PERFORMANCE EVALUATION OF SENSORLESS CONTROL OF SRM DRIVE

Abstract

The switched reluctance motor (SRM) drive is receiving increasing attention from various researches as well as industry as a variable candidate for adjustable speed and servo applications. The switched reluctance motor simple in construction At not only feature salient pole stator with concentrated coils, but also feature salient pole rotor, which has no conductors or magnets and is thus the simplest of all electric machine rotors. Combining the unique features of an SRM with simple and efficient power converter that it uses, a superior motor drive system emerges which may be preferable for many applications compared to other ac or do motor drives. A new sensorless control scheme for the switched reluctance motor (SRM) drive at low speed is presented in this thesis. The incremental inductance of each active phase is estimated using the terminal measurement of this phase. The estimated phase incremental inductance is compared to an analytical model, which represents the functional relationships between the phase incremental inductance, phase current, and rotor position, to estimate the rotor position. The presented sensorless control scheme requires neither extra hardware nor huge memory space for implementation. It can provide accurate rotor position information even as the magnetic characteristics of the SRM change due to aging. Combined with other inductance model-based sensorless control techniques, the proposed method can be used to develop an inductance model-based sensorless control scheme to run the SRM from standstill to high-speed. Simulation results are presented to verify the proposed scheme