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.

Keywords

• Virtual synchronous generators (VSG)
• inertia support power
• damping power
• amplitude-frequency characteristics
• active power oscillation