Research on pre-synchronization control strategy of the micro-grid with multi-VSG

Abstract

Seamless switching is an important guarantee for the inverter to work continuously without stopping when grid-connected power generation system is the transient process from grid-connected to isolated island and from isolated island reclosing. Based on the principle of pre-synchronous operation of traditional synchronous generators, this paper analyzes the principle of pre-synchronous process and its effect on the steady-state of micro grid with multiple virtual synchronous generators. At the same time, the paper analyzes the transient influence of the closed pre-synchronous switch on the power distribution of the micro grid under different phase modes. This paper proposes a pre-synchronous control strategy based on phase recognition. MATLAB/Simulink simulation software is used to verify the correctness and validity of the proposed method. Keywords: Virtual synchronous generator(VSG), Power allocation, Pre-synchronization, Phase identification