Patent ID: 9217782
Filing Date: 2015-12-22
Classification: G01R

Abstract:
1. A method for measuring current in an electrical network, comprising at least one first electric line and at least one second electric line, the method comprising: linking the first electric line to a first circuit breaker comprising a first protection coil and having a wall traversed by a magnetic field emitted by the first coil; linking the second electric line to a second circuit breaker comprising a second protection coil having a wall traversed by a magnetic field emitted by the second coil; arranging, on the wall of the first circuit breaker, a first synchronous three-axis digital magnetometer (Mi) on a semiconductor chip; arranging, on the wall of the second circuit breaker, a second synchronous three-axis digital magnetometer on a semiconductor chip; measuring, by way of the first digital magnetometer, at least one component of the magnetic field emitted by the first coil; and measuring, by way of the second digital magnetometer, at least one component of the magnetic field emitted by the second coil; correcting the components measured by each of the first and second magnetometers by subtracting from each component a fraction of the component measured by the other of the first and second magnetometers, so as to neutralize a phenomenon of magnetic interference between the first and second circuit breakers; and determining the value of a current traversing each electric line from the corrected components, wherein the correction step comprises determining, for each of the first and second circuit breakers, an interference parameter of one of the first and second circuit breakers on the magnetometer associated with the other of the first and second circuit breakers, representative of a variation in the magnetic field detected by the magnetometer associated with the other of the first and second circuit breakers, when the magnetic field emitted by the one of the first and second circuit breakers varies, and wherein the step of determining the interference parameter comprises: sampling in a synchronous manner, at two successive times, a component of the magnetic field measured by the first magnetometer and a component of the magnetic field measured by the second magnetometer; determining a variation in the first in the first component and a variation in the second component; and determining the interference parameter of the one of the first and second circuit breakers on the magnetometer associated with the other of the first and second circuit breakers by dividing the smallest of the two variations in absolute value by the highest of the two variations in absolute value.