In order to achieve a good dynamical response of a full-bridge AC-DC voltage source converters (VSC). The bandwidth of PI controller must be relatively wide. This leads to the voltage ripple produced in the control signal, as known that its ripple frequency has twice of the line frequency and cause the 3rd harmonic of an input current. A Ripple Voltage Estimator (RVE) algorithm and Feed-Forward Compensation (FFC) algorithm are proposed and added to the conventional control. The RVE algorithm estimated the ripple signal to subtract it occurring in the voltage loop. As a result, the 3rd harmonic of the input current can be reduced, and hence the Total Harmonic Distortion of input current (THDi) are improved. In addition, the FFC algorithm will offer a better dynamical response of output voltage. The performance evaluation was conducted through the simulation and experiment at 110Vrms/50Hz of the input voltage, with a 600 W load and 250 Vdc output voltage. The overall system performances are obtained as follows: the power factor at the full load is higher 0.98, the harmonic distortion at AC input power source of the converter is under control in IEC61000-3-2 class A limit, and the overall efficiency is greater than 85%.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
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
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Single Stage Single Phase Active Power Factor Corrected Ĉuk Topology Based AC...IJPEDS-IAES
This paper focuses on the analysis of a power factor correction (PFC) converter using close loop Ĉuk topology. Regardless of the input line voltage and output load variations, input current drawn by the buck or buck-boost converter is always discontinuous. The Boost converter suffers from high voltage stresses across the power electronic devices. The input current in Ĉuk converter is comparable to boost converter’s input current. In this paper output voltage is controlled by inner current and outer voltage control loop along with power factor correction (PFC). It shows less input current THD, nearly unity power factor and better output voltage regulation of AC-DC converter under variable input voltage and output load. In this paper the relative performance between normal diode rectifier, open loop Ĉuk rectifier and close loop Ĉuk rectifier is presented. An algorithm for implementing close loop Ĉuk rectifier in digital domain is developed and simulated.
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.
Source current harmonic mitigation of distorted voltage source by using shunt...IJECEIAES
In this paper, three-phase, four-wire shunt active power filter (SAPF) is utilized to mitigate system harmonics of distorted voltage source for unbalanced and nonlinear loads. Basically, the source voltage should be pure sinusoidal waveform to get a good mitigation of source current harmonics. In this under study system, the source voltage is assumed to be harmonic distortion non-sinusoidal voltage source. The phase locked loop (PLL) control circuit is wielded for extracting the fundamental component of the distorted source voltage to use it as an input signal to the SAPF control. Another input signal to the SAPF is the distorted load current. The SAPF control system uses (p-q) theory to calculate the optimum instantaneous current to be injected by the SAPF to mitigate the source current harmonics even the source voltage is harmonic distorted. MATLAB/SIMULINK software package is utilized to simulate the system under study. The effect of SAPF is tested when it’s used with and without the PLL control circuit. The simulation results show that, the THD of source current when using the PLL control circuit is improved to comply with the harmonic limits given in the IEEE 519-1992 and IEC 61000-4-7 standards.
The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
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
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Single Stage Single Phase Active Power Factor Corrected Ĉuk Topology Based AC...IJPEDS-IAES
This paper focuses on the analysis of a power factor correction (PFC) converter using close loop Ĉuk topology. Regardless of the input line voltage and output load variations, input current drawn by the buck or buck-boost converter is always discontinuous. The Boost converter suffers from high voltage stresses across the power electronic devices. The input current in Ĉuk converter is comparable to boost converter’s input current. In this paper output voltage is controlled by inner current and outer voltage control loop along with power factor correction (PFC). It shows less input current THD, nearly unity power factor and better output voltage regulation of AC-DC converter under variable input voltage and output load. In this paper the relative performance between normal diode rectifier, open loop Ĉuk rectifier and close loop Ĉuk rectifier is presented. An algorithm for implementing close loop Ĉuk rectifier in digital domain is developed and simulated.
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.
Source current harmonic mitigation of distorted voltage source by using shunt...IJECEIAES
In this paper, three-phase, four-wire shunt active power filter (SAPF) is utilized to mitigate system harmonics of distorted voltage source for unbalanced and nonlinear loads. Basically, the source voltage should be pure sinusoidal waveform to get a good mitigation of source current harmonics. In this under study system, the source voltage is assumed to be harmonic distortion non-sinusoidal voltage source. The phase locked loop (PLL) control circuit is wielded for extracting the fundamental component of the distorted source voltage to use it as an input signal to the SAPF control. Another input signal to the SAPF is the distorted load current. The SAPF control system uses (p-q) theory to calculate the optimum instantaneous current to be injected by the SAPF to mitigate the source current harmonics even the source voltage is harmonic distorted. MATLAB/SIMULINK software package is utilized to simulate the system under study. The effect of SAPF is tested when it’s used with and without the PLL control circuit. The simulation results show that, the THD of source current when using the PLL control circuit is improved to comply with the harmonic limits given in the IEEE 519-1992 and IEC 61000-4-7 standards.
The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Distribution Static Synchronous Compensator (DSTATCOM) is a shunt compensating device which is used
to improve current profile by exchanging of reactive power with unbalanced and nonlinear load. DSTATCOM is a
shunt compensating device used for power quality improvement in distribution systems. Relevant solutions are
applied for harmonics, fluctuation of voltage, voltage deviation, unbalance of three phase voltage and current and
frequency deviation. Different controlling schemes such as Phase Control Method (PCM), Fryze Power Theory
(FPT), Synchronous Reference Frame Theory (SRFT) and Instantaneous Reactive Power Theory (IRPT) are used
for reactive power compensation with the help of Voltage source Inverter (VSI). In this project we are going to
balance the source current using different control schemes. The results of different source currents are compared
with a different control schemes in terms of active and reactive power and in terms of Total Harmonic Distortion
(THD) for nonlinear load using Fryze Power Theory (FPT) and Instantaneous Reactive Power Theory (IRPT).
Reference currents are generated by the different control schemes have been dynamically traced in a hysteresis
current controller. The performance of DSTATCOM for different control schemes is validated for load balancing
and harmonic elimination by using simulation models in MATLAB/SIMULINK
Application of Backstepping to the Virtual Flux Direct Power Control of Five-...IJPEDS-IAES
This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.
Power Quality development using PV based boost cascaded inverter system is one of the reliable methods. This paper handle with modeling and fuzzy logic control of boost to boost cascaded three phase inverter system with PV as source. MATLAB simulink model for BBCIS has been developed using the elements of simulink and cascaded loop investigations are performed with PI and Fuzzy Logic Controllers. The dynamic responses of the above systems are compared in terms of time domain parameters. The consequences point to that maximum power is obtained with minimum THD using FLC.
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.
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.
Fuzzy Logic Controller Based High Frequency Link AC-AC Converter For Voltage ...IJTET Journal
Abstract—In this paper, an advanced high frequency link AC-AC Push-pull cycloconverter for the voltage compensation is proposed in order to maintain the power quality in electric grid. The proposed methodology can be achieve arbitrary output voltage without using large energy storage elements. So that the system is more steadfast and less costly compared with the conventional inverter topology. Additionally, the proposed converter does not contain any line frequency transformer, which reduces the cost further. The control scheme for the push pull cycloconverter employs the fuzzy logic controller based sinusoidal pulse width modulation (SPWM) to accomplish better performance on voltage compensation, like unbalanced voltage harmonics elimination. The simulation results are given to show the effectiveness of the proposed high frequency link AC-AC converter and fuzzy logic controller based SPWM technology
Compensation of Harmonics of Fully Controlled Loads by Using SAHFIOSRJEEE
In this paper, Three Phase Shunt Active Harmonic Filter is used for harmonic compensation of fully Controlled loads by using new thyristorized Pulse Generator Circuits which generates 12 Pulses for two NonLinear three phase Loads. The three phase Non-Linear Loads are connected at the secondary of three phase Transformers with Three Phase Breakers having Transition time 5/60seconds. A new Pulse Generator topology is used for generating pulses for each of three phase non-linear loads. The Circuit used for Compensation of Harmonics having three phase IGBT based Inverter. The IGBT base d Shunt Active Harmonic Filter gets firing Pulses from PLL phase Locked Loop& Hysteresis Switching HS. The used PLL extracts the Fundamental component of load current which is then multiplied with same RMS gain for generating the Reference current for Hysteresis Current Controller. The used Hysteresis Current Controller compares the reference current
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A novel three phase bidirectional AC buck converter circuit using power
MOSFET is analyzed for input power factor, harmonic profile and efficiency of the
converter for power quality improvement. The equal PWM (EPWM) technique is a used to
increase number of pulses per half cycle (P) in order to vary these parameters. The rms
value of the fundamental component of the output voltage can be increased by varying the
duty ratio (K) of the pulses. It is observed from the simulation results obtained using
MATLAB/simulink that the proposed scheme using EPWM technique significantly reduces
low order harmonics, eliminates certain harmonics for certain values of P, improves input
power factor and hence significantly reduces the filter size of the converter.
POWER STABILITY ANALYSIS OF A TRANSMISSION SYSTEM WITH A UNIFIED POWER FLOW C...IJITE
The unified power quality conditioner is the equipment used for regulated voltage distortion and voltage
unbalance in a power system. UPFC can enhance the power to flow through the transmission system by
controlling the power flow and voltage stability of the transmission line within their limits. This paper
presents a control scheme and Theoretical derivation of the unified power flow conditioner and the
simulation results are compared and contrasted in detail. UPFC is a combination of shunt Active and
series active power filters. UPFC contains a DC link capacitor in a single-phase voltage source inverter
with two back to back connected, three-phase three-wire and three-phase four-wire are arranged. The
fundamental target of this work is to determine the causes and impacts of power quality problems,
specifically voltage sag, voltage swell, power factor, and Total Harmonics Distortion (THD) and enhance
the power quality of a transmission system by UPFC based Transformative Intrinsic Algorithm (TIA). The
Simulation of the proposed method is developed by Mat lab Simulink software, and the simulation result
shows, the proposed method gives better solutions to control the power imbalance in the distribution
system with its cost-effectiveness.
