Title:
MIXING DETECTION METHOD FOR DIFFERENT FREQUENCY SYSTEM
Document Type and Number:
Japanese Patent JP3329062
Kind Code:
B2
Abstract:
PURPOSE: To make easier the discrimination of accident contents by detecting a mixing accident in a different frequency system in a section where 50Hz electric region and 60Hz electric region are mixed together.
CONSTITUTION: A current detected by a current transformer CT1 is input to first and second mixing current discriminating portions DEC1 and DEC2. The first mixing current discriminating portion DEC1 sends out an output when the relation between the input frequency during mixing and a current If after mixing satisfies If ≥53Hz. Also, the second mixing current discriminating portion DEC2 sends out an output when the relation between the input frequency during mixing and a current If after mixing satisfies If ≤57Hz. Outputs from the first and second mixing current discriminating portions DEC1 and DEC2 are given to an AND circuit AND. The AND circuit AND operates when If is higher than 53Hz and lower than 57Hz and the output is sent out. This output, that is, if mixing is judged, then the operation is successively performed by an extended feeder from either one of them (50Hz or 60Hz).
Inventors:
Masaharu Emoto
Hideo Watanabe
Hideo Watanabe
Application Number:
JP8081094A
Publication Date:
September 30, 2002
Filing Date:
April 20, 1994
Export Citation:
Assignee:
KABUSHIKI KAISHA MEIDENSHA
International Classes:
H02H3/46; B60M3/04; (IPC1-7): H02H3/46; B60M3/04
Domestic Patent References:
| JP1269068A | ||||
| JP7170608A | ||||
| JP7212960A | ||||
| JP6393640A | ||||
| JP6331837A |
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)