Research On The Control Of Doubly Salient Permanent Magnet Motor

A new type of doubly salient permanent magnet motor (DSPMM) is explored in this dissertation to find whether it is suitable for commercial applications. DSPMM features a simple structure due to the doubly salient structure with stationary permanent magnets, which is amenable to automated manufacture. The basic principle of the DSPMMs is presented from the point of view of control. Among these, the back electromotive force (BEMF) is emphasized. However, a set of sufficient conditions for no cogging torque, somewhat associated with motor design, is obtained. Research is based on a prototype DSPMM that is employed in electric bicycle. As a result of the similarity of control characteristics between the DSPMM and brushless dc motor (BLDCM), the prototype is driven in 120-degrees-conducting scheme. On account of the imprecision of the mechanical position sensor and the phase-shift problem of an existing sensorless method, a novel sensorless strategy is proposed. The accuracy of this new method is well demonstrated by simulation. Furthermore, although primitively, the feasibility is proven by a driver based on an MCU's system.