call for papers, research paper publishing, where to publish research paper, journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJEI, call for papers 2012,journal of science and technolog
This document summarizes a research paper that proposes using a particle swarm optimization (PSO) algorithm to design hybrid active power filters (HAPFs) for 3-phase 4-wire power systems with variable and nonlinear loads. The objectives are to minimize harmonic distortion, reactive power capacity, and costs while satisfying constraints. PSO is applied to find optimal filter parameters and component ratings. Simulation results show PSO designs outperform conventional trial-and-error methods in meeting standards for harmonic mitigation and power factor correction.
RF and Mixed Signal Circuits for a DVB-H ReceiverRFIC-IUMA
This document presents the design of RF and mixed signal circuits for a DVB-H receiver. It describes the low noise amplifier, mixer, synthesizer, and ADC circuits. The LNA uses a cascode configuration to achieve low power and noise with wide bandwidth. The mixer uses a Gilbert cell. The VCO employs techniques like emitter degeneration and capacitor divider to improve phase noise and amplitude. Two ADC structures are presented, including a delta sigma ADC. Measurements and simulations show the circuits meet requirements for a DVB-H receiver in terms of frequency range, sensitivity, noise figure, linearity, phase noise, gain and dynamic range.
This paper presents a controller for regulating the voltages of a split capacitor used in a four-wire selective active power filter. The controller balances the voltages of the two capacitors while also controlling the total voltage. A dynamic model is derived showing the capacitor voltage dynamics are decoupled, simplifying the controller design. Simulations and experiments demonstrate the benefits of regulating both the total voltage and voltage balance with the proposed controller.
This document outlines the documentation requirements and approval process for fabrication of truss gateways at Chennai Airport. It details the documentation needed at each stage of fabrication for A, B, and BA trusses. This includes jig surveys, pipe dimensions, welding reports, NDT reports, and final inspection reports. Approval is required from HAL, BV, IMP, and HPI-CCCL at various stages. The goal is to ensure quality control and traceability throughout the fabrication process.
Analysis of High-Order Residual-Based Dissipation for Unsteady Compressible F...kgrimich
A comprehensive study of the numerical properties of high-order residual-based dissipation terms for unsteady compressible flows leads to the design of well-behaved, low dissipative schemes of third-, fifth- and seventh-order accuracy. The dissipation and dispersion properties of the schemes are then evaluated theoreticaly, through Fourier space analysis, and numerically, through selected test cases including the inviscid Taylor-Green Vortex flow.
The document discusses the implementation of advanced process controllers (APCs) on two identical trains of continuous catalytic reforming (CCR) plants at Kuwait National Petroleum Corporation's (KNPC) Mina Al-Ahmadi refinery. The primary benefit was an increase in reformate octane barrel yield from operating the plant at its economic constraints. APCs were able to increase throughput, improve heavy naphtha recovery, and increase reactor bed temperatures while reducing reactor pressure. The APC project paid for itself within a few months. Key aspects of the project included developing models of each unique train using an automated step testing methodology and implementing inferential and online kinetic models. Controllers were designed to maximize reformate octane
This document discusses risk assessment of connecting a 170 kV gas insulated substation (GIS) to a combined cable and overhead line network in Denmark. Simulations were conducted to analyze the effects of shielding failures and back flashovers on the network under varying conditions of surge front time, soil resistivity, and cable length between the GIS and transformers. The simulations showed transformer overvoltages exceeding safe levels set by standards in some scenarios, requiring further investigation into mitigation approaches.
ملخص مشروع six sigma..مهندس عادل حجازىguest6ead29e
six sigma محاولة فهم و تطبيق نظام
هو المخرج الوحيد لحل أكثر المشاكل التى تواجة تعثر المصانع و المؤسسات و تجنب الخسائر الفادحة فى السوق المصرى ..عادل حجازى
RF and Mixed Signal Circuits for a DVB-H ReceiverRFIC-IUMA
This document presents the design of RF and mixed signal circuits for a DVB-H receiver. It describes the low noise amplifier, mixer, synthesizer, and ADC circuits. The LNA uses a cascode configuration to achieve low power and noise with wide bandwidth. The mixer uses a Gilbert cell. The VCO employs techniques like emitter degeneration and capacitor divider to improve phase noise and amplitude. Two ADC structures are presented, including a delta sigma ADC. Measurements and simulations show the circuits meet requirements for a DVB-H receiver in terms of frequency range, sensitivity, noise figure, linearity, phase noise, gain and dynamic range.
This paper presents a controller for regulating the voltages of a split capacitor used in a four-wire selective active power filter. The controller balances the voltages of the two capacitors while also controlling the total voltage. A dynamic model is derived showing the capacitor voltage dynamics are decoupled, simplifying the controller design. Simulations and experiments demonstrate the benefits of regulating both the total voltage and voltage balance with the proposed controller.
This document outlines the documentation requirements and approval process for fabrication of truss gateways at Chennai Airport. It details the documentation needed at each stage of fabrication for A, B, and BA trusses. This includes jig surveys, pipe dimensions, welding reports, NDT reports, and final inspection reports. Approval is required from HAL, BV, IMP, and HPI-CCCL at various stages. The goal is to ensure quality control and traceability throughout the fabrication process.
Analysis of High-Order Residual-Based Dissipation for Unsteady Compressible F...kgrimich
A comprehensive study of the numerical properties of high-order residual-based dissipation terms for unsteady compressible flows leads to the design of well-behaved, low dissipative schemes of third-, fifth- and seventh-order accuracy. The dissipation and dispersion properties of the schemes are then evaluated theoreticaly, through Fourier space analysis, and numerically, through selected test cases including the inviscid Taylor-Green Vortex flow.
The document discusses the implementation of advanced process controllers (APCs) on two identical trains of continuous catalytic reforming (CCR) plants at Kuwait National Petroleum Corporation's (KNPC) Mina Al-Ahmadi refinery. The primary benefit was an increase in reformate octane barrel yield from operating the plant at its economic constraints. APCs were able to increase throughput, improve heavy naphtha recovery, and increase reactor bed temperatures while reducing reactor pressure. The APC project paid for itself within a few months. Key aspects of the project included developing models of each unique train using an automated step testing methodology and implementing inferential and online kinetic models. Controllers were designed to maximize reformate octane
This document discusses risk assessment of connecting a 170 kV gas insulated substation (GIS) to a combined cable and overhead line network in Denmark. Simulations were conducted to analyze the effects of shielding failures and back flashovers on the network under varying conditions of surge front time, soil resistivity, and cable length between the GIS and transformers. The simulations showed transformer overvoltages exceeding safe levels set by standards in some scenarios, requiring further investigation into mitigation approaches.
