An experimental study on composite control of switched reluctance motors

It is shown how to supply two-time-scale nonlinear control design techniques to switched reluctance motors. A nonlinear dynamic model is developed and decomposed into separate slow and fast subsystems. A feedback control is designed so that, whenever the fast subsystem is at equilibrium, the dynamics of the slow subsystem are input-output equivalent to a second-order transfer function. The use of reduced-order feedback linearization methods leads to improved performance by reducing torque ripple. Experimental results from a laboratory implementation of a position control system are presented. On the basis of measured overshoot, risetime, and settling time, the prototype response is consistent with the desired linear response to within 23% error on average. The transient behavior of the motor can thus be adjusted over a wide range, and in a reasonably predictable fashion, by simply varying the gains of the outermost loop.>