Transfer trip system using quadrature carrier modulation with coherent detection

Claim 2

A quadrature carrier transfer trip system for an interconnecting power grid network having at least first and second power stations, said system comprising: a. at least first and second transmitter means, each said transmitter means generating at least two independent informations over the same channel, said information signals being in quadrature with one another, said first transmitter means operatively connected to the first power station and said second transmitter means operatively connected to the second power station; b. at least first and second receiver means, said first receiver means communicating with said second transmitter means for providing an output signal defining said information generated by said second transmitter means, said second receiver means communicating with said first transmitter means for providing an output signal defining said information generated by said first transmitter means; and c. means operatively connected to said first and second receiver means and the first and second power stations for isolating the power stations from one another, the first power station being isolated from the grid network in response to said output signal from said second receiver means and the second power station being isolated from the grid network in response to said output signal from said first receiver means.

Claim 3

The system as claimed in claim 1 wherein each said first and second transmitter means comprises: a. an input having a first signal applied thereto; b. a source for providing a second signal; c. a reference source for providing a reference signal; d. first means operatively connected to said input and reference source for modulating said first signal with the in phase component of said reference signal; e. second means operatively connected to said source and reference source for modulating said second signal with the quadrature component of said reference signal; f. a summing amplifier operatively connected to said first and second means for adding the modulated signals as at the output of said first and second means; g. filter means connected to said summing amplifier for removing interference signals from the signal as at the output of said summing amplifier; and h. output means electrically connected to said filter means for rendering available the signal as at the output of said filter.

Claim 4

A quadrature carrier transfer trip system comprising: a. transmitter means for generating at least two independent information signals over the same channel, said information signals being in quadrature with one another; b. receiver means for providing an output defining said information generated by said transmitter means; and c. means for communicatively connecting said transmitter and receiver; said receiver means including: i. an input having a signal applied thereto; ii. an automatic gain control operatively connected to said input for providing a substantially constant signal at its output; iii. a phase-locked loop for recovering the correct carrier signal from the signal as at said input; iv. first means connected to the output of said automatic gain control and a first output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the in phase component of the signal as at the first output of said phase-locked loop; v. second means operatively connected to the output of said automatic gain control and a second output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the qUadrature component of the signal as at the second output of said phase-locked loop; vi. a phase shifter connected to the output of said automatic gain control and the input of said phase-locked loop; vii. a first filter connected to the output of said first means for removing interference signals as at the output of said first means; viii. a first detector connected to the output of said first filter for detecting the signal from said transmitter means; ix. output means operatively connected to said first detector for providing a signal responsive to the signal as at the output of said first detector; x. an inhibitor connected between the output of said detector and the input of said output means for controlling the signal as at said output means; xi. a second filter operatively connected to said second means for removing interference signals as at the output of said second means; xii. a second detector connected at the output of said second filter for sensing the signal as at the output of said second means; xiii. a squelch circuit having a first of its inputs connected to said second detector and ist output connected to said inhibitor for controlling the signal as at the output of said inhibitor; xiv. a level detector having its input connected to the output of said automatic gain control and its output connected to said squelch circuit for controlling said squelch circuit as a function of the level of the signal as at the output of said automatic gain control; and xv. control means connected between the output of said inhibitor and the input of said phase-locked loop for controlling the signal as at the input of said phase-locked loop.

