一种可抑制环流的微电网逆变器并联控制策略

A PARALLELING CONTROL STRATEGY OF MICROGRID INVERTERS TO RESTRAIN CIRCULATING CURRENT

以孤岛微电网中的多逆变器并联装置为研究对象,在分析系统环流产生机理的基础上,通过在电压电流环采用准比例谐振(PR)控制,并引入虚拟电阻,实现逆变器输出电压的无静差控制,并使得逆变器的总输出阻抗尽可能地由虚拟电阻决定;提出用恒定参考电压替代传统下垂控制的方法,并分析恒定参考电压配合虚拟电阻方法与传统下垂控制在原理上的一致性。所提方法能有效抑制系统环流,仿真和试验可验证其有效性。

For the parallel multi-inverters in island microgrid, based on the analysis of the mechanism of circulating current, the quasi proportional-resonant control is applied to realizezero steady-state error control of the inverter output voltage involtage and current control loop, and virtual resistance is also introduced to achieve that the total output impedance of inverter is determined by the virtual resistance as possible.The traditional droop control is replaced by the constant reference vohagecontrol, and the principle of the constant reference voltage with virtual resistance method is proved to be same as the principle of the traditional droop control. The proposed control strategy can restrain the circulating current, the effectiveness is verifiedby simulation and experiments.