International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
A Simplified Design and Modeling of Boost Converter for Photovoltaic Sytem IJECEIAES
The Photovoltaic standalone system is gaining its high importance mostly for rural application like pv water pumping, solar lighting, battery charging etc.Considering environmental effects and scarcity of fossil fuel the trend has developed towards the use of more and more renewable energy.In this paper a basic circuit of boost converter is designed in MATLAB/Simulink with constant dc source voltage. However a comparative study has also been done for the converter connected with pv system directly with the converter connected with mppt tracking technique. Perturb and Observance (P&O) algorithm is implemented for providing the necessary duty pulse and makes the system operate at maximum power point.The boost converter connected with PV system without mppt operates at any other point other then the maximum power point and hence the output voltage decreases.But with mppt the proposed system performs better.
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.
Emc model for modern power electronic systems for harmonics, losses & emi...eSAT Journals
Abstract
Electromagnetic compatibility of power electronic systems becomes an engineering discipline and it should be considered at the
beginning stage of a design. Thus, a power electronics design becomes more complex and challenging and it requires a good
communication between EMI and Power electronics experts. Three major issues in designing a power electronic system are Losses,
EMI and Harmonics. These issues affect system cost, size, efficiency and quality and it is a tradeoff between these factors when we
design a power converter, filter. In this paper the EMC model is discussed which should be considered while designing the power
electronics systems. The design considerations in this paper help us to remove losses, harmonics & EMI elimination and power
quality improvement of Power systems.
Index Terms: Converter, EMI, EMC, Filter, Harmonics
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
A Simplified Design and Modeling of Boost Converter for Photovoltaic Sytem IJECEIAES
The Photovoltaic standalone system is gaining its high importance mostly for rural application like pv water pumping, solar lighting, battery charging etc.Considering environmental effects and scarcity of fossil fuel the trend has developed towards the use of more and more renewable energy.In this paper a basic circuit of boost converter is designed in MATLAB/Simulink with constant dc source voltage. However a comparative study has also been done for the converter connected with pv system directly with the converter connected with mppt tracking technique. Perturb and Observance (P&O) algorithm is implemented for providing the necessary duty pulse and makes the system operate at maximum power point.The boost converter connected with PV system without mppt operates at any other point other then the maximum power point and hence the output voltage decreases.But with mppt the proposed system performs better.
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.
Emc model for modern power electronic systems for harmonics, losses & emi...eSAT Journals
Abstract
Electromagnetic compatibility of power electronic systems becomes an engineering discipline and it should be considered at the
beginning stage of a design. Thus, a power electronics design becomes more complex and challenging and it requires a good
communication between EMI and Power electronics experts. Three major issues in designing a power electronic system are Losses,
EMI and Harmonics. These issues affect system cost, size, efficiency and quality and it is a tradeoff between these factors when we
design a power converter, filter. In this paper the EMC model is discussed which should be considered while designing the power
electronics systems. The design considerations in this paper help us to remove losses, harmonics & EMI elimination and power
quality improvement of Power systems.
Index Terms: Converter, EMI, EMC, Filter, Harmonics
Influencing Power Flow and Transient Stability by Static Synchronous Series C...ijeei-iaes
In the present world, modern power system networks, being a complicated combination of generators, transmission lines, transformers, circuit breakers and other devices, are more vulnerable to various types of faults causing stability problems. Among these faults, transient fault is believed to be a major disturbance as it causes large damage to a sound system within a certain period of time. Therefore, the protection against transient faults, better known as transient stability control is one of the major considerations for the power system engineers. This paper presents the control approach in the transmission line during transient faults by means of Static Synchronous Series Compensator (SSSC) in order to stabilize Single Machine Infinite Bus (SMIB) system. In this paper, SSSC is represented by variable voltage injection associated with the transformer leakage reactance and the voltage source. The comparative results depict that the swing curve of a system increases monotonically after the occurrence of transient faults However, SSSC is effective enough to make it stable after a while.
10 17sep 8310 10079-1-ed pulse density (edit ari)IAESIJEECS
Switched mode power supply (SMPS) converter is a dc-dc power electronic converter which is used to step up or step down the dc output voltage. A dimmable driver circuit for Light Emitting Diode (LED) lamp for automotive lighting with dimming feature is used in this paper. A flyback converter is used as a driver circuit operated in discontinuous conduction mode to perform dimming control of LEDs. High overall circuit efficiency is achieved by regulating the current through the LED lamps using pulse density modulation scheme. The LED driver circuit design and operating principle is discussed in detail. A gentle current control feature is achieved by pulse density modulation technique. The high performance driver circuit is designed for 25 W LED lamps.
