基于多智能体系统的微电网分散协调控制策略

Multi-Agent System Based Decentralized Coordinated Control Strategy for Micro-grids

针对微电网在外界干扰情况下的动态稳定性问题,提出了基于多智能体系统的微电网分散协调控制策略。多智能体系统构建为两层,在下层智能体中,各分布式发电单元的分散控制设计为双环就地控制器,即由基于下垂特性的外环功率控制器和基于分数阶PID的内环电压电流控制器组成;在上层智能体中,微电网协调控制设计为H∞鲁棒控制器。构建了微电网电压稳定性评估指标,当微电网承受小干扰时,评估指标在安全域内,此时则仅依靠分散控制策略来维护系统的电压;而当有大干扰发生时,评估指标超出安全域,此时则起动协调控制,并与分散控制一起维护电压稳定。最后,仿真结果验证了控制策略的有效性。

For the dynamic stability of the micro-grid in the case of the outside disturbance,this paper proposes a decentralized coordinated control strategy for the micro-grid based on the multi-agent system. The multi-agent system has two levels. In the lower level agents,the decentralized control of the distributed power generation unit is designed as a double loop controller,including an outer power controller based on the droop characteristic and the fractional order PID inner voltage and current controllers. In the upper level agents,the coordinated controller of the micro-grid system is designed as the H∞robust controller. The mode of the coordinated controller is determined by the voltage stability, so this paper proposes the voltage stability risk index. When the micro-grid suffers slight disturbances,the voltage stability risk index is in the safety threshold,and the decentralized control is used to maintain the voltage stability of the system alone. When a severe disturbance occurs,the voltage stability risk index is out of the safety threshold, and the coordinated control starts and operates together with the decentralized control to maintain the voltage stability of the system. Finally,simulation studies demonstrate the effectiveness of the control scheme.