Research On The Direct Instantaneous Torque Control Of Switch Reluctance Motor

Switched Reluctance Motor(SRM) has simple structure, low manufacturing cost, strong fault-tolerant ability, high temperature resistance and suitable for high speed operation. SRM will become more and more important in the field of motor speed control. However, SRM is a variable, nonlinear and strong coupling system. It is difficult to obtain excellent performance by using the traditional control strategy. Large torque ripple is its obvious issue. These problem have restricted the application of SRM. In order to Applica ting SRM better, solving the torque ripple of Switched Reluctance motor Drive system is necessary.To reduce the torque ripple and improve the performance of SRD system, this paper researches on Direct Instantaneous Torque Control strategy of SRM, focuses on the design and simulation of DITC scheme. Also, this paper has proposed a new method to reduce the torque ripple. The main contents as follows:(1) Introducing the basic structure and principle of SRM. Providing the mathematical model of SRD system. Presenting the characteristics, causes and effects of torque ripple by analysis simple linear model.(2) This paper use the instantaneous torque as the direct control object, design a DITC system for SRM, build a simulation model by using simulation tool in Matlab. Through the simulation, result shows that the control system can achieve the target in the rated working point. But, when the motor speed is too low or too high, simulation result shows that the control system cannot achieve the target.(3) In order to solve the problem in special speed, this paper puts forward a new method. By using four quadrant DC/DC circuit at the fore of asymmetrical half bridge circuit, this paper control the bus voltage can reduce torque ripple at low and high speed.(4) Last, this paper give the realization way of experiment system.