An Improved VSG Control Strategy Based on the Amplitude-frequency Characteristics of Virtual Power

Abstract

There are contradictions between the steady-index and dynamic characteristics of active power responses, when virtual synchronous generator (VSG) is connected to grid as a PQ source. The concept of virtual power was proposed for explaining the physical meaning of the control parameters in this paper. Furthermore, the amplitude–frequency characteristics of virtual power were analyzed and corrected to improve system characteristics, and a general expression of improved VSG control scheme is demonstrated. Afterward, the related control parameters were analyzed and designed for a specific case, and the implement steps were conducted. Finally, the effectiveness of the proposed control method was verified.