ملخص مشروع six sigma..مهندس عادل حجازىguest6ead29e
six sigma محاولة فهم و تطبيق نظام
هو المخرج الوحيد لحل أكثر المشاكل التى تواجة تعثر المصانع و المؤسسات و تجنب الخسائر الفادحة فى السوق المصرى ..عادل حجازى
International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document presents a comparison of PID and fuzzy PID controllers for position control of a DC motor. It first describes the modeling of a DC motor transfer function. It then provides details on designing a PID controller using Ziegler-Nichols tuning methods. A fuzzy PID controller is also designed using triangular membership functions for error and change in error inputs. Simulation results in MATLAB/Simulink show that the fuzzy PID controller provides better tracking of setpoint changes with less overshoot compared to the ZN-tuned PID controller. The fuzzy PID controller therefore demonstrates better performance for position control of DC motors.
This document summarizes previous research on the deformation of endodontic obturator tips using finite element modeling (FEM). It discusses how FEM has been used to analyze stress distributions and deformation patterns in gutta percha cutter tips when subjected to thermal and mechanical loads. The document reviews literature on using tools like ANSYS to model different tip geometries and materials. It also discusses how FEM can help optimize tip design by predicting failure modes and analyzing stresses under various loading conditions. FEM is presented as an effective tool for analyzing complex dental structures when direct measurement is difficult.
This document discusses implementing trust in cloud computing using public key infrastructure (PKI). It begins by providing background on PKI and how it uses public/private key cryptography to provide security services like authentication, confidentiality, and integrity. It then discusses cloud computing models and the Windows Azure platform. The paper proposes three trust models using PKI: 1) a public root CA and public CA, 2) a public root CA and enterprise CA, and 3) an enterprise root CA and enterprise CA. It details methodologies for implementing each model to establish trust between cloud services and customers. The enterprise root CA model provides the most security and trust but has higher costs and complexity.
This document presents a framework for optimizing transportation costs when supplying resources to construction sites. It identifies renewable and non-renewable resources and considers the locations of storage facilities and construction sites. The objective is to minimize total transportation costs by determining optimal quantities to ship from each storage location to each site. A mathematical model is formulated to represent the transportation costs as a function of shipping quantities between sources and sinks, subject to supply and demand constraints. The model aims to develop a tradeoff between transportation costs and transshipment quantities for efficiently supplying resources in construction projects.
The document compares the low field electron transport properties in compounds of groups III-V semiconductors by solving the Boltzmann equation using an iterative technique. It calculates the temperature and doping dependencies of electron mobility in InP, InAs, GaP and GaAs. The electron mobility decreases with increasing temperature from 100K to 500K for each material due to increased electron-phonon scattering. Electron mobility also increases significantly with higher doping concentration at low temperatures. The iterative results show good agreement with other calculations and experiments. Electron mobility is highest in InAs and lowest in GaP at 300K, due to differences in their effective masses.
This document summarizes a research paper that proposes using the firefly algorithm to solve the NP-hard optimization problem of assigning cells in a cellular network to switches in a way that minimizes total costs. The total cost includes handoff costs for calls between adjacent cells and cabling costs for connecting cells to switches, subject to constraints like switch capacity. It describes modeling the problem mathematically and comparing the firefly algorithm to the particle swarm optimization (PSO) algorithm. The firefly algorithm is shown to solve the cell-to-switch assignment problem faster than existing approaches like PSO.
This document summarizes a research paper that proposes a fuzzy self-adaptive PID controller for temperature control of an electric heating furnace. It begins with an introduction to electric furnaces and challenges with using conventional PID controllers for nonlinear and time-varying temperature processes. It then describes tuning various PID controller gains using algorithms and comparing responses. Next, it designs a fuzzy logic controller and fuzzy-PID controller for the system using MATLAB/Simulink. Membership functions and fuzzy rules are defined for the fuzzy inference systems. The results show that the proposed fuzzy self-adaptive PID controller provides the best dynamic performance for temperature control of the electric furnace.
This document discusses methods for interpolating rainfall data using modified inverse distance weighting (MIDW) techniques. It examines four general forms of the MIDW method where the effects of distance and elevation difference can take positive or negative weights. The authors apply genetic algorithms to optimize the MIDW interpolation equation regionally and compare integrated vs. separated dimensionless weighting approaches. Daily rainfall data from 49 stations in the Mashhad plain catchment area of Iran over 16 years is analyzed. The results show that accounting for elevation improves interpolation and that regional optimization of the MIDW method leads to better performance than local optimization.
The document summarizes a research paper that proposes a new topology for a DSTATCOM (Distribution Static Compensator) to improve power quality in three-phase four-wire distribution systems. The proposed topology integrates a three-leg voltage source converter with a T-connected transformer. This helps mitigate neutral current and allows the DSTATCOM to compensate for load harmonics, reactive power, and imbalance. The design and control strategy of the DSTATCOM are described. Its performance is validated using MATLAB simulation for applications like power factor correction and voltage regulation along with neutral current compensation and harmonic reduction with nonlinear loads.
IRJET-Shunt Hybrid Active Power Filter for Eradication of Current HarmonicsIRJET Journal
1) The document presents a design for a shunt hybrid passive-active power filter to compensate for harmonic current produced by a nonlinear load.
2) A synchronous reference frame control method is used to generate reference compensation currents for the shunt hybrid active power filter. This method transforms load currents to a rotating reference frame to extract harmonic components.
3) Simulation results show that a hybrid filter using both passive and active elements is able to better compensate current harmonics compared to using only a passive or active filter alone. The hybrid filter is able to eliminate both lower and higher order harmonics.
Comparison of Two Compensation Control Strategies for Shunt Active Power Filt...ijtsrd
Use of nonlinear loads has been increased in large extent in industries now-a-days which injects harmonic currents in supply system. These harmonics creates power quality issue. Shunt Active Power Filter (SAPF) is the popular and efficient solution to reduce these harmonics. SAPF can overcome voltage sag, eliminate harmonics and improves power factor. SAPF reduces total harmonic distortion (THD) to acceptable level. Reference current generation is the heart of APF. Reference current generation using instantaneous reactive power (IRP) theory is presented in this paper. IRP theory is widely used to control active power filters (APFs). Modeling of this technique is implemented in MATLABsimulink. The system is experimentally implemented using DS1104 card of d SPACE system. Mr. Amit Kumar Rajan | Dr. E Vijay Kumar"Comparison of Two Compensation Control Strategies for Shunt Active Power Filter in three Systems" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18198.pdf http://www.ijtsrd.com/engineering/electrical-engineering/18198/comparison-of-two-compensation-control-strategies-for-shunt-active-power-filter-in-three-systems/mr-amit-kumar-rajan
Neuro fuzzy control technique in hybrid power filter for power quality improv...Alexander Decker
This document describes a study on using a hybrid power filter with a neuro-fuzzy controller to improve power quality in a three-phase power system supplying a non-linear load. The hybrid power filter combines a passive C-type high-pass filter with an active filter to compensate for voltage/current harmonics. A three-phase converter load was chosen for simulation. Simulation results showed that the proposed neuro-fuzzy controlled hybrid power filter approach provided better compensation of harmonics compared to without a filter, as indicated by lower total harmonic distortion values. The filter design, controller structure, simulation model, and results are discussed in detail.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A proportional resonant current controller for selective harmonic compensathareesh hari
This paper deals with reactive power compensation
and harmonics elimination inmedium-voltage industrial networks
using a hybrid active power filter. It proposes a hybrid filter as a
combination of a three-phase, two-level, voltage-source converter
connected in parallel with the inductor of a shunt, single-tuned,
passive filter. This topological structure greatly decreases the
voltage and current stress over the elements of the active filter.
