基于主从结构的微电网系统平滑切换控制策略

Control Strategy for Smooth Switching of Micro-grid System Based on Master-slave Structure

针对微电网系统模式切换不够快速、平滑等问题,若采用适当的控制措施便可实现并网模式和孤岛模式,以及两种模式的平滑切换。为此,建立主从结构的风光储微电网系统,分析主控逆变器结构及控制方法,总结出综合控制策略;再根据微电网切换过程中存在的问题改进了控制策略,并在MATLAB/Simulink上建立微电网动态模型,对原始综合控制策略和改进后的控制策略分别进行仿真分析。通过仿真结果对比可知,改进后的控制策略有效抑制了微电网母线电压的暂态震荡,保证了系统切换过程中电压幅值、相位和电流的平滑性。仿真结果验证了设计的控制策略的有效性和可行性。

In allusion to problems of micro-grid system mode being not fast and smooth in switching,it is suggested to adopt proper control measures to realize grid-connection mode and island mode,as well as smooth switching of these two modes.Therefore,hypothctic micro-grid system with wind power,photovoltaic power and stored energy is established,structure and control method of the main control inverter is analyzed and comprehensive control strategies are summarized.In allusion to existing problems in microgrid switching,control strategies are improved and dynamic model of micro-grid is established on MATLAB/Simulink platform to conduct simulation analysis on original comprehensive control strategies and improved control strategies.Simulation results indicate that improved control strategies could effectively constrain transient shock of bus voltage of the micro-grid and ensure smoothness of voltage amplitude,phase and current in process of system switching.Results also verify effectiveness and feasibility of designed control strategies.