Abstract: A generator transfer function regulator incorporating two control loops. The first control loop produces a first generator excitation control signal (U) which varies to compensate for variations in the magnitude of the generator output voltage (V.sub.1) . The second generator loop produces a second generator excitation control signal (U.sub.e) which varies so as to maintain substantially constant the response of the generator system to variations in the generator output. The two control signals are combined and applied to a conventional generator exciter circuit (2). As a result, the generator terminal voltage (V.sub.1) control performance achieved by the AVR under open circuit conditions is effectively maintained when the generator is loaded over its range of operation, irrespective of the power system which the generator feeds.