Since the topology is composed of a single-tuned branch, the
control algorithm also has to ensure sufficient filtering at other
harmonic frequencies. We propose using a proportional-resonant,
multiloop controller. Since the controller is implemented in a
synchronous-reference frame, it allows us to use half the number
of resonators, compared with the solution using proportional-integral
controllers in the harmonic-reference frame. Theoretical
analyses and simulation results obtained from an actual industrial
network model in PSCAD verify the viability and effectiveness
of the proposed hybrid filter. In addition, the simulation results
are validated by a comparison with the results obtained from a
real-time digital simulator.
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.
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.
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
Performance Enhancement in Active Power Filter (APF) by FPGA Implementation IJECEIAES
The generated electrical power in present days is not able to meet its end-user requirement as power demand is gradually increasing and expected to be increasing more in future days. In the power quality management, the parameters/factors like harmonic currents (HC) and reactive power (RP) yields the major issues in the power distribution units causing transformer heating, line losses, and machine vibration. To overcome these issues, several control mechanisms have been presented and implemented in recent past. The control algorithm based on synchronous reference frame (SRF) offers a better response by dividing the HC and RP. But the SRF based control algorithm requires better synchronization among the utility voltage and input current. To achieve this, the existing researches have used digital signal processing (DSP) and microcontroller, but these systems fail to provide better performance as they face issues like limited sampling time, less accuracy, and high computational complexity. Thus, to enhance the performance of active power filter (APF), we present an FPGA based approach. Also, to validate the performance of the proposed approach, we have used Xilinx 14.7 and Modelsim (6.3f) simulator and compared with other previous work. From the results analysis, it is found that the approach has good performance.
Harmonic Mitigation using Modified Synchronous Reference Frame TheoryIRJET Journal
This document summarizes a research paper that presents a new control algorithm called the Modified Synchronous Reference Frame (MSRF) Theory to generate reference currents for a three-phase shunt active power filter (SAPF) to mitigate harmonics in power systems. The SAPF injects compensating currents to cancel out harmonic currents from nonlinear loads, making the source current sinusoidal. The MSRF method calculates the transformation angle from the AC network voltages rather than a phase-locked loop, allowing it to better isolate harmonics. Simulation results showed the SAPF reduced the total harmonic distortion to 3.25% using the MSRF control algorithm. Passive filters are limited and can cause resonance, while the SAPF
Design of shunt hybrid active power filter for compensating harmonic currents...TELKOMNIKA JOURNAL
This document summarizes a research paper that designed a shunt hybrid active power filter to compensate for harmonic currents and reactive power in electrical systems. The hybrid filter combines a passive power filter and active power filter in a shunt configuration. It uses several control methods, including p-q theory, PI controllers, and hysteresis current control, to extract reference compensation currents and regulate the DC bus voltage. Simulation results in MATLAB/Simulink showed the filter can reduce total harmonic distortion below 5% according to IEEE standards and improve the power factor by compensating reactive power. The hybrid filter aims to overcome limitations of previous filter designs by providing effective harmonic mitigation while avoiding issues like resonance or high costs.
The document describes a fuzzy logic hysteresis current controlled shunt active power filter (SAPF) for power quality improvement. A SAPF uses a voltage source inverter to inject compensating currents to correct power factor, balance loads, and eliminate harmonics. The paper compares a conventional PI controller to a fuzzy logic controller for regulating the DC bus voltage and generating PWM signals. Simulation results using Matlab/Simulink show the fuzzy controller has better dynamic performance than the PI controller, maintaining steady state conditions and responding faster to transients or load changes.
Evaluation of Fundamental d-q Synchronous Reference Frame Harmonic Detection ...IJPEDS-IAES
Active Power Filter has become popular choice to address the harmonic pollution present in power system. It relies on fast and accurate detection of reference current to guarantee efficient compensation performance. In this paper harmonic extraction using d-q Synchronous Reference Frame (SRF) for single phase system and various aspects defining its performance is presented. The effect of the orthogonal signal generation on the harmonic current extraction is analyzed. Three different filtering approaches are compared based on their time and frequency domain characteristics. The effect of DC offset in the measured load current, introduced during measurement and data processing is derived. Accordingly a novel method to eliminate this DC offset is proposed with minimum compromise on the dynamics of the system. The discussions presented are validated using simulation results.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document presents a comparison of PID and fuzzy PID controllers for position control of a DC motor. It first describes the modeling of a DC motor transfer function. It then provides details on designing a PID controller using Ziegler-Nichols tuning methods. A fuzzy PID controller is also designed using triangular membership functions for error and change in error inputs. Simulation results in MATLAB/Simulink show that the fuzzy PID controller provides better tracking of setpoint changes with less overshoot compared to the ZN-tuned PID controller. The fuzzy PID controller therefore demonstrates better performance for position control of DC motors.
This document summarizes previous research on the deformation of endodontic obturator tips using finite element modeling (FEM). It discusses how FEM has been used to analyze stress distributions and deformation patterns in gutta percha cutter tips when subjected to thermal and mechanical loads. The document reviews literature on using tools like ANSYS to model different tip geometries and materials. It also discusses how FEM can help optimize tip design by predicting failure modes and analyzing stresses under various loading conditions. FEM is presented as an effective tool for analyzing complex dental structures when direct measurement is difficult.
This document discusses implementing trust in cloud computing using public key infrastructure (PKI). It begins by providing background on PKI and how it uses public/private key cryptography to provide security services like authentication, confidentiality, and integrity. It then discusses cloud computing models and the Windows Azure platform. The paper proposes three trust models using PKI: 1) a public root CA and public CA, 2) a public root CA and enterprise CA, and 3) an enterprise root CA and enterprise CA. It details methodologies for implementing each model to establish trust between cloud services and customers. The enterprise root CA model provides the most security and trust but has higher costs and complexity.
This document presents a framework for optimizing transportation costs when supplying resources to construction sites. It identifies renewable and non-renewable resources and considers the locations of storage facilities and construction sites. The objective is to minimize total transportation costs by determining optimal quantities to ship from each storage location to each site. A mathematical model is formulated to represent the transportation costs as a function of shipping quantities between sources and sinks, subject to supply and demand constraints. The model aims to develop a tradeoff between transportation costs and transshipment quantities for efficiently supplying resources in construction projects.
