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US 5,694,103 AGranted
Laminated figure 8 power meter core
AssigneeSchlumberger Industries
InventorsR. Wendell Goodwin, David N. Makinson, Richard Timko
Life of this patent
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AssigneeSchlumberger Industries
InventorsR. Wendell Goodwin, David N. Makinson, Richard Timko
Estimating the term…
An improved laminated ferromagnetic FIG. 8 power meter core is provided. The core is fabricated from a plurality of ferromagnetic plates and is formed in the general shape of a FIG. 8. The central leg of the core has a cross-sectional area that is larger than the cross-sectional area of other parts of the core. The core gap, in which a Hall-effect sensor is located, has gap faces with chamfered or rounded over edges to reduce fringing and bypassing effects. The core is formed without discontinuous corners that can result in local saturation and, in use, accommodates electrical power conductors in an over-under looping relationship through the openings of the core to provide a more homogeneous magnetic flux within the core and thus more reliable metering. The overall result is a core with a higher saturation point and thus a wider dynamic range than prior art cores.
A ferromagnetic power meter core for converting an electrical current flowing in a conductor to a proportional magnetic flux for detection by a magnetic flux sensor, said power meter core comprising:
A FIG. 8 power meter core formed of ferromagnetic material and having a first lobe defining a first arcuate opening and a second lobe defining a second arcuate opening spaced from said first opening, said first opening being separated from said second opening by a central leg of said core, said central leg being severed to define an air gap between first and second gap faces of said central leg for accommodating a magnetic flux sensor in said gap.
A laminated FIG. 8 power meter core comprising a plurality of ferromagnetic plates interlocked together, said core having a first lobe defining a first opening and a first leg of said core on one end thereof and a second lobe defining a second opening spaced from said fast opening and a second leg of said core on the other end thereof, said first and second legs having a cross-sectional area, said first opening being separated from said second opening by a central leg of said core, said central leg being severed to define an air gap between first and second gap faces of said central leg and having a cross-sectional area about twice the cross-sectional area of said first and second legs, each of said gap faces having a peripheral edge that is contoured to reduce magnetic fringing and bypassing, a magnetic flux sensor located within said gap for sensing magnetic flux therein, and at least one conductor looped through said first opening and back through said second opening whereby a current flowing in said conductor induces magnetic fluxes within the lobes of the core that combine in the central leg and traverse the gap where the flux is detected as an indication of the magnitude of the current within the conductor.
Dependencies are inferred from the claim text.