Segregated phase comparison relaying apparatus

Claim 2

In a phase comparison unblocking relaying apparatus, a receiving apparatus, said receiving apparatus normally maintaining a first pair of normal logic signal outputs whenever a normal non-fault signal is being received by said receiving apparatus, a first comparing network having a plurality of input terminals and an output terminal, means interconnecting a first of said input terminals of said comparing network to said receiving apparatus for energization by one of said first normal logic signal outputs, said receiving apparatus being effective to supply a first operating logic signal to said first input terminal of said comparing network when said receiving apparatus is receiving said one non-fault normal logic signal output, a timer having an input and an output and operable to delay the change in energization of its said output for a predetermined timing interval subsequent to a change in energization of its said input, means operatively connecting said input of said timer to said receiving apparatus whereby the removal of said one normal non-fault logic signal output of said receiving apparatus will change the energization of said input of said timer, an AND network having a plurality of input terminals and an output terminal, circuit means operatively connecting said receiving apparatus to a first of said input terminals of said AND network to provide a second operating logic signal to said first input terminal of said AND network soleLy in the absence of a selected one of said first pair of normal logic signal outputs from said receiving apparatus, circuit means operatively connecting said output of said timer to a second of said input terminals of said AND network to provide a third operating logic signal to said second input terminal of said AND network solely prior to the timing out of said timer, a fault detector having an output terminal connected to a third of said input terminals of said AND network and to a second of said input terminals of said comparing network, said fault detector being effective to supply fourth and fifth operating logic signals to said third input terminal of said AND network and said second input terminal of said comparing network respectively solely as a consequence of the operation of said fault detector in response to a fault, said receiving apparatus being effective to provide a second output signal which changes in character in response to changes in the character of said transmitted fault signal, a local signal supplying means having a local signal which changes in character, a signal character comparing network connected to be energized by said second output signal provided by said receiving apparatus and by said local signal provided by said local signal supplying means, means connecting said signal character comparing network to a third of said input terminals of said first comparing network, said signal comparing network being effective to provide a sixth operating logic signal to said third input terminal of said first comparing network solely at first predetermined relative relations of said characters of said second output signal from said receiving apparatus and said normal local signal from said local signal supplying means, said first comparing network being effective to provide a first tripping signal at its said output terminal solely when operating logic signals are being supplied to its said first and second and third input terminals, said AND network being effective to provide a second tripping signal at its said output terminal solely when operating logic signals are being supplied to its said first and second and third input terminals.

Claim 3

The apparatus of claim 1 in which said output of said timer is operatively connected to a fourth of said input terminals of said first comparing network whereby a seventh operating signal is applied thereto by said timer prior to the timing out of its said timing interval and a non-operating signal is applied thereto by said timer upon the timing out of its said timing interval.

Claim 4

The apparatus of claim 2 in which there is provided a second and a third timer, each said second and third timer having an input and an output and being effective to delay the change in energization of its said output for a predetermined timing interval subsequent to a change in energization of its said input from a first to a second condition, said second timer having its said input operatively connected to said output terminal of said first comparing network whereby the energization of its said input is changed from its said first to its said second condition as a consequence of the occurrence of said first tripping signal, said third timer having its said input operatively connected to said output terminal of said AND network whereby the energization of its said input is changed from its said first to its second condition as a consequence of the occurrence of said tripping signal at said output terminal of said AND network.

Claim 5

The apparatus of claim 3 in which said third timer has a longer said predetermined timing interval than said predetermined timing interval of said second timer.

Claim 6

The apparatus of claim 4 in which each of said second and third timers reset to its initial condition or a consequence of the change in energization of its said input from its said second to its said first condition, the time required for said third timer to reset to its initial condition being longer than the time requiRed for said second timer to reset to its initial condition.

