Abstract
This thesis is mainly concerned with the development of a DSP-based position sensorless permanent-magnet synchronous motor (PMSM) drive with single-phase switch-mode rectifier (SMR) front-end. First, a standard SMR-fed PMSM drive is established with the control schemes being designed to yield satisfactory motor driving performance and AC line drawn power quality. The control algorithms of two power stages are realized in a common digital signal processor (DSP). Then the key issues affecting the operation characteristics of PMSM drive are explored and evaluated experimentally, these include commutation shift, field excitation and DC-link voltage boosting, etc. Particularly, the static and dynamic field-weakening control approaches are proposed to enhance the PMSM performance under higher speed. Next, the possible origins of torque ripple and vibration of PMSMs are explored, and some existing remedies in their reductions are understood. Then the experimental observation of vibration characteristics for the established PMSM drive is made. And the random pulse width modulation (PWM) is applied to randomize the winding current harmonic spectrum distribution, and thus to effectively achieve its vibration reduction. Finally, having reviewed some commonly used existing position sensorless control methods of PMSM drive, a sensorless control scheme based on high-frequency signal injection is developed. It possesses the following features: (i) unidirectional starting is achieved based on magnetic anisotropy via narrow voltage pulse excitation; (ii) rotor absolute position is estimated to yield good low-speed driving performance; and (iii) a simple robust control is employed to enhance the dynamic response of rotor position estimation.