Brief description of solar PV system and study of Maximum Power point tracking techniques. Here two methods has been discussed - 1) Perturbation and observation 2) Incremental conductance.
Grid-Connected Pv-Fc Hybrid System Power Control Using Mppt And Boost ConverterIJERA Editor
This paper proposes a method for operating a grid connected hybrid system. This system composed of a Photovoltaic (PV) array and a Proton exchange membrane fuel cell (PEMFC) is considered. As the variations occur in temperature and irradiation during power delivery to load, Photo voltaic (PV) system becomes uncontrollable. In coordination with PEMFC, the hybrid system output power becomes controllable. Two operation modes are the unit-power control (UPC) mode and the feeder-flow control (FFC) mode, can be applied to the hybrid system. All MPPT methods follow the same goal that is maximizing the PV system output power by tracking the maximum power on every operating condition. Maximum power point tracking technique (Incremental conductance) for photovoltaic systems was introduced to maximize the produced energy. The coordination of two control modes, coordination of the PV array and the PEMFC in the hybrid system, and determination of reference parameters are presented. The proposed operating strategy systems with a flexible operation mode change always operate the PV array at maximum output power and the PEMFC in its high efficiency performance band. Also thus improving the performance of system operation, enhancing system stability, and reducing the number of operating mode changes.
Brief description of solar PV system and study of Maximum Power point tracking techniques. Here two methods has been discussed - 1) Perturbation and observation 2) Incremental conductance.
Grid-Connected Pv-Fc Hybrid System Power Control Using Mppt And Boost ConverterIJERA Editor
This paper proposes a method for operating a grid connected hybrid system. This system composed of a Photovoltaic (PV) array and a Proton exchange membrane fuel cell (PEMFC) is considered. As the variations occur in temperature and irradiation during power delivery to load, Photo voltaic (PV) system becomes uncontrollable. In coordination with PEMFC, the hybrid system output power becomes controllable. Two operation modes are the unit-power control (UPC) mode and the feeder-flow control (FFC) mode, can be applied to the hybrid system. All MPPT methods follow the same goal that is maximizing the PV system output power by tracking the maximum power on every operating condition. Maximum power point tracking technique (Incremental conductance) for photovoltaic systems was introduced to maximize the produced energy. The coordination of two control modes, coordination of the PV array and the PEMFC in the hybrid system, and determination of reference parameters are presented. The proposed operating strategy systems with a flexible operation mode change always operate the PV array at maximum output power and the PEMFC in its high efficiency performance band. Also thus improving the performance of system operation, enhancing system stability, and reducing the number of operating mode changes.
power management strategies for a grid-connected PV-FC Hybrid systemAsoka Technologies
This paper presents a method to operate a grid connected hybrid system. The hybrid system composed of a Photovoltaic (PV) array and a Proton exchange membrane fuel cell (PEMFC) is considered. The PV array normally uses a maximum power point tracking (MPPT) technique to continuously deliver the highest power to the load when variations in irradiation and temperature occur, which make it become an uncontrollable source. In coordination with PEMFC, the hybrid system output power becomes controllable. Two operation modes, the unit-power control (UPC) mode and the feeder-flow control (FFC) mode, can be applied to the hybrid system. The coordination of two control modes, the coordination of the PV array and the PEMFC in the hybrid system, and the determination of reference parameters are presented. The proposed operating strategy with a flexible operation mode change always operates the PV array at maximum output power and the PEMFC in its high efficiency performance band, thus improving the performance of system operation, enhancing system stability, and decreasing the number of operating mode changes.
Development of wind and solar based ac microgrid with power quality improveme...Asoka Technologies
This work proposes a microgrid (μ-grid) integrating wind and solar photovoltaic (PV) resources, along with the battery energy storage (BES) to the three phase grid feeding the nonlinear load. The μ-grid disconcerted by probabilistic nonlinear time dependent parameters and their effects are compensated by cohesive controllers used for utility grid side voltage source converter (GVSC) and machine side VSC (MVSC). The switching controls and the reconfigurability of the μ-grid are addressed on imperative aspects of improving power quality (PQ), power reliability, nonlinear load compensation and economic utilization of resources. The nonlinear load compensation and PQ enhancement are achieved by executing modified version of the adaptive filtering technique including “momentum” based least mean square (MLMS) control technique, utilized for providing the switching control signals to the GVSC. It utilizes two preceding gradient weights for obtaining updated weight thereby improving the convergence rate and overcoming the limitation of conventional control of the same family. The MVSC acquires its switching signals from conventional vector control scheme and the encoderless estimation of speed and rotor position of the synchronous generator (SG) driven by wind turbine through back electromotive force control technique. The external environmental disturbances are overcome by utilizing perturb and observe (P&O) maximum power point (MPP) for wind optimal power extraction and adaptive P&O with variable perturbation step size for solar MPP estimation. Test results are obtained from the laboratory prototype under steady state and dynamic conditions including altering wind speed, intermittent solar insolation and variable load conditions. The PQ issues are addressed and investigated successfully.
