Protection of a generator without measuring temperature
First Claim
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1. A method for providing protection to a generator, comprising:
- determining a reference out of rated capability of the generator;
determining, based on the reference, and generator field current and output conditions of the generator, a drop in generator performance without measuring a temperature of the generator;
modifying operation of the generator to a generator output limit mode, accounting for the determined drop in generator performance,wherein the step of determining a drop in generator performance comprises a comparison based on the reference, the generator field current, and the output conditions of the generator, and wherein the drop in generator performance is determined based on the comparison;
measuring a generator output current of the generator to monitor the output condition of the generator; and
determining a generator speed of the generator,wherein the determining a reference out of rated capability of the generator includes determining a magnitude of the generator output current as a function of the generator speed and the generator field current and setting the reference to the determined magnitude of the generator output current; and
wherein the determining a generator speed of the generator includes monitoring an engine speed of an engine drivingly coupled to the generator and multiplying the monitored engine speed by a speed ratio between the engine and the generator.
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Abstract
A method and an apparatus for providing protection to a generator are disclosed. A reference is determined out of rated capability of the generator. Based on the reference, and field current and output conditions of the generator, there is determined a drop in generator performance due to a temperature condition of the generator. Accounting for the drop in generator performance, operation of the generator may be modified to a generator output limit mode.
16 Citations
15 Claims
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1. A method for providing protection to a generator, comprising:
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determining a reference out of rated capability of the generator; determining, based on the reference, and generator field current and output conditions of the generator, a drop in generator performance without measuring a temperature of the generator; modifying operation of the generator to a generator output limit mode, accounting for the determined drop in generator performance, wherein the step of determining a drop in generator performance comprises a comparison based on the reference, the generator field current, and the output conditions of the generator, and wherein the drop in generator performance is determined based on the comparison; measuring a generator output current of the generator to monitor the output condition of the generator; and determining a generator speed of the generator, wherein the determining a reference out of rated capability of the generator includes determining a magnitude of the generator output current as a function of the generator speed and the generator field current and setting the reference to the determined magnitude of the generator output current; and wherein the determining a generator speed of the generator includes monitoring an engine speed of an engine drivingly coupled to the generator and multiplying the monitored engine speed by a speed ratio between the engine and the generator. - View Dependent Claims (2, 3, 4)
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5. A method for providing protection to a generator, comprising:
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determining a reference out of rated capability of the generator; determining, based on the reference, and generator field current and output conditions of the generator, a drop in generator performance without measuring a temperature of the generator; modifying operation of the generator to a generator output limit mode, accounting for the determined drop in generator performance, wherein the step of determining a drop in generator performance comprises a comparison based on the reference, the generator field current, and the output conditions of the generator, and wherein the drop in generator performance is determined based on the comparison; measuring a generator output voltage to monitor the output condition of the generator; and monitoring duty ratio of a transistor of a field current circuit provided for regulating field current in the generator, wherein the determining a reference out of rated capability of the generator includes determining the magnitude of the generator field current as a function of the generator output voltage and the monitored duty ratio and setting the reference to the determined magnitude of the generator field current. - View Dependent Claims (6, 7)
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8. An apparatus for providing protection to a generator, comprising:
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means for determining a reference out of rated capability of the generator; means for determining, based on the reference, and generator field current and output conditions of the generator, a drop in generator performance without measuring a temperature of the generator; means for modifying operation of the generator to a generator output limit mode, accounting for the determined drop in generator performance, wherein the means for determining a drop in generator performance comprises means for performing a comparison based on the reference, the generator field current, and the output conditions of the generator, wherein the drop in generator performance is determined based on the comparison; wherein the output condition of the generator is monitored by a measure of a generator output current of the generator; and wherein the apparatus is operable with a generator drivingly coupled with an internal combustion engine; and further comprising means for receiving an engine speed of the engine and means for multiplying the engine speed by a speed ratio between the engine and the generator. - View Dependent Claims (9, 10)
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11. An apparatus for providing protection to a generator without measuring a temperature of the generator, comprising:
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a reference determining block having as inputs, a generator speed of the generator and a generator field current thereof, and determining out of rated capability of the generator, a reference in terms of the magnitude of generator output current; and a generator performance drop monitoring block receiving the determined reference and a measure of generator output current, calculating one of a difference and a ratio between the determined reference and the measure, comparing the calculated one of the difference and the ratio to a predetermined value, and outputting a drop in generator performance without measuring a temperature of the generator when the comparing result indicates that the calculated one of the difference and the ratio is less than the predetermined value. - View Dependent Claims (12, 13, 14, 15)
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Specification