Convergence test of model reference signal adaptive SRM drives

Abstract

Nowadays switched reluctance motor (SRM) drives have been widely used in the field of controlled electric motor drives. The paper proposes a model reference signal adaptive control method for SRM drives. The main goal of the drive control is to improve dynamical performance by compensating for the motor nonlinearities. The adaptation practically works only in a relatively narrow speed error track (adaptation range) which is equal to approximately 20-100 revolution/min absolute value of speed error. The drawback of this limitation is the relatively short time for the algorithm to operate. At the same time the convergence of the algorithm is extremely fast which significantly reduces the effect of this drawback. Two more important advantages emerge when adaptation works only with small speed errors. First of all the controller at changing drive parameters adapts to parameters around the value specified by speed reference signal which also assists to speed the adaptation. The other significant positive effect is the disappearing of the problem coming from nonlinear systems that the response of the system can even differ in its character when the value, amplitude of the reference signal is changed. The convergence test of this control method was performed in an experimental drive system. A SRM of 6/8 pole and 4 kW rated power was used. Simulation and experimental results are presented.