A new approach to model switched reluctance motor drive application to dynamic performance prediction, control and design

In this paper a new model for the switched reluctance motor (SRM) based on phase currents as state variables is presented. Position dependency of the phase inductance is represented by a limited number of Fourier series terms and the nonlinear variation of the inductance with phase current is expressed by means of polynomial functions. The coefficients of the terms in the Fourier series are determined by the aligned position inductance, the unaligned position inductance and the inductance at the midway point from the aligned position. The main advantage of the proposed model is that it requires minimum amount of measurements and predicts the complete dynamic performance of the drive system, viz., constant torque, constant power and natural mode regions. Any type of control strategy can be incorporated in the simulation. A low-voltage, high current SRM drive has been simulated and the results are validated by comparing with finite element and experimental results.