Multivoltage-Vector-Modulation-Based Integrated Direct Torque Control of Dual in-Wheel PM Motors for Distributed Drive Electric Vehicles

To improve the coordinate control performance of the multiple motors in the distributed drive (DD) electric vehicle (EV) system, an integrated direct torque control with multiple voltage vector (MVV) modulation is developed and implemented in this article. It focuses on the integrated modulation principle considering dynamic operating demands and interaction between the independent drive wheels, where the frequency ratio integrated modulation and virtual vector integrated modulation are proposed and investigated. And then, a 1/2 DD system with the dual in-wheel permanent magnet (DIW-PM) motors which is represented in the front and rear drive wheels is selected as the control example. Based on the six-leg inverter, the dual in-wheel permanent magnet motor drive system is established and the mathematic model is derived. The different modulation methods are discussed and compared. Finally, the experiments are conducted on the DD system with two different power levels and configurations in-wheel PM motors, and the experimental results are presented to verify the effectiveness of the proposed integrated direct torque control method for the EV distributed drive systems.