An optimal control method of virtual angular acceleration to improve transient response based on virtual synchronous generator

Abstract

The virtual synchronous generator (VSG) is a control scheme applied to the grid-tied inverter to increase system inertia by imitating the rotor inertia of synchronous generator (SG). However, due to the imitation on rotor inertia VSG control may lead to the power and frequency oscillation after a change or disturbance, which decreases the reliability of inverters. In this paper, the process of active power and frequency oscillation is divided into four stages and analyzed in detail. Then the optimal criterion of virtual angular acceleration in the four stages are provided to improve the transient response of power and frequency. An optimal control method of virtual angular acceleration is proposed according to the optimal criterion. Simulation and experiment results are presented to validate the effectiveness of the proposed method.