Claim 5

A quadrature carrier transfer trip system comprising: a. transmitter means for generating at least two independent information signals over the same channel, said information signals being in quadrature with one another; b. receiver means for providing an output defining said information generated by said transmitter means; and c. means for communicatively connecting said transmitter and receiver; said receiver means including: i. an input having a signal applied thereto; ii. an automatic gain control operatively connected to said input for providing a substantially constant signal at its output; iii. a phase-locked loop for recovering the correct carrier signal from the signal as at said input; iv. first means connected to the output of said automatic gain control and a first output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the in phase component of the signal as at the first output of said phase-locked loop; v. second means operatively connected to the output of said automatic gain control and a second output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the qUadrature component of the signal as at the second output of said phase-locked loop; vi. a phase shifter connected to the output of said automatic gain control and the input of said phase-locked loop; vii. a first filter connected to the output of said first means for removing interference signals as at the output of said first means; viii. a first detector connected to the output of said first filter for detecting the signal from said transmitter means; ix. output means operatively connected to said first detector for providing a signal responsive to the signal as at the output of said first detector; x. an inhibitor connected between the output of said detector and the input of said output means for controlling the signal as at said output means; xi. a second filter operatively connected to said second means for removing interference signals as at the output of said second means; xii. a second detector connected at the output of said second filter for sensing the signal as at the output of said second means; xiii. a squelch circuit having a first of its inputs connected to said second detector and ist output connected to said inhibitor for controlling the signal as at the output of said inhibitor; xiv. a level detector having its input connected to the output of said automatic gain control and its output connected to said squelch circuit for controlling said squelch circuit as a function of the level of the signal as at the output of said automatic gain control; and xv. control means connected between the output of said inhibitor and the input of said phase-locked loop for controlling the signal as at the input of said phase-locked loop.

Claim 6

The receiver as claimed in claim 3 wherein said first and second means are product modulators.

Claim 7

A quadrature carrier transfer trip system comprising: a. transmitter means for generating at least two independent information signals over the same channel, said information signals being in quadrature with one another; b. receiver means for providing an output defining said information generated by said transmitter means; and c. means for communicatively connecting said transmitter and receiver; said receiver means including: i. an input having a signal applied thereto; ii. an attenuator operatively connected to said input for lowering the signal level at said input; iii. a first filter operatively connected to said attenuator for removing unwanted noise components and signals from the signal as at the output of said attenuator; iv. an automatic gain control for providing a substantially constant signal at its output, the output of said filter being connected to the input of said automatic gain control; v. a phase-locked loop for recovering the correct carrier signal from the signal as at said input; vi. first means connected to the output of said automatic gain control and a first output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the in phase component of the carrier signal as at the first output of said phase-locked loop; vii. second means operatively connected to the output of said automatic gain control and a second output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the quadrature component of the carrier signal as at the second output of said phase-locked loop; viii. a 45* phase shifter connected to the output of said automatic gain control and the input of said second means; ix. a 90* phase shifter connected to the output of said automatic gain control and a first input of said phase-locked loop; x. a second filter connected to the output of said first means for removing interference signals as at the output of said first means; xi. a first detector connected to the output of said second filter for detecting the character of the signal from said transmitter means; xii. output means operatively connected to said first detector for providing a signal responsive to the signal as at the output of said first detector; xiii. an inhibitor connected between the output of said detector and the input of said output means for controlling the signal as at said output means; xiv. a third filter operatively connected to said second means for removing interference signals as at the output of said second means; xv. a second detector connected at the output of said third filter for sensing the signal as at the output of said second means; xvi. a squelch circuit having a first of its input connected to said second detector and its output connected to said inhibitor for controlling said inhibitor; xvii. a level detector having its input connected to the output of said automatic gain control and its output connected to said squelch circuit for controlling said squelch circuit as a function of the level of the signal as at the output of said automatic gain control; and xviii. first control means connected between the output of said inhibitor and the input of said phase-locked loop for controlling the signal as at the output of said phase-locked loop.

