逆变器串并联型微电网的一种本地主从协调控制策略

A local master-slave coordinated control strategy for series-parallel inverter microgrids

逆变器串并联型微电网吸收了传统并联型和串联型系统的优点,但其结构的复杂性给系统的控制策略设计带来了新的挑战。针对逆变器并联型和串联型微电网功率均分策略之间的矛盾,提出了一种基于虚拟阻抗技术的本地主从协调控制策略。该控制策略将每个微源串中靠近公共连接点(Point of Common Coupling, PCC)的微源设置为主控单元,其采用无通信的改进下垂控制实现微源串之间的同步和功率一致,其余串联微源在本地跟随主控单元运行,最终实现了全局的功率均分。全局无通信的设计提高了系统的可靠性和灵活性,降低了运行成本。仿真结果验证了所提方案的可行性和有效性。

Hybrid microgrids with series-connected and parallel-connected inverters incorporate the advantages of series inverter and parallel inverter systems,but their complex structures bring new challenges to the control strategy design of the systems.A local master-slave coordinated control scheme based on virtual impedance is proposed to solve the contradiction between parallel and series microgrid control strategies.The inverters near a PCC in each string are set as master control units,which adopt improved droop control without communication to realize synchronization and power equalization,and the other series inverters run with the master control units locally,finally achieving global power sharing.The global non-communication design improves the reliability and flexibility of the system and reduces the operating cost.Simulation results show the feasibility and effectiveness of the proposed scheme.