The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The growing demand for electricity and the increasing integration of clean energies into the electrical grids requires the multiplication and reinforcement of high-voltage direct current (HVDC) projects throughout the world and demonstrates the interest in this electricity transmission technology. The transmitting system of the voltage source converter-high-voltage direct current (VSC-HVDC) consists primarily of two converter stations that are connected by a dc cable. In this paper, a nonlinear control based on the backstepping approach is proposed to improve the dynamic performance of a VSC-HVDC transmission system, these transport systems are characterized by different complexities such as parametric uncertainties, coupled state variables, neglected dynamics, presents a very interesting research topic. Our contribution through adaptive control based on the backstepping approach allows regulating the direct current (DC) bus voltage and the active and reactive powers of the converter stations. Finally, the validity of the proposed control has been verified under various operating conditions by simulation in the MATLAB/Simulink environment.
A new bidirectional multilevel inverter topology with a high number of voltage levels with a very reduced number of power components is proposed in this paper. Only TEN power switches and four asymmetric DC voltage sources are used to generate 25 voltage levels in this new topology. The proposed multilevel converter is more suitable for e-mobility and photovoltaic applications where the overall energy source can be composed of a few units/associations of several basic source modules. Several benefits are provided by this new topology: Highly sinusoidal current and voltage waveforms, low Total Harmonic Distortion, very low switching losses, and minimum cost and size of the device. For optimum control of this 25-level voltage inverter, a special Modified Hybrid Modulation technique is performed. The proposed 25-level inverter is compared to various topologies published recently in terms of cost, the number of active power switches, clamped diodes, flying capacitors, DC floating capacitors, and the number of DC voltage sources. This comparison clearly shows that the proposed topology is cost-effective, compact, and very efficient. The effectiveness and the good performance of the proposed multilevel power converter (with and without PWM control) are verified and checked by computational simulations.
Fast photovoltaic IncCond-MPPT and backstepping control, using DC-DC boost c...IJECEIAES
In this paper, we present our contribution in photovoltaic energy optimization subject. In this research work, the goal is to determinate fastly the optimal PV Module working point, allowing maximum power extraction. In this work we use DC-DC Boost converter to control the working point, by adjusting PV voltage trough duty cycle. In order to achieve our goal, we use the combination of incremental conductance MPPT technique and DC-DC Boost converter backstepping control. The validation of this control is made by Matlab simulation; the obtained results prove its effectiveness and its good maximum power tracking dynamics for different irradiance and temperature profiles.
Design and Development of Power Electronic Controller for Grid-connected PV A...IJAPEJOURNAL
Design and simulation of a simple power electronic interface for grid-connected PV array has been proposed using boost converter and line-commutated inverter with maximum power point tracking (MPPT) controller. The output of PV array varies with irradiation, and hence the duty cycle of the PI controller is adjusted automatically to supply a constant DC voltage to the inverter circuit, the output of which is directly connected to the grid. The MPPT controller extracts maximum power from the solar array and feeds it to the single-phase utility grid. The proposed scheme has been modeled in the MATLAB 7.1 software and the complete system has been simulated for open loop and closed loop configurations. The active power fed to the grid is taken for different firing angles in open loop mode and the firing angle for maximum power has been determined. This is compared with the firing angle obtained from the closed loop mode and found that both results agree with each other.
Performance Evaluation of Photo-Voltaic fed Brushless Direct Current Motor fo...IJERA Editor
This work presents an effective approach towards reduction of steps in power conversion from solar
photovoltaic system to load. When a Photovoltaic system is fed to an induction motor, it requires MPPT
controller and an Inverter circuit in first and second stages since Induction motor works with a.c supply. By
eliminating the Inverter circuit and employing a BLDC motor the efficiency of the system can be improved. The
BLDC motor works under Electronic commutation principle with VSI embedded in the motor. A PV Panel fed
to the "R" load with Hill Climbing MPPT is considered along with practical irradiance data. Simulation is
carried out by formulating the mathematical model for the photovoltaic source, MPPT, Motor. System
performance‟s are investigated under different levels of solar insolation.
Environmental factors such as air pollution and increase in global warming by using polluting fuels are the most important reasons of using renewable and clean energy that runs in global community. Wind energy is one of the most suitable and widely used kind of renewable energy which had been in consideration so well. This paper introduces an electric power generation
system of wind based on Y-source and improved Y-source inverter to deliver optimal electrical power to the network. This new converter is from impedance source converters family. This presented converter has more degrees of freedom to adjust voltage gain and modulation. Also, by limiting the range of simultaneous control (shooting through) while it maintains the
highest power of maximizer, it can operate in higher modulation range. This causes the reduce of stress in switching and thus it will improve the quality of output. Recommended system had been simulated in MATLAB/Simulink and shown results indicate accurate functionality.
“MODELING AND ANALYSIS OF DC-DC CONVERTER FOR RENEWABLE ENERGY SYSTEM” Final...8381801685
This project portrays a comparative analysis of DC-DC Converters for Renewable Energy System. The electrolysis method which increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. The converter operates in lagging PF mode for a very wide change in load and supply voltage variations, thus ensuring ZVS for all the primary switches. The peak current through the switches decreases with load current.This paper portrays a comparative analysis of DC-DC Converters for Renewable Energy System . The simulation and experimental results show that the power gain obtained by this method clearly increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. Theoretical predictions of the selected configuration have been compared with the MATLAB simulation results. The simulation and experimental results indicate that the output of the inverter is nearly sinusoidal. The output of rectifier is pure DC due to the presence of LC filter at the output. It can be seen that the efficiency of DC-DC converter with transformer is 15% higher than the converter without transformer.
The growing demand for electricity and the increasing integration of clean energies into the electrical grids requires the multiplication and reinforcement of high-voltage direct current (HVDC) projects throughout the world and demonstrates the interest in this electricity transmission technology. The transmitting system of the voltage source converter-high-voltage direct current (VSC-HVDC) consists primarily of two converter stations that are connected by a dc cable. In this paper, a nonlinear control based on the backstepping approach is proposed to improve the dynamic performance of a VSC-HVDC transmission system, these transport systems are characterized by different complexities such as parametric uncertainties, coupled state variables, neglected dynamics, presents a very interesting research topic. Our contribution through adaptive control based on the backstepping approach allows regulating the direct current (DC) bus voltage and the active and reactive powers of the converter stations. Finally, the validity of the proposed control has been verified under various operating conditions by simulation in the MATLAB/Simulink environment.
