An Adaptive Control Strategy with a Mutual Damping Term for Paralleled Virtual Synchronous Generators System

When multiple virtual synchronous generators (VSGs) operate in parallel, load disturbance or the change of setpoint can induce serious frequency and active power oscillations. To address this problem, an adaptive control strategy with a mutual damping term is proposed in this paper. Firstly, the impacts of the moment of inertia and damping coefficient on the characteristics of the VSGs are analyzed comprehensively. Then, an adaptive control method considering the frequency deviation and rate of change of frequency is proposed to improve the frequency dynamics. In order to further dampen the power oscillations of the system with multi-paralleled-VSGs, a mutual damping term is added. The stability proof of the proposed method is based on the Lyapunov Stability Theorem and design parameters guidelines are given. Finally, simulations in Matlab/Simulink and experiments are carried out to verify the effectiveness of the proposed method.