US4135128A — Apparatus for sensing the reactive or real compon…

Claim 1

Independent Claim 296 words

Reactive current supply apparatus for an a-c electric power system including a critical voltage supply bus electrically separated by series impedance from load terminals which are adapted for connection to a load subject to rapid oscillatory variation of reactive current demand comprising: fixed capacitor means connected across said load terminals, fixed inductor means connected across said load terminals in series circuit relation with static switching means, said static switching means including gating means for phase controlling the conduction angle of said switching means thereby to control the magnitude of reactive current traversing said inductor means, means for generating a first electrical signal representative in direction of a phase relation of the reactive component of load current at said load terminals and representative in magnitude of the magnitude of said reactive component of load current, means responsive to said first electrical signal for so controlling said gating means that the sum of the reactive current traversing said fixed capacitor means and said fixed inductor means is substantially equal and opposite to said reactive component of load current, wherein said means for generating said first electrical signal representative of the phase relation and magnitude of said reactive component of load current further comprises: means for rendering said first electrical signal representative of the phase relation and magnitude of said reactive component of load current more than two times per cycle of source frequency, said rendering means including means for generating second and third electrical signals respectively representative of said load current and the time rate of change of said load current, said rendering means including signal processing means for processing said second and third electrical signals with electrical signals representative of line to neutral voltage waveforms which are derived from a selected reference location in said power system.

Claim 2

Dependent Claim 296 words

Reactive current supply apparatus for an a-c electric power system including a critical voltage supply bus electrically separated by series impedance from load terminals which are adapted for connection to a load subject to rapid oscillatory variation of reactive current demand comprising: fixed capacitor means connected across said load terminals, fixed inductor means connected across said load terminals in series circuit relation with static switching means, said static switching means including gating means for phase controlling the conduction angle of said switching means thereby to control the magnitude of reactive current traversing said inductor means, means for generating a first electrical signal representative in direction of a phase relation of the reactive component of load current at said load terminals and representative in magnitude of the magnitude of said reactive component of load current, means responsive to said first electrical signal for so controlling said gating means that the sum of the reactive current traversing said fixed capacitor means and said fixed inductor means is substantially equal and opposite to said reactive component of load current, wherein said means for generating said first electrical signal representative of the phase relation and magnitude of said reactive component of load current further comprises: means for rendering said first electrical signal representative of the phase relation and magnitude of said reactive component of load current more than two times per cycle of source frequency, said rendering means including means for generating second and third electrical signals respectively representative of said load current and the time rate of change of said load current, said rendering means including signal processing means for processing said second and third electrical signals with electrical signals representative of line to neutral voltage waveforms which are derived from a selected reference location in said power system.

Claim 3

Dependent Claim 41 words

Reactive current supply apparatus in accordance with claim 1 in which said means for generating said second and third signals representative of said load current and the time rate of change of said load current comprises at least one R-L network.

Claim 4

Dependent Claim 61 words

Reactive current supply apparatus in accordance with claim 1 wherein said means for rendering said first electrical signal representative of the phase relation and magnitude of said reactive component of load current comprises means for rendering said first electrical signal representative of the phase relation and magnitude of said reactive component of load current twelve times per cycle of source frequency.

Claim 5

Dependent Claim 65 words

Reactive current supply apparatus in accordance with claim 3 in which said rendering means includes means for generating twelve zero crossing pulses per cycle of source frequency and pulse processing means for generating an output signal which is representative of the phase relation and magnitude of said reactive component of load current at each of said twelve zero crossing pulses per cycle of source frequency.

Claim 6

Dependent Claim 42 words

Reactive current supply apparatus in accordance with claim 4 in which said means for generating said twelve zero crossing pulses per cycle comprises summation means for processing said electrical signals representative of line to neutral voltage waveforms at said critical voltage bus.

