Research On DTC Of Switched Reluctance Motor

Switched reluctance motor is widely concerned for its simple and strong structure, superior speed regulation performance and wide speed range. But due to its doubly salient structure, working in the saturated zone of magnetic chain and the nonsinusoidal phase current, switched reluctance motor have many shortcomings such as large torque ripple and big vibration noise in operation. These weaknesses make switched reluctance motor not suitable for application in torque ripple demanded occasions, which greatly limits the application of switched reluctance motor. In addition, because of the difficulties to get the accurate mathematical model of switched reluctance motor, analyzing the reasons of motor torque ripple and designing the method of reducing torque ripple are very difficult. Based on the above reasons, in this paper we introduce the direct torque control technology to the control process of switched reluctance motor, which effectively reduces the torque ripple of switched reluctance motor when running.Because the structure and the mathematical model of switched reluctance motor are quite different from AC induction motor, the direct torque control methods used in AC induction motor cannot be applied to switched reluctance motor directly. In this paper, the direct torque control theory of AC induction motor is described frist, and then trough the analysis of the similarities and differences between switched reluctance motor and AC induction motor, a direct torque control method suitable for switched reluctance motor is given. Through the analysis of the problems using basic voltage vector of direct torque control, the paper gives an optimized direct torque control method of switched reluctance motor.In order to verify the correctness and effectiveness of the optimized direct torque control method, this paper firstly simulates the systems using Current-Angle control, using basic voltage vector of direct torque control, and using the optimized direct torque control in MATLAB/Simulink, then compare the simulation results with each other. Finally design the experimental platform of switched reluctance motor and do the experimental test. Both the simulation results and experimental results prove that the optimized direct torque control of switched reluctance motor have good effect for reducing torque ripple.