A Study of Shading Effect on Photovoltaic Modules with Proposed P&O Checking ...Yayah Zakaria
Sun irradiation levels and associated temperature changes are the main factors that influence the conversion of solar energy into electricity. Most energy is produced during a hot sunny day as the sun irradiation is at the maximum level and uniform throughout the solar photovoltaic (PV). However, most solar PV were frequently get shadowed, completely or partially, by the neighbouring buildings, trees and passing clouds. Consequently, the solar PV has lower voltage and current output, hence,
multiple maximum power points (MPP) are existed on the PV curve, which could cause confusion to the conventional Maximum Power Point Tracker (MPPT) to track the true MPP for the PV system. Thus, it is important to examine the impacts of partial shading on the solar PV in order to extract the maximum possible power. This paper presents a MATLAB-based modelling for simulation and experimental setup to study the I-V and P-V characteristics of a solar module under a non-uniform irradiation due to partial shading condition (PSC). Furthermore, this study is also proposed an effective method (a variable step size of P&O with checking algorithm) that is low cost and higher tracking efficiency. Thus, this study is essential in improving and evaluating any new MPPT algorithm under the PSC.
A simplified phase shift pwm-based feedforward distributed mppt method for gr...Asoka Technologies
The modularity and decreased filter size properties have made cascaded multilevel inverters (MLIs) more applicable than conventional two-level inverters, especially in high and medium power photovoltaic (PV) applications. However, partial shading of PV modules will affect negatively the output power of the unshaded modules. There are several existing solutions in the literature to address this challenge, however almost all of them suffer from complex implementations, low efficiency, and high cost. This paper presents a new simplified feedforward distributed maximum power point tracking (MPPT) method for three-phase grid-connected cascaded MLIs. The cascaded MLI provides a modular, and highly efficient single stage power conversion for PV systems. The proposed distributed MPPT method is depending on the phase-shift pulse width modulation (PSPWM) method with a simplified implementation. The proposed method is developing a feedforward signal that is proportional to the maximum power of the individual module. Then, the current controller, and the modulating signal are multiplied with the proportionality factor of the module maximum power. Furthermore, a modified modulation compensation method without using proportional-integral (PI) controllers is introduced to solve the problem of the unbalanced three-phase PV output currents that results from PV power mismatches and shading. A case study is implemented for 15 kW PV system to investigate the performance of the proposed method. In addition, comprehensive comparisons with the previous attempts in the literature are provided to verify the superior performance of the new proposed control method.
Design and Performance Analysis of Three-Phase Solar PV Integrated UPQCAsoka Technologies
This paper deals with the design and performance analysis of a three-phase single stage solar photovoltaic integrated unified power quality conditioner (PV-UPQC). The PV-UPQC consists of a shunt and series connected voltage compensators connected back to back with common DC-link.The shunt compensator performs the dual function of extracting power from PV array apart from compensating for load current harmonics. An improved synchronous reference frame control based on moving average filter is used for extraction of load active current component for improved performance of the PVUPQC. The series compensator compensates for the grid side power quality problems such as grid voltage sags/swells. The compensator injects voltage in-phase/out of phase with point of common coupling (PCC) voltage during sag and swell conditions respectively. The proposed system combines both the benefits of clean energy generation along with improving power quality. The steady state and dynamic performance of the system are evaluated by simulating in Matlab-Simulink under a nonlinear load. The system performance is then verified using a scaled down laboratory prototype under a number of disturbances such as load unbalancing, PCC voltage sags/swells and irradiation variation.
