Performance Analysis of VSG Controlled Low Voltage Ridethrough in Optical Storage Joint System

Photovoltaic configuration for energy storage is currently the mainstream way to provide stable frequency and voltage support. This paper proposes a strategy of using virtual synchronous generators (VSG) in optical storage commutation control systems. Traditional control systems for photovoltaic energy storage do not have low voltage traversal. Firstly, according to the power angle characteristics of VSG, the synchronous operation of VSG and grid side under fault is maintained by reducing the active power command. Then the self synchronization characteristic of VSG is analyzed. The VSG running synchronously can provide the phase angle for the coordinate transformation of low voltage ride through control, and facilitate the command switching back after the fault is removed. On this basis, it is proposed to switch the VSG current command of the balanced current control loop to the command of the fault when the fault occurs, so as to limit the fault impulse current and provide power support for the system. After the fault is removed, the current command switches back to the VSG.