Claim 7

Dependent Claim 107 words

Reactive current supply apparatus in accordance with claim 5 in which said pulse processing means includes: first means for developing a first intermediate signal representative of the product of said second representative signal and a first variable coefficient at each time instant corresponding to each one of said twelve zero crossing pulses per cycle and second means for developing a second intermediate signal representative of the product of said third representative signal and a second variable coefficient at each of said time instants; and means for summing said intermediate signals and generating an output signal representative of said summed intermediate signals at each of said time instants.

Claim 8

Dependent Claim 51 words

Reactive current supply apparatus in accordance with claim 6 in which said means for generating said output signal representative of said summed intermediate signals includes means for continuing to generate said output signal representative of said summed intermediate signals during the time interval between consecutive ones of said zero crossing pulses.

Claim 9

Dependent Claim 73 words

Reactive current supply apparatus in accordance with claim 7 in which said second variable coefficient represents the value of one of said electrical signals representative of line to neutral voltage waveforms at said critical voltage bus and said first variable coefficient represents the value of the difference between the two remaining electrical signals representative of line to neutral voltage waveforms at said critical voltage bus in a three phase a-c electric power system.

Claim 10

Dependent Claim 60 words

Reactive current supply apparatus in accordance with claim 1 wherein said means for rendering said first electrical signal representative of the phase relation and magnitude of said reactive component of load current comprises means for rendering said first signal continuously representative of the phase relation and magnitude of said reactive component of load current during each cycle of source frequency.

Claim 11

Dependent Claim 41 words

Reactive current supply apparatus in accordance with claim 9 in which said means for generating said second and third signals representative of said load current and the time rate of change of said load current comprises at least one R-L network.

Claim 12

Dependent Claim 241 words

Reactive current supply apparatus in accordance with claim 10 for a three phase a-c electric power system, which further comprises: (a) first summation means for processing electrical signals representative of the line to neutral voltage waveforms in two phases of said three phase system at said critical bus and generating an output signal therefrom; (b) first multiplier means for receiving said output signal of said first summation means and said second signal representative of said load current and generating an output signal representative of the product thereof; (c) first coefficient block means for multiplying said first multiplying means output signal by the value of about 1/√3 and generating an output signal therefrom; (d) second multiplier means for receiving an electrical signal representative of the remaining line to neutral voltage waveform of the third phase at said critical bus and said third signal representative of the time rate of change of said load current and generating an output signal representative of the product thereof, (e) second coefficient block means for multiplying said second multiplier means output signal by a value R/ωL and generating an output signal therefrom, where R comprises the resistance and L comprises the inductance in said R-L network; and, (f) second summation means for receiving said output signals of said first and second coefficient blocks and generating an output signal therefrom which is continuously representative of the sum of said output signals of said first and second coefficient blocks.

Claim 13

Dependent Claim 66 words

System for sensing a predetermined component of system current in a polyphase a-c electric power system, which comprises: (a) means for generating a first electrical signal representative of said system current at a selected area in said power system; (b) means for generating a second electrical signal representative of the time rate of change of said system current at said selected area in said power system;

Claim 14

Dependent Claim 66 words

System for sensing a predetermined component of system current in a polyphase a-c electric power system, which comprises: (a) means for generating a first electrical signal representative of said system current at a selected area in said power system; (b) means for generating a second electrical signal representative of the time rate of change of said system current at said selected area in said power system;

Claim 15

Dependent Claim 80 words

(c) means for deriving electrical signals representative of line to neutral voltage waveforms associated with said polyphase power system at a selected reference location in said power system; (d) signal processing means for processing said first and second electrical signals with said signals representative of line to neutral voltage waveforms, said signal processing means including means for generating an output signal therefrom, said output signal being representative of said predetermined component more than two times per cycle of source frequency.

Claim 16

Dependent Claim 80 words

(c) means for deriving electrical signals representative of line to neutral voltage waveforms associated with said polyphase power system at a selected reference location in said power system; (d) signal processing means for processing said first and second electrical signals with said signals representative of line to neutral voltage waveforms, said signal processing means including means for generating an output signal therefrom, said output signal being representative of said predetermined component more than two times per cycle of source frequency.