Novel High Performance Stand Alone Solar PV System with High Gain, High Effic...Asoka Technologies
This paper proposes a novel 3- stand-alone solar PV system configuration that uses high gain, high efficiency (96%) dc-dc converters both in the forward power stage as well as the bidirectional battery interface. The high voltage gain converters enable the use of low voltage PV and battery sources. This results in minimization of partial shading and parasitic capacitance effects on the PV source. Series connection of a large number of battery modules is obviated, preventing the overcharging and deep discharging issues that reduce the battery life. Also, the proposed configuration facilitates "required power tracking (RPT)" of the PV source as per the load requirements eliminating the use of expensive and 'difficult to manage' dump loads. High performance inverter operation is achieved through abc to dq reference frame transformation, which helps in generating precise information about the load's active power component for RPT, regulation of ac output voltage and minimization of control complexity. Inverter output voltage is regulated by controlling the modulation index of sinusoidal pulse width modulation, resulting in a stable and reliable system operation. The active power demand is controlled by regulating the dc link voltage. All the analytical, simulation and experimental results of this work are presented.
A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV S...Asoka Technologies
Due to the still increasing penetration of grid connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control to achieve the power reserve. In this method, the solar irradiance and temperature measurements that have been used in conventional power reserve control schemes to estimate the available PV power are not required, and thereby being a sensorless approach with reduced cost. Experimental tests have been performed on a 3-kW two-stage single-phase grid-connected PV system, where the power reserve control is achieved upon demands.
An Improved Constant Voltage Based MPPT Technique for PMDC MotorIAES-IJPEDS
Stand-alone photovoltaic (SAPV) systems are being used in remote areas
and are being seen as one of the promising solution in this regard. The SAPV
system as presented in the paper consists of solar PV panel, a DC-DC
converter, a controller and a PMDC motor. The current-voltage and powervoltage
characteristics being nonlinear, the SAPV system require maximum
power point techniques (MPPT) control techniques to extract maximum
power available from the PV cell. A voltage based MPPT technique which is
capable of tracking MPP has been selected because of numerous advantages
it offers such as: simple and low cost of implementation. The limitation of
constant voltage method is that its efficiency is low as the PV panel has to be
disconnected from the load for measurement of the open circuit voltage
(Voc). In the presented paper, the authors have removed this limitation by
using a pilot PV panel for measurement of Voc. A proportional-integrator (PI)
based controller is used in implementation of constant voltage MPP
technique and the modeling is done in MATLAB®/SIMULINK simulation
environment. The simulation results are presented and discussed in the paper,
the results shows that the efficiency of the system has increased.
A Unified Control and Power Management Scheme for PV-Battery-Based Hybrid Mic...Asoka Technologies
Battery storage is usually employed in Photovoltaic (PV) system to mitigate the power fluctuations due to the characteristics of PV panels and solar irradiance. Control schemes for PV-battery systems must be able to stabilize the bus voltages as well as to control the power flows flexibly. This paper proposes a comprehensive control and power management system (CAPMS) for PV-battery-based hybrid microgrids with both AC and DC buses, for both grid-connected and islanded modes. The proposed CAPMS is successful in regulating the DC and AC bus voltages and frequency stably, controlling the voltage and power of each unit flexibly, and balancing the power flows in the systems automatically under different operating circumstances, regardless of disturbances from switching operating modes, fluctuations of irradiance and temperature, and change of loads. Both simulation and experimental case studies are carried out to verify the performance of the proposed method.
Control strategy for power flow management in a pv system supplying dc loadsAsoka Technologies
The growing concern for energy saving has increased the usage of LED-based street lights, electronic chokes, compact fluorescent lamps, and inverter-fed drives. Hence, the load profile seen by the electrical grid is undergoing a notable change as these devices have to operate from a dc source. Photovoltaics (PV) being a major energy source, the aforementioned loads can be connected directly to the dc bus. A grid-connected PV system involves a power source (PV array), a power sink (load), and two power sources/sink (utility and battery), and hence, a power
flow management system is required to balance the power flow among these sources. One such system is developed for selecting the operating mode of the bidirectional converter by sensing the battery voltage. The viability of the scheme has been ascertained by performing experimental studies on a laboratory prototype. The control strategy is digitally implemented on an Altera Cyclone II Field Programmable Gate Array (FPGA) board, and the algorithm is verified for different modes of operation by varying the load. Experimental results are presented to bring out
the usefulness of the control strategy.
