Digital protective relay apparatus
AssigneeKabushiki Kaisha Toshiba
InventorYasuchika Nishitani
Life of this patent
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Abstract
A digital protective relay apparatus comprising an analog input section, a correction value-calculating section, a storage section, a correction section, a protective calculation section. A correction value for correcting the error of the analog input section is predetermined and stored in the storage section. Digital data obtained through the analog input circuit is corrected by the correction section using the correction value. The protective calculation section performs predetermined calculation using the corrected digital data, thereby determining whether or not a trip instruction should be supplied to a breaker.
Claims12
A digital protective relay apparatus for outputting a trip instruction to a breaker provided in a power system for protecting the same when a fault occurs therein, comprising:
- an analog input section for sampling an analog amount of electricity in the power system to subject the sampled electricity to predetermined processing;
- A/D converter means for receiving the analog amount of electricity output from the analog input section to convert the same to digital data;
- correction value-calculating means for receiving the digital data from the A/D converter means to calculate a correction value for correcting an error contained in the digital data when the digital data passes through the analog input section and the A/D converter means;
- storage means for storing the correction value obtained by the correction value-calculating means;
- correction means for correcting the digital data output from the A/D converter means by the use of the correction value stored in the storage means;
- and
- protective calculating means for receiving the corrected digital data, and operating predetermined calculation using the received data, and outputting the trip instruction to the breaker when a calculation result indicates that the fault occurs in the power system.
Dependencies are inferred from the claim text.