含异构分布式电源的微电网无功功率分散分层控制策略

无功功率—电压下垂与电压—无功功率下垂是多逆变器孤岛微网系统中两种典型的分布式电源无功控制方式。针对含异构分布式电源的微电网,提出了无功功率的分散分层控制策略:①通过改进空载电压,能够在阻抗不匹配的情况下实现无功功率的合理分配,并将公共连接点(PCC)电压恢复至额定值;②基于不同时间尺度搭建分层结构,能够满足微网静态和动态性能的需求;③摆脱传统控制中通信的制约,实现分布式电源即插即用效果。最后,小信号分析、时域仿真以及RT-LAB硬件在环仿真实验验证了控制策略的可行性和有效性。

Decentralized and Hierarchical Reactive Power Control Strategy for Microgrid with Heterogeneous Distributed Generators

The reactive power-voltage droop and the voltage-reactive power droop are two typical reactive power control strategies of distributed generators in the multi-inverter paralleled islanded microgrid. A decentralized and hierarchical reactive power distribution control strategy for the microgrid with heterogeneous distributed generators is proposed, whose characteristics include: (1) by adjusting floating voltage, the reactive power distribution error caused by the mismatched feeder impedance can be reduced and the voltage regulation can be achieved; (2) hierarchical structure is built based on multi-time scale, and both fast dynamic and static characteristics of microgrid are satisfactory; (3) the constraint of communication system in the traditional control is relieved, and the plug-and-play effect of distributed generators is achieved. Finally, simulation results verify the feasibility and effectiveness of the control strategy.