Improved virtual synchronous generator control strategy for the flexible interconnection system in distribution transformer areas

Abstract

• An improved virtual synchronous generator control strategy is proposed for the flexible interconnection system. • The DC side impedance small signal model is built. • The stability of the flexible interconnection system is analyzed mathematically. • The controller hardware-in-the-loop experiment is designed for verification. The flexible interconnection system (FIS) in the distribution transformer areas containing high-penetration distributed photovoltaics plays a significant role in balancing the load and improving new energy consumption. This paper proposes an improved virtual synchronous generator (VSG) control strategy for the FIS. Firstly, the impedance small signal model of the FIS is developed for analyzing the influence of the conventional VSG control strategy on the stability margin of the FIS in the case of bidirectional power flow. Then, the improved VSG control strategy is proposed based on the analysis, which can improve the stability of the FIS in the negative power direction. Finally, the controller hardware-in-loop experiments of the FIS verify the effectiveness of the proposed improved VSG control strategy.