A new bidirectional multilevel inverter topology with a high number of voltage levels with a very reduced number of power components is proposed in this paper. Only TEN power switches and four asymmetric DC voltage sources are used to generate 25 voltage levels in this new topology. The proposed multilevel converter is more suitable for e-mobility and photovoltaic applications where the overall energy source can be composed of a few units/associations of several basic source modules. Several benefits are provided by this new topology: Highly sinusoidal current and voltage waveforms, low Total Harmonic Distortion, very low switching losses, and minimum cost and size of the device. For optimum control of this 25-level voltage inverter, a special Modified Hybrid Modulation technique is performed. The proposed 25-level inverter is compared to various topologies published recently in terms of cost, the number of active power switches, clamped diodes, flying capacitors, DC floating capacitors, and the number of DC voltage sources. This comparison clearly shows that the proposed topology is cost-effective, compact, and very efficient. The effectiveness and the good performance of the proposed multilevel power converter (with and without PWM control) are verified and checked by computational simulations.
Fast photovoltaic IncCond-MPPT and backstepping control, using DC-DC boost c...IJECEIAES
In this paper, we present our contribution in photovoltaic energy optimization subject. In this research work, the goal is to determinate fastly the optimal PV Module working point, allowing maximum power extraction. In this work we use DC-DC Boost converter to control the working point, by adjusting PV voltage trough duty cycle. In order to achieve our goal, we use the combination of incremental conductance MPPT technique and DC-DC Boost converter backstepping control. The validation of this control is made by Matlab simulation; the obtained results prove its effectiveness and its good maximum power tracking dynamics for different irradiance and temperature profiles.
Design and Development of Power Electronic Controller for Grid-connected PV A...IJAPEJOURNAL
Design and simulation of a simple power electronic interface for grid-connected PV array has been proposed using boost converter and line-commutated inverter with maximum power point tracking (MPPT) controller. The output of PV array varies with irradiation, and hence the duty cycle of the PI controller is adjusted automatically to supply a constant DC voltage to the inverter circuit, the output of which is directly connected to the grid. The MPPT controller extracts maximum power from the solar array and feeds it to the single-phase utility grid. The proposed scheme has been modeled in the MATLAB 7.1 software and the complete system has been simulated for open loop and closed loop configurations. The active power fed to the grid is taken for different firing angles in open loop mode and the firing angle for maximum power has been determined. This is compared with the firing angle obtained from the closed loop mode and found that both results agree with each other.
Performance Evaluation of Photo-Voltaic fed Brushless Direct Current Motor fo...IJERA Editor
This work presents an effective approach towards reduction of steps in power conversion from solar
photovoltaic system to load. When a Photovoltaic system is fed to an induction motor, it requires MPPT
controller and an Inverter circuit in first and second stages since Induction motor works with a.c supply. By
eliminating the Inverter circuit and employing a BLDC motor the efficiency of the system can be improved. The
BLDC motor works under Electronic commutation principle with VSI embedded in the motor. A PV Panel fed
to the "R" load with Hill Climbing MPPT is considered along with practical irradiance data. Simulation is
carried out by formulating the mathematical model for the photovoltaic source, MPPT, Motor. System
performance‟s are investigated under different levels of solar insolation.
Environmental factors such as air pollution and increase in global warming by using polluting fuels are the most important reasons of using renewable and clean energy that runs in global community. Wind energy is one of the most suitable and widely used kind of renewable energy which had been in consideration so well. This paper introduces an electric power generation
system of wind based on Y-source and improved Y-source inverter to deliver optimal electrical power to the network. This new converter is from impedance source converters family. This presented converter has more degrees of freedom to adjust voltage gain and modulation. Also, by limiting the range of simultaneous control (shooting through) while it maintains the
highest power of maximizer, it can operate in higher modulation range. This causes the reduce of stress in switching and thus it will improve the quality of output. Recommended system had been simulated in MATLAB/Simulink and shown results indicate accurate functionality.
“MODELING AND ANALYSIS OF DC-DC CONVERTER FOR RENEWABLE ENERGY SYSTEM” Final...8381801685
This project portrays a comparative analysis of DC-DC Converters for Renewable Energy System. The electrolysis method which increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. The converter operates in lagging PF mode for a very wide change in load and supply voltage variations, thus ensuring ZVS for all the primary switches. The peak current through the switches decreases with load current.This paper portrays a comparative analysis of DC-DC Converters for Renewable Energy System . The simulation and experimental results show that the power gain obtained by this method clearly increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. Theoretical predictions of the selected configuration have been compared with the MATLAB simulation results. The simulation and experimental results indicate that the output of the inverter is nearly sinusoidal. The output of rectifier is pure DC due to the presence of LC filter at the output. It can be seen that the efficiency of DC-DC converter with transformer is 15% higher than the converter without transformer.
SRF THEORY BASED STATCOM FOR COMPENSATION OF REACTIVE POWER AND HARMONICSIAEME Publication
The power electronic devices like converters and inverters inject harmonic currents into AC
system due to their non linear characteristics. These devices draw high amount of reactive power
from source. The commencement of Nonlinear Load into the ac power system will have the effect of
harmonics. The presence of harmonics in system it will effected with power quality problems. Due
to this high amount of power losses and disoperation of power electronics devices is caused, along
with this Harmonics have a number of undesirable effects like Voltage disturbances. These
harmonics are needed to mitigate for Power Quality Enhancement in distributed system. Here the
device called STATCOM is one of the FACTS Devices which can be used to mitigate the harmonics
and reactive power compensation. The voltage source converter is core of the STATCOM and the
hysteresis current control is indirect method of controlling of VSC. In this paper we implement with
SRF based STATCOM control. SRF theory is implemented for the generation of controlling
reference current signals for controller of STATCOM. The Matlab\Simulink based model is
developed and simulation results are showed for linear and nonlinear load conditions.