A Novel Compensating Technique for Power Factor Improvement in Power Electron...IDES Editor
Power electronics systems are non-linear systems,
which consume more reactive power and also the loads they
feed are mostly inductive loads which leads to a poor power
factor. Various compensation techniques are available to bring
the power factor nearer to unity. In this paper, a novel
compensator is proposed, where in-phase and quadrature
components of the supply current are vector-controlled.
Implementation of this compensator in a power electronic
system operating with a very poor power factor (and hence
high THD), shows that the system then draws a leading
current. A conventional power electronic system, A
conventional power electronic system with one of the
traditional static VAR compensators and the conventional
power electronic system incorporated with the proposed
compensator are simulated and the simulation results are
obtained. It is shown that the proposed method offers only
0.7% THD, which also implies that the power factor is
improved.
The aim of this paper is illustrating and exposing the performance of a Series Active Power Filter (SAPF) with PI controller and Fuzzy controller within simulation and experimental validations. This performance is best manifested in compensating the sags and the swells voltages and in eliminating the harmonic voltage and regulate the terminal voltage of the load by injecting a voltage component in series with source voltage which is increased or decreased from the source voltage, hence, maintaining the load side waveforms as pure sinusoidal. The control method used in this work is not so complex and it is based on a phase locked loop (PLL) that is used to control the active filter. It is valid only in the phase system. The efficiency of the method I suggested is affirmed through simulation results by MATLAB\Simulink® and some prototypes experiments. These results shows the capability of the proposed prototypes.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Transistor mismatch effect on common-mode gain of cross-coupled amplifierTELKOMNIKA JOURNAL
In this paper, the analytical approach of MOS transistor mismatch effect on common-mode gain
of cross-coupled amplifier is presented. Transconductance (MOS transistor parameter) mismatch effect on
common-mode gain of cross-coupled amplifier was analyzed. This study was started with mathematical
derivation for representing the mismatch effect of transconductance between 2 differential pairs of crosscoupled
amplifier due to common-mode voltage. The derivation result was simulated based on Monte
Carlo simulation with random transconductance mismatch rate from 0.05% until 1%. The common-mode
gain increases 36.9 dB and average common-mode gain is -81.1 dB. The transconductance mismatch rate
increases followed by increase in common-mode gain. The results can be used by circuit designers to
design analog circuits, especially operational amplifier used for biosignals processing to minimize the
common-mode gain of their circuits. This research presents aid to circuit designers to improve their circuits
performance.
Analysis of a Quasi Resonant Switch Mode Power Supply for Low Voltage Applica...IDES Editor
QRC provides efficient and regulated switch mode
power supplies for robotic and satellite applications. This paper
addresses the enhanced controller techniques for high
frequency isolation based push-pull Quasi Resonant
Converter. This technique is similar to the conventional PI
controller technique but varies only the enhancement
constants to improve the time domain response of the
converter. The proposed converter is designed for low output
voltage and power rating, characteristically 5V and 5 W, with
the comprehension of current design trends towards enhanced
performance. At the primary stage, to validate the design of
the converter, simulation is performed in PSIM for ±50% load
variations. A prototype model of this converter is developed.
The results obtained from the experimental set-up are
presented and analysed in detail. The results reveal the
superiority of the proposed method.
Optimal coordinated design of PSS and UPFC-POD using DEO algorithm to enhance...IJECEIAES
Low-frequency oscillations (LFO) are an inevitable problem of power systems and they have a great effect on the capability of transfer and power system stability. The power system stabilizers (PSSs) as well as flexible AC transmission system (FACTS) devices can help to damp LFO. The target of this study is to tackle the problem of a dual-coordinated design between PSS and unified power flow controller (UPFC) implementing the task of power oscillation damping (POD) controller in a single machine infinite bus (SMIB) system. So, dolphin echolocation optimization (DEO) technique is utilized as an optimization tool to search for optimal parameter tunings based on objective function for enhancing the dynamic stability performance for a SMIB. DEO an algorithm has a few parameters, simple rules, provides the optimum result and is applicable to a wide range of problems like other meta-heuristic algorithms. Use DEO gave the best results in damping LFO compared to particle swarm optimization (PSO) algorithm. From the comparison results between PSO and DEO, it was shown that DEO provides faster settling time, less overshoot, higher damping oscillations and greatly improves system stability. Also, the comparison results prove that the multiple stabilizers show supremacy over independent controllers in mitigationg LFO of a SMIB.
Control of inverters to support bidirectional power flow in grid connected sy...eSAT 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.
This paper presents a grid-connected photovoltaic (PV) interface for delivering both active and reactive powers. The PV interface employs H-bridge topology DC-DC converter and inverter with analog control technology. The power flow is controlled solely by the adjustable DC output voltage of the DC to DC converter. In order to evaluate the PV interface system’s performances, it is tested by delivering power to the grid with low pawer factor. The experimental results show that at 300W active load, the inverter could deliver the reactive power of 400VAR. The PV interface could also produce very low harmonic voltage and current distorsions. The laboratory measurements show that the total harmonic distortions of inverter output voltage and current are 0.46% and 0.05%, respectively.
