An Improved VSG control strategy for Microgrid
Fangying Zhu, Zishun Peng, Wen Hu, Huan Wang, Chun Zhang, Zhenxing Zhao, Yuxing Dai
Abstract
New energy power generation system, droop control field and ship distributed system have been widely used the control strategy of virtual synchronous generator (VSG). However, the traditional VSG control strategy neglects power decoupling ability and inertia in the torque governor and excitation control. Therefore, the voltage and angular frequency of the distributed generators units (DGs) based on the traditional VSG control strategy are easily affected by the power fluctuations and high-frequency noises, and the adjustment of the power is also easily affected by the coupling of the DGs. To solve these problems, an improved VSG control strategy combing coupling compensation, improved torque governor and excitation control is proposed. Its coupling compensation can make the impact less by the uncontrollable power coupling. The improved torque governor and excitation control make the VSG control strategy have voltage inertia and angular frequency inertia,which can slow down the change ratio of the voltage and angular frequency, and the high-frequency noises from the DGs can also been effectively eliminated. The experimental results verify the effectiveness of the proposed improved VSG control strategy.