Stability Improvement of Power System with a Wind Farm by the Virtual Synchronous Generator Control of Battery

Abstract

As the introduction of renewable energy sources (RESs) increases, there is a concern that the inertia and synchronizing power of power systems will decrease and the system stability will deteriorate. In particular, if a large-scale wind farm is disconnected from the grid in compliance with the grid code due to a grid fault, the entire grid may become unstable. Under such a background, this paper proposes a storage battery system which has the functions of reactive power control and virtual synchronous generator (VSG) control as well as control of system frequency fluctuations due to fluctuating output from the wind farm. In addition, a new control method is also implemented in the battery control system in order to improve the total charge/discharge efficiency of the battery by suppressing unnecessary charging and discharging. The proposed battery system is composed of multiple batteries installed at different locations and they are controlled coordinately. Effectiveness of the battery system for system stabilization is verified by simulation analyses.