Method for measuring electric current in a plurality of conductors

• US 7,895,004 B2
• Filed: 06/30/2005
• Issued: 02/22/2011
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: Valeo Equipements Electriques Moteur (Valeo SE)
• Original Assignee: Valeo Equipements Electriques Moteur (Valeo SE)
• Inventors: Bernard, François-Xavier, Leroux, Frédéric, Chemin, Michaël
• Primary Examiner(s): TSAI, CAROL S W
• Application Number:
  US11/570,931
• Publication Number:
  US 20080312854A1
• Time in Patent Office: 2,063 Days
• Field of Search: 702/64, 702/115, 702/183, 324/244, 324/260, 324/117.R, 324/117.H, 324/127, 324/251, 318/431, 318/430, 318/432, 318/433, 318/434, 361/98, 361/100, 361/154, 361/187
• US Class Current: 702/64
• CPC Class Codes: G01R 15/202 using Hall-effect devices Hall elements in arrangements for measuring electrical power G01R21/08
• CPC Class Codes: G01R 31/007 using microprocessors or computers

Abstract

A method and system for measuring electric current in a plurality (n) of conductors. According to the invention, the method comprises the following steps: an electric current transducer is place substantially opposite to each conductor (I, i=1, . . . , n); a decorrelation matrix ([G]), which is a function of the position of the transducers in relation to the conductors, is constructed; the current (I_mesi) in each conductor (i) is measured with the aid of electric current transducers and real currents (I_réeli) are deduced with the aid of the decorrelation matrix ([G]) and the measured currents (I_mesi).

Claims

1. A method of measuring an electric current in a plurality (n) of conductors, said method comprising the steps of:

placing an electric current transducer substantially opposite each conductor (I, I=1, . . . , n), one conductor being rigid,

constructing a decorrelation matrix that is a function of the position of the electric current transducers with respect to said conductors,

measuring the currents in each conductor by means of said electric current transducers and deducing therefrom real currents by means of said decorrelation matrix and said measured currents;

wherein said decorrelation matrix comprises elements that are determined by successively applying in each conductor a calibrated current, the current applied in the other conductors being zero, and measuring by means of said transducers an electric current signal associated with each conductor.

2. The method according to claim 1, wherein said real currents are deduced from the measured currents by applying the inverse matrix of the decorrelation matrix.

5. The method according to claim 1, wherein said electric current transducers are Hall effect sensors.

6. A device for implementing the method according to claim 1, wherein said method comprises the steps of situating a plurality of electric current transducers, each transducer being placed substantially opposite each conductor.

7. A device according to claim 6, wherein said electric current transducers are Hall effect sensors.

8. The method according to claim 1, wherein said method further comprises the step of:

applying said measurement of the electric current in input/output conductors of poles of a stator of a rotary electrical machine.

11. Application of the method according to claim 1, to the measurement of the electric current in a battery management system.

12. Application of the method according to claim 1 to the measurement of the electric current in a voltage converter system.

3. A method of measuring an electric current in a plurality (n) of conductors, said method comprising the steps of:

placing an electric current transducer substantially opposite each conductor (I, I=1, . . . , n), one conductor being rigid,

constructing a decorrelation matrix that is a function of the position of the electric current transducers with respect to said conductors,

measuring the currents in each conductor by means of said electric current transducers and deducing therefrom real currents by means of said decorrelation matrix and said measured currents;

wherein said method also comprises a step of determining an offset matrix whose elements are equal to the currents measured in each conductor in the absence of current supplied in said conductors, the real currents being deduced from the currents measured by means of the decorrelation matrix and said offset matrix.

4. The method according to claim 3, wherein a matrix of real currents is obtained by subtracting the offset matrix from a matrix of the measured currents and applying the inverse matrix of the decorrelation matrix to the result obtained.

9. A method of measuring an electric current in a plurality (n) of conductors, said method comprising the steps of:

placing an electric current transducer substantially opposite each conductor (I, I=1, . . . , n), one conductor being rigid,

constructing a decorrelation matrix that is a function of the position of the electric current transducers with respect to said conductors,

measuring the currents in each conductor by means of said electric current transducers and deducing therefrom real currents by means of said decorrelation matrix and said measured currents;

wherein said method further comprises the step of;

applying said measurement of the electric current in input/output conductors of poles of a stator of a rotary electrical machine;

wherein an inverse projection matrix is multiplied by the inverse matrix of a decorrelation matrix in order to produce a single matrix applied to the measured output currents of the stator in order to effect a numeric regulation of currents of the said rotary electrical machine.

10. Application according to claim 9, wherein, prior to the application of the single matrix to the measured currents, an offset matrix is applied to the measured output currents of the stator.

13. A system for measuring an electric current in a plurality of conductors associated with poles of a stator in an electric motor, said system comprising:

a plurality of electric current transducers situated in operative relationship opposite each of said plurality of conductors, respectively; and

a measuring circuit for measuring current in each of said plurality of conductors using said plurality of electric current transducers and deducing therefrom real currents using a decorrelation matrix and said measured currents;

wherein said decorrelation matrix is a function of a position of the electric current transducers with respect to said plurality of conductors;

wherein said decorrelation matrix comprises elements that are determined by successively applying in each of said plurality of conductors a calibrated current, the current applied in the other of said plurality of conductors being zero, said measuring circuit using said plurality of electric current transducers to measure an electric current signal associated with each of said plurality of conductors.

14. The system as recited in claim 13, wherein said real currents are deduced from measured currents by applying an inverse matrix of the decorrelation matrix.

17. The system as recited in claim 13, wherein said plurality of electric current transducers are Hall effect sensors.

18. The system as recited in claim 13, wherein each of said plurality of electric current transducers is placed substantially opposite each of said plurality of conductors.

15. A system for measuring an electric current in a plurality of conductors associated with poles of a stator in an electric motor, said system comprising:

a plurality of electric current transducers situated in operative relationship opposite each of said plurality of conductors, respectively; and

a measuring circuit for measuring current in each of said plurality of conductors using said plurality of electric current transducers and deducing therefrom real currents using a decorrelation matrix and said measured currents;

wherein said decorrelation matrix is a function of a position of the electric current transducers with respect to said plurality of conductors, wherein said measuring circuit uses an offset matrix whose elements are equal to the currents measured in each of said plurality of conductors in the absence of current supplied in said plurality of conductors, said real currents being deduced from the currents measured using said decorrelation matrix and said offset matrix.

16. The system as recited in claim 15, wherein said real currents are deduced into a matrix of real currents that is obtained by subtracting said offset matrix from a matrix of the measured currents and applying an inverse matrix of the decorrelation matrix to the result obtained.