Utility distribution networks have sensitive industrial loads and critical commercial operations suffer from various types of outages and service interruptions which can cost significant financial losses. Because of sensitivity of consumers on power quality and advancement in power electronics. Active power filter technology is the most efficient way to compensate reactive power and cancel out low order harmonics generated by nonlinear loads. The shunt active power filter was considered to be the most basic configuration for the APF. This paper reviews the basic principle of shunt active power filter, along with the current tracking circuit based on the instantaneous reactive power theory and the main circuit performing as an inverter with PWM hysteresis control. The instantaneous active and reactive current component (id-iq) method and instantaneous active and reactive power (p-q) method are two control strategies which are extensively used in active filters. A shunt active filter based on the instantaneous active and reactive current component (id-iq) method is proposed. This method aims to compensate harmonic and first harmonic unbalance. A Comprehensive control method is analyzed and a harmonic Compensation simulation is conducted, the result of which verifies The harmonic detection algorithm is well-proposed and the power Quality of the grid is overall-enhanced. The results are obtained using MATLAB/SIMULINK software.
Simulation and Design of SRF based Control Algorithm for Three Phase Shunt Ac...idescitation
Active power filters are effective in mitigating line
current harmonics and compensating for the reactive power
in the line. There are basically two types of Active Power
Filters (APFs): shunt type and series type. Shunt active power
filters (SAPFs) represent the most important and most widely
used filters in industrial purposes, this is due not only to the
fact that eliminate the harmonic current but also they are
suitable for a wide range of power ratings. In this paper,
Synchronous Reference Frame (SRF) theory is employed to
calculate compensating currents while the three phase source
is feeding a highly non-linear load. The main objective is to
study and investigate the performance of Shunt active power
filter using SRF theory. The algorithm is simulated under
M ATLAB
7.8
environment
using
Simulinkand
SimPowerSystems toolbox. The results shown are within the
IEEE Standard 512-1992.
presentation of Conference On Electrical And Electronic Engineering 2015sager alswed
The designed three phase SAPF based on instantaneous p-q theory was simulated in MATLAB /SIMULINK by using different load conditions i.e. R-L load, suddenly connected R-L load, and additional unbalance R load. Its application was successfully proved and the validity achieved by minimizing the harmonics and improving PF as summarized in Table 2. Consequently, the supply current is almost pure sinusoidal. THD observed was fund to be within the prescribed limits of 5% as recommended by IEEE-519 standard.
Power system harmonics are a menace to electric power system with disastrous consequence. Due to the presence of non linear load, power quality of the system gets affected. To overcome this, shunt active power filter have been used near harmonic producing loads or at the point of common coupling to block current harmonics. The shunt active power filter is designed to minimize harmonics in source current and reactive power in the non linear power supplies which are creating harmonics. In this paper, Instantaneous power of p-q theory is employed to generate the reference currents and PI controller is used to control the dc link voltage. In addition to this, Artificial Intelligence (AI) technique is used to minimize the harmonics produced by nonlinear load. The main objective of this paper is to analyze and compare THD of the source current with PI controller and by artificial neural network based back propagation algorithm. The proposed system is designed with MATLAB/SIMULINK environment.
Simulation and Design of SRF based Control Algorithm for Three Phase Shunt Ac...idescitation
Active power filters are effective in mitigating line
current harmonics and compensating for the reactive power
in the line. There are basically two types of Active Power
Filters (APFs): shunt type and series type. Shunt active power
filters (SAPFs) represent the most important and most widely
used filters in industrial purposes, this is due not only to the
fact that eliminate the harmonic current but also they are
suitable for a wide range of power ratings. In this paper,
Synchronous Reference Frame (SRF) theory is employed to
calculate compensating currents while the three phase source
is feeding a highly non-linear load. The main objective is to
study and investigate the performance of Shunt active power
filter using SRF theory. The algorithm is simulated under
M ATLAB
7.8
environment
using
Simulinkand
SimPowerSystems toolbox. The results shown are within the
IEEE Standard 512-1992.
presentation of Conference On Electrical And Electronic Engineering 2015sager alswed
The designed three phase SAPF based on instantaneous p-q theory was simulated in MATLAB /SIMULINK by using different load conditions i.e. R-L load, suddenly connected R-L load, and additional unbalance R load. Its application was successfully proved and the validity achieved by minimizing the harmonics and improving PF as summarized in Table 2. Consequently, the supply current is almost pure sinusoidal. THD observed was fund to be within the prescribed limits of 5% as recommended by IEEE-519 standard.
Power system harmonics are a menace to electric power system with disastrous consequence. Due to the presence of non linear load, power quality of the system gets affected. To overcome this, shunt active power filter have been used near harmonic producing loads or at the point of common coupling to block current harmonics. The shunt active power filter is designed to minimize harmonics in source current and reactive power in the non linear power supplies which are creating harmonics. In this paper, Instantaneous power of p-q theory is employed to generate the reference currents and PI controller is used to control the dc link voltage. In addition to this, Artificial Intelligence (AI) technique is used to minimize the harmonics produced by nonlinear load. The main objective of this paper is to analyze and compare THD of the source current with PI controller and by artificial neural network based back propagation algorithm. The proposed system is designed with MATLAB/SIMULINK environment.
