Study On Low Torque Ripple And Noise Reduction For Switched Reluctance Motor

Switched reluctance motor(SRM) control system is a kind of high-efficiency and energy-saving motor driving system. As SRM dose not need magnetic steel, its factory-cost is low, and it isn’t influenced by the market price of magnetic steel and has good economic benefit. Moreover, SRM has advantages of simple structure, good braking performance, wide speed variation range, high starting torque and efficiency. It has been paid widespread attention in recent years, with good development prospects. And it also meets the policy about energy saving and pollution reduction, with great significance on energy saving and environmental protection. SRM has been successfully applied to some applications in different degree at present, such as electric vehicle, forging equipment, textile machinery, aviation, general industry, household appliances. However, torque ripple and noise of SRM restrict the applying in some areas, such as some high-performance electric vehicle and driving lift system. Therefore, the thesis does a research on how to reduce noise and torque ripple of SRM, which has great theoretical significance and practical significance.The thesis focuses on the study of reduction about torque ripple and noise for SRM. Firstly, in-depth study on the relevant literature at home and abroad about research status of SRM and its torque ripple and noise study. Based on its working principle, analyze its research difficulties. Analyze and study deeply on the generation mechanism of noise and the cause of torque ripple. Based on this, the thesis gives a strategy of direct torque control, according to the working principle and mathematical model of SRM. Also, use the Matlab/Simulink software platform to build simulation models and contrastively analyze the performance for SRD system with the control strategy and the method of chopped current control. In addition, based on an experimental prototype, the thesis proposes that an appropriate carrier frequency, a proper winding connection and an appropriate chopping mode of PWM are helpful to improvement on noise of SRM.Based on the theoretical analysis, focus on a 5.5k W four phase 8/6 poles switched reluctance motor as prototype, design the control driver based on Texas Instruments TMS320F28035 control chip and use the sin/cos-encoder as the position and speed sensor. Also, build an experiment dragging platform for SRM, and use the control driver designed to research on some methods to reduce torque ripple and noise for SRM. The results show that the control methods proposed could effectively improve the performance of SRM, which play an active role in extending several new applications and have important significance.