Simulation Study Of Vector Control System For A Fault Tolerant Permanent Magnet Motor

Electric propulsion system is characterized by simple structure, flexible arrangement, fast response, low energy consumption, easy for automatic management, etc. Therefore, in many cases, the electric propulsion system has been applied more and more widely. In the safety critical areas such as aerospace, submarines and electric vehicles, the fault of motor and its control system may lead to disasters in the harsh environments and result in personnel and economic losses.The motor in above areas should have the capability of the fault tolerance. Therefore, Fault-tolerant Permanent Magnet Motor (FTPM) and its control system become a hot research topic. The essence of controlling motor is controlling the magnetic torque. In order to obtain high static, dynamic torque characteristics, a vector control method for a six-phase FTPM motor is proposed in this thesis.Firstly, the structure of a six-phase FTPM motor is analyzed and the mathematical models for this motor drive are established. Secondly, based on the coordinate transformation theory, the mathematical models are decoupled. Then, connecting with the transform circuit of the FTPM motor drive, the SVPWM control strategy is determined to build the fault tolerant permanent magnet motor vector control system with the speed and the current double closed loop control structure. For the problems of motor starting, braking and speed or load changing suddenly in traditional closed loop motor speed regulation system, the PI regulator is designed to realize anti-saturation output.In order to validate the correctness of the control strategy, the six-phase fault tolerant permanent magnet motor model is built in the MATLAB/Simulink environment.And through the reference voltage vector size and its direction and the sector distribution to calculate the switches effect time and order, six-phase SVPWM waves are generated.So the motor vector control simulation modeling is realized.The simulation results show that, compared to the traditional motor speed control system, the designed vector control system for a six-phase FTPM motor drive has more wide speed regulation range, good dynamic response feature and excellent anti- disturbance and this design has certain practical value.