The document compares the low field electron transport properties in compounds of groups III-V semiconductors by solving the Boltzmann equation using an iterative technique. It calculates the temperature and doping dependencies of electron mobility in InP, InAs, GaP and GaAs. The electron mobility decreases with increasing temperature from 100K to 500K for each material due to increased electron-phonon scattering. Electron mobility also increases significantly with higher doping concentration at low temperatures. The iterative results show good agreement with other calculations and experiments. Electron mobility is highest in InAs and lowest in GaP at 300K, due to differences in their effective masses.
This document summarizes a research paper that proposes using the firefly algorithm to solve the NP-hard optimization problem of assigning cells in a cellular network to switches in a way that minimizes total costs. The total cost includes handoff costs for calls between adjacent cells and cabling costs for connecting cells to switches, subject to constraints like switch capacity. It describes modeling the problem mathematically and comparing the firefly algorithm to the particle swarm optimization (PSO) algorithm. The firefly algorithm is shown to solve the cell-to-switch assignment problem faster than existing approaches like PSO.
This document summarizes a research paper that proposes a fuzzy self-adaptive PID controller for temperature control of an electric heating furnace. It begins with an introduction to electric furnaces and challenges with using conventional PID controllers for nonlinear and time-varying temperature processes. It then describes tuning various PID controller gains using algorithms and comparing responses. Next, it designs a fuzzy logic controller and fuzzy-PID controller for the system using MATLAB/Simulink. Membership functions and fuzzy rules are defined for the fuzzy inference systems. The results show that the proposed fuzzy self-adaptive PID controller provides the best dynamic performance for temperature control of the electric furnace.
This document discusses methods for interpolating rainfall data using modified inverse distance weighting (MIDW) techniques. It examines four general forms of the MIDW method where the effects of distance and elevation difference can take positive or negative weights. The authors apply genetic algorithms to optimize the MIDW interpolation equation regionally and compare integrated vs. separated dimensionless weighting approaches. Daily rainfall data from 49 stations in the Mashhad plain catchment area of Iran over 16 years is analyzed. The results show that accounting for elevation improves interpolation and that regional optimization of the MIDW method leads to better performance than local optimization.
The document summarizes a research paper that proposes a new topology for a DSTATCOM (Distribution Static Compensator) to improve power quality in three-phase four-wire distribution systems. The proposed topology integrates a three-leg voltage source converter with a T-connected transformer. This helps mitigate neutral current and allows the DSTATCOM to compensate for load harmonics, reactive power, and imbalance. The design and control strategy of the DSTATCOM are described. Its performance is validated using MATLAB simulation for applications like power factor correction and voltage regulation along with neutral current compensation and harmonic reduction with nonlinear loads.
call for papers, research paper publishing, where to publish research paper, ...
Similar to call for papers, research paper publishing, where to publish research paper, journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJEI, call for papers 2012,journal of science and technolog
IRJET-Shunt Hybrid Active Power Filter for Eradication of Current HarmonicsIRJET Journal
1) The document presents a design for a shunt hybrid passive-active power filter to compensate for harmonic current produced by a nonlinear load.
2) A synchronous reference frame control method is used to generate reference compensation currents for the shunt hybrid active power filter. This method transforms load currents to a rotating reference frame to extract harmonic components.
3) Simulation results show that a hybrid filter using both passive and active elements is able to better compensate current harmonics compared to using only a passive or active filter alone. The hybrid filter is able to eliminate both lower and higher order harmonics.
Comparison of Two Compensation Control Strategies for Shunt Active Power Filt...ijtsrd
Use of nonlinear loads has been increased in large extent in industries now-a-days which injects harmonic currents in supply system. These harmonics creates power quality issue. Shunt Active Power Filter (SAPF) is the popular and efficient solution to reduce these harmonics. SAPF can overcome voltage sag, eliminate harmonics and improves power factor. SAPF reduces total harmonic distortion (THD) to acceptable level. Reference current generation is the heart of APF. Reference current generation using instantaneous reactive power (IRP) theory is presented in this paper. IRP theory is widely used to control active power filters (APFs). Modeling of this technique is implemented in MATLABsimulink. The system is experimentally implemented using DS1104 card of d SPACE system. Mr. Amit Kumar Rajan | Dr. E Vijay Kumar"Comparison of Two Compensation Control Strategies for Shunt Active Power Filter in three Systems" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18198.pdf http://www.ijtsrd.com/engineering/electrical-engineering/18198/comparison-of-two-compensation-control-strategies-for-shunt-active-power-filter-in-three-systems/mr-amit-kumar-rajan
Neuro fuzzy control technique in hybrid power filter for power quality improv...Alexander Decker
This document describes a study on using a hybrid power filter with a neuro-fuzzy controller to improve power quality in a three-phase power system supplying a non-linear load. The hybrid power filter combines a passive C-type high-pass filter with an active filter to compensate for voltage/current harmonics. A three-phase converter load was chosen for simulation. Simulation results showed that the proposed neuro-fuzzy controlled hybrid power filter approach provided better compensation of harmonics compared to without a filter, as indicated by lower total harmonic distortion values. The filter design, controller structure, simulation model, and results are discussed in detail.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A proportional resonant current controller for selective harmonic compensathareesh hari
This paper deals with reactive power compensation
and harmonics elimination inmedium-voltage industrial networks
using a hybrid active power filter. It proposes a hybrid filter as a
combination of a three-phase, two-level, voltage-source converter
connected in parallel with the inductor of a shunt, single-tuned,
passive filter. This topological structure greatly decreases the
voltage and current stress over the elements of the active filter.
Since the topology is composed of a single-tuned branch, the
control algorithm also has to ensure sufficient filtering at other
harmonic frequencies. We propose using a proportional-resonant,
multiloop controller. Since the controller is implemented in a
synchronous-reference frame, it allows us to use half the number
of resonators, compared with the solution using proportional-integral
controllers in the harmonic-reference frame. Theoretical
analyses and simulation results obtained from an actual industrial
network model in PSCAD verify the viability and effectiveness
of the proposed hybrid filter. In addition, the simulation results
are validated by a comparison with the results obtained from a
real-time digital simulator.
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.
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.
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
Performance Enhancement in Active Power Filter (APF) by FPGA Implementation IJECEIAES
The generated electrical power in present days is not able to meet its end-user requirement as power demand is gradually increasing and expected to be increasing more in future days. In the power quality management, the parameters/factors like harmonic currents (HC) and reactive power (RP) yields the major issues in the power distribution units causing transformer heating, line losses, and machine vibration. To overcome these issues, several control mechanisms have been presented and implemented in recent past. The control algorithm based on synchronous reference frame (SRF) offers a better response by dividing the HC and RP. But the SRF based control algorithm requires better synchronization among the utility voltage and input current. To achieve this, the existing researches have used digital signal processing (DSP) and microcontroller, but these systems fail to provide better performance as they face issues like limited sampling time, less accuracy, and high computational complexity. Thus, to enhance the performance of active power filter (APF), we present an FPGA based approach. Also, to validate the performance of the proposed approach, we have used Xilinx 14.7 and Modelsim (6.3f) simulator and compared with other previous work. From the results analysis, it is found that the approach has good performance.
