Common mode voltage reduction with harmonics study using different PWM techniques for a three phase & five phase BLDC motor

Multiphase motor drives have caught serious attention universally among the motor drives research community since the beginning of this century. The increased number of switching possibilities in space vector pulse width modulation (SVPWM) has led to the development of SVPWM methods for multiphase machines. In spite of the intense effort to develop multiphase modulations and control schemes, there has not been enough scientific analysis of the common mode voltage (CMV) reduction. SVPWM technique analyzed in this paper, reduces peak CMV by 80% compared to standard five-phase modulation. Sinusoidal pulse width modulation (SPWM) & Hysteresis current control (HCC) for five phase drives are the other techniques analyzed in this paper. But reduction of CMV will generate harmonics in the voltage/current output waveform. So study of harmonics while using these three techniques for the reduction of CMV is also discussed and analyzed in this paper. Simulation results of both three-phase & five-phase drives using SPWM, SVPWM & HCC are also presented.