Design of a PM Brushless Motor Drive for Hybrid Electrical Vehicle Application

Visual Computing Systems (VCS) and Oak Ridge National Laboratory are partnered in a research effort to design and build a power inverter for use with an automotive traction permanent magnet (PM) motor provided by VCS. The inverter is designed to fit within the volume of the housing, which is integrated with the motor. Moreover, a modular design for both the inverter and motor is employed to reduce the development cost by stacking modular units to meet the requirement of higher power ratings. The motor is operated in brushless DC mode. The effect of different commutation and current-sensing strategies on current control is analyzed. Torque and regeneration control algorithms are implemented with a digital signal processor. A traction motor drive system is constructed by using two modular inverters and a PM motor with two sets of stator coils. Each inverter separately drives a set of stator coils. The drive system will be used to repower a hybrid vehicle converted from a Chevrolet Suburban and will increase its fuel economy substantially. Design, analytical, and experimental results are included in the paper.