Parallel insulation fault detection system
First Claim
1. A system for detecting and locating parallel arc faults in a set of wires, at least, a parallel arc fault being defined as a condition in which wires in the set of wires are close enough to produce an arc, the arc being capable of producing an incident waveform and a reflected waveform, the two waveforms together forming a pulse that has a width, the system comprising:
- a first device that includes;
a controller for receiving information and for processing the information to produce a number of control signals;
a current source having a first terminal coupled to a first node and a second terminal coupled to ground, the current source being controlled by the controller to produce a direct current so as to charge a capacitance up to the testing voltage, the capacitance being defined between a wire under test and the remaining wires of the set of wires;
a timing circuit interfaced to the controller, the timing circuit having a first terminal coupled to the first node and a second terminal coupled to ground, the timing circuit being receptive to the incident waveform and the reflected waveform at the first terminal so as to measure the width of the pulse, the width being approximately proportional to the distance from the device to the arc;
a sequencer for coupling the wire under test to the first node while grounding the remaining wires of the set of wires, the sequencer defining the wire under test as a previous wire under test when the device cannot detect the arc on the wire under test, the sequencer being adapted to choose another wire of the remaining wires of the set of wires and define the another wire as the wire under test while grounding the previous wire under test and the remaining wires; and
a reflection minimizer interposed between the sequencer and at least one wire from the remaining set of wires, the reflection minimizer being capable of minimizing the attenuation of the amplitude of the pulse.
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Accused Products
Abstract
A device for detecting and locating arcs in a set of wires is discussed. The device comprises a probe for discharging controlled current to an exposed portion of a wire in the set of wires. The probe includes a handleable enclosure and an elongated structure which projects from the enclosure for conducting a gas and for enclosing a needle that has a tip. A suitable gas includes gases that have low electron attachment, such as helium. The device further comprises a control unit for communicating control signals as well as the gas to the probe. The control unit includes a controller, a valve being controllable by the controller and being capable of regulating the flow of the gas, and a high-voltage generator being controllable by the controller to generate a high-voltage signal, which can be communicated to the probe by the control unit.
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Citations
19 Claims
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1. A system for detecting and locating parallel arc faults in a set of wires, at least, a parallel arc fault being defined as a condition in which wires in the set of wires are close enough to produce an arc, the arc being capable of producing an incident waveform and a reflected waveform, the two waveforms together forming a pulse that has a width, the system comprising:
a first device that includes;
a controller for receiving information and for processing the information to produce a number of control signals;
a current source having a first terminal coupled to a first node and a second terminal coupled to ground, the current source being controlled by the controller to produce a direct current so as to charge a capacitance up to the testing voltage, the capacitance being defined between a wire under test and the remaining wires of the set of wires;
a timing circuit interfaced to the controller, the timing circuit having a first terminal coupled to the first node and a second terminal coupled to ground, the timing circuit being receptive to the incident waveform and the reflected waveform at the first terminal so as to measure the width of the pulse, the width being approximately proportional to the distance from the device to the arc;
a sequencer for coupling the wire under test to the first node while grounding the remaining wires of the set of wires, the sequencer defining the wire under test as a previous wire under test when the device cannot detect the arc on the wire under test, the sequencer being adapted to choose another wire of the remaining wires of the set of wires and define the another wire as the wire under test while grounding the previous wire under test and the remaining wires; and
a reflection minimizer interposed between the sequencer and at least one wire from the remaining set of wires, the reflection minimizer being capable of minimizing the attenuation of the amplitude of the pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for detecting parallel arc faults in a set of wires, the method comprising:
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selecting a first wire of the set of wires and defining the first wire as a wire under test while grounding the remaining wires in the set of wires to define these remaining wires as ground wires;
charging a capacitance defined between the wire under test and the ground wires using a current source to ramp up the voltage on the wire under test to a maximum test voltage lever;
determining that an arc has occurred when the voltage on the wire under test drops precipitously; and
calculating the approximate distance to an arc when the arc has occurred on the wire under test by determining the difference in arrival times among incident and reflected waveforms from the arc. - View Dependent Claims (16, 17, 18, 19)
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Specification