This paper presents an analysis of virtual-flux direct power control (VFDPC) technique for the three-phase pulse width modulation (PWM) ac-dc converter. The proposed VFDPC is developed by assuming the grid voltage and converter line filters quantities are related to a virtual three-phase ac motor. The controller works with less number of sensors by eliminating the voltage sensors used for measuring the three-phase grid voltage. The grid virtual flux which is proportional to the grid voltage will be estimated from the information of converter switching states, line current, and dc-link output voltage. Several analyses are performed in order to study the steady state and dynamic performance of the converter, particularly during the load and DC voltage output reference variations. The proportional integral (PI) controller at the outer voltage control loop of VFDPC is tuned properly and the entire PWM ac-dc converter system is simulated using MATLAB/Simulink to ensure the dc output voltage follow the desired output voltage under steady state and dynamic conditions. Ac-dc converter utilizing the proposed VFDPC is able to generate three-phase input current waveforms that are almost sinusoidal with low harmonics contents which is less than 5% and near unity power factor (pf) operation.
Distribution Static Synchronous Compensator (DSTATCOM) is a shunt compensating device which is used
to improve current profile by exchanging of reactive power with unbalanced and nonlinear load. DSTATCOM is a
shunt compensating device used for power quality improvement in distribution systems. Relevant solutions are
applied for harmonics, fluctuation of voltage, voltage deviation, unbalance of three phase voltage and current and
frequency deviation. Different controlling schemes such as Phase Control Method (PCM), Fryze Power Theory
(FPT), Synchronous Reference Frame Theory (SRFT) and Instantaneous Reactive Power Theory (IRPT) are used
for reactive power compensation with the help of Voltage source Inverter (VSI). In this project we are going to
balance the source current using different control schemes. The results of different source currents are compared
with a different control schemes in terms of active and reactive power and in terms of Total Harmonic Distortion
(THD) for nonlinear load using Fryze Power Theory (FPT) and Instantaneous Reactive Power Theory (IRPT).
Reference currents are generated by the different control schemes have been dynamically traced in a hysteresis
current controller. The performance of DSTATCOM for different control schemes is validated for load balancing
and harmonic elimination by using simulation models in MATLAB/SIMULINK
Application of Backstepping to the Virtual Flux Direct Power Control of Five-...IJPEDS-IAES
This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.
Power Quality development using PV based boost cascaded inverter system is one of the reliable methods. This paper handle with modeling and fuzzy logic control of boost to boost cascaded three phase inverter system with PV as source. MATLAB simulink model for BBCIS has been developed using the elements of simulink and cascaded loop investigations are performed with PI and Fuzzy Logic Controllers. The dynamic responses of the above systems are compared in terms of time domain parameters. The consequences point to that maximum power is obtained with minimum THD using FLC.
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.
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.
Fuzzy Logic Controller Based High Frequency Link AC-AC Converter For Voltage ...IJTET Journal
Abstract—In this paper, an advanced high frequency link AC-AC Push-pull cycloconverter for the voltage compensation is proposed in order to maintain the power quality in electric grid. The proposed methodology can be achieve arbitrary output voltage without using large energy storage elements. So that the system is more steadfast and less costly compared with the conventional inverter topology. Additionally, the proposed converter does not contain any line frequency transformer, which reduces the cost further. The control scheme for the push pull cycloconverter employs the fuzzy logic controller based sinusoidal pulse width modulation (SPWM) to accomplish better performance on voltage compensation, like unbalanced voltage harmonics elimination. The simulation results are given to show the effectiveness of the proposed high frequency link AC-AC converter and fuzzy logic controller based SPWM technology
Compensation of Harmonics of Fully Controlled Loads by Using SAHFIOSRJEEE
In this paper, Three Phase Shunt Active Harmonic Filter is used for harmonic compensation of fully Controlled loads by using new thyristorized Pulse Generator Circuits which generates 12 Pulses for two NonLinear three phase Loads. The three phase Non-Linear Loads are connected at the secondary of three phase Transformers with Three Phase Breakers having Transition time 5/60seconds. A new Pulse Generator topology is used for generating pulses for each of three phase non-linear loads. The Circuit used for Compensation of Harmonics having three phase IGBT based Inverter. The IGBT base d Shunt Active Harmonic Filter gets firing Pulses from PLL phase Locked Loop& Hysteresis Switching HS. The used PLL extracts the Fundamental component of load current which is then multiplied with same RMS gain for generating the Reference current for Hysteresis Current Controller. The used Hysteresis Current Controller compares the reference current
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
A novel three phase bidirectional AC buck converter circuit using power
MOSFET is analyzed for input power factor, harmonic profile and efficiency of the
converter for power quality improvement. The equal PWM (EPWM) technique is a used to
increase number of pulses per half cycle (P) in order to vary these parameters. The rms
value of the fundamental component of the output voltage can be increased by varying the
duty ratio (K) of the pulses. It is observed from the simulation results obtained using
MATLAB/simulink that the proposed scheme using EPWM technique significantly reduces
low order harmonics, eliminates certain harmonics for certain values of P, improves input
power factor and hence significantly reduces the filter size of the converter.
POWER STABILITY ANALYSIS OF A TRANSMISSION SYSTEM WITH A UNIFIED POWER FLOW C...IJITE
The unified power quality conditioner is the equipment used for regulated voltage distortion and voltage
unbalance in a power system. UPFC can enhance the power to flow through the transmission system by
controlling the power flow and voltage stability of the transmission line within their limits. This paper
presents a control scheme and Theoretical derivation of the unified power flow conditioner and the
simulation results are compared and contrasted in detail. UPFC is a combination of shunt Active and
series active power filters. UPFC contains a DC link capacitor in a single-phase voltage source inverter
with two back to back connected, three-phase three-wire and three-phase four-wire are arranged. The
fundamental target of this work is to determine the causes and impacts of power quality problems,
specifically voltage sag, voltage swell, power factor, and Total Harmonics Distortion (THD) and enhance
the power quality of a transmission system by UPFC based Transformative Intrinsic Algorithm (TIA). The
Simulation of the proposed method is developed by Mat lab Simulink software, and the simulation result
shows, the proposed method gives better solutions to control the power imbalance in the distribution
system with its cost-effectiveness.
This paper presents an analysis of virtual-flux direct power control (VFDPC) technique for the three-phase pulse width modulation (PWM) ac-dc converter. The proposed VFDPC is developed by assuming the grid voltage and converter line filters quantities are related to a virtual three-phase ac motor. The controller works with less number of sensors by eliminating the voltage sensors used for measuring the three-phase grid voltage. The grid virtual flux which is proportional to the grid voltage will be estimated from the information of converter switching states, line current, and dc-link output voltage. Several analyses are performed in order to study the steady state and dynamic performance of the converter, particularly during the load and DC voltage output reference variations. The proportional integral (PI) controller at the outer voltage control loop of VFDPC is tuned properly and the entire PWM ac-dc converter system is simulated using MATLAB/Simulink to ensure the dc output voltage follow the desired output voltage under steady state and dynamic conditions. Ac-dc converter utilizing the proposed VFDPC is able to generate three-phase input current waveforms that are almost sinusoidal with low harmonics contents which is less than 5% and near unity power factor (pf) operation.
POWER QUALITY IMPROVEMENT BY SSSC AND STATCOM USING PI CONTROLLERJournal For Research
This paper presents the enhancement of voltage stability using Static Synchronous compensator (STATCOM) and Static Synchronous series compensator (SSSC). In recent past years, along with the rapid increasing electrical power requirement has caused system to be heavily loaded leading to voltage instability. Under this condition there may be insufficient reactive power causing voltage to drop at various buses. The result would be the occurrence of voltage collapse which leads to total blackout of the whole system. FACT controllers have been used for solving various stability control problems. In this paper, SSSC and STATCOM are used to investigate the effect of these devices in controlling active and reactive powers to maintain voltage stability. The PI Controller is used to tune the circuit and to provide the zero signal error. Simulation results have been presented in MATLAB/Simulink environment for two machines four buses system.
An Experimental Study of the Unbalance Compensation by Voltage Source Inverte...IJPEDS-IAES
This work presents an experimental study of the unbalance compensation
caused by the high speed railway substations in the high-voltage power grid
with a shunt voltage source inverter based STATCOM. This experimental
study is realized on a reduced scale prototype. The Control of inverter is
implemented in a DSP card. The practical results presented in this paper are
shown the performance of unbalance compensation by VSI_STATCOM in
static and dynamic regime.
Simulation of D-STATCOM to study Voltage Stability in Distribution systemijsrd.com
This paper presents the simulation of D-statcom to understand the improvement of voltage stability [1] of distribution system. The power circuits of the D-STATCOM and distribution networks are made up of simpower system blocks, while the control circuits made with the simulink blocks The STATCOM is applied to regulate transmission voltage to allow greater power flow in a voltage limited transmission network, in the same manner as a static var compensator (SVC), the STATCOM has further potential by giving an inherently faster response and greater output to a system with depressed voltage and offers improved quality of supply. The main applications of the STATCOM are; Distribution STATCOM (D-STATCOM) exhibits high speed control of reactive power to provide voltage stabilization and other type of system control. The DSTATCOM protects the utility transmission or distribution system from voltage sag and /or flicker caused by rapidly varying reactive current demand. During the transient conditions the D-STATCOM provides leading or lagging reactive power to active system stability, power factor correction and load balancing.
