基于VSG控制的微网逆变器工频振荡现象研究

分布式电源多采用电力电子变流器作为接口与电网进行能量交互,虚拟同步发电机控制技术因模拟传统同步机内外部性能优良的特点成为目前研究的热点.但电力电子装置因其动作快速性容易激发线路电感,其电流的瞬态过程会对系统产生不利影响.考虑线路电感的瞬变过程,建立系统输出功率的动态小信号模型,分析产生振荡的原因与系统输出阻抗有关.采用...

Power frequency oscillation of a microgrid inverter based on VSG control

Distributed generation mostly uses a power electronic converter as interface to interact with the power grid. Virtual synchronous generator (VSG) control technology has become a new scheme of inverter control because of its excellent internal and external performance in simulating a traditional synchronous generator. However, it is easy to excite the current transient process of the line inductance in fast-moving power electronic devices, and this will have adverse effects on the system. Considering the transient process of line inductance, a dynamic small signal model of system output power is established. From the model, the reason for oscillation is related to the output impedance of the system. In this paper, a new damping control strategy is adopted. By introducing virtual complex impedance into the voltage outer loop, the impedance characteristics of the system can be reshaped and the power oscillation can be suppressed. Both simulation and experiment verify the power frequency oscillation in VSG and the effectiveness of the proposed control strategy.This work is supported by the National Natural Science Foundation of China (No. 62076243).