Dynamic performance of synchronous machines in control systems

Synchronous motors appear to offer a number of advantages over induction motors when used on variable-frequency supplies for the final drive of a high-power servo. The paper examines two aspects of such drives relevant to synchronous motors when so used; limiting acceleration and frequency-response characteristics, and their dependence on certain pertinent variables such as field excitation and amplitude of excursion. Analytical and semianalytical methods, backed by experimental results, are given to predict the dynamic behaviour of synchronous motors.