US 12,146,900 B2
Current measurement system
Damien Coutellier, Miribel (FR); Arnaud Labbe, St. Girod (FR); Atef Lekdim, Villeurbanne (FR); and Albert Tournilhac, Chateauneuf de Galaure (FR)
Assigned to LEM INTERNATIONAL SA, Meyrin (CH)
Appl. No. 17/791,418
Filed by LEM INTERNATIONAL SA, Meyrin (CH)
PCT Filed Jan. 8, 2021, PCT No. PCT/EP2021/050312
§ 371(c)(1), (2) Date Jul. 7, 2022,
PCT Pub. No. WO2021/140226, PCT Pub. Date Jul. 15, 2021.
Claims priority of application No. 20151245 (EP), filed on Jan. 10, 2020.
Prior Publication US 2023/0029921 A1, Feb. 2, 2023
Int. Cl. G01R 15/18 (2006.01); G01R 35/00 (2006.01)
CPC G01R 15/18 (2013.01) [G01R 35/005 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A current measurement system comprising a multi-phase open loop current transducer for measuring phase currents (I1, I2, I3) flowing in a plurality n of primary conductors of a multi-phase electrical system, the transducer comprising a housing, a magnetic core including a first magnetic core part and a second magnetic core part and a plurality n+1 of magnetic field detectors mounted in the housing between the first and second magnetic core parts in which portions of the primary conductors traversing the current transducer housing are positioned, the system further comprising a non-volatile memory in which information on at least one coupling matrix (K) of dimension [n+1]×n, pre-defined in a calibration procedure, is stored, said at least one coupling matrix (K) linking the phase currents (I1, I2, I3) flowing in the primary conductors to magnetic induction fields (B1, B2, B3, B4) detected by said magnetic field detectors, and a computation unit configured to compute the values of said n phase currents from the outputs of said n+1 magnetic field detectors using the coupling matrix, wherein the computation unit is further configured to redundantly estimate the n phase currents in a degraded mode using n+1 degraded mode coupling matrices, each of dimension n×n based on the outputs of a subset of n of said n+1 magnetic field detectors taking into account all the n phase currents for each of the magnetic induction fields detected by said subset of magnetic field detectors, and detect faults in the magnetic field detectors, leakage currents, or overcurrents based on the redundantly estimated n phase currents.