Implementation for Controller to Unified Single Phase Power Flow Using Digita...IJERA Editor
Presenting in his paper, Digital signal processor (DSP)-based implementation of a single phase unified power flow controller (UPFC). For shunt side and series side An efficient UPFC control algorithm is achieved. Discussing the laboratory experimental results using DC source are taken as an UPFC linked by two ll-bridge PWM voltage source converters.
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.
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.
A novel power converter that can perform both voltage and frequency conversion was proposed. Inappropriate power supply can damage sensitive sub-components and render the connected device inoperable. Henceforth, the proposed voltage–frequency converter acts as an interface to plug any electrical device directly into an electrical socket and provide the voltage and frequency required. The converter used a synchronous reference frame proportional–integral (SRFPI) controller to regulate the instantaneous output voltage and to improve steady state performance. Because the PI controller works together with the synchronous reference frame controller, it is difficult to tune the PI control parameters. To overcome this issue, a new meta heuristic optimization technique called lightening search algorithm (LSA) optimization was used to identify the optimum PI parameter values. A detailed description of the system operation and control strategy was presented. Finally, the performance of the converter was analyzed and verified by simulation and experimental results. The experimental result has shown that the proposed system has satisfactory output voltage and frequency under different input voltages.
This paper introduces the modelling of a novel three phase AC-AC converter with indirect use of a capacitor as DC voltage link. The proposed converter has high efficiency because it uses Space Vector PWM (SVPWM) technique at both rectificier and inverter stages to operate the pulse width modulation in IGBT switches. The novel converter is equipped with a power factor control to shape the rectifier input current waveform to be sinusoidal and to be in phase with the input voltage. To keep the DC voltage stable, the converter utilizes PI controllers. Simulations are conducted for output voltage from 120 to 300 Volts with output frequency ranging from 30 Hz to 60 Hz. The simulation results show that the converter is able to maintain stable the DC voltage and current. Furthermore, the model demonstrates the benefits of proposed converter in terms of acquiring high input power factor and sinusoidal current waveform at the output side of the inverter.
The aim of this paper is illustrating and exposing the performance of a Series Active Power Filter (SAPF) with PI controller and Fuzzy controller within simulation and experimental validations. This performance is best manifested in compensating the sags and the swells voltages and in eliminating the harmonic voltage and regulate the terminal voltage of the load by injecting a voltage component in series with source voltage which is increased or decreased from the source voltage, hence, maintaining the load side waveforms as pure sinusoidal. The control method used in this work is not so complex and it is based on a phase locked loop (PLL) that is used to control the active filter. It is valid only in the phase system. The efficiency of the method I suggested is affirmed through simulation results by MATLAB\Simulink® and some prototypes experiments. These results shows the capability of the proposed prototypes.
In grid connected system, unity power factor current injection into the grid is vital. This can be achieved by choosing the right inverter topology, passive filter components, current controllers, and PWM switching scheme. This paper compares the output current harmonics profile between when using the conventional proportional resonant (PR) current controller and when using the modified PR current controller. By applying the latter technique, via experimental validation using TMS320F2812, the THD of the injected grid current in a parallel connected inverters system is improved.
This paper proposes a new voltage frequency converter (VFC) that converts both voltage and frequency to the required level of voltage and frequency in low voltage networks used in various countries. The proposed converter could be used as a universal power supply for sensitive AC loads. The converter is composed of, input voltage and frequency detection circuitry, full bridge boost rectifier and a DC to AC inverter. In addition, to improve the feasibility and performance of the converter, synchronous reference based PI (SRFPI) controller is adopted, where the system behaves similar to a DC-DC converter. The parameter selection of PI controller is done using a recent optimisation technique called Lightning Search Algorithm (LSA). The simulation of VFC is conducted in MATLAB/Simulink environment. The simulation results shows that LSA based PI controller provides better output voltage regulation with respect to the reference value under various load and input conditions.
This paper presents the improved single phase AC-DC super lift Luo converter for enhancing quality of power by mitigating the issues. The proposed converter is used for output voltage control, power factor improvement and reduced source current harmonics at supply side. The main intention of this work is to design appropriate closed loop controllers for this AC-DC super lift Luo converter to achieve unity power factor in the source end. The designed control system comprises of two control loops, voltage control in outer loop and the current controller is devised in the inner loop. Fuzzy controller is used for current controller whereas PI controller as voltage controller. In the MATLAB/SIMULINK platform, simulation of the proposed AC-DC super lift Luo converter is done. It is clear from the simulation results that PI integrated fuzzy controller for voltage and control is proven to be better than classical PI with hysteresis controllers. The proposed system is able to achieve high input power factor along with supply current harmonic distortions of less than 5%.
This paper presents a grid-connected photovoltaic (PV) interface for delivering both active and reactive powers. The PV interface employs H-bridge topology DC-DC converter and inverter with analog control technology. The power flow is controlled solely by the adjustable DC output voltage of the DC to DC converter. In order to evaluate the PV interface system’s performances, it is tested by delivering power to the grid with low pawer factor. The experimental results show that at 300W active load, the inverter could deliver the reactive power of 400VAR. The PV interface could also produce very low harmonic voltage and current distorsions. The laboratory measurements show that the total harmonic distortions of inverter output voltage and current are 0.46% and 0.05%, respectively.
Comparative Study of Three Phase Grid Connected Photovoltaic Inverter Using P...IJPEDS-IAES
A comparative study of three phase grid connected photovoltaic (PV)
inverter using Proportional-Integral (PI) controller and Fuzzy logic controller
(FLC) is presented in this paper. Proposed three phase inverter with single DC
source employing three phase transformer for grid connected PV system
controlled by using space vector pulse width modulation (SVPWM) technique.
PI and FLC are used as current controller for regulating the current. Perturb and
observe maximum power point technique (MPPT) is used for tracking of
maximum power from the PV panel. Finally total harmonic distortion (THD)
comparison made between two controllers for validation of results.
Furthermore swithing losses of inverter are also presented. The simulation
results are obtained using MATLAB simulink.
Implementation of Fan6982 Single Phase Apfc with Analog ControllerIJRESJOURNAL
ABSTRACT:Active power factor orrection technique can improve the input power factor and reduce the harmonic component of the input current. In small power applications, the single-phase active power factor correction circuit of high frequency switching (APFC), reduction of the boost inductance decreases the boost inductor and filter capacitor volume, reducing the net side current ripple, improve efficiency. On the basis of describing the principle of single-phase single-stage boost APFC double closed loop control, a new duty cycle compensation method is proposed, which is based on the FAN6982 simulation and the single phase APFC of the rated output power 500W is achieved. The results show that the effect of current ripple rejection is obvious, and the input current is consistent with the input voltage phase.
Similar to Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter (20)
The aim of this research is the speed tracking of the permanent magnet synchronous motor (PMSM) using an intelligent Neural-Network based adapative backstepping control. First, the model of PMSM in the Park synchronous frame is derived. Then, the PMSM speed regulation is investigated using the classical method utilizing the field oriented control theory. Thereafter, a robust nonlinear controller employing an adaptive backstepping strategy is investigated in order to achieve a good performance tracking objective under motor parameters changing and external load torque application. In the final step, a neural network estimator is integrated with the adaptive controller to estimate the motor parameters values and the load disturbance value for enhancing the effectiveness of the adaptive backstepping controller. The robsutness of the presented control algorithm is demonstrated using simulation tests. The obtained results clearly demonstrate that the presented NN-adaptive control algorithm can provide good trackingperformances for the speed trackingin the presence of motor parameter variation and load application.
This paper presents a fast and accurate fault detection, classification and direction discrimination algorithm of transmission lines using one-dimensional convolutional neural networks (1D-CNNs) that have ingrained adaptive model to avoid the feature extraction difficulties and fault classification into one learning algorithm. A proposed algorithm is directly usable with raw data and this deletes the need of a discrete feature extraction method resulting in more effective protective system. The proposed approach based on the three-phase voltages and currents signals of one end at the relay location in the transmission line system are taken as input to the proposed 1D-CNN algorithm. A 132kV power transmission line is simulated by Matlab simulink to prepare the training and testing data for the proposed 1D- CNN algorithm. The testing accuracy of the proposed algorithm is compared with other two conventional methods which are neural network and fuzzy neural network. The results of test explain that the new proposed detection system is efficient and fast for classifying and direction discrimination of fault in transmission line with high accuracy as compared with other conventional methods under various conditions of faults.
Among the most widespread renewable energy sources is solar energy; Solar panels offer a green, clean, and environmentally friendly source of energy. In the presence of several advantages of the use of photovoltaic systems, the random operation of the photovoltaic generator presents a great challenge, in the presence of a critical load. Among the most used solutions to overcome this problem is the combination of solar panels with generators or with the public grid or both. In this paper, an energy management strategy is proposed with a safety aspect by using artificial neural networks (ANNs), in order to ensure a continuous supply of electricity to consumers with a maximum solicitation of renewable energy.