Power Quality Improvement in 3-Φ Power System with Shunt Active filter using ...AI Publications
Research paper focuses on enhancement of the power quality, Harmonic reduction and Reactive power compensation . Power quality problems became the foremost important concern now a days. Active filters with synchronous detection methodologies are vividly employed in distribution system to be sure that the harmonics generated by non-linear loads is reduced and leads to less voltage distortion and leads to lesser power superiority problems. The three physical characteristics that mostly underline the power quality and a power quality issues are Voltage, Current and Frequency. Harmonics is defined as a disturbance demonstrated in current or voltage or frequency waveforms which result in devastation, or failure of final equipment ..This paper examines the control of Shunt Active Power Filter with Synchronous Detection Method . Simulation results using MATLAB SIMULINK demonstrates the application of these methods to the control of Active Power Filter . Moreover, this work shows that how the power quality improvement in 3 phase is done with Synchronous Detection Method .
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.
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.
Unified Power Quality Conditioner Model Based with Series and Shunt FiltersIAES-IJPEDS
With the increase of the complexion in the power distribution system, it is very possible that several kinds of power quality disturbances are happened in a power distribution system simultaneously.This paper proposes a unified power quality conditioner (UPQC) including a series and a shunt active power filter (APF) to compensate harmonics in both the distorted supply voltage and nonlinear load current. In the series APF control scheme, a proportional-integral (PI) controller, meanwhile a PI controller and are designed in the shunt APF control scheme to relieve harmonic currents produced by nonlinear loads. The DC voltage is maintained constant using Two degree of freedom proportional integral voltage controller (2DoFPI). The performance of the proposed UPQC is significantly improved compared to the conventional control strategy. The feasibility of the proposed UPQC control scheme is validated through the simulations.
Closed Loop Non Linear Control of Shunt Hybrid Power Filter for Harmonics Mit...IAES-IJPEDS
In recent years, the amount of non-linear loads has increased considerably since there were improvements in power electronic equipment (such as adjustable speed drives or converter ac-dc, ac-ac, dc-ac and dc-dc) in industrial sectors which cause deterioration of the quality of the electric power supply through distortion of supply voltage and supply current. This has led to improvement of many stringent needs regarding generation of harmonic current, which are found in IEEE519 and IEC61000 standards. This paper proposes a non-linear function based closed loop control strategy (without load current extraction) for three-phase Shunt Active Power Line Conditioner and LC passive filter to compensate harmonics, power factor improvement and enhance the dynamic performance of Shunt Hybrid Power Filter (SHPF). By using a PI controller the DC bus voltage of the Shunt Active Power Filter is maintained constant. Results obtained from simulation shows the performance of expected hybrid filter in transient and steady state operation . This indicates that the controller is able to compensate even under severe load current imbalances.
Performance analysis of three phase shunt hybrid active power filtereSAT Journals
Abstract Active filtering of electric power has now become a mature technology for harmonic and reactive power Compensation in AC networks. The past several years have seen a rapid increase of power electronics-based loads connected to low and medium voltage power distribution systems. These loads draw non-sinusoidal current from the mains, degrading the power quality by causing harmonic distortion. This paper proposes a three phase Shunt Hybrid Active Filter (SHAF) topology for harmonic reduction and power factor improvement in low voltage power distribution systems. The compensation current reference for the proposed SHAF topology is obtained by using synchronous reference frame theorem. This theorem simplifies the equations for the current reference estimation in d-q co-ordinates thus leading to a more efficient and fast computation. To generate the compensation current that follows the current reference, the hysteresis current control method is adopted for 2-level VSI in low voltage system, the system is verified by developing simulation model using MATLAB/Simulink simulation package and the results are presented. The performance of shunt active filter and the proposed shunt hybrid active filter topology in reducing total harmonic distortion (THD) is compared for low voltage distribution system. Keywords: SAPF, SHPF, PI control, THD, Hysteresis current pulse width modulation, D-Q reference frame theory.
Power Quality Improvement in Distribution System using ANN Based Shunt Active...IAES-IJPEDS
This paper focuses on an Artificial Neural Network (ANN) controller based Shunt Active Power Filter (SAPF) for mitigating the harmonics of the distribution system. To increase the performance of the conventional controller and take advantage of smart controllers, a feed forward-type (trained by a back propagation algorithm) ANN-based technique is implemented in shunt active power filters for producing the controlled pulses required for IGBT inverter. The proposed approach mainly work on the principle of capacitor energy to maintain the DC link voltage of a shunt connected filter and thus reduces the transient response time when there is abrupt variation in the load. The entire power system block set model of the proposed scheme has been developed in MATLAB environment. Simulations are carried out by using MATLAB, it is noticed that the %THD is reduced to 2.27% from 29.71% by ANN controlled filter. The simulated experimental results also show that the novel control method is not only easy to be computed and implemented, but also very successful in reducing harmonics.
In This paper we present experimental comparative study of feedBack Linearized and Proportional Integral (PI) Controller of the DC bus voltage of three phase shunt Active Power Filter (APF). The FeedBack Linearized and PI controllers are introduced to improve tracking performance characteristics, power quality and minimized consumption of the reactive power. The algorithm used to identify the reference currents is based on the Self Tuning Filter (STF). The firing pulses of the IGBTs inverter are generated using a hysteresis current controller; which is implemented on an analogue card. Finally, the above study, under steady state and transient conditions, is illustrated with signal-flow graphs and corresponding analysis. This study was verified by experimental tests on hardware prototype based on dSPACE-1104. The experimental results show the feasibility and the effectiveness of the designed active filter, associated with Feedback Linearized and PI controllers and are capability in meeting the IEEE 519-1992 recommended harmonic standard limits.
