The Research On Sensorless Control Of12/10Flux-Switching Permanent Magnet Motor

Flux-switching permanent magnet (FSPM) machines are novel brushless machines havingmagnets in the stator and currently are under intensive research due to their novel features, e.g. simpleand robust rotor similar to Switched Reluctance Motors (SRMs), flux focusing, sinusoidal phaseback-EMF, high torque/power density and high efficiency, thus favorable for cooling and high-speedoperation. For the control of FSPM machines, explicit sensors (e.g. encoder and resolvers) arecommonly used to fulfill the high performance control. However, in the meantime additional cost andvolume, noise problems and related reliability issues are caused. To solve these problems, the positionsensorless drive techniques of12/10FSPM machine have been studied in this paper.Firstly sensorless control of12/10FSPM machine with high-frequency sinusoidal signalinjection was carried out on the basis of salient pole verification. The theories and formulas of bothrotating and pulsating sinusoidal signal injection were analyzed, and then experiments were carriedout to verify the validity of analysis on12/10FSPM machine.Based on the analysis of traditional pulsating sinusoidal signal injection, high frequency squarewave and triangular wave signal were injected to achieve the zero speed and low speed sensorlesscontrol. Different position error signal processing methods had been analyzed; consequently the zerovelocity position tracking, magnetic pole direction identification and position estimation convergencewere analyzed as well. Then various designed experiments verified the validity and feasibility ofproposed methods on the12/10FSPM machine with high frequency square wave and triangular wavesignal injection.In addition, this paper also studied the sensorless direct torque control (DTC) of12/10FSPMmachine. Initially back-EMF sliding-mode observer rotor position estimation method was proposed,and then the estimated speed of motor was obtained through a PLL controller. Three kinds ofSVM-DTC/DTFC algorithms were studied, i.e. increment of torque angel based SVM control strategy,sliding mode observer based SVM control strategy and SVM direct flux and torque control algorithmrespectively. Their principles and the realization methods were analyzed in detail, eventually validityand feasibility of the proposed methods were verified by experiments.