Energy management System(EMS) based fuzzy logic controller of hybrid system (...Binod kafle
Renewable energy systems (RES) are being widely accepted as an alternative to standard conventional energy sources due to depletion of natural resources and their consequential environmental impact. One of the increasing uses of stand-alone RES is in powering the remote areas where grid power is significantly expensive due to transportation. However, the energy management of such systems is quite complex. This paper deals with fuzzy logic-based controller design for power management of a stand-alone hybrid renewable energy systems (HRES). The proposed intelligent energy management aims to minimise the operation cost and the environmental impact of a microgrid while significantly improving the economic and technical performance of power supply. The proposed fuzzy logic controller (FLC) ensures the power management between renewable energy generation, energy storage, and load. The simulation results clearly show that the controller demonstrated high performance under various load and generation conditions.
The energy consumption of urban railway stations is very large and ever increasing. To reduce the national electrical grid consumption, the first step is optimizing the equipment size and the second step is adding other available electrical sources like the train residual braking energy. Many of local energies productions use Direct Current (DC. The actual internal station grid is in Alternative Current (AC) but the majority of the equipment has an AC/DC converter to be supplied in DC. This paper describes the project led by Efficacity Institute, which addresses the use of additional existing energies and to develop a more adapted station grid to reducing the daily energy consumption peak. One Efficacity energetic concept aims to store the braking energy of the trains with a stationary electrical saving system. This energy is integrated to the power supply of a railway station thanks to a micro grid. First step of this micro grid are studied in this paper to develop the more adapted grid structure
Power Management in PV-Battery-Hydro Based Standalone MicrogridAsoka Technologies
This paper proposes a high-efficiency two stage three-level grid-connected photovoltaic inverter. This work deals with the frequency regulation, voltage regulation, power management and load levelling of solar photovoltaic (PV)-battery-hydro based microgrid (MG). In this MG, the battery capacity is reduced as compared to a system, where the battery is directly connected to the DC bus of the voltage source converter (VSC). A bidirectional DC–DC converter connects the battery to the DC bus and it controls the charging and discharging current of the battery. It also regulates the DC bus voltage of VSC, frequency and voltage of MG. The proposed system manages the power flow of different sources like hydro and solar PV array. However, the load levelling is managed through the battery. The battery with VSC absorbs the sudden load changes, resulting in rapid regulation of DC link voltage, frequency and voltage of MG. Therefore, the system voltage and frequency regulation allows the active power balance along with the auxiliary services such as reactive power support, source current harmonics mitigation and voltage harmonics reduction at the point of common interconnection. The experimental results under various steady state and dynamic conditions, exhibit the excellent performance of the proposed system and validate the design and control of proposed MG.
power management strategies for a grid-connected PV-FC Hybrid systemAsoka Technologies
This paper presents a method to operate a grid connected hybrid system. The hybrid system composed of a Photovoltaic (PV) array and a Proton exchange membrane fuel cell (PEMFC) is considered. The PV array normally uses a maximum power point tracking (MPPT) technique to continuously deliver the highest power to the load when variations in irradiation and temperature occur, which make it become an uncontrollable source. In coordination with PEMFC, the hybrid system output power becomes controllable. Two operation modes, the unit-power control (UPC) mode and the feeder-flow control (FFC) mode, can be applied to the hybrid system. The coordination of two control modes, the coordination of the PV array and the PEMFC in the hybrid system, and the determination of reference parameters are presented. The proposed operating strategy with a flexible operation mode change always operates the PV array at maximum output power and the PEMFC in its high efficiency performance band, thus improving the performance of system operation, enhancing system stability, and decreasing the number of operating mode changes.
Development of wind and solar based ac microgrid with power quality improveme...Asoka Technologies
This work proposes a microgrid (μ-grid) integrating wind and solar photovoltaic (PV) resources, along with the battery energy storage (BES) to the three phase grid feeding the nonlinear load. The μ-grid disconcerted by probabilistic nonlinear time dependent parameters and their effects are compensated by cohesive controllers used for utility grid side voltage source converter (GVSC) and machine side VSC (MVSC). The switching controls and the reconfigurability of the μ-grid are addressed on imperative aspects of improving power quality (PQ), power reliability, nonlinear load compensation and economic utilization of resources. The nonlinear load compensation and PQ enhancement are achieved by executing modified version of the adaptive filtering technique including “momentum” based least mean square (MLMS) control technique, utilized for providing the switching control signals to the GVSC. It utilizes two preceding gradient weights for obtaining updated weight thereby improving the convergence rate and overcoming the limitation of conventional control of the same family. The MVSC acquires its switching signals from conventional vector control scheme and the encoderless estimation of speed and rotor position of the synchronous generator (SG) driven by wind turbine through back electromotive force control technique. The external environmental disturbances are overcome by utilizing perturb and observe (P&O) maximum power point (MPP) for wind optimal power extraction and adaptive P&O with variable perturbation step size for solar MPP estimation. Test results are obtained from the laboratory prototype under steady state and dynamic conditions including altering wind speed, intermittent solar insolation and variable load conditions. The PQ issues are addressed and investigated successfully.