Harmonic Mitigation using Modified Synchronous Reference Frame TheoryIRJET Journal
This document summarizes a research paper that presents a new control algorithm called the Modified Synchronous Reference Frame (MSRF) Theory to generate reference currents for a three-phase shunt active power filter (SAPF) to mitigate harmonics in power systems. The SAPF injects compensating currents to cancel out harmonic currents from nonlinear loads, making the source current sinusoidal. The MSRF method calculates the transformation angle from the AC network voltages rather than a phase-locked loop, allowing it to better isolate harmonics. Simulation results showed the SAPF reduced the total harmonic distortion to 3.25% using the MSRF control algorithm. Passive filters are limited and can cause resonance, while the SAPF
Design of shunt hybrid active power filter for compensating harmonic currents...TELKOMNIKA JOURNAL
This document summarizes a research paper that designed a shunt hybrid active power filter to compensate for harmonic currents and reactive power in electrical systems. The hybrid filter combines a passive power filter and active power filter in a shunt configuration. It uses several control methods, including p-q theory, PI controllers, and hysteresis current control, to extract reference compensation currents and regulate the DC bus voltage. Simulation results in MATLAB/Simulink showed the filter can reduce total harmonic distortion below 5% according to IEEE standards and improve the power factor by compensating reactive power. The hybrid filter aims to overcome limitations of previous filter designs by providing effective harmonic mitigation while avoiding issues like resonance or high costs.
The document describes a fuzzy logic hysteresis current controlled shunt active power filter (SAPF) for power quality improvement. A SAPF uses a voltage source inverter to inject compensating currents to correct power factor, balance loads, and eliminate harmonics. The paper compares a conventional PI controller to a fuzzy logic controller for regulating the DC bus voltage and generating PWM signals. Simulation results using Matlab/Simulink show the fuzzy controller has better dynamic performance than the PI controller, maintaining steady state conditions and responding faster to transients or load changes.
Evaluation of Fundamental d-q Synchronous Reference Frame Harmonic Detection ...IJPEDS-IAES
Active Power Filter has become popular choice to address the harmonic pollution present in power system. It relies on fast and accurate detection of reference current to guarantee efficient compensation performance. In this paper harmonic extraction using d-q Synchronous Reference Frame (SRF) for single phase system and various aspects defining its performance is presented. The effect of the orthogonal signal generation on the harmonic current extraction is analyzed. Three different filtering approaches are compared based on their time and frequency domain characteristics. The effect of DC offset in the measured load current, introduced during measurement and data processing is derived. Accordingly a novel method to eliminate this DC offset is proposed with minimum compromise on the dynamics of the system. The discussions presented are validated using simulation results.
In this paper, a problem of allocation and sizing of multiple active power-line conditioners (aplcs) in power systems is handled with novel formulation. The utilized objective function comprises two main factors such as reduction of total harmonic distortion and the total cost of active power-line conditioners (aplcs). The formulated problem is solved by optimization technique SHUFFLE FROG LEAP ALGORITHM (SHFLA) using MATLAB. To evaluate the competence of the proposed formulation, the IEEE 18-busdistorted distribution test system is employed and investigated with various number of aplcs placement. These cases are based on the discrete and limited size for aplcs, requiring the optimization method to solve the constrained and discrete nonlinear problems. The comparison of results in this paper showed that the proposed SHFLA is the most effective result among others in determining optimum location and size of APLC in distribution systems.
This document discusses the use of passive harmonic trap filters called HarmonicGuard filters to meet IEEE 519-1992 harmonic limits. It provides an overview of IEEE 519-1992, which sets limits for both voltage and current harmonics. The document explains key terms used in IEEE 519-1992, particularly Point of Common Coupling (PCC), which is important for determining the proper harmonic limits. It also presents examples to illustrate how to interpret the harmonic limits in IEEE 519-1992 based on the PCC location and other factors.
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.
PhD thesis presentation - Advanced Control Strategies for UPQC to Improve Pow...Trinh Quoc Nam
The document presents a thesis on advanced control strategies for unified power quality conditioners (UPQC) to improve power quality in distribution power systems. The thesis proposes control strategies to compensate for current and voltage harmonics, voltage sags, and voltage unbalances. Specifically, it introduces a control method for a shunt active power filter (APF) that eliminates the need for load current measurement and harmonic detection. This is achieved by directly controlling the DC link voltage and supply current. A proportional-integral-virtual phase lead (PI-VPI) current controller is designed to compensate for dominant 6nth harmonic currents without requiring additional filters or controllers. The proposed control strategy aims to simplify UPQC control systems and improve compensation performance.
Advanced Techniques in Harmonic Suppression via Active Power Filter: A ReviewIJPEDS-IAES
This paper intends to present the recent development of artificial intelligence
(AI) applications in active power filter (APF). As a result of the development
in power electronic technology, (APF) continues to attract ample attention.
Compared with the traditional reactive LC filter, active power filter is
considered to be more effective in compensating harmonic current generated
by nonlinear loads. APF, can correct the power quality and improve the
reliability and stability on power utility. A brief explanation of some
important areas in AI and a comprehensive survey of the literature along the
main categories of AI is presented to introduce the readers into the wideranging
topics that AI encompasses. Plenty of relevant literatures have been
selected in the review, mostly emphasized on better accuracy, robustness,
efficiency, stability and tracking ability of the system.
Design Of Hybrid Series Active Filters for Harmonic Reduction in Single Phase...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.
Performance Evaluation of GA optimized Shunt Active Power Filter for Constant...ijeei-iaes
Sinusoidal Current Control strategy for extracting reference currents for shunt active power filters have been modified using Genetic Algorithm and its performances have been compared. The acute analysis of Comparison of the compensation capability based on THD and speedwell be done, and recommendations will be given for the choice of technique to be used. The simulated results using MATLAB model are shown, and they will undoubtedly prove the importance of the proposed control technique of aircraft shunt APF.
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This document presents a novel technique for solving the transcendental equations of selective harmonics elimination pulse width modulation (SHEPWM) inverters based on the secant method. The proposed algorithm uses the secant method to simplify the numerical solution of the nonlinear equations and solve them faster compared to other methods. Simulation results validate that the proposed method accurately estimates the switching angles to eliminate specific harmonics from the output voltage waveform and achieves near sinusoidal output current for various modulation indices and numbers of harmonics eliminated.
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1. International Journal of Engineering Inventions
ISSN: 2278-7461, www.ijeijournal.com
Volume 1, Issue 4 (September2012) PP: 39-46
The Application of PSO to Hybrid Active Power Filter Design for
3phase 4-Wire System with Variable Load
B. Suresh Kumar1, Dr. K. Ramesh Reddy2
Abstract––An optimal design method for and hybrid active power filters (HAPFs) set at high voltage levels to satisfy the
requirements of Harmonic filtering and reactive power compensation. Multi objective Optimization models for HAPF
were constructed. Detuning effects and faults were also considered by constructing Constraints during the optimal
process, which improved the reliability and practicability of the designed filters. An effective Strategy was adopted to solve
the multi objective optimization Problems for the designs of HAPF. Furthermore, the Particle swarm optimization
algorithm was developed for searching an optimal solution of planning of filters. An application of the method to an
industrial case involving harmonic and reactive Power problems indicated the superiority and practicality of the proposed
design methods.
