Research And Design Of A New Type Of Switch Reluctance Motor Controller Based On XMC4500

Switched Reluctance Motors are gradually replacing the traditional motor used in electric vehicles because of its superior performance such as simple structure, reliable operation, larger starting torque and can start or stop frequently, and be greatly popular and concerned by more and more various types of electric vehicle research and development staff. However, its drawback is the presence of a large torque ripple and noise at low speed rotation.This paper first describes domestic and international research trends of the Switched Reluctance Motors, then elaborates on the structural characteristics of the motor, as well as the working principle and the cause of torque ripple generated. After carefully investigation and analysis of some general motor control methods used at present, this paper establishes a mathematical model of the motor to make in-depth analysis on the motor torque related to the inductor and the winding current changes, and then introduces a new dual-loop motor control strategy combined micro-step torque control and speed VSC control based on XMC4500 high-speed microprocessor to realize the torque ripple minimization. The control system gives full play to the control chip’s advantages of high-speed computing and various integrated industry peripherals, and it also greatly improve the control circuit reliability and structural simplicity with high-performance IGBT switching device and optocoupler drive chip. At the same time, high-frequency and fast adjusting the sum of two-phase torque could be done to smooth control two-phase torque change in accordance with a given desired torque curve through the correct current of torque distribution based on inductance change rate during commutation process of two phases of the Switched Reluctance Motor. In order to overcome the problem that the optical rotary encoder cannot determine the initial position of the rotor, the method of measuring coil winding current rate of change to calculate inductance is proposed, and then compare it with the existing location-inductance data to get the initial position when the position of the motor is stationary.Finally, this paper does some actual study through experiment platform based on 3KW SRM motor with 12/8 pole. The results show that the control system could ensure the stable operation of the motor, and partly suppress the higher torque ripple of switched reluctance motor at low speed.