光伏微电网反孤岛下垂控制研究

Research on Anti Islanding Droop Control of Photovoltaic Microgrid

光伏微电网并网/孤岛切换过程中,光伏微电网具有间歇性和不确定性。在这种控制模式下,如果微电网负荷功率的分配能力不足,将导致系统功率分配不能均分优化,电网频率波动偏差较大。在分析下垂控制策略的基础上,将虚拟阻抗技术引入下垂控制中,重构线路阻抗,可以有效提高微电网的功率共享效果,改善电能质量。仿真结果验证了该改进策略的有效性。

PV micro grid has intermittence and uncertainty in the process of grid connection/island switching,which is usually improved by traditional droop control.In this control mode,if the micro grid load power distribution capacity is insufficient,it will lead to the system power distribution can not be equally optimized,and the grid frequency fluctuation deviation is large.Based on the analysis of droop control strategy,virtual impedance technology is introduced into droop control to reconstruct line impedance,which can effectively improve the power sharing effect of microgrid and improve power quality.The simulation results verify the effectiveness of the improved strategy.