In this paper, the artificial neural network (ANN) has been utilized for rotating machinery faults detection and classification. First, experiments were performed to measure the lateral vibration signals of laboratory test rigs for rotor-disk-blade when the blades are defective. A rotor-disk-blade system with 6 regular blades and 5 blades with various defects was constructed. Second, the ANN was applied to classify the different x- and y-axis lateral vibrations due to different blade faults. The results based on training and testing with different data samples of the fault types indicate that the ANN is robust and can effectively identify and distinguish different blade faults caused by lateral vibrations in a rotor. As compared to the literature, the present paper presents a novel work of identifying and classifying various rotating blade faults commonly encountered in rotating machines using ANN. Experimental data of lateral vibrations of the rotor-disk-blade system in both x- and y-directions are used for the training and testing of the network.
This paper focuses on the artificial bee colony (ABC) algorithm, which is a nonlinear optimization problem. is proposed to find the optimal power flow (OPF). To solve this problem, we will apply the ABC algorithm to a power system incorporating wind power. The proposed approach is applied on a standard IEEE-30 system with wind farms located on different buses and with different penetration levels to show the impact of wind farms on the system in order to obtain the optimal settings of control variables of the OPF problem. Based on technical results obtained, the ABC algorithm is shown to achieve a lower cost and losses than the other methods applied, while incorporating wind power into the system, high performance would be gained.
The significance of the solar energy is to intensify the effectiveness of the Solar Panel with the use of a primordial solar tracking system. Here we propounded a solar positioning system with the use of the global positioning system (GPS) , artificial neural network (ANN) and image processing (IP) . The azimuth angle of the sun is evaluated using GPS which provide latitude, date, longitude and time. The image processing used to find sun image through which centroid of sun is calculated and finally by comparing the centroid of sun with GPS quadrate to achieve optimum tracking point. Weather conditions and situation observed through AI decision making with the help of IP algorithms. The presented advance adaptation is analyzed and established via experimental effects which might be made available on the memory of the cloud carrier for systematization. The proposed system improve power gain by 59.21% and 10.32% compare to stable system (SS) and two-axis solar following system (TASF) respectively. The reduced tracking error of IoT based Two-axis solar following system (IoT-TASF) reduces their azimuth angle error by 0.20 degree.
Kosovo has limited renewable energy resources and its power generation sector is based on fossil fuels. Such a situation emphasizes the importance of active research and efficient use of renewable energy potential. According to the analysis of meteorological data for Kosovo, it can be concluded that among the most attractive potential wind power sites are the locations known as Kitka (42° 29' 41" N and 21° 36' 45" E) and Koznica (42° 39′ 32″ N, 21° 22′30″E). The two terrains in which the analysis was carried out are mountain areas, with altitudes of 1142 m (Kitka) and 1230 m (Koznica). the same measuring height, about 84 m above the ground, is obtained for these average wind speeds: Kitka 6,667 m/s and Koznica 6,16 m/s. Since the difference in wind speed is quite large versus a difference in altitude that is not being very large, analyses are made regarding the terrain characteristics including the terrain relief features. In this paper it will be studied how much the roughness of the terrain influences the output energy. Also, that the assumption to be taken the same as to how much they will affect the annual energy produced.
Large-scale grid-tied photovoltaic (PV) station are increasing rapidly. However, this large penetration of PV system creates frequency fluctuation in the grid due to the intermittency of solar irradiance. Therefore, in this paper, a robust droop control mechanism of the battery energy storage system (BESS) is developed in order to damp the frequency fluctuation of the multi-machine grid system due to variable active power injected from the PV panel. The proposed droop control strategy incorporates frequency error signal and dead-band for effective minimization of frequency fluctuation. The BESS system is used to consume/inject an effective amount of active power based upon the frequency oscillation of the grid system. The simulation analysis is carried out using PSCAD/EMTDC software to prove the effectiveness of the proposed droop control-based BESS system. The simulation result implies that the proposed scheme can efficiently curtail the frequency oscillation.
This study investigates experimentally the performance of two-dimensional solar tracking systems with reflector using commercial silicon based photovoltaic module, with open and closed loop control systems. Different reflector materials were also investigated. The experiments were performed at the Hashemite University campus in Zarqa at a latitude of 32⁰, in February and March. Photovoltaic output power and performance were analyzed. It was found that the modified photovoltaic module with mirror reflector generated the highest value of power, while the temperature reached a maximum value of 53 ̊ C. The modified module suggested in this study produced 5% more PV power than the two-dimensional solar tracking systems without reflector and produced 12.5% more PV power than the fixed PV module with 26⁰ tilt angle.
This paper focuses on the modeling and control of a wind energy conversion chain using a permanent magnet synchronous machine. This system behaves a turbine, a generator, DC/DC and DC/AC power converters. These are connected on both sides to the DC bus, where the inverter is followed by a filter which is connected to the grid. In this paper, we have been used two types of controllers. For the stator side converter, we consider the Takagi-Sugeno approach where the parameters of controller have been computed by the theory of linear matrix inequalities. The stability synthesis has been checked using the Lyapunov theory. According to the grid side converter, the proportional integral controller is exploited to keep a constant voltage on the DC bus and control both types of powers. The simulation results demonstrate the robustness of the approach used.
The development of modeling wind speed plays a very important in helping to obtain the actual wind speed data for the benefit of the power plant planning in the future. The wind speed in this paper is obtained from a PCE-FWS 20 type measuring instrument with a duration of 30 minutes which is accumulated into monthly data for one year (2019). Despite the many wind speed modeling that has been done by researchers. Modeling wind speeds proposed in this study were obtained from the modified Rayleigh distribution. In this study, the Rayleigh scale factor (Cr) and modified Rayleigh scale factor (Cm) were calculated. The observed wind speed is compared with the predicted wind characteristics. The data fit test used correlation coefficient (R2), root means square error (RMSE), and mean absolute percentage error (MAPE). The results of the proposed modified Rayleigh model provide very good results for users.
This paper deals with an advanced design for a pump powered by solar energyto supply agricultural lands with water and also the maximum power point is used to extract the maximum value of the energy available inside the solar panels and comparing between techniques MPPT such as Incremental conductance, perturb & observe, fractional short current circuit, and fractional open voltage circuit to find the best technique among these. The solar system is designed with main parts: photovoltaic (PV) panel, direct current/direct current (DC/DC) converter, inverter, filter, and in addition, the battery is used to save energy in the event that there is an increased demand for energy and not to provide solar radiation, as well as saving energy in the case of generation more than demand. This work was done using the matrix laboratory (MATLAB) simulink program.
The objective of this paper is to provide an overview of the current state of renewable energy resources in Bangladesh, as well as to examine various forms of renewable energies in order to gain a comprehensive understanding of how to address Bangladesh's power crisis issues in a sustainable manner. Electricity is currently the most useful kind of energy in Bangladesh. It has a substantial influence on a country's socioeconomic standing and living standards. Maintaining a stable source of energy at a cost that is affordable to everyone has been a constant battle for decades. Bangladesh is blessed with a wealth of natural resources. Bangladesh has a huge opportunity to accelerate its economic development while increasing energy access, livelihoods, and health for millions of people in a sustainable way due to the renewable energy system.
When the irradiance distribution over the photovoltaic panels is uniform, the pursuit of the maximum power point is not reached, which has allowed several researchers to use traditional MPPT techniques to solve this problem Among these techniques a PSO algorithm is used to have the maximum global power point (GMPPT) under partial shading. On the other hand, this one is not reliable vis-à-vis the pursuit of the MPPT. Therefore, in this paper we have treated another technique based on a new modified PSO algorithm so that the power can reach its maximum point. The PSO algorithm is based on the heuristic method which guarantees not only the obtaining of MPPT but also the simplicity of control and less expensive of the system. The results are obtained using MATLAB show that the proposed modified PSO algorithm performs better than conventional PSO and is robust to different partial shading models.
A stable operation of wind turbines connected to the grid is an essential requirement to ensure the reliability and stability of the power system. To achieve such operational objective, installing static synchronous compensator static synchronous compensator (STATCOM) as a main compensation device guarantees the voltage stability enhancement of the wind farm connected to distribution network at different operating scenarios. STATCOM either supplies or absorbs reactive power in order to ensure the voltage profile within the standard-margins and to avoid turbine tripping, accordingly. This paper present new study that investigates the most suitable-location to install STATCOM in a distribution system connected wind farm to maintain the voltage-levels within the stability margins. For a large-scale squirrel cage induction generator squirrel-cage induction generator (SCIG-based) wind turbine system, the impact of STATCOM installation was tested in different places and voltage-levels in the distribution system. The proposed method effectiveness in enhancing the voltage profile and balancing the reactive power is validated, the results were repeated for different scenarios of expected contingencies. The voltage profile, power flow, and reactive power balance of the distribution system are observed using MATLAB/Simulink software.
The electrical and environmental parameters of polymer solar cells (PSC) provide important information on their performance. In the present article we study the influence of temperature on the voltage-current (I-V) characteristic at different temperatures from 10 °C to 90 °C, and important parameters like bandgap energy Eg, and the energy conversion efficiency η. The one-diode electrical model, normally used for semiconductor cells, has been tested and validated for the polemeral junction. The PSC used in our study are formed by the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Our technique is based on the combination of two steps; the first use the Least Mean Squares (LMS) method while the second use the Newton-Raphson algorithm. The found results are compared to other recently published works, they show that the developed approach is very accurate. This precision is proved by the minimal values of statistical errors (RMSE) and the good agreement between both the experimental data and the I-V simulated curves. The obtained results show a clear and a monotonic dependence of the cell efficiency on the studied parameters.
