Seamless Transfer of Control Mode for Modular Multilevel Converter with Integrated Battery Energy Storage System

This paper analyzes the equivalent model of modular multilevel converter (MMC) with integrated battery energy storage system (BESS). The control strategies of the system based on current source mode (CSM) and voltage source mode (VSM) are compared and discussed to conclude their respective scope of application. After that, a seamless transfer method between two control modes is proposed to ensure the system operation uninterrupted during the control mode transition. The simulation and experimental results validate the feasibility and effectiveness of the proposed seamless transfer method.