Dynamic Power Factor Correction in a Non Linear Environmentiosrjce
Electric power quality mainly refers to maintaining a near sinusoidal power distribution bus voltage
at rated magnitude and frequency. In modern electric power supply distribution systems, there is a sharp rise in
use of both single phase and three-phase non-linear loads and due to these non-linear loads, non-sinusoidal
unbalanced current is drawn from ac mains resulting in harmonic injection, burden of reactive power, more
neutral currents and unbalanced loading of ac mains. In this paper the simulation of ideal shunt active power
filter is carried out to eliminate harmonics and also improving the power factor for three-phase, three-wire
system. In addition to this, simulation of shunt APF for three-phase, three-wire distribution system using time
domain p-q theory has been carried out to eliminate harmonics. Also an attempt is made to find out various
power quality problems and among these problems most prominent and frequently occurring problem
harmonics is analyzed and its causes, effects and mitigating or improving techniques are explained in detail. A
case study using ideal shunt AF and Shunt AF using p-q theory is also carried out in this paper.
Harmonic analysis and Power factor improvement with UPQC under two Novel cont...IJERA Editor
This paper presents unified power quality conditioner (UPQC)for power quality improvements in terms of
harmonics compensation and power factor correction in a three-phase four-wire distribution system.The UPQC
is implemented with PWM controlled voltage source converter (VSC) and switching patterns are generated
through Indirect PI and Synchronous Reference Frame controller. The selected topology for voltage source
converter is the three-leg and six-leg VSC for Indirect PI and Synchronous reference frame (SRF) control
strategies respectively. The behavior of UPQC has been analyzed by considering a case study with switching of
three phase half bridge diode rectifier and a parallel star connected unbalanced R-L loads. Harmonic spectrum
of the source current and load voltage are compared in between without UPQC and with UPQC by considering
both control strategies. The complete system has been modeled using MATLAB software with its stimulus’s
sim power system toolboxes.
Simulation and Comparison of DVR and DSTATCOM Used for voltage sag mitigation...paperpublications3
Abstract: Power Quality problem in a system leads to various disturbances such as voltage fluctuations, transients and waveform distortions that results in a mis-operation or a failure of end user equipment. There are different types of custom power devices like Distribution Static Compensator (D-STATCOM) and Dynamic Voltage Restorer (DVR) which can effectively use for mitigation of different type of power quality problems. This paper describes the technique of correcting the supply voltage sag distributed system and also describes performance comparison are presented between DVR and DSTATCOM to know how both the devices successfully been applied to power system for regulating system voltage effectively. DSTATCOM and DVR both of them based on VSI principle. A DVR is a series compensation device which injects a voltage in series with system and a DSTATCOM is a shunt compensation device which injects a current into the system to correct the power quality problems. This paper presents a power system operation with PI controller with abc to dq0 convertor approach. Total Harmonics Distortion (THD) is also calculated for the system with and without compensation. Results are presented to assess the performance of devices as a potential custom power solution. Improve dynamic voltage control and thus increase system load ability. This paper presents modeling and simulation of DVR & DSTATCOM in MATLAB/Simulink.
Improving Stability of Utility-Tied Wind Generators using Dynamic Voltage Res...IJMTST Journal
The generation of electricity using wind power is significantly increasing and has received considerable attention in recent years. One important problem with the induction generator based wind farms is that they are vulnerable to voltage disturbances and short circuit faults. Any such disturbance may cause wind farm outages. Since wind power contribution is in considerable percentage, such outages may lead to power system stability issues and also violate the grid code requirements. Thus, improving the reliability of wind farms is essential to maintain the stability of the system. The proposed strategy is to use Dynamic Voltage Restorer (DVR), which is one of the promising devices to compensate the voltage disturbance and to improve the stability of the system. It provides the wind generator with the fault ride through capability and improves the reliability of the system. Fuzzy Logic controller is used as a controller in order to control the dc link voltages and to reduce the harmonics. Simulation results for a 2 MW wind turbine are presented, especially for asymmetrical grid faults. They show the effectiveness of the DVR in comparison to the low voltage ride-through of the DFIG using a crowbar that does not allow continuous reactive power production. Extensive simulation results are included to illustrate the operation of DVR and fault compensation.
