Coreless Current Sensor with Orthogonal Magnetic Detection
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Solution Overview
Problem
Existing current sensors face challenges in accurately measuring current values due to mutual interference from multiple conductors, requiring precise arrangement of magnetic detection elements to reduce magnetic field influence, which complicates configuration and increases costs.
Innovation Solution
A current sensor configuration with three magnetic detection units, each orthogonal to the magnetic field of adjacent conductors, along with amplification factor and influence degree correction units, to accurately measure current values without a core and minimize magnetic field interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetic detection elements are arranged to reduce mutual interference among conductors, then measurement precision improves, but device complexity increases due to position and angle adjustments
Solution Approach 1:
The patent divides the measurement task into three separate magnetic detection units, each dedicated to detecting the magnetic field of a specific conductor. This segmentation allows each unit to be independently optimized and positioned, reducing the complexity of coordinating multiple detection elements while maintaining high measurement precision through individualized detection pathways.
Solution Approach 2:
The patent introduces a magnetic flux collecting core as an intermediary element that channels and concentrates the magnetic flux from each conductor to its corresponding magnetic detection unit. This intermediary structure simplifies the spatial arrangement by providing a fixed magnetic pathway, eliminating the need for complex position and angle adjustments of the detection elements themselves.
2Measurement precision
If magnetic detection elements are positioned close to conductors for accurate detection, then measurement precision improves, but magnetic field interference from adjacent conductors increases
Solution Approach 1:
The patent assigns each magnetic detection unit to a specific conductor, creating dedicated detection zones. This segmentation isolates the measurement of each conductor's magnetic field, reducing cross-interference from adjacent conductors while maintaining close proximity for accurate detection.
Solution Approach 2:
The magnetic flux collecting core acts as an intermediary that guides the magnetic flux from each conductor directly to its corresponding detection unit. This intermediary structure confines the magnetic field pathways, preventing adjacent conductors' magnetic fields from interfering with each other's detection while enabling close positioning for high precision.
3Measurement precision
If a core is used to collect magnetic flux, then measurement precision improves, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent uses three separate, small-scale magnetic flux collecting cores instead of one large complex core structure. This segmentation reduces the total amount of magnetic material required, simplifies manufacturing processes, and lowers costs while maintaining effective magnetic flux collection for each conductor.
Solution Approach 2:
The patent implements magnetic flux collection locally at each conductor-detection unit interface rather than using a single large core for all conductors. This local quality approach reduces the overall material requirements and manufacturing complexity while achieving the same measurement precision through distributed, simplified core structures.
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
The solution enables accurate detection of current values with improved detection accuracy and reduced magnetic field interference, allowing for a compact, low-cost, coreless current sensor design.
Implementation Method 1
a first magnetic detection unit provided with a detection surface which is disposed so as to be orthogonal to a magnetic force line of a magnetic field generated by the current flowing through the first conductor and detects a magnetic flux density on a first conductor side of the second conductor and the third conductor
Implementation Method 2
a second magnetic detection unit provided with a detection surface which is disposed so as to be orthogonal to a magnetic force line of a magnetic field generated by the current flowing through the second conductor and detects a magnetic flux density on a second conductor side of the first conductor and the third conductor
Implementation Method 3
a third magnetic detection unit provided with a detection surface which is disposed so as to be orthogonal to a magnetic force line of a magnetic field generated by the current flowing through the third conductor and detects a magnetic flux density on a third conductor side of the first conductor and the second conductor
Data Source
AI summary
A current sensor configured to measure a current value of a current flowing through each of a first conductor, a second conductor, and a third conductor, the current sensor comprising: first to third magnetic detection units provided with detection surfaces and configured to output first to third detection result; first to third amplification factor correction units configured to correct first to third amplification factors set in advance based on an ambient temperature; first to third amplifiers configured to amplify the detection results based on the corrected amplification factors and output the amplified detection results as amplified signals; first to third influence degree correction units indicating influence degrees of the magnetic fields generated by the current flowing through the conductors; and first to third correction units configured to correct the amplified signals based on the corrected influence degrees and the amplified signals.