Model reference adaptive control of thyristor driven DC motor systems with resonant loading

Direct model reference output adaptive control procedures, which do not require the existence of model matching conditions, have been applied to the speed control of a thyristor driven DC motor system with resonant loading. Taking into account both current and current rate limitations, the adaptive algorithm was used to generate the set point for a dual mode thyristor current regulator which was also adjusted depending upon whether or not the thyristor circuit was in the continuous or discontinuous conduction mode. A mathematical representation of this system was then shown to be stable, and a systematic method was developed for selecting the adaptation weights. Tests with representative variations in inertia and torque load showed the adaptive algorithm to be more robust than a conventional PI speed control system.