Optimization Control Strategy of Self-Adjusting Parameter Based on Dual-Parallel Virtual Synchronous Generators

Abstract

There are the problems of active power oscillation and frequency fluctuation for dual-parallel virtual synchronous generators (VSGs) with the fixed moment of inertia and damping coefficient, therefore, an optimization control strategy of self-adjusting parameters is proposed in this paper. Firstly, a small signal model of the parallel VSG system is established, and the influence of moment of inertia and damping coefficient on output active power is analyzed. Secondly, the parameter optimization control for the self-adjusting inertia and damping coefficient is introduced according to the change rate and the deviation of rotor angular velocity within the restricted range of satisfying the dynamic and steady state performance of the system. Finally, the effectiveness of the proposed control method is verified by simulation results. This method can not only suppress the active power oscillation during the process of VSG connecting with AC bus and ensure the stable operation of the system, but also improve the frequency support ability.