The inverter is the principal part of the photovoltaic (PV) systems that assures the direct current/alternating current (DC/AC) conversion (PV array is connected directly to an inverter that converts the DC energy produced by the PV array into AC energy that is directly connected to the electric utility). In this paper, we present a simple method for detecting faults that occurred during the operation of the inverter. These types of faults or faults affect the efficiency and cost-effectiveness of the photovoltaic system, especially the inverter, which is the main component responsible for the conversion. Hence, we have shown first the faults obtained in the case of the short circuit. Second, the open circuit failure is studied. The results demonstrate the efficacy of the proposed method. Good monitoring and detection of faults in the inverter can increase the system's reliability and decrease the undesirable faults that appeared in the PV system. The system behavior is tested under variable parameters and conditions using MATLAB/Simulink.
The electrical distribution network is undergoing tremendous modifications with the introduction of distributed generation technologies which have led to an increase in fault current levels in the distribution network. Fault current limiters have been developed as a promising technology to limit fault current levels in power systems. Though, quite a number of fault current limiters have been developed; the most common are the superconducting fault current limiters, solid-state fault current limiters, and saturated core fault current limiters. These fault current limiters present potential fault current limiting solutions in power systems. Nevertheless, they encounter various challenges hindering their deployment and commercialization. This research aimed at designing a bridge-type nonsuperconducting fault current limiter with a novel topology for distribution network applications. The proposed bridge-type nonsuperconducting fault current limiter was designed and simulated using PSCAD/EMTDC. Simulation results showed the effectiveness of the proposed design in fault current limiting, voltage sag compensation during fault conditions, and its ability not to affect the load voltage and current during normal conditions as well as in suppressing the source powers during fault conditions. Simulation results also showed very minimal power loss by the fault current limiter during normal conditions.
This paper provides a new approach to reducing high-order harmonics in 400 Hz inverter using a three-level neutral-point clamped (NPC) converter. A voltage control loop using the harmonic compensation combined with NPC clamping diode control technology. The capacitor voltage imbalance also causes harmonics in the output voltage. For 400 Hz inverter, maintain a balanced voltage between the two input (direct current) (DC) capacitors is difficult because the pulse width modulation (PWM) modulation frequency ratio is low compared to the frequency of the output voltage. A method of determining the current flowing into the capacitor to control the voltage on the two balanced capacitors to ensure fast response reversal is also given in this paper. The combination of a high-harmonic resonator controller and a neutral-point voltage controller working together on the 400 Hz NPC inverter structure is given in this paper.
Direct current (DC) electronic load is a useful equipment for testing the electrical system. It can emulate various load at a high rating. The electronic load requires a power converter to operate and a linear regulator is a common option. Nonetheless, it is hard to control due to the temperature variation. This paper proposed a DC electronic load using the boost converter. The proposed electronic load operates in the continuous current mode and control using the integral controller. The electronic load using the boost converter is compared with the electronic load using the linear regulator. The results show that the boost converter able to operate as an electronic load with an error lower than 0.5% and response time lower than 13 ms.
More from International Journal of Power Electronics and Drive Systems (20)
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Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
2. ISSN: 2088-8694
IJPEDS Vol. 8, No. 2, June 2017 : 869 – 881
870
flow to be bi-directional. For this reason, they play an important role in renewale energy such as energy from
solar cell or wind turbine for injecting energy into utility grid of a AC power system.
The normal simple cascade control structure has been presented in [7]-[9], where outer loop is a
output voltage controller and inner loop is an input current controller. To achieve a good dynamical response
of the output voltage, the crossover frequency which is set in the PI controller must be relatively high. The
current loop forces the input current to track the reference current signal, which is obtained by multiplying a
sinusoidal signal template by a amplitude signal from feedback voltage in the voltage loop. Thus, if the
feedback voltage is a DC value, the reference input current signal will be sinusoidal. Then, the input current
can be forced to sinusoidal if the input current is perfectly controlled to track this reference signal. In
practical, a ripple signal at twice of the line frequency (100Hz for 50Hz line frequency) in the voltage error
signal is natural exist. Consequently the 3rd harmonic signal in the reference input current is occurred which
causes the distortion of reference input current and also the input line current. In order to reduce the ripple
voltage, an easy solution is to add a bulk-electrolytic capacitor at the output. However, this capacitor causes
to increase size and cost of the VSC, but cannot get rid of the double line frequency component in the voltage
control loop.
A standard design of voltage loop to reduce the THDi is placed a Low-Pass Filter (LPF) next after
an output voltage sensor. The LPF is tuned to offer cutoff frequency or bandwidth around 10Hz-20Hz, then
the ripple flowing from output voltage is attenuated. Although this design has improved the THDi of the
system, but the main disadvantage is lack of output voltage response. Conversely, if the LPF is loosened or
higher bandwidth, the responsibility will improve but the THDi will be increased. In some paper [10], the
voltage loop was controlled by the fuzzy controller, but the THDi was more 5%.
The power-balanced control algorithm or Feed-Forward Compensation (FFC) proposed by [4], the
main aim of them is to add the load information which is the disturbance before current loop. As a result the
output voltage dynamic response is improved, but the THDi will not be improved by this technique.
In [4] has been proposed the method for reducing the 3rd harmonic in PFC type CUK topology. The
output voltage is sampled to voltage loop. The sample period is at every zero crossing point of the input
voltage. So that only a DC value is collected to be multiply with the sinusoidal template. Therefore the
reference current signal will be perfectly sinusoidal. However the response of output voltage is still poor
because if the updating reference is occurred only 2 times in a line periode.
This paper will consider the situation in which the bandwidth of the LPF and the crossover
frequency of the PI controller is high value. The first part of paper presents an analysis of the conventional
cascade control VSC. Then propose the simple method to reduce a ripple voltage in voltage loop of the VSC
by using a Ripple Voltage Estimation (RVE) algorithm but offer better responsibility by using the FFC
algorithm. The output ripple is estimated by the RVE algorithm and subtract it from voltage error signal. The
result of this, the 3rd harmonic of the input current is reduced, and hence the THDi is improved. The concept
of the FFC technique is the same as the power balance control technique in feeding load information into
control system. These algorithms are implemented based on a microcontroller. Finally, the simulation and
experimental resuls are shown.
(a) (b) (c)
Figure 1. (a) The power circuit is a Voltage Source Converter (VSC) built from full-bridge AC-DC converter
and its cascade control. (b) The ripple in voltage loop which is the cause of distorted-reference input current
(c) Analysis the direction of output current.
vs C
LOAD
-
+
-
+
is L
T1 io
icap
T1,T4 T2,T3
VORef
Controller
Voltage
KI
Controller
Current
Kp
sin(ωt)
LPF
K2
PLL
vo
Current Control Loop
K1
K2
K2
K1
Voltage Control Loop
Power Section
ve
Sinusoidal template
ILoad
T3
T2
T4
vc
t
100Hz
0
f
t
0
Distored
2
3
C
Load
+
vo(Lt)
IODC
io(Lt) =IODC+io2(Lt)+io4(Lt)
io2(Lt)+io4(Lt)
isRef (t)
vcAC (t)
vc(t)=VCDC+vcAC (t)
VCDC
vo(t)=VODC+voAC (t)
3. IJPEDS ISSN: 2088-8694
Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter (Jedsada Jaroenkiattrai)
871
2. ANALYTICAL MODEL OF THE CASCADE CONTROL VSC
The controlling objectives of the VSC are to
a. Maintain the output voltage VO to the desired value
b. Control the input current is to nearby sinusoidal waveform and meets the necessary harmonic standards
c. Control the phase of the input current is to synchronize with the phase of the input voltage vs in order to
succeed in unit power factor.
The conventional control configuration, which comprises two feedback loop as shown in
Figure 1(a). The control system has the outer voltage loop regulating output voltage VO, to aspire a value of
reference output voltage VORef and sending a controlled signal vc to the inner current loop (remark that the
vc is a value of peak reference input current). Inner current loop, the is is controlled to track the reference
current by a hysteresis controller. A Phase Lock Loop (PLL) generates a purely sinusoidal signal sin (ωt)
which synchronizes with the phase of vs. In steady state condition, the controlled-signal vc should be a DC
signal so that the isRef obtained from the product of the vc and sin (ωt) remains perfectly sinusoidal signal.
In practical, there is a ripple voltage which rides on the vc. The fundamental reason is widely known that the
output voltage (vo) compose of an average DC voltage and a ripple voltage which has twice of line
frequency. Then after the vo is sensed, the vo will be subtracted from the VORef, which is a constant value.
The result of subtraction is an error signal (ve) where that ripple still remain as shown Figure 2(a).
Consequently, the signal from high bandwidth voltage controller, will not constant but comprise the ripple as
well. However, if low cutoff frequency of voltage controller is used, the will be a DC value. Therefore, the
input current can be controlled to be sinusoidal as the input current reference signal as shown in Figure 2(b).
(a) (b)
Figure 2. The effect of the ripple output voltage in case of conventional control technique when: (a) there is
the ripple in voltage loop. (b) there is not the ripple in voltage loop
2.1. The Input Current
Assume that, the power circuit is controlled, then the input voltage
ˆ
( ) sin( )
s L S L
v t V t
.
