System and method for directly and instantaneously controlling exciter of generator
AssigneeKyungsung University Industry Cooperation Foundation
InventorsJinwoo Ahn, Donghee Lee
Life of this patent
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Abstract
A system for directly and instantaneously controlling the exciter of a generator. A voltage error calculator calculates a voltage error of output voltage of the generator which is regulated by an instruction voltage and a time constant. A switching signal generator generates switching signals in response to the voltage error. An exciter controller controls the exciter in response to the switching signals. Thus, the system can induce the maximum response characteristic of a power converter only by setting the time constant of a controller without a complicated design for determining gains of the controller. Further, the system can considerably inhibit overshoot from occurring in a transient response state.
Claims6
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.
A method for directly and instantaneously controlling an exciter of a generator, the method comprising the steps of:
- calculating a voltage error of output voltage of the generator which is regulated by an instruction voltage and a time constant;
- generating different switching signals in response to a band of the voltage error;
- controlling one of the exciter and the generator in response to the switching signals;
- and
- restricting over-excitation and under-excitation of the generator by controlling a state of each switching signal,
- wherein the switching signals are output as two state signals by a chopper type inverter based on an insulated gate bipolar transistor that can be continuously switched;
- and
- the two state signals include a first state signal by which the insulated gate bipolar transistor is turned on to apply field voltage, and a second state signal by which the insulated gate bipolar transistor is turned off to enter free wheeling.
Dependencies are inferred from the claim text.