Claim 7

In a protective relaying system for protecting a transmission line having local and remote terminals, first and second relaying apparatus located at said local and said remote terminals respectively, each said apparatus having a line current sensing device coupled to the said line portion with which it is associated and effective to provide phase and magnitude indications of the current sensed thereby, a communication channel between said terminals, each said apparatus including a receiver and a transmitter connected to said channel for receiving signals from and transmitting signals to said channel at the portions thereof adjacent said terminal with which said apparatus is associated, each said receiver providing at least two output quantities when a fault condition exists at said remote terminal, a first of said output quantities having a characteristic which represents the current characteristic at said remote terminal, a second of said quantities having a characteristic which indicates a satisfactory reception of the fault signal from said channel each said apparatus including first circuit means connecting its said current sensing device to its said transmitter whereby its said transmitter is keyed to transmit a signal having a first characteristic determined by the phase of the current sensed by its said current sensing device, each said apparatus having a first and a second comparing network, each said comparing network having a plurality of input terminals and an output terminal, each said comparing network being effective to provide an actuating signal at its said output terminal solely when each of its said input terminals is supplied with an operating signal, each said apparatus including a current magnitude sensor, each said apparatus having a second circuit means connecting its said current magnitude sensor to its said current sensing device and to a first of said input terminals of its said comparing networks, each said current magnitude sensor being effective to provide an operating signal over its associated said second circuit means to said first input terminals of its associated said comparing networks solely when the magnitude of the current sensed by its associated said current sensing device is above a predetermined minimum magnitude, each said apparatus including a first timer having an input and an output and normally effective to provide an operate signal at its said output, each said apparatus including a third circuit means connecting said input of its said timer to its said receiver for energization by its said second quantity, said first timer being effective in response to the continuing absence of said first quantity to provide a non-operate signal at its said output subsequent to a predetermined time interval after the initiation of the absence of said first quantity, each said apparatus including a fourth circuit means connecting said output of its said timer to a second of said input terminals of its said comparing networks and normally effective to supply said operate signal to the said input terminals to which it is connected, fourth circuit means connected to a third of said input terminals of the said comparing networks of the said apparatus with which it is associated and energized by said second quantity, each said apparatus including signal comparing means having a first input circuit connecting to the said receiver of the associated said apparatus for energization by its said first quantity and a second input circuit connected to the said first circuit means of the associated said apparatus for energization of said second input circuit by the said first characteristic, said signal comparing means having an output circuit connected to a fourth input terminal of the associated said first comparing network each said apparatus having a second and a third timer for timing out a timed interval, said second timer having an input connected to said output terminal of the associAted said first comparing network, said third timer having an input connected to said output terminal of the associated said second comparing network, each said timer being effective to time out its said interval in response to the occurrence of said actuating signal at the said output terminal to which it is connected, each said apparatus including a breaker tripping circuit operatively connected to said output terminals of its said second and its said third timers.

Claim 8

In a protective relaying system for protecting a transmission line having local and remote terminals, first and second relaying apparatus located at said local and said remote terminals respectively, each said apparatus having a line current sensing device coupled to the said line portion with which it is associated and effective to provide phase and magnitude indications of the current sensed thereby, a communication channel between said terminals, each said apparatus including a receiver and a transmitter connected to said channel for receiving signals from and transmitting signals to said channel at the portions thereof adjacent said terminal with which said apparatus is associated, each said receiver providing at least two output quantities when a fault condition exists at said remote terminal, a first of said output quantities having a characteristic which represents the current characteristic at said remote terminal, a second of said quantities having a characteristic which indicates a satisfactory reception of the fault signal from said channel each said apparatus including first circuit means connecting its said current sensing device to its said transmitter whereby its said transmitter is keyed to transmit a signal having a first characteristic determined by the phase of the current sensed by its said current sensing device, each said apparatus having a first and a second comparing network, each said comparing network having a plurality of input terminals and an output terminal, each said comparing network being effective to provide an actuating signal at its said output terminal solely when each of its said input terminals is supplied with an operating signal, each said apparatus including a current magnitude sensor, each said apparatus having a second circuit means connecting its said current magnitude sensor to its said current sensing device and to a first of said input terminals of its said comparing networks, each said current magnitude sensor being effective to provide an operating signal over its associated said second circuit means to said first input terminals of its associated said comparing networks solely when the magnitude of the current sensed by its associated said current sensing device is above a predetermined minimum magnitude, each said apparatus including a first timer having an input and an output and normally effective to provide an operate signal at its said output, each said apparatus including a third circuit means connecting said input of its said timer to its said receiver for energization by its said second quantity, said first timer being effective in response to the continuing absence of said first quantity to provide a non-operate signal at its said output subsequent to a predetermined time interval after the initiation of the absence of said first quantity, each said apparatus including a fourth circuit means connecting said output of its said timer to a second of said input terminals of its said comparing networks and normally effective to supply said operate signal to the said input terminals to which it is connected, fourth circuit means connected to a third of said input terminals of the said comparing networks of the said apparatus with which it is associated and energized by said second quantity, each said apparatus including signal comparing means having a first input circuit connecting to the said receiver of the associated said apparatus for energization by its said first quantity and a second input circuit connected to the said first circuit means of the associated said apparatus for energization of said second input circuit by the said first characteristic, said signal comparing means having an output circuit connected to a fourth input terminal of the associated said first comparing network each said apparatus having a second and a third timer for timing out a timed interval, said second timer having an input connected to said output terminal of the associAted said first comparing network, said third timer having an input connected to said output terminal of the associated said second comparing network, each said timer being effective to time out its said interval in response to the occurrence of said actuating signal at the said output terminal to which it is connected, each said apparatus including a breaker tripping circuit operatively connected to said output terminals of its said second and its said third timers.