Improving Electrical Power Grid of Jordan and Control the Voltage of Wind Tur...IJAPEJOURNAL
In this paper, we improved the national grid of Jordan country by adding a renewable resources specifically a wind turbines generation unites distributed on different places in Jordan to compensate the losses of the power in Jordan and to dispense with using the generation of fuel and gas by representing the national grid of Jordan in ETAB simulator and we solved the voltage problems of wind turbines using a new mythology using smart grid techniques
Real Time Implementation of Variable Step Size Based P&O MPPT for PV Systems ...IJPEDS-IAES
Nowadays Solar energy is an important energy source due to the energy crisis and environment pollution. Maximum power point tracking (MPPT) algorithm improves the utilization efficiency of a photovoltaic systems. In this paper an improved P&O MPPT algorithm is developed and simulated using MATLAB / SIMULINK to control the DC/DC buck converter. The obtained simulink model is also verified using dspace tool. Both the simulated and experimental results are validated by also comparing them with conventional MPPT methods. The performance measures show the increase in the efficiency of PV system by the proposed model.
Distributed Generation Sources are becoming an inseparable part of modern electrical grids. Finding the control strategies which can help them to be as much as possibly beneficial for the grid has been a big concern among the researchers. In this work, a PQ controller for connecting A DC source simulates the effect of a Distributed Generation to the grid based on the decoupling of Active and Reactive powers has been proposed. The Simulation results which have been in the MATLAB/Simulink environment show the effectiveness of this control technique for injecting the defined value of active and reactive power to the grid.
Synchronverters: Inverters that Mimic Synchronous GeneratorsQing-Chang Zhong
Inverters are made mathematically equivalent to conventional synchronous generators, which considerably facilitates the integration of renewable energy and distributed generation into smart grids.
MPPT oscillations minimization in PV system by controlling non-linear dynamic...IJECEIAES
Solar PV power generation has achieved rapid growth in developing countries which has many merits such as absence of noise, longer life, no pollution, less time for installation, and ease of grid interface. A maximum power point tracking circuit (MPPT) consists of DC-DC power electronics converters that are used to improve the energy attainment from solar PV array. This paper presents a detailed analysis to control of chaos, a non-linear dynamic in SEPIC DC-DC converter interfaced solar PV system, to minimize the oscillations near to MPP. In SEPIC DC-DC converter, the input inductor current is continuous and capable of sweeping the whole I-V curve of a PV module from open circuit voltage (V oc ) to short circuit current (I sc ) operating points. To trace the true maximum power point and to nullify the oscillations near to MPP, the yield output voltage needs to ensure period-1 operation.
Grid-Connection Control and Simulation of PMSG Wind Power System Based on Mul...ijsrd.com
This dissertation proposes a wind energy conversion system is composed of a wind turbine PMSG, a rectifier, and an inverter. The wind turbine PMSG transforms the mechanical power from the wind into the electrical power, while the rectifier converts the AC power into DC power and controls the speed of the PMSG. The controllable inverter helps in converting the DC power to variable frequency and magnitude AC power. With the voltage oriented control, the inverter also possesses the ability to control the active and reactive powers injected into the grid. Multilevel inerter is used to step up the voltage and to reduce the THD. Here nine level and eleven level inverter are used and the voltage increases and THD reduces from 12.87 % to 7.46 %. Active and reactive power is controlled dc stabilization and the reactive power is near to unity Here PI controller is used to control the inverter output rms voltage and LC filter is used to remove the harmonics available in the system.
LOW CAPACITANCE CASCADED H BRIDGE MULTILEVEL BASED STATCOMASWATHYSANAND1
This project aims at a new low capacitance cascade H-Bridge multilevel inverter based StatCom. This system is able to operate with extremely low dc capacitance values.
SIMULATION OF REDUCED SWITCH INVERTER BASED UPQC WITH FUZZY LOGIC AND ANN CON...MABUSUBANI SHAIK
ABSTRACT
This paper presents a new methodology to reduce harmonic distortion in UPQC using artificial neural network
and fuzzy logic controller. So this paper main aim is improve power quality by using UPQC with ANN and FLC. The most purpose of the proposed (ANN & FLC) is capable of providing good static and dynamic performances compared to PI controller. The UPQC is to control on voltage flicker/unbalance, reactive power and harmonics. In different words, the UPQC has the potential of up power quality at the purpose of installation on power industrial power systems. The appliance of computing is growing quick within the space of power electronics and drives. From olden days to now days we are using twelve switches used in back to back configuration. But now we are using nine switches instead of 12
switches. In 9 switch UPQC converter given the most useful benefits compared to 12 switches power converter. The nine switches UPQC converter gets the best results by using of three methods. They are one is PI controller technique, ANN controller technique and FLC controller technique. By contrast PI, FLC and ANN, ANN is better than (FLC & PI) for power quality enhancement and voltage sag and voltage swell mitigations. The factitious neural network (ANN) is taken into account as a replacement tool to style management electronic equipment for power quality (PQ) devices. A whole
simulation study is administrated to analysis the performance of the ANN controller and compares its performance with the quality FLC & PI controller’s results. The nine-switch convertor has already been proved to possess sure benefits,
additionally to its part saving topological feature. Despite these benefits, the nine-switch convertor has thus far found restricted applications because of its several perceived performance tradeoffs like requiring associate degree outsized
dc-link capacitance, restricted amplitude sharing, and unnatural part shift between its 2 sets of output terminals. Rather than acceptive these tradeoffs as limitations, a nine-switch power conditioner is projected here that nearly “converts” most of those topological short comings into fascinating performance benefits. Aiming more to cut back its switch losses,
Harmonics, Voltage Sag & Swell associate degree acceptable discontinuous modulation theme is projected and studied here thoroughly to doubly make sure that top reduction of commutations is achieved. With associate degree suitably
designed management theme with PI and ANN with Fuzzy logic controller then incorporated, the nine-switch convertor is shown to favorably raise the general power quality in Simulation, thus justifying its role as an influence conditioner at a reduced value.
