| As a new driving system, switched reluctance motor (SRM) has been the focus of intensive research efforts because of the advantages of simple structure, low cost, high reliability and so on Meanwhile, it has a high market potential and research value. But it has been the main reason for restricting SRM application that the large output torque ripple, due to its salient structure and switch-mode power supply. This thesis carries out the modeling and control of SRM research work, which can provide some basic work for the development and perfection of the technology.At first, a detail study is made about the mathematical model of SRM in this thesis, and SRM includes two types of bearing and bearingless structures. The working principle of SRM has no essential difference, and it is consisted in SRM mathematical model that the circuit equation, mechanical equation and torque equation. While suspension windings analysis of bearingless SRM is the key to establish the analytical model of radial force. The correctness of the radial force analytical model has a decisive effect on the rotor steady suspension running for bearingless SRM. The most typical motor structure is the double windings bearingless SRM, but the electromagnetic coupling relationship is very complex between rotation and suspension windings in this type motor so that the control system is also very intricacy. Due to the complex electromagnetic coupling relationship between two sets of windings, single winding and double stator of two new bearingless BSRM have been carrying out research work. Currently, the rotor radial eccentricity has not been taken into account while calculating radial force of the two new bearingless BSRM in related references. Based on the structure properties of those two motors, the radial force analytical models are derived, considering the influence of the rotor eccentric. And the two analytical models provide a theoretical basis for the subsequent control studies.And then, the three-phase12/8ploes SRM finite element model is established by JMAG-Designer simulation software, and it’s analyzed based on this model that the electromagnetic characteristics of SRM. Simultaneously, the motor performance is compared between traditional SRM and dual-channel SRM, for different winding ways of the interwinding. Compared with the traditional SRM, dual-channel SRM has higher reliability and more flexible control. But the cost of its control circuit is higher and the structure of windings is more complex. Subsequently, the control study of SRM is done, based on the finite element analysis software and MATLAB/SIMULINK, including motor modeling and control strategies. In this thesis, two modeling methods are introduced. One is based on look-up table which establishes the nonlinear inductance model of SRM. And the other uses JMAG-SIMULINK software to build a magnetic circuit co-simulation model. In comparison, the second method is more simple and accurate. And then the advantages and disadvantages of some traditional control methods, such as current chopping control, angle position control, direct torque control and torque distribution control, are introduced.At last, in order to verify the results of the above study, a control platform is built based on DSP control. While it is completed that the design, fabrication and debugging working of software programs and hardware circuit. And finally, the prototype achieves working properly without load. By comparing the simulation results with test waveforms, the results verify the correctness and reasonableness of the dynamic simulation model and control strategy. |
