Abstract
This thesis is mainly concerned with the development of a standard and a position sensorless switched-reluctance motor (SRM) drives equipped with two kinds of power factor corrected (PFC) AC/DC front-end converters. First, for comprehending the basics and key issues of SRM, a standard SRM drive with asymmetric bridge converter is established. Good driving characteristics obtained via properly designing its schematic and control scheme are confirmed experimentally. Next, a SRM position sensorless control scheme based on narrow pulse voltage injection is proposed. The voltage pulses with suited frequency and duration are injected into the unexcited phase winding via the embedded DSP PWM channel. An observed Hall signal is yielded from the sensed current and used for making the commutation operation of SRM drive. Then the adaptive and intuitive tunings for the commutation instant are performed to achieve the equivalent maximum torque per ampere (TPA) characteristics. The established position sensorless controlled SRM drive possesses good driving performance comparable to those of standard one in acceleration/deceleration, dynamic response, reversible and regenerative braking operating characteristics. Next, a three-phase six-switch four-quadrant boost SMR is developed and used as the front-end of the SRM drive. The DC-link voltage of the SRM drive is adjustable and well regulated for effectively enhancing the SRM driving performance under higher speeds. Moreover, the recovery of regenerative braking energy back to the mains is achievable. Furthermore, a new PFC front-end consisting of a diode rectifier and an anti-paralleled active power filter (APF) is proposed. It allows the use of IGBT module with lower rating to achieve the regenerative braking and PFC functions. However, the DC-link voltage boosting and regulating abilities are sacrificed. Finally, the SRM drive powered from the three-phase six-switch SMR and the proposed APF based PFC front-end are comparatively evaluated their performances.