Research On Direct Instantaneous Torque Control Of Switched Reluctance Motor

In recent years, with the development of power electronics technology and the application of microprocessor, the switched reluctance motor drive system (SRD) aroused wide attention of scholars both at home and abroad. The switched reluctance motor (SRM) has the advantages of simple structure, high reliability, low manufacturing cost, etc. These advantages make SRM applied in a great number of fields include textile industry, aviation, mining, household appliances and electric vehicle. However, many disadvantages limit its further application, such as the large torque ripple and noise during rotation, how to obtain accurate model, etc.In this paper, the direct instantaneous torque control (DITC) of SRM is chosen to reduce torque ripple. Firstly, this paper analyzes and compares several methods of obtaining the flux parameters. On this basis, this paper proposes a new method for obtaining flux-linkage characteristics based on the chopped current control (CCC) of SRM. The proposed method can easily obtain the flux-linkage during current chopping operation period. However, this method cannot obtain the flux-linkage data of the position which is out of the current chopping operation period. So it can be used as a supplement to other measurement methods without rotor clamping devices. The validity and accuracy of two simplified nonlinear modeling methods are analyzed after obtaining the flux-linkage data of several specific positions.Secondly, this paper realizes the DITC after obtaining the simplified nonlinear model of the SRM. The DITC can achieve good control of torque. But the phase current will have large peak during the commutation period, because it is not controlled. This paper proposes a new DITC using commutation angle control. The proposed method can effectively suppress the peak value of the phase current during the commutation area in a wide speed range, thus improving the performance of the DITC.Finally, a 7.5-kW three-phase 12/8-pole SRD experimental platform is built, on which the load and speed test has been completed, and the proposed control algorithms are verified.