Dynamic voltage restorer (DVR) is a device that can compensate harmonic, voltage sag and voltage swell condition that exists in a three-phase system. Other than that, DVR can also be used to enhance the energy efficiency or energy saving by reducing excessive amount of incoming power via the reduction incoming voltage at allowable limit. The DVR can inject the required voltage in the system so that the interruption of supply voltage can be compensated. The compensation of voltage supply interruption is improved based on the hysteresis voltage output of controller used in the DVR to detect the difference between reference voltage and disrupted voltage. The hysteresis voltage control mainly controlled by relays switching so that the signal can be sent to IGBT switches controller. The hysteresis voltage control and unipolar SPWM is supplied to control the IGBT switches by the DC supply for voltage interruption compensation. The unipolar SPWM technique converts the DC supply voltage into AC supplied voltage, thus making the DVR injection become easier to inject the AC voltage into the system to compensate voltage sag and voltage swell.
Influencing Power Flow and Transient Stability by Static Synchronous Series C...ijeei-iaes
In the present world, modern power system networks, being a complicated combination of generators, transmission lines, transformers, circuit breakers and other devices, are more vulnerable to various types of faults causing stability problems. Among these faults, transient fault is believed to be a major disturbance as it causes large damage to a sound system within a certain period of time. Therefore, the protection against transient faults, better known as transient stability control is one of the major considerations for the power system engineers. This paper presents the control approach in the transmission line during transient faults by means of Static Synchronous Series Compensator (SSSC) in order to stabilize Single Machine Infinite Bus (SMIB) system. In this paper, SSSC is represented by variable voltage injection associated with the transformer leakage reactance and the voltage source. The comparative results depict that the swing curve of a system increases monotonically after the occurrence of transient faults However, SSSC is effective enough to make it stable after a while.
10 17sep 8310 10079-1-ed pulse density (edit ari)IAESIJEECS
Switched mode power supply (SMPS) converter is a dc-dc power electronic converter which is used to step up or step down the dc output voltage. A dimmable driver circuit for Light Emitting Diode (LED) lamp for automotive lighting with dimming feature is used in this paper. A flyback converter is used as a driver circuit operated in discontinuous conduction mode to perform dimming control of LEDs. High overall circuit efficiency is achieved by regulating the current through the LED lamps using pulse density modulation scheme. The LED driver circuit design and operating principle is discussed in detail. A gentle current control feature is achieved by pulse density modulation technique. The high performance driver circuit is designed for 25 W LED lamps.
A Novel Compensating Technique for Power Factor Improvement in Power Electron...IDES Editor
Power electronics systems are non-linear systems,
which consume more reactive power and also the loads they
feed are mostly inductive loads which leads to a poor power
factor. Various compensation techniques are available to bring
the power factor nearer to unity. In this paper, a novel
compensator is proposed, where in-phase and quadrature
components of the supply current are vector-controlled.
Implementation of this compensator in a power electronic
system operating with a very poor power factor (and hence
high THD), shows that the system then draws a leading
current. A conventional power electronic system, A
conventional power electronic system with one of the
traditional static VAR compensators and the conventional
power electronic system incorporated with the proposed
compensator are simulated and the simulation results are
obtained. It is shown that the proposed method offers only
0.7% THD, which also implies that the power factor is
improved.
The aim of this paper is illustrating and exposing the performance of a Series Active Power Filter (SAPF) with PI controller and Fuzzy controller within simulation and experimental validations. This performance is best manifested in compensating the sags and the swells voltages and in eliminating the harmonic voltage and regulate the terminal voltage of the load by injecting a voltage component in series with source voltage which is increased or decreased from the source voltage, hence, maintaining the load side waveforms as pure sinusoidal. The control method used in this work is not so complex and it is based on a phase locked loop (PLL) that is used to control the active filter. It is valid only in the phase system. The efficiency of the method I suggested is affirmed through simulation results by MATLAB\Simulink® and some prototypes experiments. These results shows the capability of the proposed prototypes.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Transistor mismatch effect on common-mode gain of cross-coupled amplifierTELKOMNIKA JOURNAL
In this paper, the analytical approach of MOS transistor mismatch effect on common-mode gain
of cross-coupled amplifier is presented. Transconductance (MOS transistor parameter) mismatch effect on
common-mode gain of cross-coupled amplifier was analyzed. This study was started with mathematical
derivation for representing the mismatch effect of transconductance between 2 differential pairs of crosscoupled
amplifier due to common-mode voltage. The derivation result was simulated based on Monte
Carlo simulation with random transconductance mismatch rate from 0.05% until 1%. The common-mode
gain increases 36.9 dB and average common-mode gain is -81.1 dB. The transconductance mismatch rate
increases followed by increase in common-mode gain. The results can be used by circuit designers to
design analog circuits, especially operational amplifier used for biosignals processing to minimize the
common-mode gain of their circuits. This research presents aid to circuit designers to improve their circuits
performance.