The extensive use of non-linear loads in industry becomes increasingly a serious problem that affects the quality of energy delivered to customers. Therefore, the shunt active power filter (SAPF) has emerged as an important industrial tool to eliminate induced harmonic currents and compensating of reactive power. This paper proposes an improved control configuration for SAPF based on a modern technique called predictive direct power control (Predictive-DPC). The principle of this control is based on the direct regulation of the instantaneous active and reactive powers to guarantee a good energy quality on the grid side. For this purpose the appropriate average voltage vector which cancels power tracking errors is calculated by a simple predictive model at the bigining of each control period. This type of control includes various features such as the lack of look up table (LUTs) and closed current loops and the constant switching frequency is achieved through the use of PWM modulation. The results of the simulation process show a high performance in the steady and transient state function for predictive-DPC control that might be a reasonable alternative to conventional DPC in the field of active power filtering.
The development of active power filter (APF) using rectifier boost technique has been identified to compensate for the pulsating nature of the distorted supply current waveform of non-linear load. In this work, investigation is carried out on the operation of rectifier without any filters function. This is then extended to operate the rectifier converter with an active power filter function. APF function is implemented by enabling the closed-loop control using standard proportional integral control to rectify the distorted supply current to become continuous, sinusoidal and in-phase with the supply voltage waveform. Consequently, the total harmonic distortion (THD) level was reduced to meet the acceptable limit defined in the standard of IEEE-519 1992. The selected simulation results obtained from MATLAB/Simulink are presented to justify the proposed filter structure.
Design of shunt active power filter to mitigate harmonicsager alswed
The designed three phase SAPF based on instantaneous p-q theory was simulated in MATLAB /SIMULINK by using different load conditions i.e. R-L load, suddenly connected R-L load, and additional unbalance R load. Its application was successfully proved and the validity achieved by minimizing the harmonics and improving PF as summarized in Table 2. Consequently, the supply current is almost pure sinusoidal. THD observed was fund to be within the prescribed limits of 5% as recommended by IEEE-519 standard.
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.
Adaptive Modified Minimally Switched Hysteresis Controlled Shunt Active Power...idescitation
The main focus of this article is to investigate the
effects of Adaptive control on the switching frequency and
Total Harmonic Distortion of a modified, minimally switched
hysteresis controlled shunt active power filter. Reference
current generation was done using Instantaneous real and
reactive power algorithm. Pulses to the minimally switched
grid interactive inverter in which only two switches are
controlled at a time, had been generated using a modified
hysteresis current controller. Use of Modified Hysteresis
controller results in reducing the switching loses to one-third
but results in increase in current THD than the conventional
hysteresis controller. To overcome this, pulses to the modified
hysteresis controller were generated employing adaptive
control by modifying pulses from a conventional hysteresis
controller. Using adaptive control instantaneous switching
frequency was reduced and maintained nearly constant and
THD was brought to the limits specified by the standards,
thus overcoming the disadvantage of conventional and modified
hysteresis controller which has variable switching frequency.
A comparison of Modified Hysteresis controller with and
without Adaptive control has been made, to show the reduction
in THD. The system was simulated using MATLAB-
SIMULINK.
Power Quality Improvement Fuzzy Logical Controlled Based on Cascaded Shunt Ac...IJMTST Journal
Improve its quality and reliability catches growing interest. In this paper, based on the analysis and
modeling of the shunt APF with close-loop control, a feed forward compensation path of load current and also
fuzzy logic control is applied to improve the dynamic performance of the APF.. The two H-bridge cascaded
inverter is used for the aeronautical APF (AAPF). Justifications for topology choosing and corresponding
system control method are given. Furthermore, the global framework and operation principle of the proposed
AAPF are presented in detail. Simulated waveforms in different load conditions indicate the good
performance of the AAPF.
Improving Power Efficiency in Cooperative Diversity and Mimo Systems by Using...IJERA Editor
In this paper, we propose a new simple relayingstrategy based on bit-interleaved convolutionally coded starquadrature amplitude modulation (QAM) along with coherent/ noncoherent detection. Exploiting this property, a hard limiter is used to enhance power amplifier (PA) efficiency at the relay.here we are using the higher order modulation for improving relay communication and also employ the accurate relay technique.Moreover, we show that the proposedapproach retains differential detectability, which results in a significant reduction of receiver complexity with robustness against phase ambiguityBy analyzing our proposed method in terms of asymptotic pairwise error probability(PEP),Furthermore, theeffectiveness of the proposed scheme in terms of PA efficiency is confirmed by comparing the statistical distributions of the corresponding instantaneous signal power.and also implement the PEP in MIMO systems for improving the power efficiency.All the theoretical results agree with those obtained by computer simulations.
Power Quality Improvement in 3-Φ Power System with Shunt Active filter using ...AI Publications
Research paper focuses on enhancement of the power quality, Harmonic reduction and Reactive power compensation . Power quality problems became the foremost important concern now a days. Active filters with synchronous detection methodologies are vividly employed in distribution system to be sure that the harmonics generated by non-linear loads is reduced and leads to less voltage distortion and leads to lesser power superiority problems. The three physical characteristics that mostly underline the power quality and a power quality issues are Voltage, Current and Frequency. Harmonics is defined as a disturbance demonstrated in current or voltage or frequency waveforms which result in devastation, or failure of final equipment ..This paper examines the control of Shunt Active Power Filter with Synchronous Detection Method . Simulation results using MATLAB SIMULINK demonstrates the application of these methods to the control of Active Power Filter . Moreover, this work shows that how the power quality improvement in 3 phase is done with Synchronous Detection Method .
