Three-Level Boost Converter for EV Charging in Bipolar Microgrids

Abstract

The rapid expansion of microgrids, the surge in electric vehicle (EV) adoption, and the widespread use of renewable energy systems have created an urgent need for a state-of-the-art DC-DC converter with regulated DC bus voltage. To meet this demand and revolutionize power regulation in EV charging stations within bipolar microgrid environments, a three-level boost converter (3-L BC) has been devised. The three-level boost converter is a game-changing interface for bipolar DC microgrids and batteries, handling diverse power levels in positive and negative DC buses. The converter features a closed-loop control system and an incremental conductance-based Maximum Power Point Tracking (MPPT) technique to control power flow adeptly across the DC link poles. A proportional-integral (PI) controller is designed for each operating point using the k-factor approach. A small signal analysis determines the output voltage to the duty cycle transfer function. The PI controller generates a control signal for any operating point using the feedback signals and MPPT technique, thereby balancing the DC bus poles. An electric vehicle (EV) battery is linked to the DC bus for charging and discharging. The converter's performance is assessed using MATLAB/Simulink, and the results emphasize its crucial role in improving voltage stability, facilitating reliable EV charging infrastructure, and promoting sustainable energy practices. © 2024 IEEE.