Where
ˆS
V is the peak value of input voltage vs(Lt) L is its angular frequency. If the controlling of VSC
force the input current is(Lt) to nearby sinusoidal, then the is(Lt) can be obtained
1
ˆ
( ) ( ) sin( ) ( )
s L sRef L S L c L
i t i t K V t v t
(1)
The controlled signal vc(Lt) composes of DC Component VCDC and AC Component vcAC(Lt), ripple in
voltage loop. So the vc(Lt) can be obtained
( ) ( )
c L CDC cAC L
v t V v t
(2)
As described earlier, it is known that the
ˆsRef
I
has twice of line frequency, thus the vcAC(Lt) can be supposed
ˆ
( ) sin(2 )
cAC L CAC L
v t V t
f
(3)
K1
-
+
VORef
t
1 O
K V
Sinusoidal template
VO
Error
0
Current Control Loop
T1,T4
T2,T3
vs(t)
Peak value input
current reference
Output voltage
Output voltage reference
Voltage Control Loop
VE
isRef (t) ˆ
SRef
I
K1
is(t)
K2
Current
Controller
-
+
Voltage
Controller
t
50Hz
0
t
0
VE
t
0
ˆ
SRef
I
t
0
( )
sRef
i t
Input current
reference
t
VORef
0
K1vs(t)
K1
-
+
VORef
Sinusoidal template
Error
Current Control Loop
T1,T4
T2,T3
vs(t)
Peak value input current reference
Output voltage
Output voltage
reference
isRef (t) ˆ
SRef
I
K1
is(t)
K2
Current
Controller
-
+
Voltage
Controller
t
0
Input current
reference
t
VORef
0
t
( ) ( )
o ODC oAC
v t V v t
0
VODC
voAC(t)
t
0
f
ˆ
ˆ ˆ
( ) ( )
sRef SRefDC sRefAC
i t I i t
ˆ ( )
sRefAC
i t
ˆ
SRefDC
I
t
100Hz
0
ve(t)
ve(t)
vo(t)
Voltage Control Loop
t
0
( )
sRef
i t
Distored
K1vs(t)
50Hz
100Hz
100Hz
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872
Substituting (2) and (3) into (1), then the is(Lt) can be obtained
1
ˆ ˆ
( ) sin( ) sin(2 )
s L S L CDC CAC L
i t K V t V V t
f
(4)
An instantaneous input power ps(Lt) can be written ( ) ( ) ( )
s L s L s L
p t i t v t
, substituting input voltage
vs(Lt) and input current is(Lt) from (1) into it, then instantaneous input power can be rearranged
2 2
1
ˆ
( ) sin ( ) 1 sin(2 )
s L CDC S L L
p t V KV t k t
f
(5)
By
ˆCAC
CDC
V
k
V
(6)
Where k is the ratio between peak of controlled signal and DC component of controlled signal, f is a phase
lag angle defined from Figure 1(b), K1 is per-unit scaling gain for voltage value (K1=1/VB) and VB is base
voltage value scaled for 1
K . An average input power (PSAVG) can be derived from the averaging value in
period of the instantaneous input power in (5), and then it can be obtain
2 2
1
0
ˆ
( ) 2 sin( )
2 4
CDC S
SAVG s L
V KV
P p t dt k
f
(7)
An average output power (POAVG) is the power appearing at the output resistive load and can be expressed as
2
ODC
OAVG
Load
V
p
R
(8)
From the power balanced technique, the average output power (POAVG) as (8) is equal to the average input
power (PSAVG) as (7) then the DC component of controlled voltage (VCDC) can be expressed as
2
2
1
4
ˆ 2 sin( )
ODC
CDC
Load S
V
V
K R V k
f
(9)
Where VODC is the average output voltage. From this expression, replace VODC in (4) and rearrange by using
trigonometric identities, then the input current can be expressed as
2
1stharmonic 3rdharmonic
4
( ) sin( ) cos( ) cos(3 )
ˆ 2 2
(2 sin )
ODC
s L L L L
Load S
V k k
i t t t t
R V k
f f
f
(10)
Where
1 3
( ) ( ) ( )
s L s L s L
i t i t i t
(11)
2
1
4
( ) sin( ) cos( )
ˆ 2
(2 sin )
ODC
s L L L
Load S
V k
i t t t
R V k
f
f (12)
2
3
2
( ) cos(3 )
ˆ (2 sin )
ODC
s L L
Load S
V
i t k t
R V k
f
f
(13)
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Where is(Lt) is the input current, is1(Lt) is the 1st harmonic content of input current, is3(Lt) is the 3rd
harmonic content of input current and RLoad is resistive load at output.
As the 2nd harmonic content of vc(Lt) in (3) is transformed into the 3rd harmonic of the input
current in (11) and (11). The input current is(Lt) consists of two terms, fundamental current is1(Lt) and the
3rd harmonics current is3(Lt) which is the main cause of the distortion of input current. If the term is3(Lt)
can be eliminated from is(Lt), then the input current will remain only the fundamental component.
Therefore, the input current will be sinusoidal.
2.2. The Output Current
An instantaneous output power (po) at the output voltage can be obtain
( ) ( ) ( )
o L o L o L
p t i t v t
(14)
From the power balanced technique, the instantaneous output power (po) as equation reference goes here is
equal to the instantaneous input power (ps) in (5), then assume the output capacitor is bulk. Therefore, the
output voltage (vo(Lt)) will only be DC component (VODC) then the input current (io(Lt)) will expresses as
2
2
1
ˆ
( ) sin ( ) 1 sin(2 )
CDC S
o L L L
ODC
V KV
i t t k t
V
f
(15)
From this expression, replace VCDC by (9) and rearrange by using trigonometric identities, then the output
current can be expressed as
2ndharmonic 4thharmonic
4 1 1
( ) sin cos 2 sin(2 ) sin(4 )
(2 sin ) 2 4 2 2 4
ODC
o L L L L
Load
DC
V k k k
i t t t t
R k
f f f
f
(16)
Where
2 4
(ω ) (ω ) (ω )
o L ODC o L o L
i t I i t i t
(17)
And
ODC
ODC
Load
V
I
R
(18)
2
2
( ) sin(2 ) cos 2
(2 sin )
ODC
o L L L
Load
V
i t k t t
R k
f
f
(19)
4 ( ) sin(4 )
(2 sin )
ODC
o L L
Load
V
i t k t
R k
f
f
(20)
Where IODC is DC component of output current, io2(Lt) is 2nd harmonics content of output current
and io4(Lt) is 4th harmonics content of output current.
2.3. The Output Voltage
The output voltage is obtained from the multiplication of the output current (16) by the output
impedance that is capacitive reactance is parallelled with resistance load. The capacitive reactance will
mainly involve the AC component due to lower impedance than the resisitive load; therefore, the components
io2(Lt) and io4(Lt) are considered to flow through the output capacitor. At the same time, The DC
component IODC is considered to flow through the resistive load. Thus, the 2nd
and 4th
harmonics content of
output voltage (vo2,4(Lt)) can be written as
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874
2,4 2,4 2,4
( ) ( )
o L o L c L
v t i t x
(21)
From this expression, substituting the output current io2(Lt) and io4(Lt) from (19) and (20) respectively,
then the output voltage vo2(Lt) and vo4(Lt) can be expressed as
2
2
( ) cos(2 ) sin 2
2 (2 sin )
ODC
o L L L
L Load
V
v t k t t
CR k
f
f
(22)
4
2
( ) cos(4 )
2 (2 sin ) 4
ODC
o L L
L Load
V k
v t t
CR k
f
f (23)
Thus, the output voltage (vo(Lt)) will be written as
2 4
( )
( ) ( ) ( )
oAC L
o L ODC o L o L
v t
v t V v t v t
(24)
Where VODC is average output voltage, vo2(Lt) is 2nd harmonics content of output voltage and vo4(Lt) is 4th
harmonics content of output voltage.
2
( ) cos(2 ) sin 2 cos(4 )
2 (2 sin ) 4
ODC
o L ODC L L L
L Load
V k
v t V k t t t
CR k
f f
f (25)
The output voltage is described by (25) is composed of DC component (VODC) and AC component (voAC(Lt))
which is the output ripple voltage. This ripple is sensed into voltage loop and cause the input current
distortion. In the case of the k equal to zero (k=0), the Equation (25) will be written as
2
0
( ) sin2
2
o L
ODC
o L ODC L
k
L Load
v t
V
v t V t
CR
(26)
If k is controlled to be zero, then the AC component disappears in the outer loop.
3. THE REDUCTION OF RIPPLE VOLTAGE IN THE VOLTAGE LOOP
To get rid of the harmonic content of the input current, the ripple voltage in voltage loop must be
eliminated. In this section, a simplifly technique to reduce those ripples is presented. The proposed technique
is to generate the estimated-ripple voltage from the ripple voltage estimator (RVE) in order to cancel the
sensed-ripple voltage.
The voAC (Lt) from (24) use for estimating the estimated-ripple voltage, but in practical, there are
three parameters can neglect. Firstly, the AC component vo4 (Lt) is not appeared into voltage loop, because
there is a LPF at the output voltage loop. The others, there are scanty value of the phase lag angle (f) and the
k. As a result, the ripple output voltage which is sensed into voltage loop only remain the vo2 (Lt). Therefore,
the estimated-ripple voltage (vRVE) can be written as
1
1 2 0
( ) sin2 sin2
2
ODC
RVE o L L RVE ODC L
L Load
V
K
v K v t t G I t
C R
f
(27)
Where vRVE is the estimated-ripple voltage and GRVE is the Ripple Voltage Estimator transfer function
7. IJPEDS ISSN: 2088-8694
Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter (Jedsada Jaroenkiattrai)
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4. TRANSFER FUNCTION OF THE SYSTEM AND CONTROLLER DESIGNED
An analysis of the Single-phase AC-DC converter transfer function is presented under the continous
conductiontion mode of operation. The transfer function is used for designing voltage controller. As the
analysis for transfer function model, there are no AC component vo2(Lt) and vo4(Lt) at the output voltage.
Thus from (16), select only DC component and let k=0, the output current is (28).
