the main issues, the transmission of active power requires a difference in angular phase between voltages at the sending and receiving points (which is feasible within wide limits), whereas the transmission of reactive power requires a difference in magnitude of these same voltages (which is feasible only within very narrow limits). The reactive power is consumed not only by most of the network elements, but also by most of the consumer loads, so it must be supplied somewhere. If we can't transmit it very easily, then it ought to be generated where it is needed." (Reference Edited by T. J. E. Miller, Forward Page ix).Thus we need to work on the efficient methods by which VAR compensation can be applied easily and we can optimize the modern power system. VAR control technique can provides appropriate placement of compensation devices by which a desirable voltage profile can be achieved and at the same time minimizing the power losses in the system. This report discusses the transmission line requirements for reactive power compensation. In this report thyristor switched capacitor is explained which is a static VAR compensator used for reactive power management in electrical systems.
Seminar Topic For Electrical and Electronics Engineering (EEE)
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
Soft power factor modification using staticchodachude
A good power quality at a system can optimize the efficiency of electrical energy utilization.
Comparison of active power and apparent power will produce a power factor (COS ø).Capacitors bank can
maintain optimum power factor with compensating some reactive power to the system. Static VAR
Compensator (SVC) is generally composed of a conventional capacitor bank in parallel with the load contactor
switch. This leads to a very large inrush current to the capacitor which will resulting damage to the
contactor switches and also capacitors. To reduce inrush current, thyristor is used as a replacement of
contactor switch. Switch can be set by adjusting the firing angle of thyristor. Power factor improvement consists
of a voltage sensor, current sensor, zero crossing detector, thyristor driver and the capacitor bank. The existing
load on the system consists of induction motor 125W, rectifier with load of series of incandescent lamp with
ballasts 85W and fluorescent lamp 20W.Cos phi variation of the load is 0.49 (lag), 0.99 (lag), 0.92 (lag) and 0.62
(lag) when all the loads connect to the system. Through the calculation, the value of capacitor that can
compensate the reactive power to the system is 5.12 µF, 2.71 µF, 2.41 µF and 9.55µF. The capacitor
installation obtain good response because it can increase the cos phi of system to 0.99 (lag) and the current
consumption of the system is smaller than the pre-installation of capacitors, which can reduce the line system
current up to 30% of the system current
Research Inventy : International Journal of Engineering and Scienceresearchinventy
This document summarizes a research paper about simulating a distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC) but eliminates the common DC link. It allows active power exchange between series and shunt converters through the transmission line at the third-harmonic frequency instead of through a DC link. Detailed simulations are conducted on a two-machine system to analyze the DPFC's control capabilities and effects on power transfer and system reliability. The document outlines the DPFC topology, operating principle of active power exchange without a DC link using non-sinusoidal power theory, and use of the third-harmonic frequency for this exchange due to its zero-sequence properties.
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KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
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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.
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.
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Null Bangalore | Pentesters Approach to AWS IAMDivyanshu
#Abstract:
- Learn more about the real-world methods for auditing AWS IAM (Identity and Access Management) as a pentester. So let us proceed with a brief discussion of IAM as well as some typical misconfigurations and their potential exploits in order to reinforce the understanding of IAM security best practices.
- Gain actionable insights into AWS IAM policies and roles, using hands on approach.
#Prerequisites:
- Basic understanding of AWS services and architecture
- Familiarity with cloud security concepts
- Experience using the AWS Management Console or AWS CLI.
- For hands on lab create account on [killercoda.com](https://killercoda.com/cloudsecurity-scenario/)
# Scenario Covered:
- Basics of IAM in AWS
- Implementing IAM Policies with Least Privilege to Manage S3 Bucket
- Objective: Create an S3 bucket with least privilege IAM policy and validate access.
- Steps:
- Create S3 bucket.
- Attach least privilege policy to IAM user.
- Validate access.
- Exploiting IAM PassRole Misconfiguration
-Allows a user to pass a specific IAM role to an AWS service (ec2), typically used for service access delegation. Then exploit PassRole Misconfiguration granting unauthorized access to sensitive resources.
- Objective: Demonstrate how a PassRole misconfiguration can grant unauthorized access.
- Steps:
- Allow user to pass IAM role to EC2.
- Exploit misconfiguration for unauthorized access.
- Access sensitive resources.
- Exploiting IAM AssumeRole Misconfiguration with Overly Permissive Role
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- Allow user to assume the role.
- Perform administrative actions.
- Differentiation between PassRole vs AssumeRole
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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.
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Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
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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
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...