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.
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.
Unified Power Quality Conditioner Model Based with Series and Shunt FiltersIAES-IJPEDS
With the increase of the complexion in the power distribution system, it is very possible that several kinds of power quality disturbances are happened in a power distribution system simultaneously.This paper proposes a unified power quality conditioner (UPQC) including a series and a shunt active power filter (APF) to compensate harmonics in both the distorted supply voltage and nonlinear load current. In the series APF control scheme, a proportional-integral (PI) controller, meanwhile a PI controller and are designed in the shunt APF control scheme to relieve harmonic currents produced by nonlinear loads. The DC voltage is maintained constant using Two degree of freedom proportional integral voltage controller (2DoFPI). The performance of the proposed UPQC is significantly improved compared to the conventional control strategy. The feasibility of the proposed UPQC control scheme is validated through the simulations.
Closed Loop Non Linear Control of Shunt Hybrid Power Filter for Harmonics Mit...IAES-IJPEDS
In recent years, the amount of non-linear loads has increased considerably since there were improvements in power electronic equipment (such as adjustable speed drives or converter ac-dc, ac-ac, dc-ac and dc-dc) in industrial sectors which cause deterioration of the quality of the electric power supply through distortion of supply voltage and supply current. This has led to improvement of many stringent needs regarding generation of harmonic current, which are found in IEEE519 and IEC61000 standards. This paper proposes a non-linear function based closed loop control strategy (without load current extraction) for three-phase Shunt Active Power Line Conditioner and LC passive filter to compensate harmonics, power factor improvement and enhance the dynamic performance of Shunt Hybrid Power Filter (SHPF). By using a PI controller the DC bus voltage of the Shunt Active Power Filter is maintained constant. Results obtained from simulation shows the performance of expected hybrid filter in transient and steady state operation . This indicates that the controller is able to compensate even under severe load current imbalances.
Performance analysis of three phase shunt hybrid active power filtereSAT Journals
Abstract Active filtering of electric power has now become a mature technology for harmonic and reactive power Compensation in AC networks. The past several years have seen a rapid increase of power electronics-based loads connected to low and medium voltage power distribution systems. These loads draw non-sinusoidal current from the mains, degrading the power quality by causing harmonic distortion. This paper proposes a three phase Shunt Hybrid Active Filter (SHAF) topology for harmonic reduction and power factor improvement in low voltage power distribution systems. The compensation current reference for the proposed SHAF topology is obtained by using synchronous reference frame theorem. This theorem simplifies the equations for the current reference estimation in d-q co-ordinates thus leading to a more efficient and fast computation. To generate the compensation current that follows the current reference, the hysteresis current control method is adopted for 2-level VSI in low voltage system, the system is verified by developing simulation model using MATLAB/Simulink simulation package and the results are presented. The performance of shunt active filter and the proposed shunt hybrid active filter topology in reducing total harmonic distortion (THD) is compared for low voltage distribution system. Keywords: SAPF, SHPF, PI control, THD, Hysteresis current pulse width modulation, D-Q reference frame theory.
Power Quality Improvement in Distribution System using ANN Based Shunt Active...IAES-IJPEDS
This paper focuses on an Artificial Neural Network (ANN) controller based Shunt Active Power Filter (SAPF) for mitigating the harmonics of the distribution system. To increase the performance of the conventional controller and take advantage of smart controllers, a feed forward-type (trained by a back propagation algorithm) ANN-based technique is implemented in shunt active power filters for producing the controlled pulses required for IGBT inverter. The proposed approach mainly work on the principle of capacitor energy to maintain the DC link voltage of a shunt connected filter and thus reduces the transient response time when there is abrupt variation in the load. The entire power system block set model of the proposed scheme has been developed in MATLAB environment. Simulations are carried out by using MATLAB, it is noticed that the %THD is reduced to 2.27% from 29.71% by ANN controlled filter. The simulated experimental results also show that the novel control method is not only easy to be computed and implemented, but also very successful in reducing harmonics.
In This paper we present experimental comparative study of feedBack Linearized and Proportional Integral (PI) Controller of the DC bus voltage of three phase shunt Active Power Filter (APF). The FeedBack Linearized and PI controllers are introduced to improve tracking performance characteristics, power quality and minimized consumption of the reactive power. The algorithm used to identify the reference currents is based on the Self Tuning Filter (STF). The firing pulses of the IGBTs inverter are generated using a hysteresis current controller; which is implemented on an analogue card. Finally, the above study, under steady state and transient conditions, is illustrated with signal-flow graphs and corresponding analysis. This study was verified by experimental tests on hardware prototype based on dSPACE-1104. The experimental results show the feasibility and the effectiveness of the designed active filter, associated with Feedback Linearized and PI controllers and are capability in meeting the IEEE 519-1992 recommended harmonic standard limits.
The extensive use of non-linear loads in industry becomes increasingly a serious problem that affects the quality of energy delivered to customers. Therefore, the shunt active power filter (SAPF) has emerged as an important industrial tool to eliminate induced harmonic currents and compensating of reactive power. This paper proposes an improved control configuration for SAPF based on a modern technique called predictive direct power control (Predictive-DPC). The principle of this control is based on the direct regulation of the instantaneous active and reactive powers to guarantee a good energy quality on the grid side. For this purpose the appropriate average voltage vector which cancels power tracking errors is calculated by a simple predictive model at the bigining of each control period. This type of control includes various features such as the lack of look up table (LUTs) and closed current loops and the constant switching frequency is achieved through the use of PWM modulation. The results of the simulation process show a high performance in the steady and transient state function for predictive-DPC control that might be a reasonable alternative to conventional DPC in the field of active power filtering.
