Research Of Switched Reluctance Motor Torque Ripple Suppression Based On Torque Distribution

Switched reluctance motor drive system is a new speed control system after frequency control system which rise up rapidly, and it can be traced back to the1840s, the earliest known as "Electromagnetic brake". Switched reluctance motor drive system get rapid development in recent years because of its simple and firm structure and low cost also has large starting torque with small starting current, and keep high efficiency over the entire speed range, also combines the advantages of DC motors and asynchronous motors. But because of the motor’s doubly salient structure and stepper rotary manner, which cause relatively large torque ripple and noise, then affected the promotion and application of SR motor on more occasions.This thesis analyzed the causes of torque ripple and noise aimed at the SRM’s shortcomings of torque ripple and noise, then studied the working principle of SRM and the method commonly used for torque ripple suppression control, after that a simulation model of SRD was established in simulink environment, and the influence on torque ripple of the opening angle and turn-off angle was studied, with a conclusion that the optimal open angle and turn-off angle can reduce the torque ripple. At last adopted a Speed and current double closed loop control mode based on cosine type torque distribution function combining with the fuzzy opening and turn-off angle optimization to suppress the torque ripple, established a simulation model, verified the feasibility of the control mode, and got a very good result for torque ripple suppression.Based on the research above, this thesis took a55kw three-phase12/8pole SR motor as the research object. A SRM drive system with DSP TMS320F2812as the core CPU, with symmetrical three-phase type half bridge as the power main circuit structure, with photoelectric sensor as the position detection device was designed, which has perfect protection circuit. A software of the control system was programmed on the platform of CCS5.2. Finally, the system debugging was carried on, and the experiment results show that this control method response fast, has a good dynamic performance and the effect of the torque ripple and noise suppression is more noticeable. Figure55, table8, references63.