Title:
PROTECTIVE DEVICE FOR SYSTEM INTERCONNECTION
Document Type and Number:
Japanese Patent JP2640628
Kind Code:
B2
Abstract:
PURPOSE: To detect the single operation of a generator upon occurrence of a fault in a nonutility power generation facility by shifting the frequency of a generator to a level detectable through a protective relay according to the functional characteristics of a function generator at the time of power interruption on the system side thereby detecting the power interruption.
CONSTITUTION: The protective device comprises a frequency detector 30a for a governor 14a in a nonutility power generation facility 1a, a function generator 31a for generating a frequency command, and a relay 28a for increasing the frequency when a reverse power flow is present. The frequency detector 30a detects a generator frequency from a terminal voltage of generator while the function generator 31a generates a special function for a frequency detected by the frequency detector 30a and the governor 14a uses the output from the function generator 31a. Even if the frequency increases slightly above a rated frequency, the frequency variation is increased and shifted through the function thus generated. Since even a micro variation of frequency is shifted to a level detectable through the frequency increase relay, the circuit breaker at a power receiving point can be opened quickly.
Inventors:
ITO HITOSHI
KATO TOYOKUNI
KATO TOYOKUNI
Application Number:
JP22320794A
Publication Date:
August 13, 1997
Filing Date:
September 19, 1994
Export Citation:
Assignee:
NISHISHIBA DENKI KK
International Classes:
H02J3/38; H02H3/46; H02H3/48; (IPC1-7): H02H3/46; H02H3/48; H02J3/38
Domestic Patent References:
| JP779533A | ||||
| JP7131931A | ||||
| JP731197A |
Attorney, Agent or Firm:
Inomata Shoaki