The Transient Response of a Thyristor-Controlled Series Motor

In this paper the series motor is looked upon as a servomotor and a simple efficient method of predicting its transient behavior is presented. The motor is assumed to be controlled by means of thyristors. A closed-loop block diagram depicting the transient behavior of the series motor is evolved using perturbation techniques. The transient response for small sudden variations of load torque or of firing angle is deduced. The results are coimpared with those obtained from a computer by numerically solving the nonlinear differential equations of the series motor. It is shown that the block diagram approach gives good results and is much simpler than the numerical method.