Title:
DIGITAL PROTECTION RELAY
Document Type and Number:
WIPO Patent Application WO/2015/189996
Kind Code:
A1
Abstract:
A digital protection relay (10) comprises: an input transformation unit functioning as an analog input circuit and receiving a signal indicating the electrical quantity of a power system as an analog signal; and an analog/digital conversion unit (15) for converting an analog signal to a digital signal. The digital protection relay (10) uses a calculation control unit (16) to execute a protection calculation on the basis of the digital signal converted by the analog/digital conversion unit (15). The calculation control unit (16) functions as: a protection calculation unit (61) for executing the protection calculation using an offset voltage value (74); an input data acquiring unit (62) for sequentially acquiring input data (71) according to a sampling timing, said input data (71) being converted to the digital signal by the analog/digital conversion unit (15); and an offset value calculation unit (65) for calculating an offset voltage value on the basis of sampled values within a period in which, based on the difference amount between sampled values, the polarities of the difference amount in the input data in at least one cycle change.
Inventors:
ODA SHIGETOO (JP)
Application Number:
PCT/JP2014/065781
Publication Date:
December 17, 2015
Filing Date:
June 13, 2014
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP (JP)
International Classes:
H02H3/02; G01R19/00; H02H3/05
Foreign References:
| JPH01198213A | 1989-08-09 | |||
| JPH09147373A | 1997-06-06 | |||
| JP2005208028A | 2005-08-04 |
Attorney, Agent or Firm:
Fukami Patent Office, p. c. (JP)
Patent business corporation Fukami patent firm (JP)
Patent business corporation Fukami patent firm (JP)
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