Research on motor driving and vehicle charging integrated system

This paper focuses on the integration technology of electric vehicle motor driving system and on-board charging system. The front-stage bi-directional AC/DC converter time-multiplexes a three-phase bridge full-control circuit into a staggered parallel totem pole power factor correction circuit and a three-phase inverter circuit, which enables the on-board charging system to have a motor control function. It can form a bidirectional AC/DC converter which can realize the function of motor control. The rear-stage DC/DC converter can realize the energy exchange between power supply and power battery or power battery and motor through dual active bridge structure. The working characteristics of the front-stage circuit and the soft switching range of the rear-stage circuit are studied. The mathematical model of the front-stage circuit and the rear-stage circuit are established by small signal analysis, and the control strategy of the front-stage double-closed loop and the rear-stage double-loop competition is adopted. The PI controller parameters are designed by using the mathematical model of the system, and the stability of the compensated system is verified by the open-loop amplitude-frequency characteristic curve. The simulation model and experimental platform are established. The charging mode is verified by the electronic load and high voltage DC source simulate the power battery. The driving mode is verified by using the 5 kW permanent magnet synchronous motor. The simulation and experimental results verify the feasibility of the system to achieve charging and driving functions.