KEYWORDS: ANN, Active Power Filters, PI Controller, Nine Switch Converter, Power Quality, UPQC
Ieee 2015 2014 power electronics project titlespowerprojects
We offer IEEE 2014 power electronics projects, IEEE 2015 power electronics projects for B.E, M.E, B.Tech, M.Tech final year students in engineering colleges. We provide all project support with project training.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
SRF THEORY BASED STATCOM FOR COMPENSATION OF REACTIVE POWER AND HARMONICSIAEME Publication
The power electronic devices like converters and inverters inject harmonic currents into AC
system due to their non linear characteristics. These devices draw high amount of reactive power
from source. The commencement of Nonlinear Load into the ac power system will have the effect of
harmonics. The presence of harmonics in system it will effected with power quality problems. Due
to this high amount of power losses and disoperation of power electronics devices is caused, along
with this Harmonics have a number of undesirable effects like Voltage disturbances. These
harmonics are needed to mitigate for Power Quality Enhancement in distributed system. Here the
device called STATCOM is one of the FACTS Devices which can be used to mitigate the harmonics
and reactive power compensation. The voltage source converter is core of the STATCOM and the
hysteresis current control is indirect method of controlling of VSC. In this paper we implement with
SRF based STATCOM control. SRF theory is implemented for the generation of controlling
reference current signals for controller of STATCOM. The Matlab\Simulink based model is
developed and simulation results are showed for linear and nonlinear load conditions.
Improving Electrical Power Grid of Jordan and Control the Voltage of Wind Tur...IJAPEJOURNAL
In this paper, we improved the national grid of Jordan country by adding a renewable resources specifically a wind turbines generation unites distributed on different places in Jordan to compensate the losses of the power in Jordan and to dispense with using the generation of fuel and gas by representing the national grid of Jordan in ETAB simulator and we solved the voltage problems of wind turbines using a new mythology using smart grid techniques
Real Time Implementation of Variable Step Size Based P&O MPPT for PV Systems ...IJPEDS-IAES
Nowadays Solar energy is an important energy source due to the energy crisis and environment pollution. Maximum power point tracking (MPPT) algorithm improves the utilization efficiency of a photovoltaic systems. In this paper an improved P&O MPPT algorithm is developed and simulated using MATLAB / SIMULINK to control the DC/DC buck converter. The obtained simulink model is also verified using dspace tool. Both the simulated and experimental results are validated by also comparing them with conventional MPPT methods. The performance measures show the increase in the efficiency of PV system by the proposed model.
Distributed Generation Sources are becoming an inseparable part of modern electrical grids. Finding the control strategies which can help them to be as much as possibly beneficial for the grid has been a big concern among the researchers. In this work, a PQ controller for connecting A DC source simulates the effect of a Distributed Generation to the grid based on the decoupling of Active and Reactive powers has been proposed. The Simulation results which have been in the MATLAB/Simulink environment show the effectiveness of this control technique for injecting the defined value of active and reactive power to the grid.
Synchronverters: Inverters that Mimic Synchronous GeneratorsQing-Chang Zhong
Inverters are made mathematically equivalent to conventional synchronous generators, which considerably facilitates the integration of renewable energy and distributed generation into smart grids.
MPPT oscillations minimization in PV system by controlling non-linear dynamic...IJECEIAES
Solar PV power generation has achieved rapid growth in developing countries which has many merits such as absence of noise, longer life, no pollution, less time for installation, and ease of grid interface. A maximum power point tracking circuit (MPPT) consists of DC-DC power electronics converters that are used to improve the energy attainment from solar PV array. This paper presents a detailed analysis to control of chaos, a non-linear dynamic in SEPIC DC-DC converter interfaced solar PV system, to minimize the oscillations near to MPP. In SEPIC DC-DC converter, the input inductor current is continuous and capable of sweeping the whole I-V curve of a PV module from open circuit voltage (V oc ) to short circuit current (I sc ) operating points. To trace the true maximum power point and to nullify the oscillations near to MPP, the yield output voltage needs to ensure period-1 operation.
Grid-Connection Control and Simulation of PMSG Wind Power System Based on Mul...ijsrd.com
This dissertation proposes a wind energy conversion system is composed of a wind turbine PMSG, a rectifier, and an inverter. The wind turbine PMSG transforms the mechanical power from the wind into the electrical power, while the rectifier converts the AC power into DC power and controls the speed of the PMSG. The controllable inverter helps in converting the DC power to variable frequency and magnitude AC power. With the voltage oriented control, the inverter also possesses the ability to control the active and reactive powers injected into the grid. Multilevel inerter is used to step up the voltage and to reduce the THD. Here nine level and eleven level inverter are used and the voltage increases and THD reduces from 12.87 % to 7.46 %. Active and reactive power is controlled dc stabilization and the reactive power is near to unity Here PI controller is used to control the inverter output rms voltage and LC filter is used to remove the harmonics available in the system.
LOW CAPACITANCE CASCADED H BRIDGE MULTILEVEL BASED STATCOMASWATHYSANAND1
This project aims at a new low capacitance cascade H-Bridge multilevel inverter based StatCom. This system is able to operate with extremely low dc capacitance values.
SIMULATION OF REDUCED SWITCH INVERTER BASED UPQC WITH FUZZY LOGIC AND ANN CON...MABUSUBANI SHAIK
ABSTRACT
This paper presents a new methodology to reduce harmonic distortion in UPQC using artificial neural network
and fuzzy logic controller. So this paper main aim is improve power quality by using UPQC with ANN and FLC. The most purpose of the proposed (ANN & FLC) is capable of providing good static and dynamic performances compared to PI controller. The UPQC is to control on voltage flicker/unbalance, reactive power and harmonics. In different words, the UPQC has the potential of up power quality at the purpose of installation on power industrial power systems. The appliance of computing is growing quick within the space of power electronics and drives. From olden days to now days we are using twelve switches used in back to back configuration. But now we are using nine switches instead of 12
switches. In 9 switch UPQC converter given the most useful benefits compared to 12 switches power converter. The nine switches UPQC converter gets the best results by using of three methods. They are one is PI controller technique, ANN controller technique and FLC controller technique. By contrast PI, FLC and ANN, ANN is better than (FLC & PI) for power quality enhancement and voltage sag and voltage swell mitigations. The factitious neural network (ANN) is taken into account as a replacement tool to style management electronic equipment for power quality (PQ) devices. A whole
simulation study is administrated to analysis the performance of the ANN controller and compares its performance with the quality FLC & PI controller’s results. The nine-switch convertor has already been proved to possess sure benefits,
additionally to its part saving topological feature. Despite these benefits, the nine-switch convertor has thus far found restricted applications because of its several perceived performance tradeoffs like requiring associate degree outsized
dc-link capacitance, restricted amplitude sharing, and unnatural part shift between its 2 sets of output terminals. Rather than acceptive these tradeoffs as limitations, a nine-switch power conditioner is projected here that nearly “converts” most of those topological short comings into fascinating performance benefits. Aiming more to cut back its switch losses,
Harmonics, Voltage Sag & Swell associate degree acceptable discontinuous modulation theme is projected and studied here thoroughly to doubly make sure that top reduction of commutations is achieved. With associate degree suitably
designed management theme with PI and ANN with Fuzzy logic controller then incorporated, the nine-switch convertor is shown to favorably raise the general power quality in Simulation, thus justifying its role as an influence conditioner at a reduced value.
