基于改进下垂控制的多微网并联运行控制策略研究

Coordination Control for Multi⁃microgrid System with Parallel Structure Based on Improved Droop Control Strategy

多微网并联的电网系统结构复杂、连接方式多样,在并网、解列的过程中由于子微网之间的频率和电压偏差,会在平衡点产生较大的电动力,对系统产生冲击,影响系统的动态稳定。本文针对多微网并网、解列过程中控制精度和动态稳定的问题,基于长距离线路电压降落和电压相角偏移,提出了一种改进的下垂控制方法,减少了系统的电压震荡和频率波动。最后基于Matlab/Simulink建立仿真模型,仿真结果验证了改进控制策略的合理性和有效性。

Multi⁃microgrid system is complex in structure because of connecting in many different ways.In the process of connection or disconnection,due to the offset of voltage and frequency on bus,it will produce large electrodynamic force to system,which will decrease the stability.To solve the problem of the grid control accuracy and the frequency stabilization in such process,based on parallel structure of multi⁃micriogrid,considering the voltage drop and phase offset of long haul line,an improved method is proposed to optimize the droop control to reduce the fluctuate of voltage and frequency.The parallel structure simulation model is established on Matlab/Simulink,and the results verify the rationality and effectiveness of the improved control strategy.