AN IMPROVEMENT IN OR RELATING TO SYNCHRONOUS MOTOR FIELD REGULATOR CONTROL

摘要

A synchronous motor field regulator system which regulates for a specific power factor within a predetermined line voltage band, providing that a minimum excitation requirement for the load on the synchronous motor is met, and incorporating means for varying the saturation level of a line voltage controller in the regulator as a function of the average synchronous motor field current whereby the synchronous motor average field current on a duty cycle basis will not exceed its rated value. This prevents the line voltage controller in a synchronous motor field regulator from calling for an average synchronous field current greater than the rated synchronous motor field current and protects the synchronous motor and its field exciter against a thermal overload condition when the synchronous motor voltage has dipped for a long period of time and the line voltage regulator is trying to maintain nominal line voltage.