APPARATUS FOR AUTOMATIC RELAY SYSTEM TESTING

• US 3,668,474 A
• Filed: 10/19/1970
• Issued: 06/06/1972
• Est. Priority Date: 10/19/1970
• Status: Expired due to Term

• Current Assignee: Marion D. Knox
• Original Assignee: Marion D. Knox
• Inventors: Knox, Marion D.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Fendelman, Harvey
• Application Number:
  US05/081,694
• Time in Patent Office: 596 Days
• Field of Search: 340/146.1,309.6,309.1,318,319 324/73 317/28,29
• US Class Current: 361/68
• CPC Class Codes: H02H 3/044 Checking correct functioning of protective arrangements, e.g. by simulating a fault for differential current circuit breakers H02H3/335

Abstract

Apparatus for periodic testing of multiple-terminal, remote trip, dual transfer trip relaying systems. The apparatus consists of periodically actuatable test units which provide a plurality of program outputs to effect transmission tests of transfer trip channels as well as proper operation of the associated relay equipment. A master test unit located at a first position initiates operation and functions with one or more slaved remote test units to key transmissions and verify reception at the transfer trip receiver equipment, while test signification is made in accordance with programmed requirement via an associated return communications link.

Claims

1. A method for automatic testing of surveillance equipment operating between spaced terminals, said surveillance equipment consisting of a uni-directional, dual-channel transfer trip transmitter and receiver interconnection, and some form of return communications link, said transfer trip transmitter normally transmitting a first frequency GUARD signal and being controllable to transmit a second frequency TRIP signal indicative of a pre-set condition, said method comprising steps of:

receiving test sequence energization and thereafter generating a series of test actuation outputs at a first terminal;

effecting energization in response to a selected one of said test actuation outputs to control a selected one of said first and second transfer trip transmitters to transmit said trip frequency sIgnal from said first terminal; and

receiving said trip frequency signal from a respective one of said first and second transfer trip receivers at a second terminal to cause characteristic energization of said return communication link thereby to indicate at said first terminal the reception of said trip frequency signal by said transfer trip receiver at the second terminal.

2. Apparatus for automatic testing of surveillance equipment operating between spaced terminals, said surveillance equipment consisting of a uni-directional, dual-channel transfer trip transmitter and receiver interconnection, and some from of return communications link, said transfer trip transmitter normally transmitting a first frequency guard signal and being controllable to transmit a second frequency trip signal indicative of a pre-set condition, said apparatus comprising:

motor means energizable to provide a constant rotational output;

program drum means receiving rotational output from said motor means;

plural program actuation means disposed as a plurality of circumferential rows about said program drum means; and

plural switch means positioned adjacent each of said plural rows of program actuation means to be actuated thereby in accordance with pre-set program sequence;

second means connected to be energized by a selected one of said test actuation outputs to control a selected one of said first and second transfer trip transmitters to transmit said trip signal; and

third means responsive to said respective one of said first and second transfer trip receivers upon receiving said second frequency trip signal to cause characteristic energization of said return communication link to indicate at said first means the reception of said trip frequency signal by said transfer trip receiver at the second terminal.

3. Apparatus as set forth in claim 2 wherein said first means comprises:

program switch means which is periodically energized to effect a plurality of said test initiation actuations in a pre-set sequence.

4. Apparatus as set forth in claim 2 wherein said third means includes:

remote program switch means energized to generate a series of second test actuations in synchronism with said first means test actuations.

5. Apparatus for automatic testing of transmission line protective relay systems of the scheme which includes uni-directional, dual-channel remote transfer trip transmission circuitry having transfer trip transmitters at a first position and transfer trip receivers at a second position with a return communications link connected between said first and second position, the apparatus comprising:

program switch means located at said first position which is periodically energized to effect a plurality of said test initiation actuations in a pre-set sequence after an initial energization;

second program means located at said second position and providing a series of second test actuations after initial energization;

guard relay means located at said second position and being enabled upon receipt of guard signal transmission from said first position to provide a guard output during a selected one of said second test actuations;

circuit means located at said second location for receiving said guard output to cause respective ring back indication for transmission by said return communications links;

second relay means located at said first position, said second relay means being energized to enable first and second trip key output; and

, first and second actuation means each conducting respective first and second trip key outputs when actuated closed by said first program means to generate said first and second trip outputs from respective first and second transfer trip transmitters.

6. Apparatus as set forth in claim 5 wherein said program switch means comprises:

motor means energizable to provide a constant rotationable output;

plural program actuation means disposed of a Plurality of circumferential rows about said program drum means; and

plural switch means positioned adjacent each of said plural rows of program actuation means to be actuated thereby in accordance with pre-set program sequence.

7. Apparatus as set forth in claim 5 wherein said second program means includes:

remote program switch means energized to generate a series of second test actuations in synchronism with said first means test actuations.

8. Apparatus as set forth in claim 7 wherein said remote program switch means comprises:

motor means energizable to provide a constant rotationable output;

plural program actuation means disposed of a plurality of circumferential rows about said program drums means; and

plural switch means positioned adjacent each of said plural rows of program actuation means to be actuated thereby in accordance with pre-set program sequence.

9. Apparatus as set forth in claim 6 which is further characterized to include:

auxiliary relay means disposed at said second position to be energized for a pre-set time by a selected one of said test actuations, thereby to disable trip circuitry.

10. Apparatus as set forth in claim 5 which is further characterized to include:

alarm circuit means at said first position;

receive relay means at said first position which is energized in response to ringback indication on said return communications link thereby to disable said alarm circuit means.

11. Apparatus as set forth in claim 10 wherein said alarm circuit means includes:

alarm actuation means periodically actuated by said first program means and connected in series with said receive relay means to enable said alarm circuit means when actuated.