Analysis of a Quasi Resonant Switch Mode Power Supply for Low Voltage Applica...IDES Editor
QRC provides efficient and regulated switch mode
power supplies for robotic and satellite applications. This paper
addresses the enhanced controller techniques for high
frequency isolation based push-pull Quasi Resonant
Converter. This technique is similar to the conventional PI
controller technique but varies only the enhancement
constants to improve the time domain response of the
converter. The proposed converter is designed for low output
voltage and power rating, characteristically 5V and 5 W, with
the comprehension of current design trends towards enhanced
performance. At the primary stage, to validate the design of
the converter, simulation is performed in PSIM for ±50% load
variations. A prototype model of this converter is developed.
The results obtained from the experimental set-up are
presented and analysed in detail. The results reveal the
superiority of the proposed method.
Optimal coordinated design of PSS and UPFC-POD using DEO algorithm to enhance...IJECEIAES
Low-frequency oscillations (LFO) are an inevitable problem of power systems and they have a great effect on the capability of transfer and power system stability. The power system stabilizers (PSSs) as well as flexible AC transmission system (FACTS) devices can help to damp LFO. The target of this study is to tackle the problem of a dual-coordinated design between PSS and unified power flow controller (UPFC) implementing the task of power oscillation damping (POD) controller in a single machine infinite bus (SMIB) system. So, dolphin echolocation optimization (DEO) technique is utilized as an optimization tool to search for optimal parameter tunings based on objective function for enhancing the dynamic stability performance for a SMIB. DEO an algorithm has a few parameters, simple rules, provides the optimum result and is applicable to a wide range of problems like other meta-heuristic algorithms. Use DEO gave the best results in damping LFO compared to particle swarm optimization (PSO) algorithm. From the comparison results between PSO and DEO, it was shown that DEO provides faster settling time, less overshoot, higher damping oscillations and greatly improves system stability. Also, the comparison results prove that the multiple stabilizers show supremacy over independent controllers in mitigationg LFO of a SMIB.
Control of inverters to support bidirectional power flow in grid connected sy...eSAT 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.
This paper presents a grid-connected photovoltaic (PV) interface for delivering both active and reactive powers. The PV interface employs H-bridge topology DC-DC converter and inverter with analog control technology. The power flow is controlled solely by the adjustable DC output voltage of the DC to DC converter. In order to evaluate the PV interface system’s performances, it is tested by delivering power to the grid with low pawer factor. The experimental results show that at 300W active load, the inverter could deliver the reactive power of 400VAR. The PV interface could also produce very low harmonic voltage and current distorsions. The laboratory measurements show that the total harmonic distortions of inverter output voltage and current are 0.46% and 0.05%, respectively.
Dynamic Power Factor Correction in a Non Linear Environmentiosrjce
Electric power quality mainly refers to maintaining a near sinusoidal power distribution bus voltage
at rated magnitude and frequency. In modern electric power supply distribution systems, there is a sharp rise in
use of both single phase and three-phase non-linear loads and due to these non-linear loads, non-sinusoidal
unbalanced current is drawn from ac mains resulting in harmonic injection, burden of reactive power, more
neutral currents and unbalanced loading of ac mains. In this paper the simulation of ideal shunt active power
filter is carried out to eliminate harmonics and also improving the power factor for three-phase, three-wire
system. In addition to this, simulation of shunt APF for three-phase, three-wire distribution system using time
domain p-q theory has been carried out to eliminate harmonics. Also an attempt is made to find out various
power quality problems and among these problems most prominent and frequently occurring problem
harmonics is analyzed and its causes, effects and mitigating or improving techniques are explained in detail. A
case study using ideal shunt AF and Shunt AF using p-q theory is also carried out in this paper.
Harmonic analysis and Power factor improvement with UPQC under two Novel cont...IJERA Editor
This paper presents unified power quality conditioner (UPQC)for power quality improvements in terms of
harmonics compensation and power factor correction in a three-phase four-wire distribution system.The UPQC
is implemented with PWM controlled voltage source converter (VSC) and switching patterns are generated
through Indirect PI and Synchronous Reference Frame controller. The selected topology for voltage source
converter is the three-leg and six-leg VSC for Indirect PI and Synchronous reference frame (SRF) control
strategies respectively. The behavior of UPQC has been analyzed by considering a case study with switching of
three phase half bridge diode rectifier and a parallel star connected unbalanced R-L loads. Harmonic spectrum
of the source current and load voltage are compared in between without UPQC and with UPQC by considering
both control strategies. The complete system has been modeled using MATLAB software with its stimulus’s
sim power system toolboxes.
