Rotror flux-Oriented Control of PMSM with synchronized carrier SVPWM and zero sequence voltage injection over-modulation for traction application in very low switching frequency

Traction application inverter runs in very low switching frequency to reduce switching losses, whereas in case of PMSM as traction applications, there is not a the whole speed range strategy can not only achieve synchronized SVPWM modulation but also transit to six-step mode. Based on zero-sequence voltage injection SVPWM, synchronized modulation and over-modulation methods, this paper put forward synchronized change mode, synthesized above three technologies as running strategy of traction PMSM, then developed Rotor-flux Oriented Control in weakening flux situation. Finally, simulation and experiment results from PMSM confirm the validity of the modulation strategy in whole speed range.