KEYWORDS: ANN, Active Power Filters, PI Controller, Nine Switch Converter, Power Quality, UPQC
Ieee 2015 2014 power electronics project titlespowerprojects
We offer IEEE 2014 power electronics projects, IEEE 2015 power electronics projects for B.E, M.E, B.Tech, M.Tech final year students in engineering colleges. We provide all project support with project training.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering and Science (The IJES)theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Simulation of various DC-DC converters for photovoltaic systemIJECEIAES
This work explains the comparison of various dc-dc converters for photovoltaic systems. In recent day insufficient energy and continues increasing in fuel cost, exploration on renewable energy system becomes more essential. For high and medium power applications, high input source from renewable systems like photovoltaic and wind energy system turn into difficult one, which leads to increase of cost for installation process. So the generated voltage from PV system is boosted with help various boost converter depends on the applications. Here the various converters are like boost converter, buck converter, buck-boost converter, cuk converter, sepic converter and zeta converter are analysed for photovoltaic system, which are verified using matlab / simulink.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
A hybrid DC/DC/AC converter connected to the grid without a three-phase transformer is controlled. The decentralized control method is applied to the hybrid DC-DC converter such that the maximum power of PV flows to the grid side. This controller must charge and discharge the battery at the proper time. It must also regulate DC-link voltage. An additional advantage of the proposed control is that the three-phase inverter does not need a separate controller such as PWM and SPWM. A simple technique is used for creating the desired phase shift in the three-phase inverter, which makes the active and reactive power of the inverter controllable. A new configuration is also proposed to transmit and manage the generation power of PV. In this scheme, the battery and fuel cell are employed as an auxiliary source to manage the generation power of PV. Finally, a real-time simulation is performed to verify the effectiveness of the proposed controller and system by considering the real characteristics of PV and FC.
This work includes the establishment of a Photovoltaic system connected to the grid by means of an inverter. The fundamental goal of the work is to incorporate an advanced active power flow management scheme in order to adopt load at any weather condition along with the advantage of maximum active power flow and zero harmonics from PV inverter to the grid. The outcome of analysis and control design of grid connected PV inverter using a Proportional-Integral (PI) control technique is based on synchronous dq rotating reference frame so as to achieve maximum output voltage and record the active power. It has been observed that the model provides a better rate of stability as compared to the existing topology.
Filter Based Solar Power Generation System with a Seven Level InverterIJMTST Journal
This paper proposes a new solar power generation system, which is composed of a DC/DC power converter and a new seven-level inverter. The DC/DC power converter integrates a DC-DC boost converter and a transformer to convert the output voltage of the solar cell array into two independent voltage sources with multiple relationships. This new seven-level inverter is configured using a capacitor selection circuit and a full-bridge power converter, connected in cascade. The capacitor selection circuit converts the two output voltage sources of DC-DC power converter into a three-level DC voltage and the full- bridge power converter further converts this three- level DC voltage into a seven-level AC voltage. In this way, the proposed solar power generation system generates a sinusoidal output current that is in phase with the utility voltage and is fed into the utility. The salient features of the proposed seven-level inverter are that only six power electronic switches are used and only one power electronic switch is switched at high frequency at any time. A prototype is developed and tested to verify the performance of this proposed solar power generation system.
In a distributed generation system, divers renewable agents are connected to the low voltage 3 phase utility grid by an inverter which is used as power condition and must assurance the higher efficiency of the renewable agent. To achieve this level of efficiency, a unitary power factor between the utility grid voltages and the inverter currents is necessary, and a synchronization algorithm is required for the perfect synchronization between the 3-phase utility grid and the renewable agent. The aim of this paper is to present the optimization of the performance of a Synchronization controller for a 3-phase photovoltaic grid-connected system, assessing its accuracy under different conditions and studying their drawbacks and advantages. A grid connected photovoltaic system with a nominal power of 5 kW is used so as to assess the behavior of the synchronization algorithm when the 3 phase utility grid is affected by some disturbances such as voltage unbalances.
Two fuzzy logic controllers are proposed in this paper to control a three phase inverter for grid connected photovoltaic system. The first controller was used to predict the DC voltage that allows the three phase inverter to track the maximum power point of photovoltaic array under different environmental conditions such as irradiances and temperature. The second was used to control the active power and reactive power injected into the grid in order to inject the maximum active power produced by photovoltaic systems into grid with high efficiency and low total harmonic distortion using the same three phase inverter. The system components are photovoltaic array, DC link voltage, three-phase inverter, inverter control, LC filter, transformer and grid. To verify the effectivnesse of the introdueced system, modeling and simulation are verified in Matlab/Simulink due to its frequent use and its effectiveness.
OPTIMAL CURRENT REGULATION STRATEGY FOR THREE-PHASE BACK-TOBACK ACTIVE POWER ...Ijorat1
Abstract: The objective of this paper is to propose a three phase back-to-back power conditioner with optimal a current
regulation strategy in microgrid. To achieve high stability ,the frequency and the voltage of the microgrid is controlled
by using bidirectional power flow control .The active and reactive power of Active Power Conditioner(APC) is used
here. The dc-link capacitor is the main component of the back-to-back power conditioner for power decoupling and
power flow balancing. Optimal current regulation strategy is developed to improve the power quality and stability of
the micro grids as well as to reduce the dc link capacitance. Under steady state, the optimal ac current regulation is
able to achieve the dc-link voltage regulation and to reduce the injected ac line current variation. Simulation result was
used to demonstrate the feasibility and performance of the proposed active power conditioner.
