The Design Of A New Power Converter For SRM Based On Fuzzy Control Methods

Switched Reluctance Drive is a new AC drive system developed in the mid ‘80s.For low-cost variable-speed drives, SRM are most widely used in competition withconventional ac motors because of their simpler design and higher operating speeds,thus becoming one of the hot topics in the Contemporary Electric Drive. However, SRMhas greater torque ripple caused noises. How to improve the performance/price ratio ofspeed control systems has become a main reason limiting the wide application of SRMin speed control.The connection and disconnection of each phase winding in SRD is inseparablefrom a specific power converter. The power converter is the supplier of energy neededto run SRM. It’s the system’s central executive body. It accounts for a large proportionin the cost of SRD. Thus, a reasonable selection and design is a key to improving theperformance/price ratio of SRD. The power converter of classic SRM requires moreswitching devices, and the cost is higher. This paper designs a new power converterwith a resonant circuit based on the classic power converter. It has only one powerswitch and one power diode in each phase, making possible to stably run SRM with thefewest power switches. It is compared with asymmetrical half-bridge and public switchpower converters using MATLAB. The result shows that the new power switch caneffectively improve the performance/price ratio of SRD.SRM is controlled with a fuzzy controller. The advantage of the fuzzy controlstrategy can solve the problems caused by the high nonlinearity and strong coupling ofSRM. The reverse compensation control of Torque-Current is realized through the fuzzyPID control technology to achieve optimized phase currents and stable torque output,able to overcome the uncertainties induced by the load disturbance and parameterchanges in the system while reducing torque ripple.