International Journal of Engineering & Computer Science IJECS-IJENS Vol:12 No:04 89 1217404-5858-IJECS-IJENS © August 2012 IJENS I J E N S Abstract— Nowadays, switched reluctance motors (SRMs) attract more and more attention. Switched reluctance machines have emerged as an important technology in industrial automation. They represent a real alternative to conventional variable speed drives in many applications. It not only features a salient pole stator with concentrated coils, which allows earlier winding and shorter end turns than other types of motors, but also features a salient pole rotor, which has no conductors or magnets and is thus the simplest of all electric machine rotors. Simplicity makes the SRM inexpensive and reliable, and together with its high speed capacity and high torque to inertia ratio, makes it a superior choice in different applications. This research attempts to create a MATLAB model of multiphase SRM using the equations governing the dynamic behavior of linear inductance profile SRM. This simulation model can then be used see the impact of any control system on SRM behavior. Simulation results also prove the exactness of the model. Index Term— Switched reluctance motor, linearized inductance profile, multiphase SRM, matlab modeling. I. INTRODUCTION The switched reluctance motor (SRM) represents one of the oldest electric motor designs around. A variation of the conventional reluctance machine has been developed and is known as the “switched reluctance” (SR) machine. This development is partly due to recent demand for variable speed drives and partly as a result of development of power electronic drives. The name “switched reluctance”, describes the two features of the machine configuration: (a), switched, the machine must be operated in a continuous switching mode, which is the main reason for the machine development only after good power semiconductors became available; (b), reluctance, it is the true reluctance machine in the sense that both rotor and stator have variable reluctance magnetic circuits or more properly, it is a doubly salient machine. The switched reluctance motor is basically a stepper motor with fewer poles and has been used in many applications as both rotary and linear steppers. The idea of using the SR configuration in a continuous mode (in contrast to a stepper mode) with power semiconductor control is due primarily to [1]-[2], at that time, only thyristor power semi-conductors were available for the relatively high-current, high-voltage type of control needed for SR machines. The switched This work was supported by Islamic University of Technology (IUT), Gazipur, Bangladesh. All authors are currently working as faculty members of the EEE department of IUT. Corresponding author email: rezaul1206@gmail.com reluctance motor, which was originally conceived in the early 1800’s [3], recently has gained considerable attention. It has the advantages of being inexpensive and rugged. Its’ simple construction makes it easy to manufacture but rugged enough to be worthy of consideration for powering traction applications such as automobiles [4]. But, it also has its drawbacks. The switched reluctance motor is inherently subject to torque ripple and acoustic noise [5]. This necessitates a more complex means of control. Until recently, it was not considered a viable candidate for traction applications, but with improved methods of control it may be possible to design a method which would allow the use of the reluctance motor where smoother torque is required. Research into this application requires computer simulation and so a computer model is required. Many researchers worked on switched reluctance motor modeling and control. A general foundation for the basic modes of operation, analysis, design considerations and experimentation from a family of prototype motors can be found in [6]. Authors of [7] has presented a timely review of the different design methods, which have been adopted for the SRM up to 1988 and broadly classified the design methods into 1) linear method; 2) nonlinear method; and 3) finite element method. A superior approach was suggested in [8] which depended on linearizing the inductance that allowed the voltage to be switched at any point in the cycle and enabled control strategies to be examined with sufficient accuracy. An evaluation of the capabilities of the switched reluctance motor drive, particularly in small integral-horsepower sizes, has been presented and was compared with those of typical induction motor drives [9]. Design and development of a single phase 2/2 switched reluctance motor as a cost-effective alternative to multiphase SRM in fan applications is presented in [10]. The finite element method has been used as a suitable technique for electrical design, performance evaluation and device optimization of switched reluctance machine in low frequency applications [11]. A finite element model was successfully used for 2-D magnetic field analysis of SRM to predict the steady state motor performance accurately in [12]. This work presents a simulation model of a multiphase switched reluctance motor created in MATLAB environment. In section II the detail mathematical model of the SRM is presented. Different steps taken to simulate the dynamic model of the SRM is presented in section III. Section IV presents the simulation results for the steady and dynamic behavior of the model. Finally, section V gives the concluding remarks. Detail of the MATLAB coding is included in the appendix. A Comprehensive Model of SRM in MATLAB Environment Md. Rezaul Hasan, Md. Ashraful Hoque and Ashik Ahmed