I. INTRODUCTION
POWER Systems have to cope with a variety of nonlinear Loads which introduce significant amounts of
harmonics. IEEE Standard 519-1992 provides a guideline for the limitation and mitigation of harmonics. Passive power
filters (PPFs), Active power filters (APFs), and hybrid active power filters (HAPFs) can all be used to eliminate harmonics.
For Medium- and high-voltage systems, PPFs and HAPFs appear to be better choices considering cost where the ratings are
of several tens of megavolt–amperes. The design of such PPFs and HAPFs is a complicated nonlinear programming
problem. Conventional trial-and-error Methods based on engineering experience are commonly used, but the results are not
optimal in most cases.
In recent years, many studies have appeared involving optimal PPF design. A Method based on the sequential
unconstrained minimization Technique has been used for PPF design because of its simplicity and versatility, but numerical
instability can limit the application of this method. PPF design using simulated Annealing has been reported, but the major
drawback is the repeated annealing.
Genetic algorithms (gas) have been widely used in PPF design, but the computing burden and convergence
problems are disadvantages of this approach. A design method for PPFs using a hybrid Differential evolution Algorithm has
also been proposed, but the algorithm is Complex, involving mutation, crossover, migrant, and accelerated
Operations For the optimal design of HAPFs, a method based on gas has been proposed in order to minimize the
rating of APF, but no other optimal design methods appear to have been Suggested. Many methods treated the optimal
design of PPFs and HAPFs as a single objective problem. In fact, filter Design should determine the optimal solution where
there are multiple objectives. As these objectives generally conflict with One another, they must be cautiously coordinated to
derive a Good compromise solution.
In this paper, optimal multi objective designs for both PPFs and HAPFs using an advanced particle swarm
optimization (PSO) algorithm are reported. The objectives and constraints were developed from the viewpoint of practicality
and the Filtering characteristics.
For the optimal design of PPFs, the capacity of reactive Power compensation, the original investment cost, and the
total Harmonic distortion (THD) were taken as the three objectives. The constraints included individual harmonic distortion,
fundamental Reactive power compensation, THD, and parallel and Series resonance with the system. For the optimal design
of HAPFs, the capacity of the APF, The reactive power compensation, and the THD were taken as the three objectives; the
constraints were as for the PPFs.
The Uncertainties of the filter and system parameters, which will Cause detuning, were also considered as
constraints during the optimal design process. A PSO-based algorithm was developed to search for the optimal solution. The
numerical results of case Studies comparing the PSO method and the conventional trial and- Error method are reported.
From which, the superiority and Availability of the PSO method and the designed filters are certified.
II. SYSTEM UNDER STUDY
A typical 10-kV 50-Hz system with nonlinear loads, as shown in Fig. 1, was studied to determine the optimal
design for both PPFs and HAPFs. The nonlinear loads are the medium frequency furnaces commonly found in steel plants
with abundant harmonic currents, particularly the fifth and seventh orders,
39
2. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
66kv
Harmonic current
Main transformer
Measurement point
10kv
Filters Furnaces Other
PPF or HAPF loads
Nonlinear
loads
Fig 1. Single diagram of system for case studies.
TABLE I : HARMONIC CURRENT DISTRIBUTIONS IN PHASE A AND UTILITY TOLERANCES
Measured National IEEE standard
Harmonic
Value Standard 519-1992
Order
(%) (%) (%)
5 6.14 2.61 4
7 2.77 1.96 4
11 1.54 1.21 2
13 0.8 1.03 2
17 0.6 0.78 1.5
19 0.46 0.7 1.5
23 0.95 0.59 0.6
25 0.93 0.53 0.6
THD 7.12 5 5
as shown in Table I. The utility harmonic tolerances given in IEEE Standard 519-1992 and the Chinese National Standard
GB/T14549-93 are listed in Table I as percentages of the fundamental current. Table I shows that current THD, and the 5th,
23rd, and 25th order harmonic currents exceed the tolerances based on both standards. In addition, the 7th and 11 th order
harmonics exceed the tolerance based on the National standard.
Filters must therefore be installed to mitigate the harmonics sufficiently to satisfy both standards. Both PPF and
HAPF are suitable and economical for harmonic mitigation in such systems. For this system with nonlinear loads as medium
frequency furnaces, the even and triple harmonics are very small and far below the standard values, so these harmonics are
not considered. In addition, the harmonic voltages are in fact very small, so the voltages are assumed to be ideal.
The fundamental current and reactive power demands are 1012 A and 3–4 MVar, respectively. The short circuit capacity is
132 MVA, and the equivalent source inductance of the system is 2.4 mH
III. HAPF DESIGN BASED ON PSO
A. HAPF Structure and Performance:
In order to demonstrate the optimal design method of HAPFs based on PSO, an HAPF was designed and is shown
in Fig. 2; it is supposed to be used in the same situation as that shown in Fig. 1. In this HAPF, PPFs are mainly used to
compensate for harmonics and reactive power, and an APF is used to improve the filtering performance .The PPF consists of
the fifth and seventh single-tuned filters and a high-pass damped filter. The APF is implemented with a three-phase voltage-
source inverter. Fig. 3(a) shows the single-phase equivalent circuits of the
HAPF, assuming that the APF is an ideal controllable voltage VAF and that the load is an ideal current source IL. ZS is the
source impedance, ZF is the total impedance of the PPF, Vpcc is the voltage of the injected point, and K is the controlling
gain of the APF.
Vs Ls
10kv bus
Nonlinear
loads
System source
C5 C7 CH C7 C7
PPF L5 L7 LH RH L7 LH L7 LH
APF
L
Coupling
C
Transformer
C
R
Fig.2. Shunt HAPF.
40
3. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
Vpcc Vpcch
zs I. . zs K
.
s IAF IAFh
+ Zf . Zf
Vs + . .
- Ish ILh
. IL
-
VAF = k . Ish
(a) (b)
Fig 3.Single-phase equivalent circuits of the HAPF (a) Equivalent circuit.
(b) Equivalent harmonic circuit.
The equivalent harmonic circuit is redrawn as in Fig. 3(b). The harmonic current Ish into the system source and the
ZF
I sh | | I Lh (1)
harmonic attenuation factor γ are given in the following equations: K ZF ZS
I Sh ZF
| | (2)
I Lh K ZF ZS
Assuming that the fundamental component of the supply voltage is fully dropped across the PPF, the voltage and current of
APF can be derived as follows [24]:
VAF VAFh Z Fh . I AFh Z Fh . I (3)
Lh
h h h
The rms value of ˙VAF is defined as
I I 1 I (4)
AF AF AFh
h
VAF V 2 AFh (5)
h 5,7,11,13,17,19,23,25
The capacity of the APF is determined by the current I˙AF and the voltage ˙VAF. It is obvious that the low VA rating of APF
can be achieved by decreasing ˙ IAF and ˙VAF. In this shunt hybrid topology, the current I˙AF is almost constant, so the
only way to reduce the VA rating of APF is to decrease the voltage VAF.
