A Thyristor Replacement for Rheostatic Voltage Regulator

Thyristor circuits have been satisfactorily applied as voltage regulating systems using d-c pilot and main exciters on large hydroelectric generators. Duty cycle modulation of thyristor switching circuits using capacitance commutation replaces rheostatic regulator control. Fail safe design withcommutation failure detection provides high reliability. Included are convenient remote voltage adjustment without intervening motors or switches, supplementary control and rapid voltage reduction for internal generator faults. Functional diagrams and descriptions are given which indicate circuit design and performance.