Title:
保護リレー装置
Document Type and Number:
Japanese Patent JP6385291
Kind Code:
B2
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:
Eiichiro Oda
Application Number:
JP2015028262A
Publication Date:
September 05, 2018
Filing Date:
February 17, 2015
Export Citation:
Assignee:
Mitsubishi Electric Corporation
International Classes:
H02H7/00; G01R31/02; H01H83/02; H01H83/20
Domestic Patent References:
| JP61248330A | ||||
| JP61248331A | ||||
| JP2211021A | ||||
| JP2010154620A | ||||
| JP9233680A | ||||
| JP7147725A |
Attorney, Agent or Firm:
Fukami patent office