B. Multi objective Optimal Design Model for HAPF:
As mentioned earlier, when designing an HAPF, it is very important to minimize the capacity of the APF
component, and there are some other objectives and constraints to be considered when the APF of the HAPF is cut off due to
faults, the PPF part keeps work in to mitigate harmonics until the APF is restored. It follows that some additional constraints
should be included in respect of such occasions. The constructions of objective functions and constraints are described next.
Three important objective functions are defined as follows.
1) Minimize the capacity of the APF, which is mainly determined by the harmonic voltage across it
min VAF
h 5,7,11,13,17,19,23,25
VAFh (6)
2
2) Minimize the current THD with HAPF
2
N
I
min THDI HAPF Ish (7)
h 2 1
where THDIHAPF is the current THD with the HAPF in place; and the definitions of Ish, I1, and N are the same as those in
(7).
3) Maximize the reactive power compensation
max
i 5,7, H
Qi (8)
Where Qi is same with that in (9)
Constraints are defined as follows.
The tolerated values quoted hereinafter are also based on the National standard.
1) Requirements of total harmonic filtering with the HAPF
THDI HAPF THDI MAX (9)
Where THDIMAX is defined in (10)
When PPF runs individually with the APF cutoff, an additional constraint is added as follows:
THDI PPF THDI MAX (10)
Where THDIPPF is the THD with the PPF alone
41
4. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
2) Requirements of individual harmonic filtering with HAPF and PPF alone: Each order harmonic should satisfy the
standards, so the following constraints are included:
I HAPFsh I hmax , h 5,7,11,13,17,19,23,25 (11)
I PPFsh I hmax , h 5,7,11,13,17,19,23,25 (12)
Where IHAPFsh and IPPFsh are, respectively, the rms values of the hth order harmonic current into the system source with the
HAPF and the PPF alone Ihmax is defined by (11).
3) Fundamental reactive power compensation limits: The fundamental reactive power must be restricted as
Qmin
i 5,7, H
Qi Qmax (13)
Where Qmin and Qmax are as defined in (12).
4) Parallel and series resonance restrictions: Parallel and series resonance with system source will rarely happen for the
HAPF due to the active damping function of the APF. Nevertheless, it is necessary to consider, during the HAPF design,
parallel and series resonance restrictions when PPF works alone with the APF cutoff. Therefore, constraints are constructed,
which are the same as those constructed during the PPF optimal design in (13)–(16).
5) Consideration of the detuning constraints: The HAPF system is not sensitive to detuning effects because of the APF
damping function. In the worst case, that the system impedance decreases by 20%, the system frequency changes to 50.5 Hz,
the capacitance of each branch increases by 5%, and the reactance also increases by 2%, then the filtering performance of the
PPF alone should still satisfy all the standards and limit described earlier, as set out in (10), (12), and (13).
C. Optimal Design for HAPF Based on PSO Based
on the objectives and constraints constructed earlier for HAPF, the multi objective optimization task is carried out
using an advanced PSO algorithm. The capacitance in each branch of the PPF and the characteristic frequency of the high-
pass damped filter are chosen as optimal variables Xi = (C5, C7, CH, fH)T, while the tuning frequencies of the fifth and
seventh single-tuned filters are predetermined as 242 and 342 Hz, respectively. According to the optimization objectives, the
corresponding fitness functions are defined as
F ' ( X ) VAF (14)
1
F2' ( X ) THDI HAPF (15)
F3' ( X )
i 5,7, H
Qi (16)
Similar methods were adopted to solve this multi objective optimization problem. The objective of minimizing the APF
capacity is chosen as the final objective, while the other two objectives are solved by using acceptable level constraints, as
shown in the following equations:
min F (17)
1
F2 1 (18)
2 F3 3 (19)
Whereα’1,α’3,and α’2 are the highest and lowest acceptable levels for the secondary objectives, respectively. The overall
optimization process for the HAPF based on PSO is similar to that of the PPF in Fig. 4.
TABLE II : Design results of HAPFs based on PSO and conventional methods
Conventional method
Design parameters Pso-method
C5=59.76uF C5=80.6uF
The 5th Single-tuned filter L5=7.24mH L5=5.37mH
Q5=60 Q5=60
C7=12.32uF C7=23.76uF
The 7th single -tuned filter L7=17.58mH L7=9.11mH
Q7=60 Q7=60
CH=52.06uF CH=15.28uF
High-pass damped filter LH=1.20mH LH=3.32mH
m=0.5 m=0.5
42
5. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
TABLE III: HARMONIC CURRENT DISTRIBUTIONS WITH HAPFs BASED ON PSO AND CONVENTIONAL
METHODS
PSO
Harmonic Conventional
Method
orders Method
(%)
(%)
5 0.24 0.17
7 0.24 0.11
11 0.25 0.71
13 0.1 0.3
17 0.07 0.16
19 0.06 0.12
23 0.13 0.26
25 0.13 0.26
THD 0.48 0.91
VAF 340.82 V
116.64 V
Reactive Power
Compensation 4MVar 3.88MVar
The design results of HAPFs using PSO and conventional trial-and-error methods are listed in Table II. The design
results based on the conventional method in Table II .It can be seen that the harmonic currents and reactive power are well
compensated by both HAPFs and that the HAPF designed using the method based on PSO can obtain better filtering
performance with lower THD (0.48%) and larger reactive power compensation (4MVar). Moreover, the voltage VAF of the
APF, in this case, was much smaller than that based on conventional method. Therefore, the investment cost of the whole
system is much reduced. Table IV shows the harmonic current distributions when the PPF is working alone, without the
APF.
A comparison is made between the PSO method and conventional method, and it can be seen that all the harmonic
currents and the THD are still within the standards, and the filtering performance of PPF based on PSO is a little better.
TABLE IV: Harmonic current distributions with PPFs alone Based on PSO and conventional methods
Harmonic PSO Conventional
orders Method Method
(%) (%)
5 1.1 0.82
7 0.76 0.39
11 0.94 1.13
13 0.26 0.60
17 0.14 0.29
19 0.11 0.21
23 0.21 0.40
25 0.20 0.38
THD 1.68 1.71
TABLE V :HARMONIC CURRENT DISTRIBUTIONS WITH HAPFS AND PPFS ALONE CONSIDERING
DETUNING EFFECTS
PSO PSO Conventional
Harmonic Method Method Method HAPF (%)
Orders PPF (%) HAPF (%)
5 2.56 0.65 0.44
7 1.72 0.75 0.27
11 0.99 0.23 0.71
13 0.30 0.1 0.27
17 0.17 0.08 0.16
19 0.13 0.06 0.13
23 0.25 0.14 0.28
43
6. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
25 0.25 0.14 0.28
THD 3.31 1.05 1.02
In order to verify the filtering performances of HAPF and PPF alone under the worst detuning situations,
comparisons are shown in Table V. It is clear that both HAPFs, using PSO method and conventional method, can obtain
excellent filtering performance in spite of detuning effects.
