配电网中基于谐波虚拟阻抗的虚拟同步发电机控制策略

A Virtual Synchronous Generator Control Strategy Based on Harmonic Virtual Impedance in Distribution Network

随着配电网中分布式电源和电力电子设备的发展,系统的旋转备用容量和转动惯量降低,采用虚拟同步发电机(VSG)技术能够改善系统的稳定性。VSG一般采用电压源型控制,其对电能质量的控制能力有限。详细介绍了VSG接口的谐波虚拟阻抗设计,从离散时间域进行分析。结果表明,所提出的虚拟阻抗能够在弱电网情况下抑制谐波,并使得稳定裕度最大化。在MATLAB/Simulink中搭建相应的仿真模型,验证了本文所提出方法的有效性。

With the development of distributed generators and power electronic equipment in distribution network,the rotating reserve capacity and inertia of the system are reduced.Virtual synchronous generator(VSG)can improve the stability of the system.As VSG adopts voltage source control,its power quality control capability is limited.This paper introduced the design of harmonic virtual impedance in VSG and analyzed it in discrete time domain.The results show that the proposed virtual impedance can suppress harmonics and maximize the stability margin in the case of weak grid.The corresponding simulation model was built in MATLAB/Simulink to verify the effectiveness of the proposed method.