EP0288998A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Self-powered electrical measuring system isolated from electrical perturbances
Assignee: Hydro-Québec
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Filing: 1988-04-27
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Granted: —
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Expires: 2008-04-27
Abstract
Abstract A self-powered electrical measuring system for measuring current in a high voltage circuit. The system comprises a Rogowski coreless coil disposed about a conductor for sensing current flowing in the conductor and producing a voltage signal proportional to the magnitude of the current. An electronic conditioning circuit is provided for conditioning the voltage signal for transmission by optical link means to a remote receiver operating which is at ground potential and totally isolated from the measuring system in the high voltage circuit. A floating supply circuit comprising a tapping coil having a magnetic core disposed about the conductor is provided whereby to produce a supply voltage for the electronic conditioning circuit means.
Inventors
- 👤 André Chénier
- 👤 André Hamel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 18:19
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/18; G01R15/181
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
90 words
A self-powered electrical measuring system for measuring current in a high-voltage circuit, said apparatus comprising: current measuring means for sensing a current flowing in a conductor and producing a voltage signal proportional to the magnitude of said current, electronic conditioning circuit means for conditioning said signal for transmission by optical link means to a remote receiver operating at ground potential and which is totally isolated from the high voltage circuit, and a floating supply means for deriving a supply voltage from the conductor for feeding said electronic conditioning circuit means.
Claim 2
Dependent Claim
90 words
A self-powered electrical measuring system for measuring current in a high-voltage circuit, said apparatus comprising: current measuring means for sensing a current flowing in a conductor and producing a voltage signal proportional to the magnitude of said current, electronic conditioning circuit means for conditioning said signal for transmission by optical link means to a remote receiver operating at ground potential and which is totally isolated from the high voltage circuit, and a floating supply means for deriving a supply voltage from the conductor for feeding said electronic conditioning circuit means.
Claim 3
Dependent Claim
85 words
A measuring system as claimed in claim 1, wherein said current measuring means is a Rogowski coreless coil disposed about said conductor, said coil producing said output signal in terms of about a few mv per Amp. and in accordance with the following formula: E = (2×10⁻⁷ · NA R )Henrys · dI dT where: E is the voltage, N the number of turns (about 1000), A the section of the coil, R the radius of the coil, I the current, and t the time.
Claim 4
Dependent Claim
90 words
A measuring system as claimed in claim 2, wherein said local supply means comprises a tapping coil having a magnetic core disposed about said conductor for tapping, by magnetic inductance caused by current flow in said conductor, sufficient voltage to feed said electronic conditioning circuit means: said tapping coil having a sufficient number of turns to generate said sufficient voltage even at low current flow in said conductor, said magnetic core having a selected dimension so as to saturate during high current surges such as occurs during a short-circuit condition.
Claim 5
Dependent Claim
49 words
A measuring system as claimed in claim 3, wherein said electronic conditioning circuit means comprises a modulator circuit for receiving said signal from said Rogowski coil and modulating same for transmission by a transmitter circuit connected thereto, said transmitter circuit generating a composite modulated signal over said link means.
Claim 6
Dependent Claim
17 words
A measuring system as claimed in claim 4, wherein said link means is an optical transmission line.
Claim 7
Dependent Claim
21 words
A measuring system as claimed in claim 4, wherein said link means is an infrared signal transmitted to said remote receiver.
Claim 8
Dependent Claim
30 words
A measuring system as claimed in claim 4, wherein said conductor forms part of a high-voltage switch assembly, said apparatus being located within an integrated module within said switch assembly.
Claim 9
Dependent Claim
29 words
A measuring system as claimed in claim 7, wherein said module is a toroidal shape metal housing disposed about said conductor and shielding said system from environmental electrical perturbances.
Claim 10
Dependent Claim
92 words
A measuring system as claimed in claim 8, wherein said high-voltage switch assembly is an automatically actuated high-voltage switch located within an insulating housing, a vacuum chamber within said housing and having a fixed contact therein secured to a high-voltage line, an axially movable conductive contact rod displaceably supported in sealing engagement with said vacuum chamber and having a portion extending exteriorly of said chamber, said toroidal shape metal housing being disposed about a portion of said contact rod exteriorly of said chamber with said Rogowski coil and tapping coil positioned thereabout.
Claim 11
Dependent Claim
46 words
A measuring system as claimed in claim 4, wherein said conditioning circuit further comprises a calibrating circuit to select a desired modulating frequency, said tapping coil being connected to a voltage rectifier and voltage regulator to feed an operating voltage to said modulator and transmitter circuits.
References Cited (Backward Citations)
No citation records indexed.
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