A Study of Shading Effect on Photovoltaic Modules with Proposed P&O Checking ...Yayah Zakaria
Sun irradiation levels and associated temperature changes are the main factors that influence the conversion of solar energy into electricity. Most energy is produced during a hot sunny day as the sun irradiation is at the maximum level and uniform throughout the solar photovoltaic (PV). However, most solar PV were frequently get shadowed, completely or partially, by the neighbouring buildings, trees and passing clouds. Consequently, the solar PV has lower voltage and current output, hence,
multiple maximum power points (MPP) are existed on the PV curve, which could cause confusion to the conventional Maximum Power Point Tracker (MPPT) to track the true MPP for the PV system. Thus, it is important to examine the impacts of partial shading on the solar PV in order to extract the maximum possible power. This paper presents a MATLAB-based modelling for simulation and experimental setup to study the I-V and P-V characteristics of a solar module under a non-uniform irradiation due to partial shading condition (PSC). Furthermore, this study is also proposed an effective method (a variable step size of P&O with checking algorithm) that is low cost and higher tracking efficiency. Thus, this study is essential in improving and evaluating any new MPPT algorithm under the PSC.
A simplified phase shift pwm-based feedforward distributed mppt method for gr...Asoka Technologies
The modularity and decreased filter size properties have made cascaded multilevel inverters (MLIs) more applicable than conventional two-level inverters, especially in high and medium power photovoltaic (PV) applications. However, partial shading of PV modules will affect negatively the output power of the unshaded modules. There are several existing solutions in the literature to address this challenge, however almost all of them suffer from complex implementations, low efficiency, and high cost. This paper presents a new simplified feedforward distributed maximum power point tracking (MPPT) method for three-phase grid-connected cascaded MLIs. The cascaded MLI provides a modular, and highly efficient single stage power conversion for PV systems. The proposed distributed MPPT method is depending on the phase-shift pulse width modulation (PSPWM) method with a simplified implementation. The proposed method is developing a feedforward signal that is proportional to the maximum power of the individual module. Then, the current controller, and the modulating signal are multiplied with the proportionality factor of the module maximum power. Furthermore, a modified modulation compensation method without using proportional-integral (PI) controllers is introduced to solve the problem of the unbalanced three-phase PV output currents that results from PV power mismatches and shading. A case study is implemented for 15 kW PV system to investigate the performance of the proposed method. In addition, comprehensive comparisons with the previous attempts in the literature are provided to verify the superior performance of the new proposed control method.
Design and Performance Analysis of Three-Phase Solar PV Integrated UPQCAsoka Technologies
This paper deals with the design and performance analysis of a three-phase single stage solar photovoltaic integrated unified power quality conditioner (PV-UPQC). The PV-UPQC consists of a shunt and series connected voltage compensators connected back to back with common DC-link.The shunt compensator performs the dual function of extracting power from PV array apart from compensating for load current harmonics. An improved synchronous reference frame control based on moving average filter is used for extraction of load active current component for improved performance of the PVUPQC. The series compensator compensates for the grid side power quality problems such as grid voltage sags/swells. The compensator injects voltage in-phase/out of phase with point of common coupling (PCC) voltage during sag and swell conditions respectively. The proposed system combines both the benefits of clean energy generation along with improving power quality. The steady state and dynamic performance of the system are evaluated by simulating in Matlab-Simulink under a nonlinear load. The system performance is then verified using a scaled down laboratory prototype under a number of disturbances such as load unbalancing, PCC voltage sags/swells and irradiation variation.
