Thermal Simulation Analysis of Vehicle Permanent Magnet Motor Vector Control Strategy and Its Controller

The mathematical model of permanent magnet motor is analyzed in dq coordinate system, and a vector control strategy is designed for hybrid electric vehicle and other applications. When the motor running speed is lower than the rated value, MTPA control is used to enhance the motor’s torque output capacity and reduce its energy loss, and the DC bus voltage utilization rate is determined according to the AC direct axis voltage calculation. When the inverter reaches saturation, the phase Angle of the stator current vector is adjusted by the weak magnetic leading Angle, so that the motor can run at high speed and stably. At the same time, a decoupling module is added to reduce the interference of coupling terms when the speed is high. Considering the heat consumption of the controller under rated working conditions, the cooling of IGBT module is realized by water cooling. The experimental results show that under this control strategy, the speed fluctuation of permanent magnet motor is small, the torque response speed is fast, and the temperature running speed range is wide. The results of thermal simulation show that this water-cooled cooling structure can meet the heat dissipation requirements of motor controller.