Automatic test apparatus for phase comparison protective relay systems and the like

Claim 2

Apparatus for testing a plural terminal powerline protective relay system which includes a transmitter and receiver interconnected with a control unit and protective relay connected to control a line circuit breaker assembly at each terminal, each of the transmitter and receivers being in mutual communication, the apparatus comprising: first programming switch means located at a first terminal and being actuatable to function for a predetermined duration; first control means which is actuated by said first programming switch means to energize the first terminal transmitter to transmit carrier energy; second programming switch means located at a second terminal and being actuatable to function for a predetermined duration; second control means which is actuated by the second terminal receiver upon receiving the transmitted carrier energy from said first terminal to actuate said second programming switch means to function for said predetermined duration; first and second auxiliary relay means located at respective first and second terminals and being energizable to remove said circuit breaker assembly from control connection to said control unit and protective relay; and first and second switching means controlled by respective first and second programming switch means to energize respective first and second auxiliary relay means during predetermined intervals of said predetermined duration.

Claim 3

Apparatus for testing a plural terminal powerline protective relays system as set forth in claim 1 which is further characterized to include: third programming switch means located at a third terminal and being actuatable to function for a predetermined duration; third control means which is actuated by the third terminal receiver upon receiving transmitted carrier energy from said first terminal to actuate said third programming means to function for said predetermined duration; third auxiliary relay means located at said third terminal and being energizable to remove the circuit breaker assembly from control connection to said third terminal control unit and protective relay; and third switching means controlled by the third programming switch means to energize a respective third auxiliary relay means during predetermined intervals of said predetermined duration.

Claim 4

Relay system testing apparatus for use with electrical transmission lines having plural terminals each of which includes an interconnected transmitter and receiver, ad a phase comparison protective relay and control unit, which control unit includes means for keying a respEctive transmitter with alternating, discontinuous fault voltages in response to a fault condition at the respective terminal, the test apparatus comprising: first means at a first local terminal for generating a first fault voltage which simulates a first trip condition; second means at a second remote terminal for generating a second fault voltage which simulates a second trip condition; verification means receiving each of said first and second fault voltages to determine phase relationship thereby to indicate a predetermined fault condition relative to said first and second terminals; and first and second program switch means automatically energized in synchronous relationship to actuate the respective first and second means simultaneously.

Claim 5

Relay system testing apparatus for use with electrical transmission lines having plural terminals each of which includes an interconnected transmitter and receiver, ad a phase comparison protective relay and control unit, which control unit includes means for keying a respEctive transmitter with alternating, discontinuous fault voltages in response to a fault condition at the respective terminal, the test apparatus comprising: first means at a first local terminal for generating a first fault voltage which simulates a first trip condition; second means at a second remote terminal for generating a second fault voltage which simulates a second trip condition; verification means receiving each of said first and second fault voltages to determine phase relationship thereby to indicate a predetermined fault condition relative to said first and second terminals; and first and second program switch means automatically energized in synchronous relationship to actuate the respective first and second means simultaneously.

Claim 6

Testing apparatus as set forth in claim 3 which is further characterized to include: first switch means actuated by said first program switch means to reverse the phase of said first fault voltage such that said verification means indicates a second predetermined fault condition.

Claim 7

Testing apparatus as set forth in claim 4 which is further characterized to include: second switch means actuated by said second program switch means to reverse the phase of said second fault voltage such that said verification means indicates a different fault condition.

Claim 8

Test apparatus for use in testing a protective relay system functioning with an electrical transmission line wherein each of local and remote terminals interconnecting said transmission line include a circuit breaker with trip circuitry to operate said circuit breaker upon reset fault indication, a transmitter and receiver equipment, and a protective relay including control circuitry for keying said transmitter in response to locally detected fault indication signals and for comparing the phase of fault indication signal received from remote transmitters with the phase of fault indication signals generated at the local transmitter to determine if the fault is internal or external of the interconnecting transmission line, the test apparatus comprising: program control means located at said local terminal and actuatable to effect selected operation of a plurality of program switches at differing intervals through a predetermined time sequence, each of said switches being connected to provide a program control output actuation; starting means for actuating said program control means; an electrical power supply; auxiliary relay means connected to said circuit breaker trip circuitry to apply electrical power to said trip circuitry when said auxiliary relay means is deenergized such that the trip circuitry will operate said circuit breaker upon preset fault indication; circuit means connecting a first program control output actuation of one of said plurality of program switches to energize said auxiliary relay means thereby to remove said electrical voltage to said trip circuitry to disable operation of said circuit breaker for the duration of said first program control output actuation; and fault simulation means energized by a second program control output actuation during said first program control output actuation thereby to energize said protective relay and control circuitry to key said transmitter and provide trip indication.