Novel High Performance Stand Alone Solar PV System with High Gain, High Effic...Asoka Technologies
This paper proposes a novel 3- stand-alone solar PV system configuration that uses high gain, high efficiency (96%) dc-dc converters both in the forward power stage as well as the bidirectional battery interface. The high voltage gain converters enable the use of low voltage PV and battery sources. This results in minimization of partial shading and parasitic capacitance effects on the PV source. Series connection of a large number of battery modules is obviated, preventing the overcharging and deep discharging issues that reduce the battery life. Also, the proposed configuration facilitates "required power tracking (RPT)" of the PV source as per the load requirements eliminating the use of expensive and 'difficult to manage' dump loads. High performance inverter operation is achieved through abc to dq reference frame transformation, which helps in generating precise information about the load's active power component for RPT, regulation of ac output voltage and minimization of control complexity. Inverter output voltage is regulated by controlling the modulation index of sinusoidal pulse width modulation, resulting in a stable and reliable system operation. The active power demand is controlled by regulating the dc link voltage. All the analytical, simulation and experimental results of this work are presented.
A Sensorless Power Reserve Control Strategy for Two-Stage Grid-Connected PV S...Asoka Technologies
Due to the still increasing penetration of grid connected Photovoltaic (PV) systems, advanced active power control functionalities have been introduced in grid regulations. A power reserve control, where namely the active power from the PV panels is reserved during operation, is required for grid support. In this paper, a cost-effective solution to realize the power reserve for two-stage grid-connected PV systems is proposed. The proposed solution routinely employs a Maximum Power Point Tracking (MPPT) control to estimate the available PV power and a Constant Power Generation (CPG) control to achieve the power reserve. In this method, the solar irradiance and temperature measurements that have been used in conventional power reserve control schemes to estimate the available PV power are not required, and thereby being a sensorless approach with reduced cost. Experimental tests have been performed on a 3-kW two-stage single-phase grid-connected PV system, where the power reserve control is achieved upon demands.
An Improved Constant Voltage Based MPPT Technique for PMDC MotorIAES-IJPEDS
Stand-alone photovoltaic (SAPV) systems are being used in remote areas
and are being seen as one of the promising solution in this regard. The SAPV
system as presented in the paper consists of solar PV panel, a DC-DC
converter, a controller and a PMDC motor. The current-voltage and powervoltage
characteristics being nonlinear, the SAPV system require maximum
power point techniques (MPPT) control techniques to extract maximum
power available from the PV cell. A voltage based MPPT technique which is
capable of tracking MPP has been selected because of numerous advantages
it offers such as: simple and low cost of implementation. The limitation of
constant voltage method is that its efficiency is low as the PV panel has to be
disconnected from the load for measurement of the open circuit voltage
(Voc). In the presented paper, the authors have removed this limitation by
using a pilot PV panel for measurement of Voc. A proportional-integrator (PI)
based controller is used in implementation of constant voltage MPP
technique and the modeling is done in MATLAB®/SIMULINK simulation
environment. The simulation results are presented and discussed in the paper,
the results shows that the efficiency of the system has increased.
A Unified Control and Power Management Scheme for PV-Battery-Based Hybrid Mic...Asoka Technologies
Battery storage is usually employed in Photovoltaic (PV) system to mitigate the power fluctuations due to the characteristics of PV panels and solar irradiance. Control schemes for PV-battery systems must be able to stabilize the bus voltages as well as to control the power flows flexibly. This paper proposes a comprehensive control and power management system (CAPMS) for PV-battery-based hybrid microgrids with both AC and DC buses, for both grid-connected and islanded modes. The proposed CAPMS is successful in regulating the DC and AC bus voltages and frequency stably, controlling the voltage and power of each unit flexibly, and balancing the power flows in the systems automatically under different operating circumstances, regardless of disturbances from switching operating modes, fluctuations of irradiance and temperature, and change of loads. Both simulation and experimental case studies are carried out to verify the performance of the proposed method.
Control strategy for power flow management in a pv system supplying dc loadsAsoka Technologies
The growing concern for energy saving has increased the usage of LED-based street lights, electronic chokes, compact fluorescent lamps, and inverter-fed drives. Hence, the load profile seen by the electrical grid is undergoing a notable change as these devices have to operate from a dc source. Photovoltaics (PV) being a major energy source, the aforementioned loads can be connected directly to the dc bus. A grid-connected PV system involves a power source (PV array), a power sink (load), and two power sources/sink (utility and battery), and hence, a power
flow management system is required to balance the power flow among these sources. One such system is developed for selecting the operating mode of the bidirectional converter by sensing the battery voltage. The viability of the scheme has been ascertained by performing experimental studies on a laboratory prototype. The control strategy is digitally implemented on an Altera Cyclone II Field Programmable Gate Array (FPGA) board, and the algorithm is verified for different modes of operation by varying the load. Experimental results are presented to bring out
the usefulness of the control strategy.
