SRM Control System Research Based On The Sliding Mode Control

Switched reluctance motor(SRM), as a kind of simple structure, large starting torque,high efficiency of the new speed motor, has a wide application in coal mining, aerospace technology and other areas of the speed control. But because of its highly nonlinear magnetic properties, it is difficult to obtain an accurate mathematical model, so the rapid smooth speed regulation and current tracking become more difficult. Variable structure control system with sliding mode(VSS), as a kind of nonlinear control method, can make the system move along a set of sliding mode motion state trajectory. It is not sensitive to external disturbance and system parameters change. It also has good dynamic characteristics and static characteristics,especially for nonlinearcontrol system.Firstly, the working principle and mathematical model of switched reluctance motor are analyzed in this dissertation. Through ANSOFT software dissertation obtained the prototype static characteristic curve of flux linkage curve, torque angle characteristic curve, etc.Nonlinear SRM simulation model is established under the environment of MATLAB/Simulink. Secondly, this dissertation analyzes VSS's advantages of stability,resistance to disturbance and system parameter change from the aspects of mathematical model. In order to improve the chattering problem, a modified reaching law is proposed. On the basis of the prototype mathematical model, modified speed sliding mode controller and modified current sliding mode controller are designed. Thirdly, the dynamic simulation model of sliding mode drive control system is built, from the aspects of the simulation verifies the correctness of the modified reaching law. Modified reaching law, is verified by comparison with traditional reaching law, can significantly weaken the chattering phenomenon, meanwhile reaching speed faster and robustness stronger.Finally, switched reluctance motor drive controller is designed based on the TMS320F28335, which is control core. This dissertation expounds the power converter drive circuit, position and current signal detection and modulation circuit and some of the software process. Simulation results of modified reaching law sliding mode drive control are verifiedthrough the experiment platform. The efficiency of the modified reaching law is verified by experiment waveform.