Simulation and Comparison of DVR and DSTATCOM Used for voltage sag mitigation...paperpublications3
Abstract: Power Quality problem in a system leads to various disturbances such as voltage fluctuations, transients and waveform distortions that results in a mis-operation or a failure of end user equipment. There are different types of custom power devices like Distribution Static Compensator (D-STATCOM) and Dynamic Voltage Restorer (DVR) which can effectively use for mitigation of different type of power quality problems. This paper describes the technique of correcting the supply voltage sag distributed system and also describes performance comparison are presented between DVR and DSTATCOM to know how both the devices successfully been applied to power system for regulating system voltage effectively. DSTATCOM and DVR both of them based on VSI principle. A DVR is a series compensation device which injects a voltage in series with system and a DSTATCOM is a shunt compensation device which injects a current into the system to correct the power quality problems. This paper presents a power system operation with PI controller with abc to dq0 convertor approach. Total Harmonics Distortion (THD) is also calculated for the system with and without compensation. Results are presented to assess the performance of devices as a potential custom power solution. Improve dynamic voltage control and thus increase system load ability. This paper presents modeling and simulation of DVR & DSTATCOM in MATLAB/Simulink.
Improving Stability of Utility-Tied Wind Generators using Dynamic Voltage Res...IJMTST Journal
The generation of electricity using wind power is significantly increasing and has received considerable attention in recent years. One important problem with the induction generator based wind farms is that they are vulnerable to voltage disturbances and short circuit faults. Any such disturbance may cause wind farm outages. Since wind power contribution is in considerable percentage, such outages may lead to power system stability issues and also violate the grid code requirements. Thus, improving the reliability of wind farms is essential to maintain the stability of the system. The proposed strategy is to use Dynamic Voltage Restorer (DVR), which is one of the promising devices to compensate the voltage disturbance and to improve the stability of the system. It provides the wind generator with the fault ride through capability and improves the reliability of the system. Fuzzy Logic controller is used as a controller in order to control the dc link voltages and to reduce the harmonics. Simulation results for a 2 MW wind turbine are presented, especially for asymmetrical grid faults. They show the effectiveness of the DVR in comparison to the low voltage ride-through of the DFIG using a crowbar that does not allow continuous reactive power production. Extensive simulation results are included to illustrate the operation of DVR and fault compensation.
Dynamic voltage restorer (DVR) is a device that can compensate harmonic, voltage sag and voltage swell condition that exists in a three-phase system. Other than that, DVR can also be used to enhance the energy efficiency or energy saving by reducing excessive amount of incoming power via the reduction incoming voltage at allowable limit. The DVR can inject the required voltage in the system so that the interruption of supply voltage can be compensated. The compensation of voltage supply interruption is improved based on the hysteresis voltage output of controller used in the DVR to detect the difference between reference voltage and disrupted voltage. The hysteresis voltage control mainly controlled by relays switching so that the signal can be sent to IGBT switches controller. The hysteresis voltage control and unipolar SPWM is supplied to control the IGBT switches by the DC supply for voltage interruption compensation. The unipolar SPWM technique converts the DC supply voltage into AC supplied voltage, thus making the DVR injection become easier to inject the AC voltage into the system to compensate voltage sag and voltage swell.
Mitigation of Fault in the Distribution System by using Flexible Distributed ...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.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
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.
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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%
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International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
We follow "Rigorous Publication" model - means that all articles appear on IJERD after full appraisal, effectiveness, legitimacy and reliability of research content. International Journal of Engineering Research and Development publishes papers online as well as provide hard copy of Journal to authors after publication of paper. It is intended to serve as a forum for researchers, practitioners and developers to exchange ideas and results for the advancement of Engineering & Technology.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
We follow "Rigorous Publication" model - means that all articles appear on IJERD after full appraisal, effectiveness, legitimacy and reliability of research content. International Journal of Engineering Research and Development publishes papers online as well as provide hard copy of Journal to authors after publication of paper. It is intended to serve as a forum for researchers, practitioners and developers to exchange ideas and results for the advancement of Engineering & Technology.
This paper focus on distribution system by applying different control techniques in order to improve the performance of the system. In the distribution system mainly concentrate on power quality issues like reactive power control, harmonic elimination, power factor correction, etc. Because of power quality problems voltage, current, frequency are continuously changing in power systems. These changes will effects the performance of power systems. Power quality problems can be compensated by placing DSTATCOM which is connected at PCC in parallel. It is shunt connected VSI along with the filters, with the help of DSTATCOM voltage sag, swell and THD can be controlled. This paper presents detailed explanation about performance and configuration of latest control techniques to control the DSTATCOM.
Performance comparison of different control strategies for the regulation of ...IJECEIAES
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paper presentaton topic on power theft prevention and quality improvement by fuzzy logic
1.
