Adaptive and robust cascade schemes for thyristor driven DC-motor speed control

Abstract

This paper is concerned with the development of improved cascaded speed control systems for thyristor driven DC-motors. The main features of the work can be summarized in the following four points: (1) Development of a digital dual-mode adaptive controller for the inner current control loop and of a model reference adaptive controller for the outer speed control loop, thus making the entire system adaptive. (2) Development of robust controllers both for the inner current loop and also for the outer speed loop, thus making the entire system robust. (3) Implementation of the above control strategies, adaptive and robust, in a 16-bit single board computer with floating-point coprocessor. (4) Comparison of the results of both robust and adaptive improved cascaded schemes with a commercially available controller. The obtained results showed that the model reference adaptive control concept and the robust control strategy can be applied with success for the speed control of a DC-motor.