The switched reluctance motor (SRM) has attracted world-wide interest as a new industrial drive. The attractive features of this machine are its compactness and simplicity. Efficiency is an important factor when handling power in the drive system of such motor. There fore, the aim of the closed loop control strategy presented by this paper is to drive the switched reluctance motor at optimum efficiency. This can be achieved by a proper choice of the best combination of control variables which ensure highest efficiency over a wide-range of speed and torque.
The decision about the best combination is based on the analysis of results obtained by a modeling computer program. This program is written to simulate the 3-phase, 1.1 kW, 800 R.P.M. prototype model already built in El-Mansoura Electrical Machine Laboratory [1]. It calculates the motor performance average torque, efficiency and the instantaneous phase current over a wide-range of speed. The carried out analysis gave the best combination of control variables and a simple relationship between them. They had been limited to be the switch-on angle (θon) and the conduction-angle (θc)
The integrated drive system, including the relevant controllers, has been built and tested. Microcomputer steering of the command signals with speed and rotor position feedback is applied. The deduced relationship between θon and θc is implemented in the control loop, simulating the basic feature of the proposed control strategy.
The comparison between the measured and calculated wave-forms of the instantaneous phase current shows a good concordance. In addition, steady operation is attained.