基于改进功率环的微电网对等控制策略研究

摘要

基于传统下垂控制方法存在的不足,同时考虑减小微电网依赖于通信系统,使负荷和分布式电源能够即插即用.提出一种基于改进功率环的微电网对等控制策略.传统的下垂控制方法会造成系统频率和交流母线电压的偏差.针对该问题,引入电压补偿环节和频率补偿环节,构建改进的功率环反馈控制器.利用该控制策略对由2台同容量分布式电源构成的微电网进行仿真分析,并和采用传统下垂控制方法所得结果进行比较.此外.在并网/孤网切换模式和负荷投切模式下,分析该控制策略下的微电网运行特性,仿真结果表明了基于改进功率环的微电网对等控制策略能够有效降低系统频率和交流母线电压的偏差.%To overcome the defect of traditional droop control method,a peer to peer control strategy for microgrid based on improved power loop is proposed.The proposed strategy can also reduce dependency of microgrid on communication system and realize plug and play for distributed generators (DG) and loads.In order to solve bus voltage amplitude and frequency deviation problem caused by traditional droop control method,a compensation unit of voltage amplitude and frequency is introduced and an improved feedback controller of power loop is established.Taken a microgrid composed by two DGs with same capacity as example,simulation results using the traditional and proposed schemes are compared and analyzed.Microgrid operation characteristics are analyzed respectively in two operation modes:grid-connected/islanding operation switching mode and load switching mode.The simulation results indicate that proposed control strategy can reduce bus voltage amplitude and frequency deviation effectively.