Hierarchical Control Design of a Modular Integrated OBC for Dual-Motor Electric Vehicle Applications

This paper presents a novel modular integrated on-board charger (MIOBC) topology and control scheme for dual-motor electric vehicle (EV) applications. Designed for effective power management across various operational states (driving, regenerative braking, and charging), the MIOBC modularises the HV battery and converters, improving fault ride-through (FRT) capability, system flexibility, safety, and efficiency. The architecture features a single-stage bidirectional isolated Cuk converter as its submodule (SM), providing inherent power factor correction (PFC), reduced current ripple, and enhanced power quality. The control strategy integrates finite control set model predictive control (FCS-MPC) with classical proportional-integral (PI) controllers in a hierarchical multi-loop framework. The FCS-MPC dynamically predicts and regulates switching states, minimising a defined cost function to achieve real-time current and voltage tracking while suppressing second-order harmonic components through an innovative capacitor-based energy buffering technique. The paper further explores the impact of the prediction horizon on stability, employing state-space modelling to analyse robustness under parameter variations. Experimental validation is conducted on a 20 kW dual-motor system controlled by a TMS28335fezdsp, demonstrating robust performance under normal and fault conditions, including mode switching and second-order harmonic suppression.