The development of active power filter (APF) using rectifier boost technique has been identified to compensate for the pulsating nature of the distorted supply current waveform of non-linear load. In this work, investigation is carried out on the operation of rectifier without any filters function. This is then extended to operate the rectifier converter with an active power filter function. APF function is implemented by enabling the closed-loop control using standard proportional integral control to rectify the distorted supply current to become continuous, sinusoidal and in-phase with the supply voltage waveform. Consequently, the total harmonic distortion (THD) level was reduced to meet the acceptable limit defined in the standard of IEEE-519 1992. The selected simulation results obtained from MATLAB/Simulink are presented to justify the proposed filter structure.
Design of shunt active power filter to mitigate harmonicsager alswed
The designed three phase SAPF based on instantaneous p-q theory was simulated in MATLAB /SIMULINK by using different load conditions i.e. R-L load, suddenly connected R-L load, and additional unbalance R load. Its application was successfully proved and the validity achieved by minimizing the harmonics and improving PF as summarized in Table 2. Consequently, the supply current is almost pure sinusoidal. THD observed was fund to be within the prescribed limits of 5% as recommended by IEEE-519 standard.
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.
Adaptive Modified Minimally Switched Hysteresis Controlled Shunt Active Power...idescitation
The main focus of this article is to investigate the
effects of Adaptive control on the switching frequency and
Total Harmonic Distortion of a modified, minimally switched
hysteresis controlled shunt active power filter. Reference
current generation was done using Instantaneous real and
reactive power algorithm. Pulses to the minimally switched
grid interactive inverter in which only two switches are
controlled at a time, had been generated using a modified
hysteresis current controller. Use of Modified Hysteresis
controller results in reducing the switching loses to one-third
but results in increase in current THD than the conventional
hysteresis controller. To overcome this, pulses to the modified
hysteresis controller were generated employing adaptive
control by modifying pulses from a conventional hysteresis
controller. Using adaptive control instantaneous switching
frequency was reduced and maintained nearly constant and
THD was brought to the limits specified by the standards,
thus overcoming the disadvantage of conventional and modified
hysteresis controller which has variable switching frequency.
A comparison of Modified Hysteresis controller with and
without Adaptive control has been made, to show the reduction
in THD. The system was simulated using MATLAB-
SIMULINK.
Power Quality Improvement Fuzzy Logical Controlled Based on Cascaded Shunt Ac...IJMTST Journal
Improve its quality and reliability catches growing interest. In this paper, based on the analysis and
modeling of the shunt APF with close-loop control, a feed forward compensation path of load current and also
fuzzy logic control is applied to improve the dynamic performance of the APF.. The two H-bridge cascaded
inverter is used for the aeronautical APF (AAPF). Justifications for topology choosing and corresponding
system control method are given. Furthermore, the global framework and operation principle of the proposed
AAPF are presented in detail. Simulated waveforms in different load conditions indicate the good
performance of the AAPF.
Improving Power Efficiency in Cooperative Diversity and Mimo Systems by Using...IJERA Editor
In this paper, we propose a new simple relayingstrategy based on bit-interleaved convolutionally coded starquadrature amplitude modulation (QAM) along with coherent/ noncoherent detection. Exploiting this property, a hard limiter is used to enhance power amplifier (PA) efficiency at the relay.here we are using the higher order modulation for improving relay communication and also employ the accurate relay technique.Moreover, we show that the proposedapproach retains differential detectability, which results in a significant reduction of receiver complexity with robustness against phase ambiguityBy analyzing our proposed method in terms of asymptotic pairwise error probability(PEP),Furthermore, theeffectiveness of the proposed scheme in terms of PA efficiency is confirmed by comparing the statistical distributions of the corresponding instantaneous signal power.and also implement the PEP in MIMO systems for improving the power efficiency.All the theoretical results agree with those obtained by computer simulations.
Presentación de Mario Morales, director del Observatorio de RSE y Transparencia en el Congreso Latinoamericano de Pymes, Santiago de Chile, enero de 2010.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
We would send hard copy of Journal by speed post to the address of correspondence author after online publication of paper.
We will dispatched hard copy to the author within 7 days of date of publication
Harmonic Compensation for Non Linear Load Using PWM Based Active Filteridescitation
In this paper the elimination of the current harmon-
ics of injected by nonlinear loads is investigated. The active
power filter proposed in this study is a Single phase voltage
source inverter (VSI) connecting to the AC mains. The dspic
controller is used to control the operation of the switches of
the inverter. Active filtering is achieved through PWM in-
verter connected next to a given nonlinear load or at the point
of the common coupling (PCC). The simulation results show
that how well the filter eliminates the harmonics of the source
current.
Power System Harmonic Compensation Using Shunt Active Power FilterIJERA Editor
This paper shows the method of improving the power quality using shunt active power filter. The proposedtopic comprises of PI controller, filter hysteresis current control loop, dc link capacitor. The switching signal generation for filter is fromhysteresis current controller techniques. With the all these element shunt active power filter reduce the total harmonic distortion. Thispaper represents the simulation and analysis of the using three phase three wire system active filter to compensate harmonics .Theproposed shunt active filter model uses balanced non-linear load. This paper successfully lowers the THD within IEEE norms and satisfactorily works to compensatecurrent harmonics.
