Design Case Study of A Nine-Phase Integrated On-Board Battery Charger

The use of electric vehicles (EVs) is expected to extensively expand worldwide in the near future. Therefore, an insistent need for efficient fully integrated on-board battery chargers has become urgent to minimize the vehicle cost leading the charging process to be publicly available. This paper considers on-board battery charging of EVs using a nine-phase system which are completely integrated in both propulsion and charging operational modes. The charging mode is employed with zero machine average torque production, while a unity power factor operation at the grid side can be concurrently achieved. All the propulsion components are utilized in the charging process; no new elements are, therefore, demanded. Moreover, hardware reconfiguration to transfer from propulsion to charging is not needed. Therefore, the electric vehicle supply equipment (EVSE) known as off-board charger infrastructure is expensed with. To this endeavor, this paper presents a design case study for a 1.5kW integrated on-board battery charger using a nine-phase induction machine, as a part of a senior project for electrical engineering undergraduate students. Both mathematical modeling and MATLAB/Simulink simulation results are given. The vehicle to grid (V2G) and propulsion regimes are experimentally verified.