2
1
0
ˆ
2
CDC S
ODC k
ODC
V KV
I
V
(28)
Applying perturbation in it to perform the small-signal approximation. Therefore, the output current can be
expressed as
ODC ODC
ODC CDC ODC
CDC ODC
I I
I V V
V V
(29)
Since the voltage source converter transfer function (GVSC) and Disturbance transfer function (GD) can be
define as
2
1
ˆ
2
ODC S
VSC
CDC ODC
I V K
G
V V
and
2
1
2
ˆ 1
2( )
ODC S CDC
D
ODC Load
ODC
I V V K
G
V R
V
(30)
The notation used in this section to describe the quantities. From (29), the variables with the sign ‘˜’ are the
small signal values.The output impedance (GZ) can be define as
( )
1
ODC Load
Z
Load
ODC
V R
G s
R Cs
I
(31)
Since the controller in the current loop, hysteresis controller, is selected, the dynamic response of
input current is fast enough to track the reference value of the input current. Thus, the transfer function of
closed current loop can be approximated as ˆS
I . In order to design voltage controller for the next issue, then
the closed-loop system block diagram is obtained from (29), (30) and (31) shown in Figure 3(a). To avoid
line current distortion in the VSC, the system crossover frequency in the voltage loop should be between
10-20 Hz (50 Hz line frequency) [4]. According to the low crossover frequency, the transient response of the
PFC circuit is limited especially under the step-load condition. In the case of voltage and current are been the
per-unit system, the plant transfer function (the voltage controller is not included) can be written
1
.
ˆ
( ) ( ) ( )
P LPF S VSC Z
P U Current
Low
Gain Control
Pass
Loop
Filter
G s K G s I G G s
(32)
Where ˆS
I is peak input current and ˆS
V is peak input voltage. The Open-Loop Transfer Function (OLTF) can
be written as
( ) ( ) ( )
CV P
OLTF s G s G s
(33)
Where the GCV(s) is voltage controller, PI controller, can be obtained as
( ) I
CV P
K
G s K
s
(34)
Where KP is proportional gain and KI is integral gain. The procedure for designing GCV(s), first, select the
phase margin m
f and crossover frequency c
f by 2
c c
f
. Then calculate the by substituting them into
Equation (35). Finally, KP and KI will be obtained by (36).
8. ISSN: 2088-8694
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876
180 ( )
180 m P c
G j
f
(35)
cos
( )
P
c
K
OLTF j
and
(sin ) 2
( )
c
I
c
f
K
OLTF j
(36)
The stability of proposed system is described by the frequency response analysis. The output voltage control
loop designed must guarantee the stability and provide enough bandwidth in all possible operation conditions
of the system. The bode plots in Figure 3(b) used as the tool for the frequency response analysis composing
of amplitude and phase of the system. After the analog PI controller design is finished, the parameters are
used to calculate the control signal of the eZdspLF2407 DSP by (37)
1
( ) ( ) ( )
n
P I s
k
u n K e n K T e n
(37)
Where u(n) is the output control signal of the digital controller, e(n) is an error signal and Ts is a sampling
time period.
5. FEED-FORWARD COMPENSATION OF VSC
In order to more increase the responsibility of the output voltage, the disturbance rejection technique
applied in the VSC is presented. The concept of it, the disturbance which is the load current is measured and
fed before it has time to affect the converter. This known as the feed-forward compensation, since
Feed-Forward Current (IFFC) which is related disturbance (D(s)) and Feed-Forward Gain (GFFC(s)) can be
written as :
( ) ( ) ( )
FFC FFC
I s D s G s
(38)
and Feed-Forward Gain (GFFC(s)) can be written as
2
1
2
ˆ
ODC
D
FFC
VSC Load S
V
G
G
G R V K
and ( ) ODC
D s V
(39)
Therefore, bring (38) and (39) obtain the block diagram for FFC as shown in Figure 4
(a) (b)
Figure 3. (a) Transfer function of system. (b) Frequency response of system
Voltage controller
+
Current control loop
-
(approximately)
Voltage feedback gain & Low Pass Filter
ˆ
S
I
1
( )
LPF
G s K
GVSC GZ
ODC
V
ORef
V
GD
ODC
I
+
+
CDC
V
Disturbance
Load impedance
VSC
GCV (s) 1
CL
G
M
a
g
n
itu
d
e
(d
B
)
P
h
a
s
e
(d
e
g
)
Frequency(Hz)
OLTF(s)
-200
-150
-100
-50
0
50
100
10
-1
100
101
102
103
104
105
-270
-180
-90
0
G
m=47dB(at1.24e+03Hz), P
m=45deg(at18Hz)
45
m
f
18
m
G
GCV (s)
GP (s)
GP (s)
GCV (s)
OLTF(s)
9. IJPEDS ISSN: 2088-8694
Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter (Jedsada Jaroenkiattrai)
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Figure 4. The proposed technique consists of the RVE and FFC
Table 1. Parameters of the proposed system
Parameters Values
VS, fLine 110 Vrms, 50 Hz
VORef 250 Vdc
L,C 15 mH, 560 µF
PoMax 600 W
(a) (b)
Figure 5. The dynamic-interval simulation results of vo when the fc is changed by 10Hz, 18Hz and 30Hz:
(a) The conventional control. (b) The conventional control with proposed technique.
(a) (b)
Figure 6. The input current and its total harmonic distortion (THDi) at 600W of the static-simulation results:
(a) The conventional control. (b) the conventional control with proposed technique
6. CIRCUIT SIMULATIONS
In this section, the simulation of the VSC is discussed. The configuration of which is simulated by
SIMULINK program. The purpose of this simulation is to test the parameter of controllers, verify the control
algorithms, and study the static and the dynamic of the proposed system. The simulation methods are the
conventional control (PI controller) and the conventional control with proposed techniques (PI controller
-
+
VORef
Voltage Controller
KP
ve
iLoad
K2
K2
2
1
2
ˆ
ORef
FFC
S
V
G
V K
-
+
-
+
From DC Voltage LPF
sinωLt
Sin(2ωLt)
Current
control loop
R
ip
p
leV
o
lta
g
eE
s
tim
a
to
r
F
e
e
d
-F
o
rw
a
rdC
o
m
p
e
n
s
a
tio
n
1
2
2
RVE
L
K
G
CK
GFFC
GRVE
FFC
I
vc
voRVE
KI
0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75
210
220
230
240
250
260
270
280
290
@ fc=30Hz
@ fc=18Hz
@ fc=10Hz
Output
Voltage
(
)
:
[V]
o
V
Time ( ) : [Sec]
t
@ fc=10Hz
@ fc=30Hz
@ fc=18Hz
Step load
200W to 600W
Step load 600W
to 200W
Output voltage fixed but different values of
m c
f
f
2
2
3
V
2
3
3
V
2
3
9
V
2
5
9
V
2
6
8
V
2
8
0
V
210
220
230
240
250
260
270
280
290
0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75
Time ( ) : [Sec]
t
Step load
200W to 600W
Step load 600W
to 200W
Output
Voltage
(
)
:
[V]
o
V
Output voltage fixed but different values of
m c
f
f
-PI Controller+FFC
-Fixed 45
m
f
-PI Controller
-Fixed 45
m
f
0.5 0.502 0.504 0.506 0.508 0.51 0.512 0.514 0.516 0.518 0.52
-15
-10
-5
0
5
10
15
0.5 0.502 0.504 0.506 0.508 0.51 0.512 0.514 0.516 0.518 0.52
-15
-10
-5
0
5
10
15
0 100 200 300 400 500 600 700 800 900 1000
0
0.2
0.4
0.6
Frequency (Hz)
Fundamental (50Hz) = 7.973 , THD= 8.93%
Mag
(%
of
Fundamental)
0 100 200 300 400 500 600 700 800 900 1000
0
0.1
0.2
0.3
0.4
0.5
Frequency (Hz)
Fundamental (50Hz) = 7.961 , THD= 5.65%
Mag
(%
of
Fundamental)
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878
with the RVE and FFC technique).The important parameters of which are shown in Table 1. The parameters
of PI controller, KP and KI, is set by fixed at 45 and selected c
f at 10Hz, 18Hz and 30Hz.
In Figure , the dynamic-interval simulation results of vo when the fc is changed by 10Hz, 18Hz and
30Hz will be compared between conventional control in Figure (a) and conventional control with proposed
techniques in Figure (b). In Figure (a) shows the capability of responsibility when the load is immediately
changed from 200W to 600W at 0.3s and stepped back to 200W at 0.6s. The value fc at 18Hz provides the
responsibility of vo is faster than fc at 10Hz while the value fc at 30Hz is faster than fc at 18Hz. As
Figure (b), when the load is immediately changed the responsibility of vo is hardly changed. It is shown that
the feed-forward gain of proposed technique is capable of offering the fastest dynamical response.
In Figure (a) and Figure (b) show static-interval simulation results, the main aims of this simulation
are to show the is waveform and its THDi at rated power 600W. For the conventional control, the is
waveform and its THDi=8.93% shown in Figure (a). For the conventional control with proposed technique,
the is waveform and its THDi=5.65% Figure (b). This indicated that the is waveform of the conventional
control with RVE technique is improved to nearby sinusoidal waveform. Obviously, the FFC technique can
improves the speed of dynamic response and the voltage loop and the RVE technique can improves static to
almost sinusoidal better than conventional control.
EXPERIMENTAL PROTOTYPE.Error! Reference source not found.In Figure 7, an
experimental prototype based on the design parameters mentioned in the above section is built and tested.