This paper presents the control for Shunt Active Power (SAPF) filter in photovoltaic (PV) systems connected to the grid. The proposed configuration of the system consists of a photovoltaic array that connected to the grid through the three-phase inverter topology that also serves as an active filter. Photovoltaic is coupled in parallel with the direct curret (DC) side of the active filter. With this configuration, can be obtained three advantages, namely the elimination of harmonic currents caused by nonlinear load, reactive power injection, and injection of active power generated photovoltaic. The p-q Theory is used to calculate the harmonic reference current to be used to control the active filter coupled fotovoltaic in generating anti-harmonic currents. The results show that system can reduce harmonic distortion from THD 27.22% to be THD 1.05%, whereas when the active power from photovoltaic injected, the THD become 2.01%. Power sharing can also be seen from this study.
Mitigation of the Harmonics under Reactive Power Compensation by SHPF-TCR Usi...IJERA Editor
In this paper, a combined system of a thyristor-controlled reactor (TCR) and a shunt hybrid power filter
(SHPF)has been designed by MATLAB/SIMULINK approach for harmonic and reactive power compensation.
The quality of the power is effected by many factors like harmonic contamination, due to the increment of nonlinear
loads, sag and swell due to the switching of the loads etc. Also control schemes based on PI and Fuzzy
logic controllers have been proposed to mitigate the harmonics and neutral current . The proposed methodology
not only reduces the complexity but also offers simplicity to implement and increases reliability of the system.
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PI and fuzzy logic controllers for shunt active power filterISA Interchange
This paper presents a shunt Active Power Filter (APF) for power quality improvements in terms of harmonics and reactive power compensation in the distribution network. The compensation process is based only on source current extraction that reduces the number of sensors as well as its complexity. A Proportional Integral (PI) or Fuzzy Logic Controller (FLC) is used to extract the required reference current from the distorted line-current, and this controls the DC-side capacitor voltage of the inverter. The shunt APF is implemented with PWM-current controlled Voltage Source Inverter (VSI) and the switching patterns are generated through a novel Adaptive-Fuzzy Hysteresis Current Controller (A-F-HCC). The proposed adaptive-fuzzy-HCC is compared with fixed-HCC and adaptive-HCC techniques and the superior features of this novel approach are established. The FLC based shunt APF system is validated through extensive simulation for diode-rectifier/R–L loads.
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Enhancement of power quality using microprocessor based shunt active power fi...IJECEIAES
Power quality is the most significant factor of power sector. The end user equipment such as induction motor, inverters, rectifiers inject harmonics into power system that influences the quality of power delivered. The presence of harmonics forces the use of instantaneous reactive power theory to calculate instantaneous power that helps in finding the compensating currents to eliminate harmonics. The control action required by active filter is accomplished by STM32F303RET6 microcontroller. Single phase induction motor is used as a dynamic nonlinear load in one of the three phases and resistive loads on the other two phases. TRIAC based RC triggering circuit was used to control the single phase induction motor. This paper presents the simulation and hardware implementation of shunt active power filter for 3 phase 4 wire unbalanced system. The hardware results show that THD in the source side has been reduced from 50.7% to 9.6% by implementing the SAPF.
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Modeling & Analysis of Shunt Active Power Filter Using IRP Theory Fed to Induction Drive
1. PABBISETTY SAI SUJATHA Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 4, Issue 10( Part - 6), October 2014, pp.121-126
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Modeling & Analysis of Shunt Active Power Filter Using IRP
Theory Fed to Induction Drive
* PABBISETTY SAI SUJATHA, ** D.S.NAGAMALLESWARARAO
*Student Scholar, Department of Electrical & Electronics Engineering, QIS College of Engineering &
Technology, Pondur road, Ongole, Prakasam (Dt); A.P, India.
**M.Tech, Assistant Professor
Department of Electrical & Electronics Engineering, QIS College of Engineering & Technology, Pondur
road, Ongole, Prakasam (Dt); A.P, India.
Abstract-
Utility distribution networks have sensitive industrial loads and critical commercial operations suffer from
various types of outages and service interruptions which can cost significant financial losses. Because of
sensitivity of consumers on power quality and advancement in power electronics. Active power filter technology
is the most efficient way to compensate reactive power and cancel out low order harmonics generated by
nonlinear loads. The shunt active power filter was considered to be the most basic configuration for the APF.
This paper reviews the basic principle of shunt active power filter, along with the current tracking circuit based
on the instantaneous reactive power theory and the main circuit performing as an inverter with PWM hysteresis
control. The instantaneous active and reactive current component (id-iq) method and instantaneous active and
reactive power (p-q) method are two control strategies which are extensively used in active filters. A shunt
active filter based on the instantaneous active and reactive current component (id-iq) method is proposed. This
method aims to compensate harmonic and first harmonic unbalance. A Comprehensive control method is
analyzed and a harmonic Compensation simulation is conducted, the result of which verifies The harmonic
detection algorithm is well-proposed and the power Quality of the grid is overall-enhanced. The results are
obtained using MATLAB/SIMULINK software.
Keywords- Harmonics, reactive power, current tracking, active power filter, hysteresis control, Induction
Machine Drive.
