A five-leg inverter for driving a traction motor and a compressor motor

This work presents an integrated inverter for speed control of a traction motor and a compressor motor to reduce the compressor drive cost in EV/HEV applications. The inverter comprises of five phase-legs; three of which are for control of a three-phase traction motor and the remaining two phase-legs for a two-phase compressor motor with three terminals. The common terminal of the two-phase motor is tied to the neutral point of the three-phase traction motor to eliminate the requirement of a third phase leg. Further cost savings are made possible by sharing the switching devices, DC bus filter capacitors, gate drive power supplies, and control circuit. Simulation and experimental results are included to verify that speed control of the two motors are independent from each other.