Published in IET Electric Power Applications Received on 5th November 2009 Revised on 26th March 2010 doi: 10.1049/iet-epa.2009.0260 ISSN 1751-8660 Establishment and control of a three-phase switched reluctance motor drive using intelligent power modules H.C. Chang 1 C.H. Chen 1 Y.H. Chiang 2 W.Y. Sean 2 C.M. Liaw 1 1 Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan 2 Mechanical and Systems Research Laboratory, Industrial Technology Research Institute, Hsinchu,Taiwan E-mail: cmliaw@ee.nthu.edu.tw Abstract: This study presents the establishment and control of a digital signal processor-based 5 kW/6000 rpm three-phase switched reluctance motor (SRM) drive. Two three-phase intelligent power modules are employed to construct its converter for achieving a compact power circuit. The motor winding inductance profile is first estimated, and it is used for performing the proper winding current switching control. In the developed ramp- comparison current control PWM scheme, in addition to the adequate feedback control, the current tracking error-adapted commutation instant tuning is made to yield improved current response and torque generating capability. As to the speed control, a feedback controller is augmented with a simple linear model following controller for yielding satisfactory speed tracking and regulation dynamic responses within a wide operation range. The driving performance of an established SRM drive is evaluated experimentally. 1 Introduction Among the existing typical motors, switched reluctance motor (SRM) [1, 2] drive possesses potential application capability owing to its inherent merits in the motor structure and converter circuit. From the aspects of self-starting torque ability, developed torque, ripple torque and energy conversion efficiency, choosing motor parameters other than four-phase 8/6, three-phase 12/8 and three-phase 6/4 is rare [3, 4]. Moreover, taking into account the number of converter power devices and the motor driving performance, the SRM with three-phase 12/8 is a good choice. The converter circuit with proper switching control is the next key issue for achieving better driving performance of an SRM drive. The typical converters and their operations have been explored in [1, 2, 5, 6], wherein, the asymmetric bridge converter with 2N (N ¼ phase number) switches is most commonly used owing to its flexible switching control capability. Unlike the three-phase AC motors, it lacks off-the-shelf power modules for compactly constructing the converter for an SRM drive. Until recently, the IPM FCAS20DN-60BB [7] for SRM has been provided by Fairchild Company. Alternatively, there were some researches [7–9] being conducted for implementing the converter using a three- phase six-switch IPM. In this paper, two three-phase IPMs are arranged to form the asymmetric bridge SRM converter. Owing to the non-linear winding inductance profile and the effect of back electromotive force (EMF), suitable control is indispensable for yielding satisfactory driving performance of an SRM drive. In winding current control, the commonly used approaches include ramp-comparison [1, 2, 10, 11] PWM, hysteresis PWM [1, 2, 12] and peak current PWM [13] controls. The ramp-comparison current-controlled PWM (RC-CCPWM) scheme is adopted in the developed SRM drive. As for the speed control, some existing control methods can be referred to [1, 2, 14–16]. In [16], a robust two-degree-of-freedom speed controller was presented for yielding good speed command tracking and load regulation responses. 772 IET Electr. Power Appl., 2010, Vol. 4, Iss. 9, pp. 772–782 & The Institution of Engineering and Technology 2010 doi: 10.1049/iet-epa.2009.0260 www.ietdl.org