Patent ID: 8525489

Claim:
A system for directly and instantaneously controlling an exciter of a generator, the system comprising: a voltage error calculator calculating a voltage error of output voltage of the generator which is regulated by an instruction voltage and a time constant, the voltage error calculator including; a voltage detector detecting the output voltage of the generator; an output voltage regulator differentiating the output voltage with respect to a predetermined time constant to regulate the output voltage; and a summer calculating the voltage error between the instruction voltage and a regulated output voltage output from the output voltage regulator; a switching signal generator generating switching signals in response to the voltage error, wherein the switching signals have different states in response to a band of the voltage error, a switching state controller which controls a state of each switching signal to be continuously turned off or on, the switching state controller including an over-excitation limiter and an under-excitation limiter to restrict over-excitation and under-excitation of the generator; and an exciter controller controlling the exciter in response to the switching signals.