Incremental Conductance MPPT Algorithm for PV System Implemented Using DC-DC ...IJERA Editor
The two basic topologies of switch mode DC-DC converters (Buck and Boost) are analyzed with a view of their use in PV (photovoltaic) systems, as the photovoltaic generator exhibits non-linear characteristics due to the change in environmental condition and load variation. As the efficiency of PV panels is low it becomes mandatory to extract maximum power from the PV panel at a given period of time. Several MPPT algorithms with different types of converters are being proposed for extracting maximum power from the PV panel. It is found that the nature of load plays an important role in the choice of topology. This paper investigates the implementation issues of Incremental Conductance method with Buck and Boost Converters. Mathematical analysis and desirable steady-state operating point of the converters are derived to give satisfactory maximum power point tracking operation.
REDUCING SOURCE CURRENT HARMONICS DUE TO BALANCED AND UN-BALANCED VOLTAGE VAR...IJCI JOURNAL
Electricity demand has been increasing due to the increase of population and industries. Hence it is very
important to feed the demand with quality of generation. Improvement of power quality is the greater
concern in advanced power system element, it is essential to congregate the need of energy by employ the
renewable energy generating sources like pv, fuel cell, biomass, wind, etc and utilizing many more
applications like grid interconnected systems, power quality improvement. The situations like harmonic,
reactive power exchanging, power factor correction, balanced and un-balanced voltage variations & so on,
due to greater effect on highly susceptible loads are to be encouraged in power distribution system. To
enhance these circumstances, custom power appliances are used to achieve high grid voltage stability. In
this paper, a voltage distortions controlled D-STATCOM based on fuzzy controller is a meticulous power
appliance for enhancing harmonic distortions from high power semiconductor switching device,
exchanging the both active & reactive power, defend the gird stability by implementing DG technology, to
regulate the power quality issues in power distribution network. This paper implements the comparative
analysis of PI and Fuzzy controlled DSTATCOM with energy backup scheme, controlled by pwm control
technique and founded that fuzzy based IPQ theory for generation of reference current signals improves the
power quality than PI based IPQ theory and this analysis is dynamically evaluated with Matlab/Simulink.
Grid-Connected Photovoltaic System without using Boost ConverterIJMTST Journal
This paper presents operation and control for improving the efficiency and size of a photovoltaic generation
system using a current-source inverter. This system is directly connected utility grid to a solar cell without
using a boosting converter. In proposed grid connected PV system the single phase CSI converter used with a
double tuned resonant filter circuit. The system uses transformer-less single-stage transformation for
tracking the most extreme power point and interfacing the photovoltaic array to the grid. The greatest power
point is kept up with a fuzzy logic controller. A proportional-resonant controller is used to control the current
injected into the grid. A modified carrier based modulation technique for the current source inverter is
proposed to magnetize the dc-link inductor by shorting one of the bridge converter legs after every active
switching cycle.
Control of Two Stage PV Power System under the Unbalanced Three Phase Grid Vo...ijtsrd
This paper proposes a dynamic power decoupling DPD strategy for the three phase grid tied PV power system without increasing the dc link capacitance. Under normal condition, the interleaved boost converter will extract the maximum power point MPP from the PV array and the three phase inverter will inject the power to the grid. During the unbalanced grid fault scenario, the input power and current of the interleaved boost converter will be controlled by the proposed DPD to achieve the power decoupling capability as well as to eliminate the dc link voltage oscillation. The proposed work has been carried out in MATLAB, and the results are presented. Manasa | Nirmaladevi ""Control of Two Stage PV Power System under the Unbalanced Three-Phase Grid Voltages"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-2 , February 2020,
URL: https://www.ijtsrd.com/papers/ijtsrd30091.pdf
Paper Url : https://www.ijtsrd.com/engineering/electrical-engineering/30091/control-of-two-stage-pv-power-system-under-the-unbalanced-three-phase-grid-voltages/manasa
Performance Analysis of DC Micro Grid with PV-Fuel Cell Hybrid GenerationIJMREMJournal
Conventional energy resources are being replaced by Renewable energy sources mainly due to increasing
environmental concerns. Photovoltaic (PV) and Fuel cell (FC) are suitable to be used in modern DC microgrids
due to their DC output. In this research work, a DC microgrid structure is proposed for small residential areas
using hybrid PV and FC generation. Power Electronic converters are used to regulate generated voltage of the
two sources for integration to a common DC bus. Proposed system is simulated using MATLAB SIMULINK to
observe its performance. Simulation results show that output voltage is properly maintained at different DC
Similar to The International Journal of Engineering and Science (IJES) (20)
Performance Analysis of DC Micro Grid with PV-Fuel Cell Hybrid Generation
The International Journal of Engineering and Science (IJES)
1. The International Journal of Engineering
And Science (IJES)
||Volume|| 1 ||Issue|| 2 ||Pages|| 158-166 ||2012||
ISSN: 2319 – 1813 ISBN: 2319 – 1805
Mppt and Simulation for a Grid-Connected Photovoltaic System
and Fault Analysis
1,
K.Manohar, 2,P.Sobha Rani
1,
Scholar M.Tech, Department of Electrical and Electronics Engineering, NBKRIST, AP, India,
2,
Associate Professor, Department of Electrical and Electronics Engineering, NBKRIST, AP, India.
-------------------------------------------------------------------Abstract------------------------------------------------------------------
This paper establishes a dynamic model of grid-connected PV system by Matlab/Simulink with d-and q-axis as
coordinates which is synchronously rotating with the grid voltage to reflect the characteristics of the system
accurately. Based on the accurate modeling system, maximum power point tracking (MPPT) and fault analysis
are studied. Grid-connected PV system includes a PV array, a control system, a distribution network and a load.
The control system of grid-connected PV system has two effective control strategies. First one is the current
control strategy can regulate the current at the point of common coupling to achieve power factor control and
regulate the dc link voltage. Second one is the voltage control strategy is used for PV output voltage to
achieve closed-loop control which can smoothly and quickly track the maximum power point of PV array.
Maximum power point tracking (MPPT) can effectively improve the solar energy conversion efficiency of PV
systems. In this paper, Perturb-and-observe (P&O) method is used to achieve this function. Finally fault
analysis is carried by creating a LLLG fault in the distribution network and observes the ac voltage, ac current
and ac power waveforms at the grid with and without a LLLG fault.
