Study On The Control System Of Multiphase Permanent Magnet BLDC Motor For Electric Vehicle Drive

Compared With the traditional three-phase motor drive systems, the multi-phase motor drive system have many advantages in the high-power, high reliability and low DC voltage power supply situation, so multi-phase motor is one of best solution of electric vehicles driving motor. It has great potential for development.Based on the systematic research of the PM BLDC motor and its drive system, in this thesis, the multi-phase BLDCM motor is further studied. Control strategy is using multiple three-phase drivers to drive a multi-phase motor, and a nine-phase BLDCM prototype motor are assembled, at the same time, the relative testing are carried out and the valuable results are achieved.In this thesis, the whole system is firstly illustrated in detail, through comparing the fluctuating torque of three-phase and nine-phase PM BLDC motors, it is concluded that the fluctuating torque of nine-phase PM BLDC motor is lower than the one of the nine-phase PM BLDC motor obviously; Then, the control strategy and commutation process of multi-phase PM BLDCM is analyzed; Finally, a set of speed regulation control system is designed and the relative test and analysis are carried out, the testing results show the reasonability of this control system and it can realize the normal starting and speed regulation of PM BLDCM motor. Furthermore, this paper also establishes the simulation model of PM BLDCM control system based on the SVPWM, and the simulation results also verify the correctness of this control method.