Claim 8

A quadrature carrier transfer trip system comprising: a. transmitter means for generating at least two independent information signals over the same channel, said information signals being in quadrature with one another; b. receiver means for providing an output defining said information generated by said transmitter means; and c. means for communicatively connecting said transmitter and receiver; said receiver means including: i. an input having a signal applied thereto; ii. an attenuator operatively connected to said input for lowering the signal level at said input; iii. a first filter operatively connected to said attenuator for removing unwanted noise components and signals from the signal as at the output of said attenuator; iv. an automatic gain control for providing a substantially constant signal at its output, the output of said filter being connected to the input of said automatic gain control; v. a phase-locked loop for recovering the correct carrier signal from the signal as at said input; vi. first means connected to the output of said automatic gain control and a first output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the in phase component of the carrier signal as at the first output of said phase-locked loop; vii. second means operatively connected to the output of said automatic gain control and a second output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the quadrature component of the carrier signal as at the second output of said phase-locked loop; viii. a 45* phase shifter connected to the output of said automatic gain control and the input of said second means; ix. a 90* phase shifter connected to the output of said automatic gain control and a first input of said phase-locked loop; x. a second filter connected to the output of said first means for removing interference signals as at the output of said first means; xi. a first detector connected to the output of said second filter for detecting the character of the signal from said transmitter means; xii. output means operatively connected to said first detector for providing a signal responsive to the signal as at the output of said first detector; xiii. an inhibitor connected between the output of said detector and the input of said output means for controlling the signal as at said output means; xiv. a third filter operatively connected to said second means for removing interference signals as at the output of said second means; xv. a second detector connected at the output of said third filter for sensing the signal as at the output of said second means; xvi. a squelch circuit having a first of its input connected to said second detector and its output connected to said inhibitor for controlling said inhibitor; xvii. a level detector having its input connected to the output of said automatic gain control and its output connected to said squelch circuit for controlling said squelch circuit as a function of the level of the signal as at the output of said automatic gain control; and xviii. first control means connected between the output of said inhibitor and the input of said phase-locked loop for controlling the signal as at the output of said phase-locked loop.

Claim 9

The receiver as claimed in claim 5 wherein said inhibitor includes: a. a first transistor having its base connected to the output of said first detector; b. a second transistor having its base resistively connected to the collector of said first transistor, the collector of said second transistor being connected to said output; c. a diode having its cathode connected to the base of said second transistor the anode of said diode being connected at the output of said squelch circuit; d. the signal as at said output being specified by the conduction states of said first and second transistors.

Claim 10

The receiver as claimed in claim 5 wherein said receiver includes: a. a first transistor having its base connected to a first output of said first control and its collector resistively connected to between the output of said 90* phase shifter and the first input of said phase-locked loop; b. a second transistor having its base connected to a second output of said first control and its collector resistively connected to the output of said automatic gain control and a second input of said phase-locked loop.

Claim 11

The receiver as claimed in claim 5 wherein said receiver includes: a. second control means having its output connected to an input of said automatic gain control for regulating the signal as at the output of said automatic gain control; and b. an RC network electrically connected between the input of said detector and the input of said second control for specifying the signal as at the output of said second control.

Claim 12

The quadrature carrier transfer trip system comprising: a. a first input having a first signal applied thereto; b. a source for providing a second signal; c. a reference source for providing a reference signal; d. a first product modulator operatively connected to said first input and reference source for modulating said first signal with the in phase component of said reference carrier signal; e. a second product modulator operatively connected to said source and reference source for modulating said second signal with the quadrature component of said reference carrier signal; f. a summing amplifier operatively connected to said first and second product modulators for adding the modulated signals as at the output of said first and second means; g. first filter means connected to said summing amplifier for removing interference signals from the signal as at the output of said summing amplifier; h. first output means electrically connected to said first filter means for rendering available the signal as at the output of said first filter; i. a second input having an information signal applied thereto; j. a second filter operatively connected to sAid second input for removing unwanted noise components and interference signals from the information signal as at said second input; k. an automatic gain control for providing a substantially constant signal at its output, the output of said second filter being connected to the input of said automatic gain control; l. a phase-locked loop for recovering the correct carrier signal from the information signal as at said second input; m. a third product modulator connected to the output of said automatic gain control and a first output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the in phase component of the carrier signal as at the first output of said phase-locked loop; n. a fourth product modulator operatively connected to the output of said automatic gain control and a second output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the quadrature component of the carrier signal as at the second output of said phase-locked loop; o. a 90* phase shifter connected to the output of said automatic gain control and the input of said phase-locked loop; p. a third filter connected to the output of said third product modulator for removing interference signals as at the output of said third product modulator; q. a first detector connected to the output of said third filter for detecting the character of the information signal as at said second input; r. second output means operatively connected to said first detector for providing a signal responsive to the signal as at the output of said first detector; s. an inhibitor connected between the output of said first detector and the input of said second output means for specifying the signal as at said second output means; t. a fourth filter operatively connected to said fourth product modulator for removing interference signals as at the output of said fourth product modulator; u. a second detector connected at the output of said fourth filter for sensing the signal as at the output of said fourth product modulator; v. a squelch circuit having a first of its input connected to said second detector and its output connected to said inhibitor for controlling the state of said inhibitor; w. a level detector having its input connected to the output of said automatic gain control and its output connected to said squelch circuit for controlling said squelch circuit as a function of the level of the signal as at the output of said automatic gain control; x. first control means connected between the output of said inhibitor and the input of said phase-locked loop for controlling the signal as at the output of said phase-locked loop; and y. second control means operatively interposed between the input of said second detector and the input of said automatic gain control for regulating the signal as at the output of said automatic gain control.

