Title:
PROTECTION RELAY
Document Type and Number:
WIPO Patent Application WO/2019/207673
Kind Code:
A1
Abstract:
A protection relay, wherein a digital processing unit (80) performs relay computation on the basis of time-series data representing the current or voltage of a power system. The digital processing unit (80) is provided with: a first filter (81), which removes DC components in the time-series data and which has a first window length; and a second filter (82), which removes DC components in the time-series data and which has a second window length, the second window length being less than the first window length. The digital processing unit (80) is further provided with a coefficient calculation unit (90) in which the amplitude value of an output signal from the first filter (81) and the amplitude value of an output signal from the second filter (82) are respectively multiplied by a first and a second coefficient (k1, k2) and combined. An operation determining unit (95) performs an operation determination on the basis of the output of the coefficient calculation unit (90). When a defect of the power system is detected, the first coefficient (k1) decreases, the second coefficient (k2) increases, and then the first coefficient (k1) and the second coefficient (k2) vary with the passage of time.
Inventors:
MURATA KAZUMA (JP)
ODA SHIGETOO (JP)
ODA SHIGETOO (JP)
Application Number:
PCT/JP2018/016757
Publication Date:
October 31, 2019
Filing Date:
April 25, 2018
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP (JP)
International Classes:
H02H3/08
Foreign References:
| JP2011250518A | 2011-12-08 | |||
| JPS60204219A | 1985-10-15 | |||
| JP2004048855A | 2004-02-12 | |||
| JP2007014052A | 2007-01-18 |
Attorney, Agent or Firm:
FUKAMI PATENT OFFICE, P.C. (JP)
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