Abstract
Permanent magnet synchronous motor (PMSM) possesses the advantages of high power density, high efficiency and excellent acceleration ability, etc, and it has been extensively applied in many applications. The purpose of this thesis is to establish a fully digitally DSP-based PMSM drive with variable-voltage DC link and perform its driving performance improvement studies. In order to familiarize with the driving characteristics of a PMSM, its structure and governing equations are first studied. It is known that the motor circuit parameters are necessary for making the analysis and design of an inverter-fed motor drive. This thesis employs a practical estimation approach to obtain the parameters of the studied PMSM. For performing the experimental tests, a DSP ADMC401-based PMSM drive is established. By properly establishing the necessary sensors, signal conditioners and control schemes, it can be operated to have performances being comparable to those of a DC motor. As generally recognized, the dynamic performance of a motor is much affected by its winding current waveforms. In the thesis, both the current-controlled PWM (CCPWM) in abc- and dq-domains are designed and implemented, and their control performances are comparatively evaluated. A robust current controller is developed to let the winding current tracking control response be rather insensitive to the changes of motor parameters and back EMF disturbance. Next, for obtaining well-regulated and variable DC-link voltage with better power quality in line drawn current, a LF-SMR is developed and applied to the established PMSM drive. As far as the tuning control for PMSM drive is concerned, the effects of field excitation and commutation instant tunings on the PMSM drive performances are first observed experimentally. Then, an intelligent tuning approach is developed to automatically determine the advance of commutation instant. The minimum current command is achieved to obtain better torque generating capability equivalently. Effectiveness of all the control schemes developed in this thesis is validated experimentally.