基于改进下垂控制的微网协调控制策略

Micro-grid coordinated control strategy based on improved droop control

微源间的无功环流是由其输出电压幅值的差异引起的。在深入分析并联运行微源间输出电压幅值差异与无功功率出力分配偏差关系的基础上,将电压幅值反馈的控制策略引入到传统下垂控制中,降低微源间输出电压的幅值差,从而抑制无功环流的形成。仿真结果验证了该控制策略的可行性,同时仿真结果还表明该策略可以有效提高微网运行的稳定性。最后将该控制策略应用到并网过程中,仿真结果表明电压幅值反馈控制策略可以有效抑制并网过程中频率和电压的震荡。

Reactive circulation is determined by the output voltage amplitude difference between different micro-sources in the micro-grid. On the basis of in-depth analysis of the relationship of the output voltage amplitude difference and reactive power output deviation between parallel operation micro-sources, this paper introduces the feedforward amplitude of the voltage feedback control strategy into conventional droop control, to reduce the amplitude differences of the output voltage between the sources, thus to suppress the reactive power circulation. Simulation results show that the control strategy is feasible and can improve the stability of micro grid operation effectively. Finally simulation results show that the feedforward amplitude of the voltage feedback control strategy can effectively suppress the shock of frequency and voltage during grid synchronization.