EP0390034A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Portable detector device for detecting partial electrical discharge in live voltage distribution cables and/or equipment
Assignee: Hydro-Québec
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Filing: 1990-03-26
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Granted: —
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Expires: 2010-03-26
Abstract
Abstract A portable detector device for detecting partial electrical discharge in live voltage distribution cables and/or equipment. The device comprises a probe secured to an insulated portable handle for manual displacement of the probe. A detector device is connected to the probe for detecting a signal in the range of 5 to 10 MHz emitted by the partial discharge. The detector has an input attenuator circuit which is connected to the probe to lower the level of the detected signal to a desired level. A transformation circuit is further provided to change the detected signal to a predetermined frequency signal substantially free of noise and representative of the magnitude of the detected partial discharge signal. An amplifier circuit amplifies the predetermined frequency signal and an output circuit generates signals indicative of the presence and magnitude of the partial discharge.
Inventors
- 👤 Antonio Gonzalez
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:10
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/12; G01R31/1227; G01R31/1263; G01R31/1272
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
136 words
A portable detector device for detecting partial electrical discharge in live voltage distribution cables and/or equipment, said device comprising a probe secured to an insulated portable means for manual displacement of said probe, a detector circuit connected to said probe for detecting a partial discharge signal in the range of 5 to 10 MHz emitted by said partical discharge, said detector device having an input attenuator circuit connected to said probe to lower the level of said detected signal to a desired level, transformation circuit means to change said detected signal to a predetermined frequency signal substantially free of noise and representative of the magnitude of said detected partial discharge signal, amplifier circuit means to amplify said predetermined frequency signal, and output circuit means for generating signals indicative of the presence and magnitude of partial discharge.
Claim 2
Dependent Claim
136 words
A portable detector device for detecting partial electrical discharge in live voltage distribution cables and/or equipment, said device comprising a probe secured to an insulated portable means for manual displacement of said probe, a detector circuit connected to said probe for detecting a partial discharge signal in the range of 5 to 10 MHz emitted by said partical discharge, said detector device having an input attenuator circuit connected to said probe to lower the level of said detected signal to a desired level, transformation circuit means to change said detected signal to a predetermined frequency signal substantially free of noise and representative of the magnitude of said detected partial discharge signal, amplifier circuit means to amplify said predetermined frequency signal, and output circuit means for generating signals indicative of the presence and magnitude of partial discharge.
Claim 3
Dependent Claim
44 words
A portable detector device as claimed in claim 1 wherein said transformation circuit means comprises a mixer circuit for mixing said detected signal with a known frequence signal from a local oscillator circuit to change said detected signal to produce predetermined lower frequency signal.
Claim 4
Dependent Claim
30 words
A portable detector device as claimed in claim 2 wherein said transformation circuit means also includes a filter circuit to remove unwanted frequency signals associates with said predetermined frequency signal.
Claim 5
Dependent Claim
43 words
A portable detector device as claimed in claim 3 wherein there is further provided an amplifier connected between said input attenuator and said mixer circuit to amplify an attenuated output signal at an output of said attenuator and representative of said detected signal.
Claim 6
Dependent Claim
32 words
A portable detector device as claimed in claim 4 wherein said amplifier circuit means comprises at least one further amplifier to amplify said predetermined frequency signal to feed said output circuit means.
Claim 7
Dependent Claim
34 words
A portable detector device as claimed in claim 5 wherein said output circuit means comprises a redressing detector circuit for redressing said predetermined frequency signal to feed a low frequency audible sound reproducing device.
Claim 8
Dependent Claim
47 words
A portable detector device as claimed in claim 5 wherein said output circuit means comprises a metering device to indicate the magnitude of said predetermined frequency signal, said predetermined frequency signal having a magnitude proportional to the magnitude of said partial discharge signal detected by said probe.
Claim 9
Dependent Claim
36 words
A portable detector device as claimed in claim 7 wherein there is further provided an audible alarm device associated with said metering device, said audible alarm device indicating an alarm condition relating to said detected signal.
Claim 10
Dependent Claim
31 words
A portable detector device as claimed in claim 8 wherein said metering device is a Vu meter fed by an output amplifier, said output amplifier also feeding said audible alarm device.
Claim 11
Dependent Claim
27 words
A portable detector device as claimed in claim 6 wherein said detector circuit is connected to an output low frequency amplifier to drive said sound reproducing device.
Claim 12
Dependent Claim
53 words
A portable detector device as claimed in claim 2 wherein said mixer circuit is a frequency converter which produces a predetermined frequency signal of 455 KHz, said detected signal being a 7 MHz signal, said oscillator frequency reducing said 7 MHz signal to said 455 KHz signal and preserving the same amplitude ratio.
Claim 13
Dependent Claim
23 words
A portable detector device as claimed in claim 2 wherein said input attenuator circuit is connected to said probe through a shielded cable.
Claim 14
Dependent Claim
45 words
A portable detector device as claimed in claim 2 wherein said input attenuator circuit is provided with a plurality of attenuating circuit, and switch means to connect said probe to a selected one of said passive attenuating circuits depending on a desired db level signal.
Claim 15
Dependent Claim
37 words
A portable detector device as claimed in claim 13 wherein said probe is constituted by a metal ring, said metal ring being disposed substantially perpendicular to distribution cables and moved therealong to detect partial electrical discharge faults.
Claim 16
Dependent Claim
28 words
A portable detector device as claimed in claim 13 wherein said probe is a metallic electrically conductive rod, said rod providing omnidirectional detection of partial electrical discharge faults.
Claim 17
Dependent Claim
26 words
A portable detector device as claimed in claim 13 wherein said probe is a contact probe formed as a metal plate having an insulating coating thereon.
Claim 18
Dependent Claim
31 words
A portable detector device as claimed in claim 13 wherein said probe is a unidirectional contact probe formed of a pair of metal plates superimposed and separated by an insulating material.
References Cited (Backward Citations)
WO1986007160A1
Cited
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