An adaptive VSG control strategy of battery energy storage system for power system frequency stability enhancement

•Establishing the adaptive VSG control-based electromechanical transient model for energy storage.•Establishing a small-signal model and analyzing the dynamic characteristics of VSG output caused by grid fluctuations.•Proposing adaptive control of VSG to provide frequency support and maintain SOC of BESS. With the steady deployment of intermittent generation, the inertia of the grid decreases, and the stability problem is becoming increasingly critical within system operation. The virtual synchronous generator (VSG) control is a means to control battery energy storage systems (BESS) to retain the dynamics of conventional synchronous generators and ensure a smooth transition toward converter-dominated power systems. Since the parameters in the VSG control can be varied, it can be turned to be an alternative to obtain an optimal response for the overall performance of frequency when the operating conditions change. In this paper, the adaptive VSG control is proposed to improve the dynamic characteristic of active power at a certain capacity. For this purpose, firstly, the electromechanical transient model of BESS based on VSG control is built. Afterward, the effect of inertia under grid disturbance by transfer function is analyzed, and the influence of key parameters on dynamic stability is identified. Finally, the proposed adaptive VSG control is verified in the modified IEEE 4-machine 2-area system and an actual power grid example. The simulation results show the effectiveness and great potential of this model in improving frequency stability.