Research On The Angles Optimization Of Switch Reluctance Motor

The Switched Reluctance Motor(SRM) has lots of advantages, such as simple and tough construction, high reliability, low cost, running with phase fault so on. In recent decades, with the development of power electronics, computer technology and control technology, the Switched Reluctance Motor driving system has become a hot research topic by the modern scholar with its excellent performance. But, due to the motor has severe nonlinearities. So it is difficult to establish the accurate mathematic model of SRM, and performance of the motor cannot be well controlled by the traditional control method. During the operation of SRM, it is important to rationally adjust the turn-on angle and turn-off angle of the motor. Therefore, this paper presents an optimization of the excitation angles, which can make the motor operate under the optimal condition.This paper takes the maximum ratio of the average torque to RMS phase current of the SRM as the optimization goal, which can be obtained by optimize the turn-on angle and turn-off angle.(1) Introducing the structure and operating principle of SRM, deducing the nonlinear mathematic model of SRM, analyzing the structure of the main circuit of the power converter, introducing the three main control method of SRM.(2) On the basis of the experimental data of SRM through the finite element analysis, modeling the motor in Matlab/Simulink using iterated interpolation method. First, finding the optimal control area of the turn-off angle through simulation. Second, online optimizing the turn-on angle by fixing the turn-off angle in the optimal control area, finding the rule of the optimal turn-on angle when the motor achieves the maximum ratio of the average torque to RMS phase current. Finally, building the simulation model of the turn-on angle when the motor working in high and low speed condition and verifying the control strategy.(3) When the optimal turn-on angle is obtained by adopting above strategy, simulating the SRM with different speed and reference current, finding the accordingly optimal turn-off angle. Optimizing the turn-off angle by using fuzzy control on the basis of the simulation experiment data. In the fuzzy controller, the speed and reference current are selected as the input variables, and the optimal turn-off angle is selected as the output variable. The fuzzy rule and the fuzzy subset are derived from the experiment data.(4) Based on the optimization methods of the turn-on angle and turn-off angle above, this paper has designed the hardware platform of the SRM controller which is based on the STM32F103VCT6 chip of ARM and also the software program of the SRM controller.