Claim 9

Test apparatus for use in testing a protective relay system functioning with an electrical transmission line wherein each of local and remote terminals interconnecting said transmission line include a circuit breaker with trip circuitry to operate said circuit breaker upon reset fault indication, a transmitter and receiver equipment, and a protective relay including control circuitry for keying said transmitter in response to locally detected fault indication signals and for comparing the phase of fault indication signal received from remote transmitters with the phase of fault indication signals generated at the local transmitter to determine if the fault is internal or external of the interconnecting transmission line, the test apparatus comprising: program control means located at said local terminal and actuatable to effect selected operation of a plurality of program switches at differing intervals through a predetermined time sequence, each of said switches being connected to provide a program control output actuation; starting means for actuating said program control means; an electrical power supply; auxiliary relay means connected to said circuit breaker trip circuitry to apply electrical power to said trip circuitry when said auxiliary relay means is deenergized such that the trip circuitry will operate said circuit breaker upon preset fault indication; circuit means connecting a first program control output actuation of one of said plurality of program switches to energize said auxiliary relay means thereby to remove said electrical voltage to said trip circuitry to disable operation of said circuit breaker for the duration of said first program control output actuation; and fault simulation means energized by a second program control output actuation during said first program control output actuation thereby to energize said protective relay and control circuitry to key said transmitter and provide trip indication.

Claim 10

Test apparatus as set forth in claim 6 wherein said fault simulation means comprises: transformer means connected to simulate a fault current indication as an AC electrical voltage; and first relay means energized by a third program control output actuation of one of said plurality of program switches to apply said AC electrical voltage fault indication to said protective relay and control circuitry.

Claim 11

Test apparatus as set forth in claim 7 which is further characterized in that: fourth and fifth program control output actuations of said plurality of program switches are periodically actuated to reverse the phase of the output AC fault indication voltage from saId first relay means.

Claim 12

Test apparatus as set forth in claim 6 wherein said remote terminal also includes test apparatus comprising: remote program control means located at said remote terminal and being actuatable to effect selected operation of a plurality of program switches at differing intervals through a predetermined time sequence, each of said switches being connected to provide a program control output actuation; carrier relay means responsive to transmission from said transmitter at the local terminal to start actuation of said remote program control means; a remote electrical power supply; remote auxiliary relay means connected to said remote circuit breaker trip circuitry to apply electrical power to said remote trip circuitry when said remote auxiliary relay means is deenergized such that the remote trip circuitry will operate said remote circuit breaker upon preset fault indication; remote circuit means at the remote station connecting a first program control output actuation of one of said plurality of program switches of the remote program control means to energize said remote auxiliary relay means thereby to remove said electrical voltage to said remote trip circuitry and to disable operation of said remote circuit breaker for the duration of said first program control output actuation; and remote fault simulation means energized by a second program control output actuation during said first program control output actuation thereby to energize said remote protective relay and control circuitry to key said remote transmitter and provide a remote trip indication.

Claim 13

Test apparatus as set forth in claim 9 wherein said remote fault simulation means comprises: transformer means connected to simulate a fault current indication as an AC electrical voltage; and first relay means energized by a third program control output actuation of one of said plurality of program switches to apply said AC electrical voltage fault indication to said protective relay and control circuitry.

Claim 14

Test apparatus as set forth in claim 10 which is further characterized to include: fourth and fifth program control output actuations of said plurality of program switches are periodically each actuated to reverse the phase of the output AC fault indication voltage from said first relay means.

Claim 15

Test apparatus as set forth in claim 6 wherein said starting means comprises: synchronous motor means mechanically coupled with an electrical switch means, said motor means functioning to close said switch means at periodic intervals.

Claim 16

Test apparatus as set forth in claim 9 which is further characterized in that: said starting means at the local terminal consists of an electrical switch closed at periodic intervals by a synchronous timing motor, and said remote terminal starting means is a relay means energized in response to receipt of carrier from the local transmitter to start a cycle of test operation at the remote terminal.