Theory for How to calculation capacitor bank
1. 81
CHAPTER 6
DETUNED CAPACITORS FOR POWER QUALITY
IMPROVEMENT – A CASE STUDY
6.1 INTRODUCTION
Reduction of harmonic contents in loads can be done with existing
load equipment. An overexcited transformer can be brought back into
normal operation by lowering the applied voltage to correct range. PWM
drives that charge the dc bus capacitor directly from the line without any
intentional impedance are exception to this problem. Adding a line reactor
or transformer in series will significantly reduce harmonics as well as
provide transient protection benefits. Phase shifting transformer
connections can benefit loads by significantly reducing the fifth and
seventh harmonics. Delta connected transformers can block the flow of
zero sequence harmonics from the line. Automatic power factor correction
system (APFC) is based on fixed and predefined amount of KVAR. However,
the reactive power consumes current capability of the harmonic filter and
hence it is not main priority of APFC.
This chapter presents a practical example of improving the
power factor of the system by an appropriate design of detuned capacitor
filters. The advantage of using detuned capacitors as harmonic filters over
the use of plain capacitors for power factor correction is presented. The
different problems originated by harmonics and how filters prevent them
are reviewed, and a comparison between them is also presented.
2. 82
6.2 NEED FOR DETUNING CAPACITORS
Non-linear loads in industry typically contain a high fifth harmonic.
At the fifth harmonic, the tuned filter has a better behavior than the detuned
filter. However, for proper operation, the capacitor bank must be rated to a
higher voltage than the voltage level required for detuned filters. Because
tuned filters absorb more harmonics, they also carry higher harmonic currents
than the detuned filters. These features make tuned filters more expensive as
mentioned by Francisco Ferrandis et al (2003).
Tuned as well as detuned filters either absorb or reject harmonic
distortion and avoid harmonic currents to flow to other equipment or the rest
of the power system. A tuned filter is tuned to a frequency slightly below the
filtered harmonic. On the other hand, a detuned filter is tuned to a frequency
far below the filtered harmonic.
6.3 EFFECTS OF DETUNING CAPACITORS
Bridgeman et al (1998) and Gagaoudakis et al (1998) installed plain
capacitors on a system with a high level of harmonics, it needs to be replaced
with those capacitors to detuned capacitor bank (capacitors and reactors). The
first effect of the reactors is to suppress the risk of resonance with the
harmonics generated by the loads and in turn to protect the capacitors. If
suppressing is not done, the resonance would lead to an over sizing of active
filter connected in the circuit.
Secondly, although the detuned bank is not a passive filter, it will
have some filtering effect and harmonic distortion will be lower than if no
capacitor was installed.
3. 83
Calculating the minimum RMS current of the active filter to install
Irms (A) = 0.013(THDi initial – THDi targeted) I1 (6.1)
Based on the appropriate voltage and frequency, active filter with
the RMS current directly superior to the minimum Irms can be used.
Besides the filtering functionality, reactive power compensation is
also possible with the active filter. Compared to traditional capacitor banks,
the reactive compensation of the power quality filter is continuous, fast and
smooth (no transients at switching). The compensation can be either
capacitive or inductive, depending on the load type.
6.4 METHODS OF MODIFYING SYSTEM FREQUENCY
RESPONSE
There are number of methods to modify adverse system
responses to harmonics in Dugan et al (2003).
- Add a shunt filter. This shunt filter eliminates a
troublesome harmonic current off the system, but it
completely changes the system response.
- Add a reactor to detune the system. Harmful resonances
generally occur between the system inductance and shunt
power factor correction capacitors. One method is to add a
reactor in series with a capacitor to move the system
resonance without actually tuning the capacitor to create a
filter. Other way is to add reactance in the line.
- Changing the capacitor size is one of least expensive
options for both utilities and industrial consumers.
4. 84
- Move a capacitor to a point on the system with different
short circuit impedance or higher losses. New bank causes
telephone interference for utilities, there by moving the
bank to another branch of the feeder may very well resolve
the problem. This is not an option for many of industrial
users because the capacitor cannot be moved far enough to
make a difference.
- Remove the capacitor and simply accept the higher losses,
lower voltage, and power factor penalty. If technically
feasible, this is occasionally the best economic choice.
6.5 DESIGN OF DETUNED CAPACITORS FOR PQ
IMPROVEMENT
The procedure used to convert an existing power factor correction
capacitor into a harmonic filter is shown in Figure 6.1. It is being utilized
for designing suitable detuned capacitor. Power factor correction capacitors
may produce harmonic resonance and magnify utility capacitor switching
transients. Therefore it is desirable to implement one or more capacitor
banks in a facility as a harmonic filter. System parameters are described as
single tuned notch filter connected to 480 V bus. The load is about
1200 KVA, power factor is 0.75 lagging. Current produced by load is of 30%
harmonics in the fundamental current. Maximum harmonics are 25% of fifth
harmonic current. It is supplied through transformer 1500 KVA with 6%
impedance.