When PPF runs alone without APF, the PPF using the PSO method can still mitigate all the harmonic currents and
THD within the tolerance, while with the PPF using the conventional method, the 11th order harmonic current exceeds the
tolerance of the National standard.
These results again verify the necessity of considering detuning effects during the design process. Fig. 4 shows the
harmonic attenuation factors of HAPF and PPF alone using the PSO design method and considering detuning effects. It can
be seen that the harmonic currents are still well attenuated, and no resonance point can be found. Furthermore, the
attenuation factor of HAPF is much smaller than that of PPF, which shows the excellent harmonic mitigation performance of
HAPF.
The simulation using the MATLAB/SIMULINK software has been run based on field measurement data., The
compensated source current with the HAPF is shown in Fig. 5. From Fig. 5, we can see that the source current is very close
to a pure sine wave, with the current THD decreasing to 0.48%.
Fig. 6 shows the convergence characteristics of the PSO algorithm developed in this paper for optimal design of
HAPF. In this paper, the PSO algorithm is run 200 times, and every time, it can converge within 360 iterations. All those can
demonstrate the efficiency and validity of PSO for the optimal HAPF design.
Fig 4. Harmonic attenuation factors of the HAPF and its PPF alone based on the PSO method.
(a) Harmonic attenuation factor of the HAPF based on the PSO method. (b) Harmonic attenuation of the PPF alone
based on the PSO method
Fig 5.Compensated source current and its THD analysis with HAPF based on the PSO method
(a) Compensated source currents of phase A with HAPF. (b) THD analysis of compensated source current.
44
7. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
Fig.6. Convergence characteristics of PSO for HAPF design.
Fig.7. Simulink model of HAPF using with & without PSO with Variable loads
45
8. The Application of PSO to Hybrid Active Power Filter Design for 3phase 4-Wire System…
Table: VI Results with Variable Load
WITHOUT PSO
WITH PSO
% Reactive
SCHEME THD P.F Power % P.F Reactive
(VAR) THD Power
(VAR)
HAPF 0.47 0.99 2.018 26.54 0.528 1.31
IV. CONCLUSION
A novel hybrid APF with injection circuit was proposed. Its principle and control methods were discussed. The
proposed adaptive fuzzy-dividing frequency control can decrease the tracking error and increase dynamic response and
robustness. The control method is also useful and applicable to any other active filters. It is implemented in an IHAPF with a
100-kVA APF system in a copper mill in Northern China, and demonstrates good performance for harmonic elimination.
Simulation and application results proved the feasibility and validity of the IHAPF and the proposed control method.
REFERENCES
1. L. Gyugyi and E. C. Strycula, “Active ac power filters,” in Proc. IEEE, Ind. Appl. Soc. Annu. Meeting, 1976, pp.
529–535.
2. N. Mohan, H. A. Peterson, W. F. Long, G. R. Dreifuerst, and J. J. Vithayathil, “Active filters for AC harmonic
suppression,” presented at the IEEE Power Eng. Soc. Winter Meeting, 1977.
3. F. Peng, H. Akagi, and A. Nabae, “A new approach to harmonic compensation in power system-a combined
system of shunt passive and series active filters,” IEEE Trans. Ind. Appl., vol. 26, no. 6, pp. 983–990, Nov. 1990.
4. C. Madtharad and S. Premrudeepreechacharn, “Active power filter for three-phase four-wire electric systems using
neural networks,” Elect. Power Syst. Res., vol. 60, no. 2, pp. 179–192, Apr. 2002.
5. H. Fujita and H. Akagi, “A practical approach to harmonic compensation in power system-series connection of
passive and active filters,” IEEE Trans. Ind. Appl., vol. 27, no. 6, pp. 1020–1025, Nov. 1991.
6. H. Fujita and H. Agaki, “The unified power quality conditioner: the integration of series and shunt-active filters,”
IEEE Trans. Power Electron., vol. 13, no. 2, pp. 315–322, Mar. 1998.
7. K. J. P. Macken, K. M. H. A. De Brabandere, I. J. L. Dnesen, and R. J. M. Belmans, “Evaluation of control
algorithms for shunt active tillers under unbalanced and nonsinusoidal conditions,” in Proc. IEEE Porta Power
Tech. Conf., Porto, Portugal, Sep. 10–13, 2001, pp. 1621–1626.
8. F. Ruixiang, L. An, and L. Xinran, “Parameter design and application research of shunt hybrid active power filter,”
Proc. CSEE, vol. 26, no. 2, pp. 106–111, Jun. 2006.
9. S. Kim and P. N. Enjeti, “A new hybrid active power filter (APF) topology,” IEEE Trans. Power Electronics, vol.
17, no. 1, pp. 48–54, Jan. 2002.
10. S. Bhattachaya, P.-T. Cheng, Deep, and M. Divan, “Hybrid solutions for improving passive filter performance in
high power applications,” IEEE Trans Ind. Appl., vol. 33, no. 3, pp. 732–747, May 1997.
11. L. Malesani, P. Mattavelli, and P. Tomasin, “High performance hysteresis modulation technique for active filters,”
IEEE Trans. Power Electron., vol. 12, no. 5, pp. 876–884, Sep. 1997.
12. S. Fukuda and R. Imamura, “Application of a sinusoidal internal model to current control of three-phase utility-
interface converters,” IEEE Trans. Ind. Electron., vol. 52, no. 2, pp. 420–426, Apr. 2005.
13. X. Yuan, W. Merk, H. Stemmler, and J. Allmeling, “Stationary-frame generalized integrators for current control of
active power filters with zero steady-state error for current harmonics of concern under unbalanced and distorted
operating conditions,” IEEE Trans. Ind. Appl., vol. 38, no. 2, pp. 523–532, Mar. 2002.
14. K. Nishida, Y. Konishi, and M. Nakaoka, “Current control implementation with deadbeat algorithm for three-
phase current-source active power filter,” Proc. Inst. Elect. Eng., Electr. Power Appl., vol. 149, no. 4, pp. 275–282,
Jul. 2002.
15. J. H. Marks and T. C. Green, “Predictive transient-following control of shunt and series active power filters,” IEEE
Trans. Power Electron., vol. 17, no. 4, pp. 574–584, Jul. 2002.
16. A. Nakajima, K. Oku, J. Nishidai, T. Shiraishi, Y. Ogihara, K. Mizuki, and M. Kumazawa, “Development of
active filter with series resonant circuit,” in Proc 19th IEEE Annu. Power Electronics Specialists Conf. Rec., Apr.
11–14, 1988, vol. 2, pp. 1168–1173.
46