I. INTRODUCTION
Nonlinear loads introduce in the power grid
current harmonics that cause considerable
drawbacks such as low power factor, low efficiency,
and electromagnetic interference. Passive filters
have been conventionally used to eliminate specific
harmonics and improve the power factor, but their
bulky size, limited compensation ability and
resonance susceptibility with the source impedance
reduce their popularity. A considerable progress has
been made then in the field of Active Power Filters
(APF) in order to overcome such Filters (APF) in
order to overcome such Problems [1-4]. A typical
APF topology consists mainly of an inverter circuit
with active devices (i.e., semiconductor switches),
which can be controlled to act as a current or voltage
harmonic generator. APFs are superior to passive
filters in terms of filtering characteristics and
stability towards a possible resonance between
reactive components.
Performance of active filters for power line
conditioning and their practical applications. The
basic principles of compensation were proposed
around 1970; however actual designs of active filters
were proposed by Gyugyi and Strycula in 1976[1].
In 1984, H. Akagi et al. [2] introduced a new
concept of instantaneous reactive power theory.
With the progress of power electronics, engineers
started the development of electronically controlled
devices that have non linear current consumption.
These devices were primordially developed to
increase the energy efficiency and the controllability
of advanced production processes, but, since they
produce harmonics, these devices are now
responsible for extra energy losses and bad operation
of the electrical distribution system and its
components [1].
To assure a good performance Passive Power Filters
have to be carefully tuned for which particular case.
. Active Power Filters can be easily installed without
any commissioning, and instantaneously compensate
the current harmonics and the power factor [3-4].
The performance of APF is primarily compatible to
the interaction of current tracking control circuit and
main circuit, the latter of which acts as an inverter
consisting of various power electronic devices that
produce the targeted compensating current under the
PWM control determined by the reference circuit.
The most widely accepted control mode is to
RESEARCH ARTICLE OPEN ACCESS
2. PABBISETTY SAI SUJATHA Int. Journal of Engineering Research and Applications www.ijera.com
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initially detect and calculate the harmonics in the
load current, then the negative value of which
represents as the reference current that triggers the
control of inverter by PWM current tracking method.
Consequentially, a high-pass filter (HPF) is required
to eliminate the high-order harmonic generation (a
byproduct of PWM hysteresis control) with
frequencies close to the carrier wave. The p-q theory
or instantaneous power theory is based on time
domain; it makes operation in steady-state or
transient state, as well as for generic voltage and
current waveforms, allowing to control the active
power filters in real-time. Another important
characteristic of this theory is the simplicity of the
calculations, which involves only algebraic
calculation.
II. THE PRINCIPLE OF SHUNT
ACTIVE POWER FILTER
A. Basic Structure
The shunt active filter approach is based on the
principle of injection of harmonic currents into the
ac system, of the same amplitude but opposite in
phase to that of the load harmonic currents.
Fig.1. Basic Principle of SAPF System.
Fig. 1 shows the active power filter
compensation principle, which is controlled in a
closed loop manner to actively shape the source
current into sinusoid.
Fig 2 demonstrates the simplified configuration
of shunt APF [4], which could be dichotomized into
reference current calculation section and its
counterpart—compensating current generator
(consisting of current control, drive and main
circuit).
Fig.2. simplified shunt APF configuration
The core function of the reference current
calculation circuit is to detect the harmonics as well
as the reactive power contributed by the non-linear
load.
B. The Calculation of Reference Current
The circuit of reference current calculation is
essentially based on three-phase instantaneous
reactive power theory [5], which suggests a novel
approach to detect the three-phase harmonic current.
As shown in Fig 3, ia, ib and ic are initially detected
and then served as the input for the next stage of
algorithm, which involves specific calculation of
instantaneous active current ip as well as reactive
current iq.
(1)
Where
(2)
In addition, a three-phase PLL section is
prerequisite in order to grasp the angle of phase A.
When ip and iq flow through the low-pass filter
(LPF), the harmonics contained could be eliminated,
and thus give rise to the DC component of the load
current known as and . With inverse
transformation of the transpose matrix of CT, hence
the three phase fundamental current of iaf, ibf and icf
could be readily obtained. Therefore, the reference
current , and is obviously the subtraction
3. PABBISETTY SAI SUJATHA Int. Journal of Engineering Research and Applications www.ijera.com
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of those fundamental three-phase currents with the
correspondingly original load currents.
Fig.3. Algorithm of the reference current
calculation circuit
C. Current Tracking Control Circuit
Current tracking is the first step for the
production of targeted compensating current, under
the basic function of obtaining the PWM signals that
are responsible for the switch modes of each device
in the main circuit. In addition, the PWM signal is
generated by the comparison between the reference
current and the real compensating current.
Fig.4.Circuit of current tracking control
The current-tracking-controlled PWM inverters
possess various forms, the most common of which is
the hysteresis current tracking control shown in Fig
4. represents the reference value and meanwhile
the tracking target of the load current. A hysteresis
error h is intentionally established in case of the high
frequency of switches in inverters. While ia ≥
h, the hysteresis controller produces high level
which drives the upper bridge arm S1 in working
mode condition, and thus increasing load current ia
even when ia is outstripping . The increase of load
current will not be affected unless ia is exactly
greater by h comparing with the reference current,
then follows the reverse working mode of hysteresis
controller by switching off S1 and simultaneously
acting on S4, which may not be necessarily switched
on, for the current flows through diode D4 is not
reversed in direction but rather begin decreasing.
When the hysteresis control is applied, the real
output of the current from inverters could maintain a
fluctuation value only within h and – h, bouncing up
and down in zigzag forms, as one of the examples
illustrated in Fig.5.