International Journal of Electrical and Electronics Engineering (IJEEE) ISSN (PRINT): 2231 – 5284, Vol-1, Iss-3, 2012
106
Power Theft Prevention and Power Quality
Improvement using Fuzzy Logic
Sriram Rengarajan & Shumuganathan Loganathan
Electrical and Electronics Engineering, Sri Sairam Engineering College, Chennai, India
E-mail : sriram.rengarajan92@gmail.com, shumu1992@gmail.com
Abstract - This paper deals with Fuzzy logic based power theft prevention and power quality improvement. It involves comparison
between the total load supplied by the distribution transformer and the total load used by the consumer and the error signal is used to
identify the power theft. Load (energy) and voltage are fed as input to the Fuzzy logic controller and the corresponding change in
output voltage is provided by the controller to improve the power quality and to prevent the power theft. Simulations are done using
MATLAB and the results of the simulations are provided. It helps us to analyze the efficiency of intelligent control in electrical
systems.
Keywords - fuzzy logic, fuzzy controller, power theft, power quality, intelligent control.
I. INTRODUCTION
Intelligent control in electrical systems can be used
to improve it’s quality and to prevent lot of mischief
which are happening in the present transmission and
distribution. One of the important mischief is the power
theft which is contributing a larger amount to the non-
technical losses in transmission and distribution. In US,
the consensus seems to be that theft costs between 0.5%
and 3.5% of annual gross revenues. In developing
countries like India, theft contributes about 35% loss to
the country.
A . Defining Power Theft:
Two kinds of theft are prevalent in power systems.
First one is the Meter tampering and the second one is
the direct rigging of the distribution line. Meter
tampering is the method of tampering the meter by
removing it’s seal or by by-passing the meter so that a
lower reading of power use is shown in this case. In this
case the meter can also be tampered and used by some
other person and the owner of the meter has to pay for
the power used by some other person. But the
prevention of power theft of this type can be detected by
placing a LDR circuit inside the meter so that it sends
the warning signal to the sub-station as soon as the
meter is tampered. So this kind of power theft is not a
major problem. But the second case of power theft is a
major problem. Here we cannot identify the power theft
automatically and it contributes a great loss to the
government. This kind of Power theft can be prevented
by using Fuzzy logic in distribution systems.
B. Defining Power Quality:
Power quality is the set of electrical limits that
allows electrical systems to function in their intended
manner without significant loss of performance or life.
The quality of electrical power may be described as a set
of values of parameters such as continuity of service,
variation in voltage magnitude, transient voltages and
currents, harmonic content in the waveforms. Over-
voltage, Under-voltage, surge, sag, non-zero low
frequency impedance, non-zero high frequency
impedance are the common problems which degrade
power quality. we can rectify these power quality
problems using fuzzy logic. While power quality is a
convenient term for many, it is the quality of voltage
which is supplied to the consumers rather than current or
power. Power quality is an issue that is becoming
increasingly important to electricity consumers at all
levels of usage. Sensitive power electronic equipment
and non-linear loads are widely used in industrial,
commercial and domestic applications leading to
distortion in voltage and current waveforms.
Improvement of PQ has a positive impact on sustained
profitability of the distribution utility on the one hand
and customer satisfaction on the other.
II. PRINCIPLE OF PREVENTING POWER
THEFT
The basic working principle of this system is the
comparison of the total load (energy) supplied by the
distribution transformer and the total load used by the
2. Power Theft Prevention and Power Quality Improvement using Fuzzy Logic
International Journal of Electrical and Electronics Engineering (IJEEE) ISSN (PRINT): 2231 – 5284, Vol-1, Iss-3, 2012
107
consumers connected to that transformer as shown in the
block diagram(below).An electronic energy meter with
GSM modem is placed at each of the consumer
terminal. It measures the total load(energy) used by the
consumers and it transfers to the substation. It is
compared with the energy meter reading of the
electronic meter placed at the distribution transformer. If
both the values are same, then there is no
problem(neglecting the losses in transmission and
distribution). However if the value of the transformer
energy meter reading is greater than the consumer’s
meter reading, then it is the case of power theft. Using
this error signal we can detect the power theft. This error
signal is sent to the fuzzy logic controller and it reduces
the secondary voltage of the distribution transformer to
a critical value so that the relay circuit in the transformer
becomes opened and the supply from the transformer
comes to a halt. The reduction in voltage level is
achieved by using a tap changer circuit. The output of
FLC is connected to the tap changer circuit and it
changes the tappings of secondary of transformer so that
the reduction in voltage level is achieved.
III. PRINCIPLE OF IMPROVING POWER
QUALITY
The difference between the actual voltage and the
nominal voltage is fed as the input to the FLC. For
example, the nominal voltage may be 230V or it may be
120V. If the difference is zero, then actual voltage is
equal to the nominal voltage and there is no problem in
power quality. If the difference is negative, then it’s the
case of under-voltage. If the difference is positive, then
it’s the case of over-voltage. We can also detect short-
circuit problems and over-load problems using this
principle. The FLC makes the corresponding change in
output voltage depending upon it’s input. For example,
if it is under-voltage then the Corresponding change in
output will be to increase the input voltage.