Keywords - grid-connected photovoltaic (PV) system, maximum power point tracking, voltag e source inverter,
and LLLG fault etc…
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Date Of Submission:1, December, 2012 Date Of Publication: 15, December 2012
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1. Introduction
Solar energy has become a very potential new energy. Grid-connected photovoltaic (PV) system does
not require bulk and lossy battery and reduces transmission losses. As Conventional sources of energy are
rapidly depleting and the cost of energy is rising, photovoltaic energy becomes a promising alternative source.
Among its advantages are that it is: 1) abundant; 2) pollution free; 3) distributed throughout the earth; and 4)
clean and noise-free source of electricity. The main drawbacks are that the initial installation cost is consid erably
high and the energy conversion efficiency is relatively low. To overcome these problems, the following two
essential ways can be used: 1) increase the efficiency of conversion for the solar array and 2) maximize the output
power from the solar array. In recent years, PV system has become one of the main ways to use solar energy. To
understand and analyze the performance of a grid connected PV system, simulation software of a grid connected
PV system is required. Grid –connected photovoltaic system is shown in fig.1.It includes a PV array, a voltage
source inverter (VSI), a control system, a distribution network, a load and a grid. The PV array consists of a
number of individual photovoltaic cells that are connected in series and parallel array to co nvert sunlight to
electricity by the use of the photovoltaic effect. The PV array produces the dc power, and hence power
electronics and control equipment points are required to convert dc to ac power. A voltage source inverter (VSI)
is used to convert dc
Fig 1: Grid-connected photovoltaic system
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2. Mppt And Simulation For A Grid-Connected Photovoltaic System…
power produced by PV array into ac power and this ac power is injected into the utility grid. The control system
consists of current control strategy and voltage control strategy. Current control strategy is used to achieve the
dc voltage regulation at dc link and unity power factor at grid and the voltage control strategy is applied to
achieve maximum power point tracking. Maximum power point tracking (MPPT) can effectively improve the solar
energy conversion efficiency of PV systems. In this paper, Perturb-and-observe (P&O) method is used to achieve
this function. This paper establishes a Dynamic model of grid - connected PV system by Matlab/Simulink with d-
and q-axis as coordinates which is synchronously rotating with the grid voltage to reflect the characteristics of
the system accurately. Based on the accurate modeling system, analyze the performance of PV systems for
different irradiations, maximum power point tracking and finally fault analysis is carried by creating a LLLG fault
in the distribution network and observe the ac voltage , ac current and ac power waveforms at the grid with and
without a LLLG fault.
2. Dynamic Model Of Grid-Connected
PHOTOVOLTAIC SYSTEM
A typical single-stage grid-connected PV system is shownin Fig.1. A PV array is connected to a
distribution network with a voltage source converter (VSC). In order to analysis and control conveniently, dq
components in d- and q-axis are presented.
2.1. Photovoltaic System Model
As reported in literature [6], PV arrays consist of series connected cells which are actually diodes, thus
the equivalent circuit is represented by a current source parallel to an ideal diode. The mathematical modeling of
PV arrays is given:
Where u dc is PV arrays voltage, n p and n s are the number of PV cells connected in parallel and in series
respectively, Iph is the photocurrent of a single solar module which is proportional to both illumination and
surface area, Irs is the saturation current of diode which is related to temperature, k is Boltzman constant (1.38e-23,
in Joules per Kelvin), q is electric charge (1.6e-19, in Coulombs), T is operating temperature, A is P-N junction
ideal factor. Rs is series resistance of the single solar module, and Irsh is the current flowing through the shunt
resistance. Ignoring the power absorbed by the inductance and the resistance of the VSC interface [9], the
dynamic equations of the PV system are:
Where C is dc-link capacitance, id and iq are the d- and q-axis currents on the converter side, u sd and u sq are d-
and q-axis components of VSC filtered voltage, L and R are resistance and inductance of the, md and mq are
control signal of VSC.
2.2. Distribution Network Model
According to Fig. 1, we can get the reference model of the
distribution network as follows:
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3. Mppt And Simulation For A Grid-Connected Photovoltaic System…
Where ig1d and ig1q are d- and q-axis components of the current between the VSC interface and the load, ig2d and
ig2q are d- and q-axis components of the current between the load and the grid, R1 and L1 are resistance and
inductance between the VSC interface and the load, R2 and L2 are resistance and inductance between the load
and the grid, u ld and u lq are d and q-axis components of load voltage, N is the transformer turns ratio, Cf is filter
capacitance, Cl is power-factor correction capacitance, and ω is the dq-system angular speed.
2.3. Load Model
The load model considered in this paper is a series R-L
circuit, it is shown as follows:
Where Rl and Ll are resistance and inductance of the load, ild and ilq are d- and q-axis components of the load
current.
3. Pv System Control
3.1. Current Control
In order to control the grid current, power, frequency and power factor efficiently, it is necessary to
transform the three-phase ac signals into proper dq-frame counterparts. Thus, the controllers process dc
equivalents rather than original sinusoidally-varying signals[8]. The block diagram of dq-frame current control is
shown in Fig. 2. The control inputs and are given as [5]:
By controlling the values md and mq in equations (3.1) & (3.2), id and iq rapidly track their respective reference
commands idref and iqref. And then active and reactive outputs of PV system are expressed as[5]:
From the above equations (3.3) & (3.4), Ps and Qs are controlled by controlling the id and iq . Control of the q-axis
current at 0 (i.e iq=0 then and power factor = unity. ) will enable power factor
unity.
Fig 2: dq-frame current control scheme
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4. Mppt And Simulation For A Grid-Connected Photovoltaic System…
3.2 Voltage Control
The purpose of voltage control is to make dc-link voltage track the voltage which corres ponds to the
maximum power
point. The dc –link voltage is given as
where c= capacitance of dc-link and ic=dc-link current
but
)
taking laplace transform on both sides
(s)
from[5],
Normally, the time constant T takes as 0.5ms.
where Gu(s) is a proportional-integral compensator=
Where, and are the proportion coefficient and integral coefficient, respectively.
Fig 3: DC-link voltage control scheme
Fig.3 shows block diagram of dc-link control scheme. MPPT track u dref (s) corresponding to maximum power. u dc (s)
compare with u dref(s) then error signal is given to a proportional-integral compensator. This proportional-integral
compensator set the idref (s). This idref(s) processed through current controller and set the id(s). The ipv(s)- id(s)
processed through an integrator and set u dc corresponding to u dref (s). In this way dc-link voltage is controlled.