Energy management System(EMS) based fuzzy logic controller of hybrid system (...Binod kafle
Renewable energy systems (RES) are being widely accepted as an alternative to standard conventional energy sources due to depletion of natural resources and their consequential environmental impact. One of the increasing uses of stand-alone RES is in powering the remote areas where grid power is significantly expensive due to transportation. However, the energy management of such systems is quite complex. This paper deals with fuzzy logic-based controller design for power management of a stand-alone hybrid renewable energy systems (HRES). The proposed intelligent energy management aims to minimise the operation cost and the environmental impact of a microgrid while significantly improving the economic and technical performance of power supply. The proposed fuzzy logic controller (FLC) ensures the power management between renewable energy generation, energy storage, and load. The simulation results clearly show that the controller demonstrated high performance under various load and generation conditions.
The energy consumption of urban railway stations is very large and ever increasing. To reduce the national electrical grid consumption, the first step is optimizing the equipment size and the second step is adding other available electrical sources like the train residual braking energy. Many of local energies productions use Direct Current (DC. The actual internal station grid is in Alternative Current (AC) but the majority of the equipment has an AC/DC converter to be supplied in DC. This paper describes the project led by Efficacity Institute, which addresses the use of additional existing energies and to develop a more adapted station grid to reducing the daily energy consumption peak. One Efficacity energetic concept aims to store the braking energy of the trains with a stationary electrical saving system. This energy is integrated to the power supply of a railway station thanks to a micro grid. First step of this micro grid are studied in this paper to develop the more adapted grid structure
Power Management in PV-Battery-Hydro Based Standalone MicrogridAsoka Technologies
This paper proposes a high-efficiency two stage three-level grid-connected photovoltaic inverter. This work deals with the frequency regulation, voltage regulation, power management and load levelling of solar photovoltaic (PV)-battery-hydro based microgrid (MG). In this MG, the battery capacity is reduced as compared to a system, where the battery is directly connected to the DC bus of the voltage source converter (VSC). A bidirectional DC–DC converter connects the battery to the DC bus and it controls the charging and discharging current of the battery. It also regulates the DC bus voltage of VSC, frequency and voltage of MG. The proposed system manages the power flow of different sources like hydro and solar PV array. However, the load levelling is managed through the battery. The battery with VSC absorbs the sudden load changes, resulting in rapid regulation of DC link voltage, frequency and voltage of MG. Therefore, the system voltage and frequency regulation allows the active power balance along with the auxiliary services such as reactive power support, source current harmonics mitigation and voltage harmonics reduction at the point of common interconnection. The experimental results under various steady state and dynamic conditions, exhibit the excellent performance of the proposed system and validate the design and control of proposed MG.
Ho Chi Minh ville dont le nom précédent est Sai gon, est un centre commercial, financière, culturel et touristique du Vietnam. Cette métropole active est une contradiction de "son homologue" au Nord, elle est noir des vélos et des motocyclettes, elle est passionnante par de nombreuse boutique et des cafés sur le trottoir.
Temps libres pour vous reposer après un long vol. Nuit à l’hôtel à HCMV.
La aplicación de la nueva estructura de tarifas de agua establecida por Emasa desde el pasado 1 de noviembre supone una disminución o no genera cambios en el importe final de la factura para el 72 por ciento de los ciudadanos.
The electric power supplied by a photovoltaic power generation system depends on the solar radiation and temperature. Designing efficient PV systems heavily emphasizes to track the maximum power operating point.
This work develops a three-point weight comparison method that avoids the oscillation problem of the perturbation and observation algorithm which is often employed to track the maximum power point. Furthermore, a low cost control unit is developed, based on a single chip to adjust the output voltage of the solar cell array.
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.
A Survey on the Performance of the Various MPPT Techniques of Standalone PV G...IJSRD
Maximum Power Point Tracking (MPPT) controller is very important part of the solar generation system. This paper presents the basic need and the various methods and techniques of maximum power tracking (MPPT) control. Every technique of MPPT control is evaluated based on its ability to detect multiple maxima, efficiency of the output solar power, cost and way of implementation, rate of convergence etc. the Perturbation and Observation technique and Incremental conductance Technique are widely used in MPPT control due to their advantages.
