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Patent Searching and Data


Title:
PROTECTIVE RELAY DEVICE
Document Type and Number:
Japanese Patent JP2016152674
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a highly reliable protective relay device in which disconnection of a fuse for VT is never detected erroneously, even when a special fault of power system, such as step-out, occurs.SOLUTION: In a protective relay device, a first relay element 62 determines whether or not the phase voltage or the line-to-line voltage is insufficient for a first set voltage. A second relay element 64 determines presence and absence of short circuit fault or ground fault in a power system based on the phase current. A step-out detector 67 detects presence and absence of step-out based on the magnitude of a change in the effective value of phase voltage or line-to-line voltage, or the magnitude of a change in the effective value of phase current in a predetermined determination period. If the second relay element does not operate when the first relay element operates, or the step-out detector does not detect step-out, a determination unit 101 determines that a fuse provided on the secondary of a voltage transformer is broken.SELECTED DRAWING: Figure 11

Inventors:
ODA SHIGETO
Application Number:
JP2015028262A
Publication Date:
August 22, 2016
Filing Date:
February 17, 2015
Export Citation:
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Assignee:
MITSUBISHI ELECTRIC CORP
International Classes:
H02H7/00; G01R31/02; H01H83/02; H01H83/20
Domestic Patent References:
JPS61248330A1986-11-05
JPS61248331A1986-11-05
JPH02211021A1990-08-22
JP2010154620A2010-07-08
JPH09233680A1997-09-05
JPS61248330A1986-11-05
JPS61248331A1986-11-05
JPH02211021A1990-08-22
JP2010154620A2010-07-08
JPH09233680A1997-09-05
JPH07147725A1995-06-06
JPH07147725A1995-06-06
Attorney, Agent or Firm:
Fukami patent office