Research Of High-Speed Two-Phase Switched Reluctance Motor And Drive System

Due to its high starting torque, compact structure, low cost and high no-load speed, grinding machines and other high-speed power tools are usually driven by single-phase series motor. But the existence of the commutator and slip ring affect their life and reliability severely. Two-phase switched reluctance motor is the ideal tool for high-speed electric motor drive, because of its good string excitation characteristics, simple structure, moderate cost and no commutator and slip ring. This paper uses the grinding machine tool as driving object, and has studied high-speed two-phase switched reluctance motor system, including the following:Firstly, basic structure and operation principle of the switched reluctance motor, especially the two-phase switched reluctance motor, were introduced, and inductance, torque and operational characteristics of the motor under the linear model were analyzed, based on which control mode of the motor was summarized.Secondly, based on the drive requirements of grinding machines, electromagnetic design for high-speed two-phase switched reluctance motor was performed. And an finite element simulation model for two-phase switched reluctance motor was established, where the impact of the size and angle of the stepped air gap,the winding turns of each phase on self-starting capability, torque ripple and other properties was studied, the motor electromagnetic optimization design was given, and the dynamic performance of the motor was researched by the dynamic finite element simulation.Again, based on the aforementioned established switched reluctance motor simulation model, control system of high-speed two-phase switched reluctance motor for grinding machine drive was studied by analyzing the output characteristics and the control strategy of the motor and applying STM8S003 MCU as the master chip and asymmetrical half-bridge circuit as a driving circuit.Finally, based on the foregoing findings, a high-speed two-phase switched reluctance motor and its drive control system were trial-produced. And laboratory tests and grinding drive tests of the prototype were performed, whose results showed that developed high-speed two-phase switched reluctance motor system has good performance and can replace the original series motor driving the grinding machine tool.