Study On Control Strategy Of Switched Reluctance Motor Based On TMS320F2812

The switched reluctance motor has a lot of merits, including low manufacturing cost, reliable operation, wide speed range, flexible control and so on, due to its simple structure. Based on these advantages, SRM is suitable for the applications in pump, textile industry, machine tool and electric vehicle. Arising from the highly nonlinear nature, the power current and the flux produced in SRM are nonlinear and difficult to calculate. Therefore, it’s hard to find a common way to model different SRMs and analyze the operation performance. Meanwhile the SRM has some issues to be further researched, such as torque ripple and noise.In order to establish an accurate model, this thesis demonstrates the structure and operating principle of SRM, and analyzes the performance based on its linear mathematical model. The magnetic field of the switched reluctance motor is researched through finite element analysis to acquire the magnetic flux-current curves. The SRM model is built and analyzed in Maxwell, which is a widespread software in the electromagnetic field simulation area, and the magnetic flux-current matrix obtained is verified by designed experiments. The flux linkage-current data is exported to Matlab to work out the torque-angle-current curves. With these data, a nonlinear model is built in Simulink. The current and the torque are calculated from the data table by the cubic spline interpolation method. The joint simulation method of Maxwell and Simplorer is adopted to verify the nonlinear model built is appropriate or not.The control strategy is researched, and a saturation correction part is applied to the integral term of the conventional PI control, to diminish the integral overshoot. The output of the controller is adjusted according to the differential of the speed to improve the operation performance. The angle position control is studied and the turn-on and turn-off angle is optimized using simulation method. The cases of abrupt change of load and multi-winding excitation and phase-deficiency operation are simulated and investigated.The prototype of control system is built based on DSP TMS320F2812, which has many modules, and the control algorithm is programmed and tested on the hardware platform. The results are presented to prove the system is workable.