Patent ID: 8111059
Filing Date: 2012-02-07
Classification: G01R

Abstract:
1. An apparatus for localizing a quantity of current vectors in an electrical device, where the electrical device produces a magnetostatic field in response to an input current and the quantity of current vectors is a known quantity equal to one or more, and where each current vector in the quantity of current vectors has a current direction, where the current direction is known and the current direction is the same among all current vectors in the quantity of current vectors, and where a total current is known, where the total current is the sum of all currents in the quantity of current vectors, comprising: an input current measurement device capable of measuring the input current, the input current measurement device having a current signal output for transmission of a signal representative of the magnitude of the input current; one or more magnetic field sensors, where the quantity of the one or more magnetic field sensors is equal to or greater than the quantity of current vectors, where each individual sensor in the one or more magnetic field sensors has a first output and a second output, and where the each individual sensor is capable of sensing a magnitude of the magnetostatic field in a first direction and transmitting a signal representative of the magnitude of the magnetostatic field in the first direction through the first output, and where the each individual sensor is capable of sensing a magnitude of the magnetostatic field in a second direction and transmitting a signal representative of the magnitude of the magnetostatic field in the second direction through the second output, and where the each individual sensor is mounted at an individual field sensing location located in a sensing plane, where the sensing plane is a geometric plane having a substantially perpendicular orientation with respect to the current direction, and where the each individual sensor is mounted on an individual sensing reference axis, where the individual sensing reference axis is a line lying in the sensing plane and passing through the individual field sensing location, and where the each individual sensor is oriented such that the first direction and the second direction both lie in the sensing plane, such that a quantity of individual field sensing locations exist, where the quantity of individual field sensing locations is equal to the quantity of the one or more magnetic field sensors, and each individual field sensing location in the quantity of individual field sensing locations is unique from any other individual field sensing location in the quantity of individual field sensing locations; and a processor in data communication with the input current measurement device and receiving the current signal output, and the processor in data communication with the each individual sensor and receiving the first output and the second output from the each individual sensor, and the processor capable of formulating, for the each individual sensor, Biot-Savart superposition equations having the form, where n=the quantity of current vectors, B B l is the total current, Θ d m and the processor capable of expressing all Θ Mi and d Mi referenced to a common point based on the relative locations of all individual sensing locations, such that the processor receives data from all of the each individual sensors and produces a set of formulated equations, and the set of formulated equations has a quantity of equations at least equal to a quantity of unknowns in the set of formulated equations, and the processor capable of simultaneously solving the set of formulated equations and determining a location for each current vector in the quantity of current vectors relative to the common point, thereby localizing the quantity of current vectors in the electrical device, where the electrical device produces a magnetostatic field in response to an input current and the quantity of current vectors is a known quantity equal to one or more.