Claim 17

Dependent Claim 47 words

System in accordance with claim 12 which includes means for generating an intermediate signal representative of said system current at said selected area and in which said means for generating said first and second electrical signals comprises at least one R-L network for receiving said intermediate signal.

Claim 18

Dependent Claim 14 words

System in accordance with claim 12 in which said system current comprises load current.

Claim 19

Dependent Claim 19 words

System in accordance with claim 14 in which said predetermined component comprises the real component of said load current.

Claim 20

Dependent Claim 19 words

System in accordance with claim 14 in which said predetermined component comprises the reactive component of said load current.

Claim 21

Dependent Claim 22 words

System in accordance with claim 16 in which said output signal is continuously representative of said reactive component of said load current.

Claim 22

Dependent Claim 283 words

System in accordance with claim 17 for a three phase a-c electric power system which includes means for generating an intermediate signal representative of said load current and in which said means for generating said first and second electrical signals comprises at least one R-L network for receiving said intermediate signal and in which said signal processing means further comprises: (a) first summation means for processing electrical signals representative of said line to neutral voltage waveforms in two phases of said three phase system at said selected reference location and generating an output signal therefrom; (b) first multiplier means for receiving said output signal of said first summation means and said first signal representative of said load current and generating an output signal representative of the product thereof; (c) first coefficient block means for multiplying said first multiplying means output signal by the value of about 1/√3 and generating an output signal therefrom; (d) second multiplier means for receiving an electrical signal representative of the remaining line to neutral voltage waveform of the third phase at said selected reference location and said second signal representative of the time rate of change of said load current and generating an output signal representative of the product thereof; (e) second coefficient block means for multiplying said second multiplier means output signal by a value R/ωL and generating an output signal therefrom, where R comprises the resistance and L comprises the inductance in said R-L network; and, (f) second summation means for receiving said output signals of said first and second coefficient blocks and generating an output signal therefrom which is continuously representative of the sum of said output signals of said first and second coefficient blocks.

Claim 23

Dependent Claim 28 words

System in accordance with claim 16 in which said output signal is representative of said reactive component of said load current twelve times per cycle of source frequency.

Claim 24

Dependent Claim 71 words

System in accordance with claim 19 for a three phase a-c electric power system in which said signal processing means includes means for generating twelve zero crossing pulses per cycle of source frequency and pulse processing means for generating an output signal which is representative of the phase relation and magnitude of said reactive component of load current at each of said twelve zero crossing pulses per cycle of source frequency.

Claim 25

Dependent Claim 33 words

System in accordance with claim 20 in which said means for generating said twelve zero crossing pulses per cycle comprises summation means for processing said signals representative of line to neutral voltage waveforms.

Claim 26

Dependent Claim 105 words

System in accordance with claim 21 in which said pulse processing means comprises: (a) first means for developing a first intermediate signal representative of the product of said first representative signal and a first variable coefficient at each instant corresponding to each one of said twelve zero crossing pulses per cycle; (b) second means for developing a second intermediate signal representative of the product of said second representative signal and a second variable coefficient at each of said time instants; and (c) means for summing said intermediate signals and generating an output signal representative of said summed intermediate signals at each of said time instants.

Claim 27

Dependent Claim 42 words

System in accordance with claim 22 in which said means for generating said output signal representative of said summed intermediate signals includes means for continuing to generate said output signal during the time interval between consecutive ones of said zero crossing pulses.

Claim 28

Dependent Claim 62 words

System in accordance with claim 23 in which said second variable coefficient represents the value of one of said electrical signals representative of line to neutral voltage waveforms at said selected reference location and said first variable coefficient represents the value of the difference between the two remaining electrical signals representative of line to neutral voltage waveforms at said selected reference location.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1982-01-15	1982-07-17	1983-01-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1986-01-15	1986-07-17	1987-01-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1990-01-15	1990-07-17	1991-01-16	$7700.00	Window Closed / Lapsed

Apparatus for sensing the reactive or real components of current

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