Claim 9

The system of claim 6 in which the said timing interval of said third timer is longer than the said timing interval of said second timer.

Claim 10

The system of claim 7 in which each said current magnitude sensor is provided with a second output which is connected to a fifth of said input terminals of the said first comparing network and a fourth of said input terminals of its said second comparing network of the said apparatus with which such said sensor is associated, each said current magnitude sensor being effective to supply an operate signal to the fourth and fifth input terminals to which it is connected solely when the magnitude of the current sensed by said magnitude sensor is above a predetermined minimum magnitude.

Claim 11

In a protective relaying system for protecting a polyphase transmission line having a line conductor for each of said phases, said system comprising an apparatus for each of said phases; each said apparatus including a plurality of AND networks, a plurality of timers, a fault detector, a receiver, a signal phase comparing network, said receiver having a first output connected to first input terminals of first and second of said AND networks for supplying signals thereto, said receiver being effective when receiving a signal indicative of the reception of a fault responsive signal to supply operating signals to each of said just-named first input terminals and to energize a first input terminal of said phase comparing network with a signal which is representative of the remote line operating characteristic being transmitted to said receiver, means connected to a second of said input terminals of said phase comparing network and effective to energize said just mentioned second input terminal with a signal which is representative of the local line operating characteristic, said fault detector having an output terminal connected to second input terminals of said first and said second AND networks and effective to provide an operating signal to said just-named second input terminals solely when said fault detector is responding to a fault condition, a first of said timers having an input connected to said receiver and an output connected to a third input terminal of said first and second AND networks, said timer being effective in the absence of an output signal from said receiver to time out a time interval and to thereafter supply a non-operating signal to said just-named third input terminals, a second of said timers having an input connected to said output of said first AND network, a third of said timers having an input connected to said output of said second AND network, said first and said second AND networks being effective to provide an operating signal to the said one of said timers associated therewith solely when all of its said input terminals are energized with an operating signal, a breaker operating network, each of said second and said third timers being effective when timed out to actuate said breaker operating network.

Claim 12

In a protective relaying system for protecting a polyphase transmission line having a line conductor for each of said phases, said system comprising an apparatus for each of said phases; each said apparatus including a plurality of AND networks, a plurality of timers, a fault detector, a receiver, a signal phase comparing network, said receiver having a first output connected to first input terminals of first and second of said AND networks for supplying signals thereto, said receiver being effective when receiving a signal indicative of the reception of a fault responsive signal to supply operating signals to each of said just-named first input terminals and to energize a first input terminal of said phase comparing network with a signal which is representative of the remote line operating characteristic being transmitted to said receiver, means connected to a second of said input terminals of said phase comparing network and effective to energize said just mentioned second input terminal with a signal which is representative of the local line operating characteristic, said fault detector having an output terminal connected to second input terminals of said first and said second AND networks and effective to provide an operating signal to said just-named second input terminals solely when said fault detector is responding to a fault condition, a first of said timers having an input connected to said receiver and an output connected to a third input terminal of said first and second AND networks, said timer being effective in the absence of an output signal from said receiver to time out a time interval and to thereafter supply a non-operating signal to said just-named third input terminals, a second of said timers having an input connected to said output of said first AND network, a third of said timers having an input connected to said output of said second AND network, said first and said second AND networks being effective to provide an operating signal to the said one of said timers associated therewith solely when all of its said input terminals are energized with an operating signal, a breaker operating network, each of said second and said third timers being effective when timed out to actuate said breaker operating network.

Claim 13

The system of claim 9 which includes a said apparatus for each of said phase conductors, each said fault detector being individually associated with the said phase conductor with which its said apparatus is associated and effective to provide a current signal which is proportional to the magnitude of the current in the said phase conductor with which it is associated, phase current interrupting circuit breaker individually associated with each of said phase conductors, each said breaker operating network being individually associateD with the one of said breakers which is associated with the one of said phase conductors with which its said apparatus is associated and being effective when actuated to trip individually the said breaker with which such breaker operating network is associated.