Fig. 1: Block diagram of power theft prevention using
fuzzy controller
A. Crisp inputs:
The crisp inputs to the system are load and voltage
where load and voltage are defined as follows:
LOAD = (TRANSFORMER LOAD) – (CONSUMER
LOAD)
VOLTAGE = (ACTUAL VOLTAGE) – (NOMINAL
VOLTAGE)
B. Fuzzy inputs:
The crisp inputs are changed into fuzzy inputs by
defining membership functions (mf) for each crisp
input. The membership function for input voltage is as
follows:
Here the voltage range is from [-230,230] (230V is
chosen as the nominal value) .There are 15 membership
functions defined for the input voltage. These 15 mfs
maps the crisp input voltage into fuzzy inputs (it maps
into the range [0,1])
The membership function of “change
voltage”(output)is same as that of input voltage because
the change in output voltage depends upon the input
voltage for power quality improvement. For example, if
the actual voltage is 180V, then the input voltage will be
-50V and the change voltage will be +50V.If the load
value is positive, then the change voltage goes below the
critical value irrespective of the input voltage value.
3. Power Theft Prevention and Power Quality Improvement using Fuzzy Logic
International Journal of Electrical and Electronics Engineering (IJEEE) ISSN (PRINT): 2231 – 5284, Vol-1, Iss-3, 2012
108
Thus all the crisp inputs are changed into fuzzy inputs
successfully.
C. Fuzzification method:
The method of fuzzification used is “mamdani”.
The membership functions are triangular. They are not
symmetrical.( that is the interval occupied by each mf
may vary). For example, in the membership functions
shown above for input voltage and change voltage, the
mf15 is slightly broader than the other mfs.
D. Control rules:
If the load (in MW) becomes positive, then it’s the
case of power theft. Therefore the rule for prevention of
power theft is as follows:
If the load is positive, then change voltage is mf1
Therefore the secondary voltage becomes very low
so that the relay in secondary will open and the supply is
stopped.
The rule for power quality depends upon the input
voltage and the load. If the load is zero, then it is the
normal functioning of the power system and there is no
power theft. Therefore the improvement in power
quality is done only for normal functioning of the power
system. Here each mf of input voltage and change
voltage covers an average of 30V (interval can be
changed depending upon the level of accuracy
needed).Therefore there are 15Mfs for the input voltage
and change voltage in the range[-230,230].
.
RULE TABLE for fuzzy controller
VOLTAGE
Vi
LOAD Li
mf1 mf2 mf3 mf4 mf5 mf6 mf7 mf8 mf9
mf
10
mf
11
mf
12
mf
13
mf
14
mf
15
pos mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1 mf1
zero
mf
15
mf14 mf13 mf12 mf11 mf10 mf9 mf8 mf7 mf6 mf5 mf4 mf3 mf2 mf1
.
From the rule table one of the rules for improving
power quality as follows:
“If the load (Li) is zero and the voltage(Vi) is mf13
then change voltage is mf3”.This is the case of over-
voltage. Similarly other rules can be framed from the
rule table.
The surface rule view of the above rules of the
fuzzy inference is
4. Power Theft Prevention and Power Quality Improvement using Fuzzy Logic
International Journal of Electrical and Electronics Engineering (IJEEE) ISSN (PRINT): 2231 – 5284, Vol-1, Iss-3, 2012
109
Fig.2. Block diagram of power quality improvement
using fuzzy controller
E. Defuzzification:
The method of Defuzzification used is “centroid”
method. The output of the defuzzified value is given to
the tap changer circuit.
F. Tap changer:
The voltage control is performed by changing the
turns ratio. This is done by provision of taps in the
winding. The volts per turn available in large
transformers is quite high and hence a change of even
one turn on the LV side represents a large percentage
change in the voltage. Changer is used.LV winding
being the inner winding in a core type transformer adds
to the difficulty of taking out of the taps. Hence
irrespective of the end use for which tapping is put to,
taps are provided on the HV winding. Provision of taps
to control voltage is called tap changing. Tap changers
are classified to off-load tap changer and on-load tap
changer. For many power transformer applications on-
load tap-changer is used. The on-load tap changer is
installed in the primary side of a power transformer to
select or adjust voltage. The advantage of this is for
solving the voltage drop issues in the secondary output
in the farthest location
IV. MATLAB RESULTS:
Result of Over-Voltage : If the voltage is 151V then the
change voltage is -151V
Result of Normal functioning: If the voltage is 230V
then the change voltage is 0V.
Result of Power Theft: Voltage is brought down below
the critical value in case of power theft.
Result of Under-Voltage: If the voltage is -55.8V then
the change voltage is 55.7V