Investigation of Water-cooled Integrated Motor-Inverter System for Vehicle Traction

This investigates the miniaturization and high performance techniques for a vehicle traction motor system. A suitable integration structure of motor and inverter with water cooling is studied. Possible structures are enumerated and benchmarked with size, electrical wiring characteristics, and piping performance as indicators. Two suitable structures are extracted and examined in detail. The size or the most suitable integrated motor-inverter structure was 10% lower than that of the second-most suitable structure. By applying a concentrated winding phase-shift dual three-phase motor that exploits an integrated structure, the efficiency was increased by 5% in the low-torque condition is achieved by driving one group of two three-phase motor. © 2019 The Institute of Electrical Engineers of Japan.