The limiter protect PV system against external faults.
3.3 Maximum Power Point Tracking (MPPT)
D=Duty cycle & =Perturbation
Fig 4: Flow Chart for MPPT Algorithm
MPPT can effectively improve the solar energy conversion efficiency of PV systems. In this paper, Perturb -and-
observe (P&O) method is used to achieve this function [7]. P&O method first measures the voltage V(K) and
current I(K) then determine power (P(K) = V(K) * I(K)) .This current output power of the array P(K) compare with
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5. Mppt And Simulation For A Grid-Connected Photovoltaic System…
P(K-1), and then adds a small perturbation (ΔD) to the original output voltage, after that, compares the current
power with the original one. If the power increased, the original disturbance would be used, if the power
decreased, the original disturbance should be changed. The control is shown in Fig. 4. MPPT track u dref
corresponding to maximum power.
4. Matlab-Based Simulation and Results
4.1Simulation of PV System
In fig.6, PV array consists of six PV modules connected in series altogether generating 133V dc voltage.
Basically PV module can be implemented as voltage input type PV module or Current input type PV module. In
this paper Current input type PV module is implemented in simulink. The simulink model for single PV module is
shown in fig.5. PV module parameters are shown in tabular column 2.
Inputs to PV module • PV current Ipv [A]
• Insolation [W/m2]
Outputs • PV voltage Vpv [V]
• PV output power Ppv [W]
Table 1: Tabular column for current input PV module
Fig 5: Single PV Module Simulink Model
open-circuit voltage Voc (volts) 22.2
short-circuit current Isc (amps) 5.45
rated current IR at maximum power point 17.2
(MPP) (amps)
rated voltage VR at MPP (volts) 4.92
pn-junction reverses saturation current 2.615e-
(Io)(amps) 01
Irradiation to short circuit current gain (G) 0.00545
Cell Parallel Resistance (Rp) (Ω) 2.742
Cell Series Resistance (Rs) (Ω) 0.01309
Default no. of cells in Series (Ns) 36
Table 2: Tabular column for PV module parameters
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6. Mppt And Simulation For A Grid-Connected Photovoltaic System…
Fig 6: PV array simulink model
Fig 7: I-V Characteristics of PV array
Fig 8: P-V Characteristics of PV array
The I-V Characteristics and P-V Characteristics of PV array when the solar irradiation level is 1000W / m2 are
shown in fig.7 and fig.8 respectively. PV array generated voltage changes when solar irradiation level changes.
Fig.9 shows PV array generated voltage change when solar irradiation level changes from 500W/m2 to 1000W/m2.
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7. Mppt And Simulation For A Grid-Connected Photovoltaic System…
Fig 9: change in array voltage due to sudden increase in Irradiation
4.2 Simulation of Grid-Connected PV system and Fault Analysis
The simulation of grid-connected PV system contain various simulation blocks of PV array, voltage
source inverter, filter circuit, distribution network, load, utility grid, current controller, voltage controller, MPPT
and phase locked-loop(PLL). In this paper, PV array generates a voltage of 133V dc for a solar irradiance of
1000W/m2, it is observed from fig.10. This dc voltage is converted into ac voltage by a voltage source inverter; it
is controlled by space vector pulse width modulation. This ac voltage is step up to 622V(max) i.e. 440V(rms) by a
step up transformer as shown in fig.11(a) finally this ac voltage is injected into utility grid. The voltage, current
and power wave forms at grid without a fault in the distribution network are shown in fig.11, fig.12 and fig.14
respectively.
Fig 10: Voltage waveform on DC side of VSC
Fig 11: Voltage waveform at grid without fault
Fig 12: Current waveforms at grid without fault
Fig 14: Output power at grid supplied by PV systems without a fault
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8. Mppt And Simulation For A Grid-Connected Photovoltaic System…
4.2.1 Fault Analysis
A three phase to ground (symmetrical) fault is created on the grid side for the purpose of fault analysis
on the grid connected PV system, generally three phase faults are most severe faults on the power system.
Simulation diagram of grid-connected PV system with a LLLG fault is shown in fig.13. Here a LLLG fault is occur
in the distribution network connected between VSI and grid as shown in fig.13. The voltage and current
waveforms at grid during the fault are shown in fig.15(a) & 15(b) respectively. The voltage waveform does not
alter do to the fault because the grid maintained at constant voltage. The Current before initialize the fault
(<.06sec) is maintained at 60A(max) , when a fault is initialized at 0.06 sec the current raises to 225A(max) and
finally the current settles to its normal value of 60A(max) after the fault period(80msec).
Fig 13: simulation diagram of grid-connected PV system with a LLLG fault
Fig 15(a): Three phase voltages on Grid side for a three phase fault
Fig 15(b): Three phase currents on Grid side for a three phase fault
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9. Mppt And Simulation For A Grid-Connected Photovoltaic System…
Fig 16: Three phase currents on Grid side with circuit breaker
Fig 17: Output power at grid supplied by PV systems with circuit breaker
The PV system supplies power to the grid under normal operating conditions and inje cts high currents during
fault which cannot sustained by the grid. The circuit breaker placed before grid enable the PV system
incorporates under safe mode only and take care of itself under contingent situation( in this case LLLG fault).
The operation of circuit breaker results in the following current and power variations shown in fig.16 & fig.17.
5. Conclusion
In this paper, a grid-connected PV system based on MATLAB has been proposed. Based on the
accurate modeling system, maximum power point tracking (MPPT) and fault analysis are studied. The control
consists of a current control strategy and a voltage control strategy. The Current control strategy permits dc -link
voltage regulation and enables power factor control. Moreover, the current –control strategy significantly
decouples dynamics of the PV system from those of the distribution network and loads. Furthermore, it is
expected that the current control strategy renders the PV system protected against external faults. Voltage
control strategy can achieve the maximum power point tracking and maximization of the real power output of the
PV system. MATLAB/SIMULINK model of grid connected photovoltaic (PV) system is useful to understand and
master the performance of PV systems and also to optimizing th e design and lowering costs. It is also useful for
shorten development cycles as well as improve system reliability and efficiency.
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