Comprehensive Investigation of Space-Vector PWM Including Novel Switching Sequences for Dual Three-Phase Motor Drives

The increasing interest in dual three-phase motor drives has led to the corresponding research on pulsewidth modulation (PWM) techniques. Compared to carrier-based PWM (CPWM), space-vector PWM (SVPWM) attracts more attention because of clear physical meaning and high design flexibility. However, it is difficult to design the method from the space-vector concept due to the complexity in the selection and the arrangement of the space vectors. In this article, with the unified comprehension of the space-vector and carrier-based approaches to PWM, a straightforward approach is proposed to develop various switching sequences. As a result, a total of ten different switching sequences are presented, including five novel switching sequences. In addition, the time distribution schemes of the applied vectors for the derived switching sequences are explored to obtain the acceptable harmonic performance with low computation burden. With the benefit of the derived switching sequences, a comprehensive investigation on the design of PWM methods can be carried out. As a result, an SVPWM method using five active vectors is proposed with excellent harmonic performance. Simulation and experimental results on a 7.5-kW dual three-phase induction motor drive are given to confirm the correctness of the theoretical analysis and the validity of the proposed method.