Dual-Group Magnetic Current Sensor Stray Field Suppression
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Solution Overview
Problem
Current current sensors, such as Hall sensors, face interference from stray magnetic fields, especially in high current measurements and three-phase driving applications, leading to noise and reduced accuracy due to limited common mode stray field suppression.
Innovation Solution
A current sensor system utilizing two groups of magnetic sensing probes, with sensor circuitry to determine differential magnetic field measurements from each group, allowing for improved accuracy by calculating the current strength based on the difference between these measurements, thereby enhancing signal-to-noise ratio and robustness against stray fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a Hall sensor is used to measure current, then the current strength can be sensed, but the measurement accuracy deteriorates due to interference from stray magnetic fields
Solution Approach 1:
The patent divides the measurement system into two separate groups of magnetic sensing probes (first group and second group), each performing differential measurements. This segmentation allows the system to process and compare measurements from both groups to cancel out stray magnetic field effects while maintaining accurate current measurement capability.
2Measurement precision
If two groups of magnetic sensing probes are used to suppress stray fields, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The patent combines two groups of magnetic sensing probes into a single integrated current sensor device with unified sensor circuitry. This merging approach achieves improved stray field suppression through differential measurements while maintaining a compact and manageable device structure, balancing accuracy improvement with acceptable 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 significantly improves the signal-to-noise ratio and provides redundancy for fault tolerance, reducing the need for complex calibration procedures, and simplifies inter-bus-bar calibration in high current applications, achieving accurate current measurements with enhanced stray field suppression.
Implementation Method 1
A Hall Effect sensor (or Hall sensor) can sense a magnetic field by generating a voltage that varies in response to a magnetic field
Data Source
AI summary
Examples relate to a current sensor and to a method for sensing a strength of an electric current using two groups of magnetic sensing probes. The current sensor includes a first group and a second group of magnetic sensing probes. The current sensor comprises sensor circuitry coupled to the first and the second group of magnetic sensing probes. The sensor circuitry is configured to determine a first differential magnetic field measurement of a magnetic field using probes of the first group of magnetic sensing probes. The sensor circuitry is configured to determine a second differential magnetic field measurement of the magnetic field using probes of the second group of magnetic sensing probes. The sensor circuitry is configured to determine a strength of the electric current based on a difference between the first differential magnetic field measurement and the second differential magnetic field measurement.