Claim 14

In a phase comparison unblocking relaying apparatus, a receiving apparatus, said receiving apparatus normally maintaining a first normal logic signal whenever a normal transmitting signal is being received by said receiving apparatus, a first comparing network having a plurality of input terminals and an output terminal, means interconnecting a first of said input terminals of said comparing network to said receiving apparatus for energization by said first normal logic signal, said receiving apparatus being effective to supply a first operating logic signal to said first input terminal of said comparing network when said receiving apparatus has said normal logic, a timer having an input and an output and operable to delay the change in energization of its said output for a predetermined timing interval subsequent to a change in energization of its said input, means operatively connecting said input of said timer to said receiving apparatus whereby the removal of said first normal logic signal of said receiving apparatus will change the energization of said input of said timer, an AND network having a plurality of input terminals and an output terminal, circuit means operatively connecting said output of said timer to a first of said input terminals of said AND network to provide a second operating logic signal to said first input terminal of said AND network solely prior to the timing out of said timer, a fault detector having an output terminal connected to a second of said input terminals of said AND network and to a second of said input terminals of said comparing network, said fault detector being effective to supply third and fourth operating logic signals to said second input terminal of said AND network and said second input terminal of said comparing network respectively solely as a consequence of the operation of said fault detector in response to a fault; said first comparing network being effective to provide a first tripping signal at its said output terminal solely when operating logic signals are being supplied to its said first and second input terminals, said AND network being effective to provide a second tripping signal at its said output terminal solely when operating logic signals are being supplied to its said first and second input terminals.

Claim 15

In a phase comparison unblocking relaying apparatus, a receiving apparatus, said receiving apparatus normally maintaining a first normal logic signal whenever a normal transmitting signal is being received by said receiving apparatus, a first comparing network having a plurality of input terminals and an output terminal, means interconnecting a first of said input terminals of said comparing network to said receiving apparatus for energization by said first normal logic signal, said receiving apparatus being effective to supply a first operating logic signal to said first input terminal of said comparing network when said receiving apparatus has said normal logic, a timer having an input and an output and operable to delay the change in energization of its said output for a predetermined timing interval subsequent to a change in energization of its said input, means operatively connecting said input of said timer to said receiving apparatus whereby the removal of said first normal logic signal of said receiving apparatus will change the energization of said input of said timer, an AND network having a plurality of input terminals and an output terminal, circuit means operatively connecting said output of said timer to a first of said input terminals of said AND network to provide a second operating logic signal to said first input terminal of said AND network solely prior to the timing out of said timer, a fault detector having an output terminal connected to a second of said input terminals of said AND network and to a second of said input terminals of said comparing network, said fault detector being effective to supply third and fourth operating logic signals to said second input terminal of said AND network and said second input terminal of said comparing network respectively solely as a consequence of the operation of said fault detector in response to a fault; said first comparing network being effective to provide a first tripping signal at its said output terminal solely when operating logic signals are being supplied to its said first and second input terminals, said AND network being effective to provide a second tripping signal at its said output terminal solely when operating logic signals are being supplied to its said first and second input terminals.

Claim 16

The apparatus of claim 11 in which said receiving apparatus is provided with an output terminal operatively connected to a third of said input terminals of said AND network to provide a fifth operating logic signal thereto upon the failure of said receiving apparatus to provide a desired output at its said output terminal.

Claim 17

The apparatus of claim 12 in which said output of said timer is operatively connected to a fourth of said input terminals of said first comparing network whereby a sixth operating signal is applied thereto by said timer prior to the timing out of its said timing interval and a non-operating signal is applied thereto by said timer upon the timing out of its said timing interval.

Claim 18

The apparatus of claim 13 in which there is provided a second and a third timer, each said second and third timer having an input and an output and being effective to delay the change in energization of its said output for a predetermined timing interval subsequent to a change in energization of its said input from a first to a second condition, said second timer having its said input operatively connected to said output terminal of said first comparing network whereby the energization of its said input is changed from its said first to its said second condition as a consequence of the occurrence of said first tripping signal, said third timing having its said input operatively connected to said output terminal of sAid AND network whereby the energization of its said input is changed from its said first to its said second condition as a consequence of the occurrence of said tripping signal at said output terminal of said AND network.

Claim 19

The apparatus of claim 14 in which said third timer has a longer said predetermined timing interval than said second timer.

Claim 20

The apparatus of claim 15 in which each of said second and third timers is reset to its initial condition as a consequence of the change in energization of its said input from its said second to its said first condition, the time required for said third timer to reset to its initial condition being longer than the time required for said second timer to reset to its initial condition.