Research on Bi-directional converter for lithium battery energy storage system

In this paper, based on the fact that lithium battery energy storage system needs to exchange energy with the grid frequently, a grid-connected conversion for lithium battery energy storage systems is introduced for the charge-discharge function. In order to achieve the current decoupling and high power factor, the synchronous rotating frame and the space vector pulse width modulation (PWM) are used for the AC/DC conversion. DC/DC conversion part of the controller is designed based on the average model. The output voltage control problem is converted into the control of the inductor current. Electromagnetic transient simulation results show that the system is correct and feasible.