Voltage sag ride-through control strategy with reactive power compensation for virtual synchronous generator

Abstract

In recent years, with the increasing number of distributed generators (DG), how to increase the stability of the power with the improvement of consumptive ability of new energy has become an important research issue. Virtual synchronous generator (VSG) is a control strategy, which can improve the friendliness of DGs by imitating the output characteristics of the traditional synchronous generators, for inverters. However, traditional VSG control strategy is not capable of suppressing overcurrent or providing reactive power during grid fault. An improved VSG control strategy with reactive power compensation for voltage sag fault is proposed in this paper. Firstly, a VSG model is established for behavior analysis during symmetrical voltage sag. Secondly, the overall and detailed control structure of improved VSG control is designed. Besides, the principle of control strategy and parameter setting are also given. Finally, the proposed control method are verified by Simulink simulation.