Detection of geomagnetically-induced currents with power line-mounted devices
First Claim
1. A device for monitoring geomagnetically-induced currents in a power line, comprising:
- a magnetic core disposed about at least part of a power line, the core being configured to provide an air gap therein;
a magnetic sensor positioned in the air gap to sense magnetic fields and produce an output signal representative of the magnetic fields; and
a signal processing unit that receives the output signal and determines the geomagnetically-induced current therefrom;
wherein the signal processing unit determines a DC component and an AC component; and
wherein the determined AC component is compared to a reference signal representative of an external measurement of the AC current in the power line and, based on the comparison, the determined DC component is adjusted in proportion thereto.
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Accused Products
Abstract
A device for use in a power transmission system to sense GICs. The device may be a part of a reactance-injecting device on a power line, it may be a standalone device, or it may be a part of another type of device. The device may include a sensor to sense magnetic fields (e.g., a Hall effect sensor). The sensor may be positioned in the air gap of a magnetic core formed concentrically around the power line. The signal from the sensor may be converted to a digital signal and separately processed to determine the magnitude of the AC current and the magnitude of the DC (or quasi-DC) current. If the output signal of another A/C current sensor is available, that output signal may be used to adjust/calibrate the determined magnitude of the DC current. The sensor may communicate with other devices in a network to provide GIC information.
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Citations
30 Claims
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1. A device for monitoring geomagnetically-induced currents in a power line, comprising:
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a magnetic core disposed about at least part of a power line, the core being configured to provide an air gap therein; a magnetic sensor positioned in the air gap to sense magnetic fields and produce an output signal representative of the magnetic fields; and a signal processing unit that receives the output signal and determines the geomagnetically-induced current therefrom; wherein the signal processing unit determines a DC component and an AC component; and wherein the determined AC component is compared to a reference signal representative of an external measurement of the AC current in the power line and, based on the comparison, the determined DC component is adjusted in proportion thereto. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A device for monitoring geomagnetically-induced currents in a power line, comprising:
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a magnetic core disposed about at least part of a power line, the core being configured to provide an air gap therein; a magnetic sensor positioned in the air gap to sense magnetic fields and produce an output signal representative of the magnetic fields; and a signal processing unit that receives the output signal and determines the geomagnetically-induced current therefrom wherein the signal processing unit separately processes AC signals and signals at or near DC with an AC processing portion and a DC processing portion, respectively; wherein the AC processing portion includes a high pass filter; wherein the AC processing portion includes a unit for determining the RMS value of the signal and providing an AC component signal representative thereof; wherein the AC processing portion includes a ratio-determining unit that determines the ratio of a reference signal to the AC component signal and produces a ratio signal representative thereof. - View Dependent Claims (27, 28)
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29. A device for monitoring geomagnetically-induced currents in a power line, comprising:
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a magnetic core disposed about at least part of a power line, the core being configured to provide an air gap therein; a magnetic sensor positioned in the air gap to sense magnetic fields and produce an output signal representative of the magnetic fields; and a signal processing unit that receives the output signal and determines the geomagnetically-induced current therefrom; wherein the signal processing unit separately processes AC signals and signals at or near DC with an AC processing portion and a DC processing portion, respectively; wherein the DC processing portion includes a unit for determining the mean of the signals and providing a DC component signal representative thereof; wherein the AC processing portion includes a unit for determining the RMS value of the signal and providing an AC component signal representative thereof; wherein the AC processing portion includes a ratio-determining unit that determines the ratio of a reference signal to the AC component signal and produces a ratio signal representative thereof; and wherein the signal processing unit includes a multiplier unit that multiplies the DC component signal by the ratio signal. - View Dependent Claims (30)
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Specification