Four-module three-phase permanent-magnet synchronous motor based PWM modulation strategy for suppressing vibration and common mode current

In high-power occasions such as locomotive traction and ship propulsion, parallel inverters are often used to drive multi-phase motors or multi-module motors to increase capacity. Under this background, this paper attempts to improve the transmission quality of the motor system at the switching frequency only by changing the modulation method. The modulation strategy based on the four-module motor proposed in this paper can simultaneously suppress the high-frequency vibration of the motor and the common-mode current To meet this requirement, a motor with 4 modules is used in this modulation scheme. In specific implementation, the proposed scheme uses both carrier phase shift and common mode voltage cancellation strategies. Use the controller to uniformly and synchronously drive the parallel inverters. This article also compares the advantages and disadvantages of different methods under different working conditions.