The structure of prototype composes of a power section and a control section. In Figure 7(a), the VSC built
from 4 IGBTs is driven by gate-drive circuit having fault-protection option. In order to isolate between power
and control section, the transducer device using magnetic effect have been used as sensors. The input current
and DC output current use hall-effect current sensor; the input voltage uses step-down transformer, and the
output voltage is sensed by a differential amplifier built from OPAMPs.
In Figure 7(b), two control strategies were implemented on a eZdspLF2407 to control the VSC for
performance comparison purposes. The implemented control methods in the experiment are the conventional
control (PI controller) and the conventional control with proposed techniques (PI controller with the RVE
and FFC technique). The PI controller parameters of these control methods were designed so that the phase
margin ( m
f ) of the compensated system was 45◦ with the 8Hz-18Hz crossover frequency. For every control
algorithms in the experiment, the sampling time period was set at 200 µs.
The testing of dynamic interval will be compared between the conventional control in Figure (a) and
the proposed technique in Figure 8(b). The configurations of PI controller are set by the same parameter as
the dynamic simulation that is select m
f at 45 and c
f at 18Hz. Figure 8 show the test dynamic results
monitored from oscilloscope. There are the value of peak reference input current ˆsRef
I or controlled-signal vc
(CH3), the input current is (CH4), the output voltage vo (CH2), and the load current io (CH1). When the load
is stepped from 200W to 600W, the io will be step from 0.8A to 2.4A. The vo of the conventional control in
Figure 8(a) is drooped 16V and settling time 60ms, while the vo of the proposed technique in Figure 8(b) is
drooped 10V and settling time 50ms. It is shown that, although c
f at 18Hz gives good dynamical response,
the proposed technique can offer the better dynamical response of output voltage than the conventional
control.
(a) (b)
Figure 7. The experimental prototype: (a) power section. (b) Control section
C
+
+
-
+
+
L
VORef,PU Voltage Controller
PLL
io
Adjust Level Signal
Board
8-Chanel , 8-Bit Digital to Analog
Converter Board
vo
Analog to Digital
Converter
T1,T4
Data Bus
Address Bus
vo,PU
e
Ripple Voltage
Estimator (GRVE)
io,PU
vRVE,PU
Kid
Kpd
Feed-Forward
Compensator
vs,PU
isRef,PU
sin(2ωt)
-
+
isRef
-
+
Ch2
Analog-out for
signal verification
Current
Controller
Digital Signal Processor Board by eZdspTM
LF2407A
vs is
vs
is io
1kHz
x4
vo
Gate Driver
T1
For step load
test
-
+
vs
VSC (Full-bridge)
Input current sensor
(Hall effect)
AC
Side
DC
Side
S3
Ch4
Ch3
Ch1 Ch5 Ch6 Ch7 Ch8
,
ˆ
SR ef PU
I
sin(ωt)
FFC
I
F
a
u
lt-d
e
te
c
tin
d
ic
a
to
r
&b
lo
c
k
in
gs
ig
n
a
l
T2,T3
T2 T3 T4
Fault- detect
signal
Output current sensor
(Hall effect)
Output voltage
sensor
(Difference Amp)
Input voltage
sensor
(Transformer)
11. IJPEDS ISSN: 2088-8694
Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter (Jedsada Jaroenkiattrai)
879
(a) (b)
Figure 8. The dynamic-interval testing results for: (a) the conventional control. (b) The conventional
control with proposed technique
(a) (b)
Figure 9. The dynamic-interval testing results: (a) the settling time versus crossover frequency. (b) The
dropped voltage of output voltage versus crossover frequency
(a) (b) (c)
Figure 10. The static-interval testing results for: (a) the conventional control (b) The conventional control
with the proposed technique (c) The THDi
In Figure 9 will be continued testing from early, but the testing of difference crossover frequency
from 8Hz to 18Hz are added. Figure 9(a) shows the settling time and Figure 9(b) shows the dropped voltage.
Both of the results compare the conventional control with the proposed technique. It is shown that the FFC
gain of proposed technique is capable of offering better dynamical response than the conventional control in
almost every fc.
In Figure 10 present the static-interval testing results. The output power was carried out by
connecting a DC load which is set at rated power 600W. The results are focus on the waveforms of the is
indicated with THDi value as shown in what is similar to the sinusoidal waveform. In addition, the waveform
of the ˆsRef
I will be presented in order to show the effective reducing the ripple voltage in voltage loop. For
the conventional control without RVE technique, Figure 10(a) presents the ˆsRef
I waveform of which ˆsRef
I
CH3: ˆ (10A/ DIV)
SRef
I
CH4: is (10A/DIV)
CH2: Vdc (200V/DIV)
CH1: Iload (2A/DIV)
16V
60ms
CH3: ˆ (10A/ DIV)
SRef
I
CH4: is (10A/DIV)
CH2: Vdc (200V/DIV)
CH1: Iload (2A/DIV)
10V
50ms
GND 1,2
GND 3,4
GND 1,2
GND 3,4
Step load
200W to 600W
Step load
600W to 200W
Step load
200W to 600W
Step load
600W to 200W
0
1
0
2
0
3
0
4
0
5
0
6
0
7
0
8
0
9
0
Crossover frequency (Hz)
Settling
time
(ms)
Conventional control
0
5
1
0
1
5
2
0
2
5
3
0
Crossover frequency (Hz)
Droped
output
voltage
(V)
8 1
0 1
2 1
4 1
6 1
8 8 1
0 1
2 1
4 1
6 1
8
Conventional control with proposed techniques
Conventional control
Conventional control with proposed techniques
CH3: ˆ (5A/DIV)
SRef
I
CH3:is (10A/DIV)
CH1:vs
CH3:is (10A/DIV)
CH1:vs
CH3: ˆ (5A/DIV)
SRef
I
ˆ 5
SRef
I A
ˆ 2.4
SRef
I A
2.30
1.14
0.77
0.40
0.33
0.21
0.15
0.195
0.048
0.010
0.010
0.011
0.009
0.003
0.135
0.021
0.014
0.024
0.010
0.014
0.003
0
0.5
1
1.5
2
2.5 IEC 1000-3-2
Conventional Technique (THDi= 4.16%)
Proposed Technique (THDi= 3%)
Frequency (Hz)
Harmonic
current
(A)
Conventional control (THDi=4.16%)
IEC 1000-3-2
Conventional control with
proposed techniques (THDi=3%)
12. ISSN: 2088-8694
IJPEDS Vol. 8, No. 2, June 2017 : 869 – 881
880
=5A and the is waveform of which the THDi=4.16% as shown in Figure 10(c). For the proposed technique,
Figure 10(b) presents the ˆsRef
I waveform of which ˆsRef
I
is improved to 2.4A. As the result, the is waveform
of which the THDi as shown in Figure 10(c) is improved to 3% and remain under the IEC 1000-3-2.
In Figure presents the key performance in case of relation of THDi versus difference the output
power by varying difference the crossover frequency, in Figure 11(a) is the result of the conventional control,
in Figure 11(b) is the result of the proposed technique. Though the high-crossover frequency will give good
dynamic response, high THDi is occurred. Moreover, the THDi is quite constant every fc when the output
power is increased. The main point of difference, The THDi of proposed technique in Figure 11(b) is lower
than 5% every fc.
In Figure 12(a) presents the performance of system which is presented in case of input power factor
versus difference output power. It achieves a high-power factor considerated nearly unity. The efficiency
versus difference output power in Figure 12(b) indicates the overall efficiency over 85%.
7. CONCLUSION
The analysis of the ripple in voltage loop and control design of the VSC converter built from full-
bridge circuit is presented. The ripple causes the 3rd
harmonic in the input current, and then the input current
is distorted. The proposed control composes of two algorithm techniques, The RVE technique which is the
simple method can reduce the 3rd harmonic of the input current and hence the THDi is improved. Moreover,
the crossover frequency high value can offer the good dynamical response; however, the FFC technique can
achieve the better than. The sensed-load current is used in the FFC technique and the RVE technique. The
control algorithm was implemented on the eZdspLF2407DSP and was tested. As a result, the proposed
control is achieved quite well for the THDi is <5%. The output voltage regulation is the better both the
transient response and the steady state. The overall performances of the system are obtained as follows: the
power factor at a full load is >0.98, the harmonic distortion at AC input power source of the converter is
under control in IEC61000-3-2 class A limit, and the overall efficiency >85%.
(a) (b)
Figure 11. The relation of THDi versus difference output power by varying difference crossover frequency
of: (a) the conventional control. (b) the conventional control with proposed technique.
(a) (b)
Figure 12. Test result of: (a) the output power versus the power factor. (b) the output power versus efficiency
1
2
3
4
5
6
7
8
9
Output power , Po (W)
Total
Harmonic
Distortion
,
THDi
(%)
1
2
3
4
5
6
7
8
9
Output power , Po (W)
Total
Harmonic
Distortion
,
THDi
(%)
300 400 500 600
fc = 18Hz
16Hz
14Hz
12Hz
10Hz
8Hz
300 400 500 600
fc = 18Hz 16Hz
14Hz 12Hz
10Hz
8Hz
0.84
0.86
0.88
0.90
0.92
0.94
0.96
0.98
1.00
Output power , Po (W)
Power
Factor
,
PF
300 400 500 600
Conventional control with
proposed techniques
Conventional control
60%
65%
70%
75%
80%
85%
90%
95%
100%
Output power , Po (W)
Efficiency
,
h
(%)
300 400 500 600
Conventional control
Conventional control with
proposed techniques
13. IJPEDS ISSN: 2088-8694
Voltage Ripple Reduction in Voltage Loop of Voltage Source Converter (Jedsada Jaroenkiattrai)
881
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