Design, Analysis And Control Of The Low-Voltage High-Current Permanent Magnet Motor

In view of the major cities in China are constantly haze weather and the world's energy shortage, energy conservation and emissions reduction is putting on the agenda again. Electric vehicle as a mainstream new energy vehicle of the 21st century, can provide an effective means to alleviate these problems. At present many products of pure electric vehicles using permanent magnet synchronous motor (PMSM) are high voltage, low current control system, which can provide higher output efficiency when the pure electric vehicle operates at high speeds. However most of the pure electric vehicles run in urban areas nowadays because of the limited mileage range. The speed of vehicles and the output efficiency of the permanent magnet synchronous motors have been quite limited. As a consequence, developing a Low-speed high-torque PMSM and its control system is one of the hot spot research problems in electric vehicle field.In this paper, a low-voltage high- current PMSM and its control system are designed according to the performance parameters and requirements for drive motor of lightweight rainbow electric vehicle which is developed by the College of Automotive Engineering, Dalian University of Technology. The main works of this paper are listed as follows.The basic dynamic performance parameters of PMSM are designed according to the performance parameters and requirements for drive motor of lightweight rainbow electric vehicle.The main geometric dimensions and structures are designed based on the power requirement of PMSM. Then the optimization design of the PMSM is conducted by the software of RMxprt to enable that the output performance can meet the design requirements. In order to further verify the rationality of the PMSM, the magnet field is analyzed in the software of Maxwell by using the method of finite element.Finally, a low-voltage high-current control system of PMSM is constructed based on the chip of DSP TMS320F28335, which is developed by Texas Instruments. The physical model of PMSM and the theory of vector control strategy are analyzed. The hardware circuit of the control system is designed. And the programs are given including vector control, SVPWM, closed loop of current and speed and the estimation of rotor position, for the control system in an environment of CCS3.3. The control system is verified by experimental tests and the experimental results are analyzed to ensure the feasibility and practicality of the vector control system of permanent magnet synchronous motor for electric vehicle.In conclusion, a system has been provided for matching in power train parameters on pure electric vehicle, designing of PMSM and it's control system, which has an important value for application.