基于下垂控制的微电网孤岛-并网平滑切换策略

Strategy for Microgrid Island-connection Smooth Switching Based on Droop Control

微电网在并网模式与孤岛模式间切换运行时会产生较大的暂态振荡。为实现在两种运行模式间的平滑切换,分析了微电网在两种模式运行时采用的不同控制方法,设计了一种基于下垂控制的平滑切换策略。在MATLAB/Simulink平台上搭建了微电网模型。试验结果表明,所提策略能够把系统模式切换时出现的暂态振荡限制在合理范围内,有效减小了并网点处电压、电流和频率的波动,取得了较好的孤岛-并网双向平滑切换效果。

When the microgrid switches between grid connection mode and island mode,it will produce large transient oscillation.In order to realize the smooth switching between the two operation modes,the different control methods used by the microgrids in the two operation modes were analyzed,and a smooth switching strategy based on droop control was designed.A microgrid model was built on the MATLAB/Simulink platform.The test results show that the proposed strategy can limit the transient oscillation during the system mode switching to a reasonable range,effectively reduce the fluctuation of voltage,current and frequency at the grid connection point,and achieve a good island-connection bidirectional smooth switching effect.