Output Voltage Control of BESS Inverter in Stand-Alone Micro-Grid Based on Expanded Inverse Model

Abstract

This paper investigates robust output voltage control of battery energy storage systems (BESS) inverter in stand-alone micro-grid. The transfer function model between the output voltage and duty cycle of the BESS inverter is established, base on which the main factors affecting the output voltage are analyzed theoretically. Then, the expanded inverse model of the BESS inverter is developed based on BP neural network, and the gravity search algorithm (GSA) is employed to search the initial values of the network's parameters in the training process. Further, a control method for the output voltage of BESS inverter is proposed by putting the expanded inverse model in series with the original system as well as performing the single-loop control with PI controller. Both simulation experiment results and prototype experiment results show that the proposed expanded inverse model control method has a strong capability of disturbance rejection and could ensure the high power quality for the output voltage of the BESS inverter.