Claim 13

The quadrature carrier transfer trip system comprising: a. a first input having a first signal applied thereto; b. a source for providing a second signal; c. a reference source for providing a reference signal; d. a first product modulator operatively connected to said first input and reference source for modulating said first signal with the in phase component of said reference carrier signal; e. a second product modulator operatively connected to said source and reference source for modulating said second signal with the quadrature component of said reference carrier signal; f. a summing amplifier operatively connected to said first and second product modulators for adding the modulated signals as at the output of said first and second means; g. first filter means connected to said summing amplifier for removing interference signals from the signal as at the output of said summing amplifier; h. first output means electrically connected to said first filter means for rendering available the signal as at the output of said first filter; i. a second input having an information signal applied thereto; j. a second filter operatively connected to sAid second input for removing unwanted noise components and interference signals from the information signal as at said second input; k. an automatic gain control for providing a substantially constant signal at its output, the output of said second filter being connected to the input of said automatic gain control; l. a phase-locked loop for recovering the correct carrier signal from the information signal as at said second input; m. a third product modulator connected to the output of said automatic gain control and a first output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the in phase component of the carrier signal as at the first output of said phase-locked loop; n. a fourth product modulator operatively connected to the output of said automatic gain control and a second output of said phase-locked loop for modulating the signal as at the output of said automatic gain control with the quadrature component of the carrier signal as at the second output of said phase-locked loop; o. a 90* phase shifter connected to the output of said automatic gain control and the input of said phase-locked loop; p. a third filter connected to the output of said third product modulator for removing interference signals as at the output of said third product modulator; q. a first detector connected to the output of said third filter for detecting the character of the information signal as at said second input; r. second output means operatively connected to said first detector for providing a signal responsive to the signal as at the output of said first detector; s. an inhibitor connected between the output of said first detector and the input of said second output means for specifying the signal as at said second output means; t. a fourth filter operatively connected to said fourth product modulator for removing interference signals as at the output of said fourth product modulator; u. a second detector connected at the output of said fourth filter for sensing the signal as at the output of said fourth product modulator; v. a squelch circuit having a first of its input connected to said second detector and its output connected to said inhibitor for controlling the state of said inhibitor; w. a level detector having its input connected to the output of said automatic gain control and its output connected to said squelch circuit for controlling said squelch circuit as a function of the level of the signal as at the output of said automatic gain control; x. first control means connected between the output of said inhibitor and the input of said phase-locked loop for controlling the signal as at the output of said phase-locked loop; and y. second control means operatively interposed between the input of said second detector and the input of said automatic gain control for regulating the signal as at the output of said automatic gain control.

Claim 14

The quadrature carrier transfer trip system as claimed in claim 9 wherein said system includes: a. a first transistor having its base connected to a first output of said first control and its collector resistively connected to between the output of said 90* phase shifter and the first input of said phase-locked loop; b. a second transistor having its base connected to a second output of said first control and its collector resistively connected to the output of said automatic gain control and a second input of said phase-locked loop; c. the conduction states of said first and second transistors specifying the signal as at the first and second inputs of said phase-locked loop, respectively.