Fig.5. One example of the hysteresis control of
the reference and
compensating current
D. Main Circuit Parameter Design
The working mode of the main circuit is
determined by the condition of its six switches.
Generally speaking, there is always a single device
switched on in all three groups (S1/S4, S3/S6 or
S2/S5), constructing six different combinations all
together. The main circuit is shown in Fig.6.
Fig.6. Main circuit
Suppose the sum of three-phase voltage source
ea+eb+ec=0 along with the current ia+ib+ic=0, then
the differential equation of phase A could be
described as
(3)
In which Ka denotes the switching coefficient,
while ea represents as the instantaneous value of the
ac side voltage and ia as the compensating current. In
addition, when the upper bridge arm of phase A is
switched on, the absolute value of Ka is -2/3;
similarly, Ka is 1/3 when the lower bridge arm is
working. Provided that the sample working time is
long enough, the average effect of AC voltage ea in
(2) would be zero. As the possibility of Ka=1/3 is
66.7% while that of Ka=2/3 is 33.3%, the mean of
Ka is hence 4/9. Within one period of time, (2) could
be reshaped as:
(4)
Signal of compensating current; the most
appropriate value of coefficient λ varies from 0.3 to
0.4 in terms of the overall effect of compensation,
4. PABBISETTY SAI SUJATHA Int. Journal of Engineering Research and Applications www.ijera.com
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which could be obtained by simulation. Taking
function (3) and safety concerns into consideration,
the prerequisite of Uc ≥ 3Em should be granted, in
which Em is the peak value of phase voltage.
Assuming that the DC side capacitor is always in
transition from charging to discharging states within
a single switching cycle, the maximum acceptable
deviation of DC side capacitor voltage is [4]:
(5)
III. MATLAB MODELING AND
SIMULATION RESULTS
Here simulation is carried out in different cases
1). Implementation of Shunt Active Power Filter
using Inverter 2). Implementation of Shunt Active
Power Filter using Multilevel Inverter.
Case 1: Implementation of Shunt Active Power
Filter using Inverter
Fig.7 shows the Matlab/Simulink Model of Proposed
Shunt Active Power Filter using Matlab/Simulink
Platform.
Fig.7 Matlab/Simulink Model of Proposed Shunt
Active Power
Filter
Fig. 8. Source voltage, current and load
current without APF
Fig. 8 shows the three phase source voltages,
three phase source currents and load currents
respectively without APF. It is clear that without
APF load current and source currents are same.
Fig. 9. Source voltage, current and load
current with APF
Fig. 9 shows the three phase source voltages,
three phase source currents and load currents
respectively with APF. It is clear that with APF even
though load current is non sinusoidal source currents
are sinusoidal.
Fig. 10. Phase-A source voltage and current
Fig. 10. Shows the phase-A source voltage and
current, even though the load is non linear RL load
the source power factor is unity.
Fig. 11. Harmonic spectrum of Phase-A Source
current without APF
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Fig. 11. Shows the harmonic spectrum of Phase
–A Source current without APF. The THD of source
current without APF is 28.29%.
Fig. 12. Harmonic spectrum of Phase-A Source
current with APF
Fig. 12. Shows the harmonic spectrum of Phase
–A Source current with APF. The THD of source
current without APF is 3.70%.
Case 2: Implementation of Shunt Active Power
Filter Applied to Induction Machine Drive.
Fig.13 Matlab/Simulink Model of Proposed Shunt
Active Power
Filter Applied to Induction Machine Drive.
Fig.13 shows the Matlab/Simulink Model of
Proposed Shunt Active Power Filter with Induction
Machine Drive using Matlab / Simulink Platform.
Fig.14 Stator Current, Speed, Electromagnetic
Torque
Fig.14 shows the Stator Current, Speed, and
Electromagnetic Torque of Proposed Shunt Active
Power Filter with Induction Machine Drive.
IV. CONCLUSION
The improvement was successfully done by
providing an alternative pathway for the distorted
current that complementary to the nonlinear current.
All power switches in the APF were well controlled
using the active PWM signal and the pulse generator
to perform safe commutation operation. The
proposed instantaneous real-power controller uses
reduced computation for reference current
calculations compared to conventional approach.
The proposed inverter switching signals are
generated using triangular-sampling Current
controller; it provides a dynamic performance under
transient and steady state conditions. On the basis of
the simulation, to detect harmonic wave and reactive
load current efficiently, compensate the load current
effectively by reshaping the source current to that
similar to sine wave and reducing the THD value to
below 5%. The compensation performance of the
simulation result provides a practical approach to the
basis of APF & applied to Induction Drive to check
the performance characteristics.
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6. PABBISETTY SAI SUJATHA Int. Journal of Engineering Research and Applications www.ijera.com
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Authors:
PABBISETTY SAI SUJATHA is an
M.Tech candidate at QIS college
of Engineering & Technology
under JNTU, Kakinada. She
received her B.Tech degree from
S.S.N Engg college, ongole, under
JNTU Kakinada. Her current
research interests are Modeling &
Analysis of Shunt Active Power Filter Using IRP
Theory Fed to Induction Drive.
D.S.NAGA MALLESWARARAO
is an assistant professor in QIS
College of Engineering
&Technology at Ongole. He got
his M.Tech degree from JNTUK
and his B.Tech degree from CEC
Engineering College . His current
research interests are power
systems, power systems control and automation,
Electrical Machines, power electronics.