US 5,666,060 AGranted

Test method and apparatus for testing a protective relay system

AssigneeKabushiki Kaisha Toshiba

InventorsYukio Sukegawa, Tetsuo Matsushima

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Abstract

A relay test apparatus for testing a protective relay operation of a protective relay system comprises GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal, simulation signal generators, respectively connected to the protective relays, each simulation signal generator generating a simulation signal and inputting the simulation signal to a corresponding protective relay, and synchronous starting units, respectively provided in the protective relays, each synchronous starting unit starting a corresponding simulation signal generator to generate the simulation signal, when time signals output from the GPS receivers coincide with a preset time at a same time.

Claims5

Dependent claims

A method for measuring a transmission delay time in a transmission system for transmitting a signal between protective relays respectively connected to electric-supply stations includes first and second electric-supply station connected through electric transmission lines, the method comprising:

a transmitting step for generating a transmission signal to be transmitted through the transmission system in the first electric-supply station including a transmission side protective relay;
and
a measuring step for measuring a the transmission delay time of the transmission signal transmitted through the transmission system in the second electric-supply station including a reception side protective relay,
the transmitting step including the sub-steps of:
a) analyzing time data included in a signal transmitted from a satellite and converting the time data to a time signal;
and
b) generating a transmission signal when a time represented by the time signal coincides with a preset time and outputting the transmission signal to the transmission side protective relay,
the measuring step including the sub-steps of:
c) analyzing time data included in a signal transmitted from the satellite and converting the time data to a time signal;
d) detecting that the reception side protective relay has received the transmission signal transmitted through the transmission system from the transmission side protective relay;
and
e) comparing a time represented by the time signal when the transmission signal is received with a preset test start time, thereby measuring the transmission delay time in the transmission system.

9 more elements

A test apparatus for measuring a transmission delay time of a transmission system for transmitting a signal between protective relays respectively provided in electric-supply stations including a first and second electric-supply station connected through electric transmission lines, the test apparatus comprising:

GPS receivers, respectively connected to the protective relays, each GPS receiver analyzing time data included in a signal transmitted from a satellite and outputting a time signal;
a transmission side test circuit, connected to a transmission side protective relay of the protective relays, for generating a transmission signal to be transmitted through the transmission system, when the time signal coincides with a preset test start time output from the corresponding GPS receiver and outputting the transmission signal to the transmission side protective relay;
and
a reception side test circuit, connected to a reception side protective relay of the protective relays, for comparing the test start time with a time represented by the time signal output from the corresponding GPS receiver, when the transmission signal transmitted through the transmission system is received by the reception side protective relay, thereby obtaining the transmission delay time in the transmission system.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 08/700,875Filed 21 Aug 1996 · division
Priority: JP 6-0132887 Feb 1994
Granted: 9 Sep 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H02H 7/263
Involving signal transmission between at least two stations: involving transmissions of measured values
G01R 31/3272
Of high voltage or medium voltage devices: apparatus, systems or circuits therefor
G01R 31/3278
Of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches: of relays, solenoids or reed…
H02H 3/044
With warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned: checking correct…