5. 85
Figure 6.1 Design procedure of detuned capacitors for PQ improvement
6.6 SIMULATION RESULTS
This section presents the results of installing detuned filters in an
industrial plant with a significant amount of non-linear loads. For studying the
effect of capacitor on harmonic resonance, various sizes of capacitor with
varied load condition are simulated by MATLAB software.
6. 86
The source voltage, current at the PCC and the current at load bus
are analyzed using waveforms. The harmonic distortion in the voltage and
current waveforms are compared for the cases of compensation. From the
figure, the cases to be considered are:
Case 1: With fixed capacitor compensation
The magnitude of harmonic currents in an individual non-linear
load depends greatly on the total effective input reactance, which is comprised
of the source reactance plus added line reactance. In the case of non-linear
load, we can predict the resultant input current harmonic spectrum based on
the input reactance. The value of source reactance and its harmonic content
are inversely proportional. The voltage and current harmonic waveforms with
fixed capacitor compensation are presented.
Figure 6.2 Voltage and current waveforms with fixed capacitor
compensation
Time in seconds
Voltage
(V),
Current
(A)
waveforms
of
source,
bus
1
and
bus
2
7. 87
Figure 6.3 THD of current at PCC (With fixed capacitor compensation)
Case 2: Compensation with detuned capacitor
To avoid these resonances, a reactor is connected in series with the
capacitor, in such a manner that the fundamental reactive power is
compensated but the harmonics are not amplified.
Figure 6.4 Voltage and current waveforms with detuned capacitor
compensation
Time in seconds
Voltage
(V),
Current
(A)
waveforms
of
source,
bus
1
and
bus
2
8. 88
The fifth order voltage and current harmonics are 4.1% and 33.3%.
The detuned capacitor bank of 75 KVAR, 525 V with 7% reactor tuned for 5th
order which has given output of 53.76 KVAR @ 415 V.
Figure 6.5 THD of current at PCC (With detuned capacitor compensation)
Table 6.1 Comparison of total harmonic distortions in different
compensation
Total harmonic distortion (THD) in %
Without
capacitor
With fixed
capacitor
Detuned
capacitor
Source voltage 17.05 15.63 1.54
Current at PCC 31.82 12.64 8.91
Current at load bus 33.82 10.15 8.96
9. 89
6.7 EXPERIMENTAL RESULTS – INDUSTRIAL CASE STUDY
This section presents the results of installing detuned filters in an
industrial plant with a significant amount of non-linear loads. The detuned
capacitor filters installed in Adwaith Textiles Private Limited at Coimbatore,
India. The filters where connected on the point of common coupling (PCC).
The capacity of plant is 1750 KVA / 1100 KW. There are three transformers
with the capacity of 750 KVA, 1000 KVA and 1600 KVA supplying energy
to linear and nonlinear loads.
It is connected with 2 nos. of 25 KVAR fixed capacitors. By replacing the
fixed capacitors by detuned capacitor bank of 75 KVAR, 525 V with 7 %
reactors, the reactors will give an output of 50 KVAR @ 415 V. Hence there
will be a definite reduction in the KW, since the harmonic currents are
reduced and the compensation will be adequate.
Parameters of industrial plant are listed below.
Capacity of the industry : 24,000 spindles.
Transformer capacity : 1) 1000 KVA with impedance : 5.49%
2) 750 KVA with impedance : 4.90%
3) 1600 KVA with impedance : 5.99%
Total sanctioned demand load : 1750 KVA / 1100 KW
Total utilized load 60% @ 40%
power cut : 1064.2 KVA
Average power factor : 0.75
Type of loading : Balanced Load
Total installed load of machines : 3265 KW
Normal loads : 2000 KW
Non linear loads (with drives) : 525 KW
Unutilized loads : 740 KW
10. 90
Non linear loads are listed below.
Ring spinning frames : 20 Nos.
Auto-coner frames : 06 Nos.
Carding machines : 23 Nos. (with drives)
Simplex frames : 08 Nos.
Linear loads are listed below.
Draw frames : 04 Nos. (without drives)
Comber frames : 15 Nos.
Compressor : 03 Nos.
Blow room machines : 01 No. (without drives)
Humidification plant : 01 No.
HT Panel meter readings
Voltage harmonics THD %
R – Phase = 6 % , Y – Phase = 6 % , B – Phase = 5 %
Current harmonics THD %
R – Phase = 14 %, Y – Phase = 14 % , B – Phase = 13 %
At transformer no : 1
1000 kVA at secondary side of the meter at the main PCC Panel.
