Research on Seamless Transfer Strategy of Micro-Grid Based on Energy Storage

2013 ◽  
Vol 805-806 ◽  
pp. 1129-1135
Author(s):  
Qi Zhang ◽  
Zai Jun Wu ◽  
Xiao Bo Dou ◽  
Chun Jun Sun ◽  
Bo Zhao
Keyword(s):  
Energy Storage ◽  
Vital Role ◽  
Control Mode ◽  
Three Phase ◽  
Point Of Common Coupling ◽  
Micro Grid ◽  
Common Coupling ◽  
Voltage Control Mode ◽  
Seamless Transfer ◽  
And Control

Energy storage plays a vital role in the reliable operation of Micro-Grid (MG) due to its characteristic of running stabilization and control flexibility. It can act as the master inverter and maintain system voltage and frequency stability as MG in off-grid mode under voltage control mode. During the transfer of MG from grid-connected mode to off-grid mode, the PCC (point of common coupling) three-phase static switch cant shut off at the same time. Moreover it needs to match the MG voltage and utility grid voltage when the islanded MG needs to reconnect to the utility grid.In order to solve these problems, a control strategy of grid-connected/off-grid seamless transfer based on energy storage is proposed. Simulation was presented from a MG platform including photovoltaic (PV), wind turbine (WT) and energy storage and the result shows the feasibility of the proposed approach.

scholarly journals Design of a Proportional Resonant Controller with Resonant Harmonic Compensator and Fault Ride Trough Strategies for a Grid-Connected Photovoltaic System

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 451 ◽  
Author(s):  
Saif Islam ◽  
Kamran Zeb ◽  
Waqar Din ◽  
Imran Khan ◽  
Muhammad Ishfaq ◽  
...  
Keyword(s):  
Fault Location ◽  
Photovoltaic System ◽  
Pv System ◽  
Simulink Model ◽  
Fault Ride Through ◽  
Three Phase ◽  
Point Of Common Coupling ◽  
Switch Type ◽  
Resonant Controller ◽  
Common Coupling

This paper presents the design and analysis of a proportional resonant controller with a resonant harmonic compensator and switch-type fault current limiter, as a fault-ride through strategy for a three-phase, grid-connected photovoltaic (PV) system under normal conditions and asymmetrical faults. The switch-type fault limiter comprised of current-limiting inductors, a bridge rectifier, a snubber capacitor, linear transformers, and energy absorption bypass. Furthermore, a critical and analytical comparison of switch-type fault limiters is carried out, with the conventional crowbar as the fault-ride through strategy, in combination with a conventionally tuned proportional integrator controller. The designed fault-ride through strategies with proportional integrator and proportional resonant controllers with resonant harmonic compensators are tested at the point of common coupling of the photovoltaic system and at a distance of 19 km from the point of common coupling, in order to analyze the impacts of fault parameter with respect to location. A MATLAB/Simulink model of a 100 kW three-phase grid-connected photovoltaic system is used for analysis. The simulation results of the proposed switch-type fault limiter with proportional resonant controller effectively validate the stable, ripple-free, and robust response compared to all other configurations. In addition, it is also verified that the grid faults on the PV system have a significant impact on fault type, and less impact on fault location.

scholarly journals Admittance Reshaping Control Methods to Mitigate the Interactions between Inverters and Grid

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2457 ◽  
Author(s):  
Ling Yang ◽  
Yandong Chen ◽  
An Luo ◽  
Kunshan Huai
Keyword(s):  
Design Method ◽  
Harmonic Distortion ◽  
Response Speed ◽  
Control Methods ◽  
Dynamics Model ◽  
Specific Design ◽  
Three Phase ◽  
Point Of Common Coupling ◽  
Common Coupling ◽  
System Phase

With the increasing impedance coupling between inverters and grid caused by the phase-locked loop (PLL), traditional three-phase inverters suffer from the harmonic distortion or instability problems under weak grid conditions. Therefore, the admittance reshaping control methods are proposed to mitigate the interactions between inverters and grid. Firstly, a dynamics model of traditional inverter output admittance including main circuit and PLL is developed in the direct-quadrature (dq) frame. And the qq channel impedance of the inverter presents as a negative incremental resistance with the PLL effect. Secondly, two admittance reshaping control methods are proposed to improve the system damping. The first reshaping technique uses the feedforward point of common coupling (PCC) voltage to modify the inverter output admittance. The second reshaping technique adopts the active damping controller to reconstruct the PLL equivalent admittance. The proposed control methods not only increase the system phase margin, but also ensure the system dynamic response speed. And the total harmonic distortion of steady-state grid-connected current is reduced to less than 2%. Furthermore, a specific design method of control parameters is depicted. Finally, experimental results are provided to prove the validity of the proposed control methods.

scholarly journals SOLAR POWERED THREE PHASE MOTOR FOR VARIOUS APPLICATIONS

2013 ◽  
pp. 41-44
Author(s):  
MOHAN S ◽  
M. N. DINESH
Keyword(s):  
Electrical Power ◽  
Vital Role ◽  
Electrical Machine ◽  
Electrochemical Processes ◽  
Three Phase ◽  
Solar Powered ◽  
Machine Drives ◽  
And Control ◽  
Hardware Circuit ◽  
Operating Cycles

The Power electronics plays a vital role in the conversion and control of the electrical power for various applications such as heating & lightning control, electrochemical processes, DC & AC electrical machine drives, electrical welding, active power line filtering, static var compensator and many more.The main aim of the paper is to analyze and design of a current fed push pull DC-DC boost converter to integrate three phase electric motor through inverter. The regulated output which is obtained by the developed converter is fed to a typical load side inverter, and then to the various loads. To analyze the CFPP DC-DC converter in different operating cycles. The hardware circuit will be designed to test for the required output.Among the existing DC/DC converters, current-fed push-pull (CFPP) converter is a better option owing to its voltage boosting, isolation and compact characteristics.

scholarly journals Simulation on microgrid connected PV system under balance and unbalance fault

2019 ◽  
Vol 13 (3) ◽  
pp. 1332
Author(s):  
Ameerul A. J. Jeman ◽  
Naeem M. S. Hannoon ◽  
Nabil Hidayat ◽  
Mohamed M. H. Adam ◽  
Ismail Musirin ◽  
...  
Keyword(s):  
Photovoltaic System ◽  
Pv System ◽  
Matlab Simulink ◽  
Three Phase ◽  
Point Of Common Coupling ◽  
Simulation Results ◽  
Common Coupling ◽  
Types Of Faults ◽  
Three Phases

<p><span>This paper presents an analysis in Matlab/Simulink of a three-phase photovoltaic system under balance and unbalance faults in Matlab/Simulink. The aim of this paper is to investigate the performance of the system under various types of fault. The simulation involved various types of faults occurring at different distances from the point of common coupling of the PV system. This paper also aimed to identify what type of fault that may severely damage the system. The simulation results presented in this paper show that the three-phase fault in the microgrid was severely affecting the system since it involved all the three phases of the system while the distance of the fault occurrence is less influenced in the system. The purpose of this research is to observe the effect on the system based on the types of faults occur and the distance faults occur.</span></p>

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