Title:
AC OVERVOLTAGE PROTECTIVE RELAY
Document Type and Number:
Japanese Patent JP3454978
Kind Code:
B2
Abstract:
PURPOSE: To gain the most approximate value of the withstanding strength of a lighting arrester and thereby protect the device by making the precise measurement of energy of the arrester.
CONSTITUTION: In an AC overvoltage protective relay that protects an arrester installed in a power system, the following means are installed; a means S1 for inputting a terminal voltage and an energizing current of the arrester, a means S2 for detecting a peak value of the terminal voltage for a specified period of time, a means S3 for calculating an integral value of the energizing current, a means S4 for calculating the absorbed energy of the arrester from the peak value of the terminal voltage and the integral value of the energizing current, a means S5 for determining whether the absorbed energy of the arrester exceeds a specified set value, and output means S6, S7 for making the output based on the result from the means S5.
Inventors:
Takafumi Maeda
Hiroshi Yamakawa
Yutaka Takiguchi
Masashi Usui
Hiroshi Saito
Rikio Sato
Yasuhiro Kurosawa
Mitsuru Yamaura
Hiroshi Yamakawa
Yutaka Takiguchi
Masashi Usui
Hiroshi Saito
Rikio Sato
Yasuhiro Kurosawa
Mitsuru Yamaura
Application Number:
JP18814195A
Publication Date:
October 06, 2003
Filing Date:
June 30, 1995
Export Citation:
Assignee:
東京電力株式会社
株式会社日立製作所
三菱電機株式会社
株式会社東芝
株式会社日立製作所
三菱電機株式会社
株式会社東芝
International Classes:
H01C7/12; H02H3/22; H02H7/24; H02H9/04; (IPC1-7): H02H3/22; H01C7/12; H02H7/24; H02H9/04
Domestic Patent References:
| JP4370687A | ||||
| JP65407A | ||||
| JP5111147A |
Attorney, Agent or Firm:
Norio Ishii
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