Abstract
Owing to its many remarkable advantages, the interior permanent magnet synchronous motor (IPMSM) is usually utilized as the actuator in many application fields. To further promote its application capability, some key technologies are developed in this thesis to improve the performance of a sensorless IPMSM drive. In order to profoundly understand the torque generating characteristics of an IPMSM, its structure and governing equations are studied first. The equivalent circuit parameters of a motor are necessary for performing its switching driving control. However, for an IPMSM they are not easy to obtain accurately via derivation owing to their nonlinear and variant properties. To solve this problem, the estimation approach is applied to find them alternatively. For performing the experimental tests, a standard DSP-based IPMSM drive is established. The DSP-based control environment possesses the capability of realizing all control schemes using digital control.As to the sensorless control for an IPMSM, the control approach based on the sensed winding terminal voltage is proposed for avoiding the undesired noise effects caused by the time derivative in making the back electromotive force (back-EMF) estimation, and the effects of phase difference between terminal voltage and back-EMF and the driving performance improvement of the IPMSM drive will be covered by the proposed commutation tuning control. A bumpless starting technique is devised in this thesis to let the motor start from the synchronous motor mode and smoothly switch to IPMSM sensorless running mode. In the tuning control for IPMSM drive, the equivalent performance of field excitation and commutation instant tuning is observed analytically and experimentally. Then accordingly, an intelligent tuning approach is developed to automatically determine the advancing angle of commutation instant. The minimum current command is achieved to obtain better torque generating capability equivalently. In dynamic control improvement, for improving the dynamic performance of the IPMSM drive, a simple robust current controller is developed to improve the winding current tracking control response. Incorporating with the commutation instant tuning, the winding current tracking performance under higher speeds can be further improved. Validity and effectiveness of the control approaches developed in this thesis are manifested and demonstrated experimentally.