A low voltage ride-through approach for virtual synchronous machines under asymmetric fault conditions

Abstract With the advancement of renewable energy generation technologies, virtual synchronous machine (VSG) technology has garnered significant attention for enhancing power system stability. However, under asymmetric grid faults, the operational stability of VSMs under low voltage conditions remains a challenge. To address this, this paper presents a low-voltage ride-through strategy that utilizes dual-loop control for managing both positive and negative sequence components, aiming to improve the dynamic response of VSG during asymmetric faults. By thoroughly analyzing the VSM topology and mathematical model, an improved control scheme is developed. The effectiveness and practicality of the proposed strategy are ultimately validated through simulations under complex fault conditions.