Portable Contactless Current Sensor Angular Spatial Filtering
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Solution Overview
Problem
Existing contactless current measurement technologies require surrounding the conductor, which is not always possible, and struggle to isolate the desired current from disturbing currents in the environment with high precision and dynamic range.
Innovation Solution
A portable contactless current measuring device with a measuring module comprising multiple magnetic field sensors arranged orthogonally to the conductor and a processing module that performs angular spatial filtering to isolate the desired current, allowing precise measurement without encircling the conductor and minimizing error from disturbing currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional contactless current sensors (Hall effect, Rogowski loops, etc.) are used, then current measurement can be performed without contact, but the conductor must be surrounded by the sensor which is not always possible or desirable
Solution Approach 1:
The sensor array is divided into multiple independent magnetic field sensors arranged in a specific geometric pattern (e.g., three sensors at vertices of an equilateral triangle). Each sensor independently measures the magnetic field component along its normal direction, and the measurements are combined through signal processing to extract the current information. This segmentation allows the sensor array to measure current without surrounding the conductor, solving the adaptability problem.
2Measurement precision
If multiple magnetic field sensors are used for spatial filtering, then angular selectivity and isolation from disturbing currents improve, but device complexity increases
Solution Approach 1:
Each magnetic field sensor is positioned at a specific location with a specific orientation (normal direction) to detect magnetic field components from specific directions. The sensors are arranged in a geometric pattern where each position contributes uniquely to the spatial filtering capability. This local quality assignment enables the system to achieve high angular selectivity and isolate the desired current from disturbing currents while maintaining manageable device complexity.
Solution Approach 2:
The sensors are arranged in an asymmetric geometric configuration (e.g., equilateral triangle vertices) with specific normal directions rather than symmetric circular arrangement. This asymmetric positioning creates distinct sensitivity patterns for different current directions, enabling effective spatial filtering and angular selectivity to isolate the target current from surrounding disturbing currents.
3Measurement precision
If the sensor array is positioned at a determined distance from the conductor, then measurement precision improves, but the device cannot adapt to different measurement scenarios
Solution Approach 1:
The device incorporates adjustable positioning mechanisms that allow the sensor array to dynamically change its distance and angular position relative to the conductor being measured. This dynamic adaptability enables the system to optimize measurement precision for different measurement scenarios while maintaining the core capability of contactless current measurement without surrounding the conductor.
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
Enables precise measurement of currents from 1 to 100 Amps with minimal error (<1%) by isolating the desired current from surrounding conductors, covering a large current measurement range without physically gripping the conductor.
Implementation Method 1
portable contactless device for measuring current by induced magnetic fields
Data Source
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AI summary
A portable, non-contact measuring device (12) for a current I flowing through an electrical conductor (10A), the device (12) comprising a measuring module (14) and a processing module (16), the measuring module (14) intended to be held by an operator in contact with the conductor (10A) in a plane P substantially orthogonal to this conductor (10A) and without enclosing this conductor (10A), comprising one or two pluralities of magnetic field sensors (140-154), and the processing module (16) being configured to perform a determined linear combination of the plurality of signals delivered by one or both pluralities of magnetic field sensors, so as to achieve angular spatial filtering isolating the current I to be measured from other disturbing currents flowing through other conductors (10B,10C).