A Modulation Method to Eliminate Common-mode Voltage of Dual Three-Phase Motor

Voltage-Fed PWM inverters have problems of common-mode voltage. The effects of common-mode over voltage are extremely problematic for everyday operations, such as damage to motor bearings, unexpected ground fault trips and premature motor insulation failure. There are many modulation methods for dual three-phase motor drive systems, and the vector space decomposition method is one of the main modulation methods. In order to reduce the common-mode voltage of the dual three-phase drive system, this paper proposed a new PWM method based on TSPWM. The new method is compared with the space vector modulation strategy, and the results of simulation and experiment are presented to prove the effect.