功率信息交互下单相逆变器并联控制

Parallel Control of Single-Phase Inverters Based on Power Information Exchange

针对逆变器并联系统馈线阻抗失配引起的环流问题,通过分析传统阻性下垂的局限性,提出一种基于功率信息交互的改进下垂控制.通过通信中心交互的平均功率信息,自适应调节有功下垂系数和所加虚拟阻抗,同时引入公共电压补偿项改善下垂机制引起的电压跌落问题.对所提方案改进并联系统功率均分性能的机理进行分析,并通过两台逆变器组成的并联系统实验平台进行验证.结果表明:所提策略能够有效减小馈线阻抗失配时并联系统的环流,提高功率均分精度.

Aiming at the circulating current problem caused by feeder impedance mismatch of the parallelled inverters,this paper analyzes the limitations of the traditional resistive droop method,and proposes an improved droop control based on power information exchanges.The active droop coefficient and added virtual impedance are adaptively adjusted through the average power information exchanged by the communication center.At the same time,the common voltage compensation term is introduced to improve the voltage drop caused by the droop mechanism.The mechanism of improving the power sharing performance of parallel system is analyzed,and the proposed scheme is verified by the parallel system experimental platform composed of two inverters.The results show that the proposed strategy can effectively reduce the circulating current and improve the power sharing accuracy of the parallel system under mismatch of feeder impedances.