Zone arc fault detection
First Claim
1. A zone arc fault detection system for detecting arc faults in a defined zone of an electrical circuit, comprising:
- a zero-sequence differential voltage arc detector for detecting series arcing faults and including;
voltage summing means for summing the voltages of all phases of said circuit at both source and load ends of said zone; and
comparing means for comparing the sum of the voltages at one of said load and source ends of each phase and the sum of the voltage that the other said load and source ends of each phase and for producing a difference signal corresponding to any difference therebetween.
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Accused Products
Abstract
A number of methods can be used for zone arc protection to detect series and/or shunt arcing faults in various electrical components and/or circuits. A differential current detector, or a di/dt based detector, may be used to detect shunt arcs, while a differential voltage detector or a zero-sequence voltage detector, is used to detect series arcs. A differential phase current detection scheme may be used for both shunt arcs and series arcs. Series arcs may also be detected using a voltage drop system or a line power loss system. Detection of arcing in joints may be monitored directly. A ground fault detector may be combined with one or more of these systems for detecting a ground fault in the circuit to be protected. Two or more of the above systems or detectors may be combined for arc monitoring and detection.
238 Citations
59 Claims
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1. A zone arc fault detection system for detecting arc faults in a defined zone of an electrical circuit, comprising:
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a zero-sequence differential voltage arc detector for detecting series arcing faults and including; voltage summing means for summing the voltages of all phases of said circuit at both source and load ends of said zone; and comparing means for comparing the sum of the voltages at one of said load and source ends of each phase and the sum of the voltage that the other said load and source ends of each phase and for producing a difference signal corresponding to any difference therebetween. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A zone arc fault detection system for detecting arcing faults in a defined zone of an electrical circuit, comprising:
- a differential phase current detector including a pair of substantially identical parallel insulated conductors for each zone of each conductor to be protected by said differential phase current detector thereby defining a protected zone comprising the length of said parallel conductors between two points where the two conductors are coupled together, a transformer current sensor inductively coupled with each said pair of parallel conductors, said transformer current sensor and said conductors being respectively configured and arranged such that the current induced in said current transformer sensor from one of said conductors is subtracted from the current induced in said current transformer sensor from the other said conductors to produce a difference current output.
- View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. A zone arc fault detector system comprising:
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a differential current arc detector for detecting line-to-line and ground fault arcing conditions; and a differential voltage arc detector for detecting series arcing faults. - View Dependent Claims (29, 30, 31, 32, 33)
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- 34. A zone arc detection system comprising a differential voltage arc detector for detecting series arc faults and a differential phase current detector for detecting both series and parallel arcing faults.
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40. A zone arc fault detector system comprising:
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a differential current arc detector for detecting line-to-line and ground fault arcing conditions; and a differential phase current detector for detecting both series and parallel arcing faults.
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41. A zone arc fault detection system for detecting series arc faults in a defined zone of electrical circuit, comprising:
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voltage sensing means for sensing the voltage in a line conductor of said electrical circuit at both source and load ends of said zone; and arc detector means coupled with said sensing means for producing a difference signal corresponding to any differences between the voltages at the source and load ends of said zone. - View Dependent Claims (42)
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43. A zone arc fault detection system for detecting arc faults in a defined zone of an electrical circuit, comprising:
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a current transformer operatively coupled with a line conductor of said electrical circuit for producing a current signal corresponding to an electrical current in said line conductor; an arc detector coupled with said current transformer for detecting a change in current due to a series arcing fault on said line conductor; and a line impedance stabilization network coupled with source and line ends within the defined zone of said line conductor. - View Dependent Claims (44, 45)
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46. A zone arc fault detection system for detecting arc faults in a defined zone of electrical circuit, comprising:
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voltage sensing means coupled with each of source and load ends within a zone of a line conductor of said electrical circuit; a current sensor coupled with said line conductor of said electrical circuit adjacent the source end of said zone; and an arc power detector operatively coupled with said voltage sensors and with said current sensor for detecting any power loss through the line conductor in said zone corresponding to a series arc in said line within said zone. - View Dependent Claims (47, 48)
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49. A zone arc fault detection system for detecting arc faults in a defined zone of an electrical circuit, comprising:
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voltage summing means for summing the voltages of all phases of said circuit at both source and load ends of said zone; comparing means for comparing the sum of the voltages of the phases at the other of said load and source ends and the sum of the voltages of the phases at the other of said load and source ends and for producing a difference signal corresponding to any difference therebetween; a differential current arc detector; and ground fault sensor means comprising a current transformer sensor operatively coupled with line and neutral conductors of said electrical circuit for detecting a difference in current therebetween and producing a corresponding ground fault signal. - View Dependent Claims (50)
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- 51. A system for monitoring for arcing faults in a joint of an electrical circuit, said system including means for monitoring for a voltage differential across said joint and for producing a corresponding arcing fault signal.
Specification