Multiphase Current Measurement Using Bypass Conductors
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Solution Overview
Problem
Existing current measuring apparatus using magnetoresistive gradient sensors are prone to inaccuracy and distortion when measuring high currents, especially above 100 A peak, due to the shifting of the sensor's operating point into a nonlinear characteristic curve range, which is exacerbated in compact designs necessary for practical applications.
Innovation Solution
The introduction of bypass conductors arranged symmetrically with respect to magnetoresistive gradient sensors to compensate the DC field component between adjacent current conductors, maintaining a linear operating range and reducing measurement distortion, even at high current levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the spacing between current conductors is reduced to achieve compact structure, then device size is reduced, but measurement accuracy deteriorates due to DC field shifting sensor operating point into nonlinear range
Solution Approach 1:
A bypass conductor is introduced as an intermediary element between the current conductors and gradient sensors. This bypass conductor carries a compensating current that generates a counter DC magnetic field, mediating the interaction between current conductors and sensors to cancel out the harmful DC field component and maintain measurement accuracy in compact configurations
Solution Approach 2:
The invention changes the electrical current distribution parameter by diverting a portion of current through the bypass conductor. By adjusting the bypass conductor's resistance and positioning, the DC field strength parameter is modified to compensate for the reduced spacing between conductors and sensors, maintaining the sensor operating point in the linear range
2Measurement precision
If bypass conductors are added to compensate DC field, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The bypass conductor serves multiple functions simultaneously: it acts as a current carrier in the electrical circuit, a magnetic field compensator for DC offset elimination, and a structural element that can be integrated into existing conductor arrangements. This multi-functionality achieves accuracy improvement without proportionally increasing device complexity
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables accurate and precise current measurement in high-current applications while maintaining a compact structure, effectively suppressing DC field components and preventing nonlinear distortion, thus enhancing measurement accuracy and applicability.
Implementation Method 1
N-1 magnetoresistive gradient sensors for determining a magnetic field strength difference in a measurement plane between conductor currents of adjacent current conductors
Implementation Method 2
at least one bypass conductor of at least one further current conductor is guided into a region of the gradient sensor, in each case for compensating a DC field component of the two adjacent current conductors
Data Source
AI summary
A multiphase current measuring apparatus and method for measuring current of a multiconductor current system with N current conductors, where N>2, by determining a magnetic field strength difference in a measurement plane between conductor currents of adjacent current conductors by using the multiphase current measuring apparatus having N−1 magnetoresistive gradient sensors. At least one bypass conductor of at least one of the further current conductors is arranged with respect to each magnetoresistive gradient sensor for compensating a DC field component of the two adjacent current conductors. The DC component of the conductor currents of the two adjacent current conductors is suppressed by passing a bypass current of the at least one further current conductor through the bypass conductor symmetrically through the measurement plane of the magnetoresistive gradient sensor.