Current harmonics :
PHASE 3rd
[Peak] 5th
[Peak] 7 th
[Peak]
R 18.8 18.8 18.7
Y 17.6 17.3 17.4
B 21.3 21.4 17.2
11. 91
Voltage harmonics :
PHASE 3rd
[Peak] 5th
[Peak] 7th
[Peak]
R—Y 3.1 @ 6.2 V 3.2 @ 12 V 3.2 @ 4.6 V
Y—B 3.1 @ 1.1 V 3.0 @ 11.4 V 3.1 @ 5.6 V
B—R 3.2 @ 0.8 V 3.3 @ 12.5 V 3.3 @ 5.5 V
Comments : Heavy duty capacitors would be fine. 525 V to be suitably
derated.
Fixed Capacitor Bank + 7 % Reactor connected in series can be erected at the
power house itself.
At transformer no : 2
750 kVA reading could not be taken because of No Load.
At transformer no : 3
1600 kVA at secondary side of the meter at the main PCC Panel.
Current harmonics :
PHASE 3rd
[Peak] 5th
[ Peak ] 7 th [ Peak ]
R 9.8 10.0 10.4
Y 9.7 10.4 10.9
B 10.3 10.4 10.4
Voltage harmonics :
PHASE 3rd
[Peak] 5th
[Peak] 7th
[Peak]
R—Y 2.4 @ 0.6 V 2.3 @ 8.9 V 2.5 @ 4.0 V
Y—B 2.4 @ 0.8 V 2.4 @ 9.4 V 2.3 @ 3.6 V
B—R 2.4 @ 0.7 V 2.5 @ 9.4 V 2.4 @ 3.4 V
12. 92
It is connected with 2 nos. of 25 KVAR fixed capacitors. By
replacing the fixed capacitors by detuned capacitor bank of 75 KVAR, 525 V
with 7 % reactors, the reactors will give an output of 50 KVAR @ 415 V.
Hence there will be a definite reduction in the KW, since the harmonic
currents are reduced and the compensation will be adequate.
Based on the industrial load, the measurements in installing the
filters before and after compensation are presented together with waveforms.
The comparison is made in Table 6.2.
Figure 6.6 THD of three phase voltage waveform
Figure 6.7 Spectrum of 5th
order voltage harmonics values
Equivalent line voltage in volts
Harmonic order
13. 93
Figure 6.8 Spectrum of 5th
order current harmonics values
Figure 6.9 voltage and current waveforms after detuned compensation
Figure 6.10 Harmonic spectrum after detuned compensation
Time in seconds
Harmonic order
Harmonic order
14. 94
Power factor is calculated based on the capacitor rating with respect
to reactive power multiplier factors. The power factor before and after
compensation was 0.75 and 0.99. The voltage THD satisfies IEEE limit and
the appropriate reduction in current THD from 57.5 to 48.8. With effect of
detuning capacitors, there is a significant reduction in power consumed about
20.16%.
6.7.1 Comparison of Results
Table 6.2 Industrial system parameters of fixed and detuned capacitors
System parameters
With detuned
capacitor bank [off]
With detuned
capacitor bank [on]
Total RMS current demand 177 Amps 142 Amps
Average kW required 94.5 kW 94.5 kW
Average kVA required 126 kVA 101 kVA
Average power factor 0.75 0.93
5th
order voltage harmonics 10.5 4.27
5th
order current harmonics 53.2 40.1
Voltage THD 18.2 4.7
Current THD 57.5 48.8
Table 6.3 Reduction in industrial system parameters
Reduction in system parameters
35 amps 19.77%
25 kVA 19.84%
By implementing the detuned capacitor banks in the above system,
there is a reduction in average current consumption from 172 A to 142 A.
Similarly the average kVA required is reduced from 126 kVA to 101 kVA.
15. 95
The reduction in system parameters shows potential improvement in terms of
efficiency as well as economical savings.
6.8 CONCLUSION
This chapter presented an industrial case study. The plant is having
a significant number of non linear loads. The installation of detuned filters
under harmonic conditions shows improvement in power factor. It establishes
a practical and economical way to recover p.f. It is found that the voltage
THD satisfies IEEE limit but the current THD reduces from 57.5 to 48.8.
With effect of detuning capacitors, there is a significant reduction in kVA
required about 19.84%. The power factor was increased from 75% to 99%
after installing detuned filters. The individual THD increases as TDD
decreases. The overall conclusion is that detuned filter ensures less power
requirement, but the effect in harmonic reduction is not so significant.