Implementation Of A High-Efficiency, High-Lifetime, And Low-Cost Converter Us...irjes
This paper proposes a new converter for photovoltaic water pumping and treatment systems without
the use of storage elements. The converter is designed to drive a three-phase induction motor directly from PV
solar energy. The use of this motor has the objective of presenting a better solution to the standard DC motor
water pumping system. The development is oriented to achieve a commercially viable solution and a market
friendly product. The converter topology is based on a Resonant Two Inductor Boost converter and a Threephase
Voltage Source inverter achieving 90% efficiency at a rated power of 210W.
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.
Inverter Design using PV System Boost ConverterIJMTST Journal
Many types of renewable energy, such as photovoltaic (PV), wind, tidal, and geothermal energy, have attracted a lot of attention over the past decade. Among these natural resources, the PV energy is a main and appropriate renewable energy for low-voltage dc-distribution systems, owing to the merits of clean, quiet, pollution free, and abundant. In the dc-distribution applications, a power system, including renewable distributed generators (DGS), dc loads (lighting, air conditioner, and electric vehicle), and a bidirectional inverter, is shown in fig. 1,in which two PV arrays with two maximum power point trackers (MPPTS) are implemented. However, the I–V characteristics of the PV arrays are nonlinear, and they require MPPTS to draw the maximum power from each PV array. Moreover, the bidirectional inverter has to fulfill grid connection (sell power) and rectification (buy power)with power-factor correction (PFC) to control the power flow between dc bus and ac grid,and to regulate the dc bus to a certain range of voltages, such as 380± 10 v.
Drive Applications of Fuzzy Logic Controlled Interleaved Boost Converter for ...EECJOURNAL
The improvement in the efficiency, a reduced ripple and reduction in the passive elements is proposed in this project through the interleaved boost converter. The interleaved boost converter operates multiple phase approach, is used for the power factor control applications. The proposed converter is used to extract the power output from the solar panel with reduced ripple losses and greater efficiency thereby obtaining the maximum power from the solar panel. The control of the current with energy saving method is obtained with the efficiency of 95%. The converter operation is controlled by the fuzzy logic controller to operate the switches with the finest and reduced power loss constrains. The proposed method is mathematically modeled and the results are analysed. A similar prototype model is designed and the results are compared with the theoretical values.
Grid Connected Solar Photovoltaic Array with MPPT Matlab Simulationijtsrd
Now a days, due to the problem of generation of electricity and consumption required is not sufficient so, solar generation system is essential. Nowadays, with generates electricity to match the required demand. So this paper is important. Here using, 1 Soltech 1STH 215 P solar panel in SIMULINK. In this paper we are control the renewable energy based solar photovoltaic system using MATLAB. The grid connected MATLAB model is studied under solar radiation and changing weather condition. In this we generate excess amount of electricity and send to the utility grid. Here we used MPPT technique which is implemented in DC DC step up converter to permit P V module to give power at maximum power point. The output of this converter is given to the 3 level inverter and it synchronized the utility grid. Payal Ganvir | Radharaman Shaha ""Grid Connected Solar Photovoltaic Array with MPPT Matlab Simulation"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-4 , June 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23832.pdf
Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/23832/grid-connected-solar-photovoltaic-array-with-mppt-matlab-simulation/payal-ganvir
here dc-dc boost converter designed in MATLAB Simulink and MPPT controller designed in 2 methods(P&O and incremental conductance).
finally, I connect it to Ac grid via the Dc-Ac converter.
this entire system called grid-connected PV system.
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Design, analysis, and implementation of solar power optimizer for dc distribution system
1. DESIGN, ANALYSIS, AND IMPLEMENTATION OF SOLAR POWER
OPTIMIZER FOR DC DISTRIBUTION SYSTEM
ABSTRACT:
This paper proposes a high step-up solar power optimizer (SPO) that efficiently harvests maximum energy
from a photovoltaic (PV) panel then outputs energy to a dc-microgrid. Its structure integrates coupled
inductor and switched capacitor technologies to realize high step-up voltage gain. The leakage inductance
energy of the coupled inductor can be recycled to reduce voltage stress and power losses. A low voltage
rating and low-conduction resistance switch improves system efficiency by employing the incremental
conductance method for the maximum power point tracking (MPPT) algorithm. Because of its high tracking
accuracy, the method is widely used in the energy harvesting of PV systems. laboratory prototypes of the
proposed SPO that have an input voltage range of 20 to 40 V and a maximum PV output power of 400
V/300 W are applied. The highest PV power conversion efficiency is 96.7%. The maximum MPPT accuracy
is 99.9%, and the full load average MPPT accuracy is 97.8%.