Current Sensor System Asymmetric Magnetic Field Gradient Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensors face challenges in accurately measuring AC currents with high frequency components, as existing technologies suffer from increased effective resistance due to the skin effect, leading to measurement inaccuracies and difficulties in determining frequency content.
Innovation Solution
A current sensor system utilizing a busbar with a beam-shaped portion and strategically positioned sensor elements to measure magnetic field gradients, allowing for accurate AC current measurement across a frequency range of 100 Hz to 2000 Hz with minimal processing power and without requiring frequency compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If magnetic sensors are used to measure AC currents with high frequency components, then galvanic separation and compact size are achieved, but measurement accuracy deteriorates due to the skin effect increasing effective resistance
Solution Approach 1:
The patent positions the two sensor elements asymmetrically relative to the busbar - one element is positioned closer to the busbar than the other. This asymmetric positioning creates different magnetic field coupling conditions for each element, allowing the differential measurement to compensate for skin effect-induced errors while maintaining galvanic separation and compact dimensions
2Measurement precision
If sensor elements are positioned closer to the busbar to improve signal strength, then measurement sensitivity increases, but the impact of skin effect on measurement accuracy worsens
Solution Approach 1:
The patent implements local quality by positioning sensor elements at specific locations with different distances from the busbar. The first sensor element is positioned at a first distance while the second sensor element is positioned at a second distance, creating localized measurement zones that exploit spatial variations in magnetic field distribution to compensate for skin effect while maintaining sensitivity
3Measurement precision
If complex frequency compensation algorithms are implemented to improve AC current measurement accuracy, then measurement precision improves, but device complexity and processing power requirements increase
Solution Approach 1:
The patent replaces complex software-based frequency compensation algorithms with a hardware-based spatial positioning solution. By strategically positioning sensor elements at specific distances from the busbar, the system achieves frequency-compensated measurements through physical geometry rather than computational processing, thereby reducing device complexity and processing power requirements
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 system achieves improved accuracy and reduced processing requirements, enabling precise measurement of AC currents with various frequency components and waveform complexities, including harmonics, while maintaining a simple measurement process.
Implementation Method 1
each sensor element being configured for measuring a magnetic field component (Bz1, Bz2) oriented in the second direction (Z)
Implementation Method 2
the sensor device being configured for determining a difference between these magnetic field components, and for determining said AC current based on said difference
Data Source
Figure 1(a)~1(c)
Figure 2(a)~2(c)
Figure 3(a)~3(c)
AI summary
A current sensor system (1500; 1600) for measuring an AC electrical current, comprising: a busbar having a beam shaped portion having a length (Lc) and a width (Wp); a sensor device comprising two sensor elements (H1, H2) spaced apart (dx) from each other in the width direction (X) of the beam shaped portion. The sensor device is configured for measuring a magnetic field difference (ΔBz) or a magnetic field gradient (dBz/dx), and for determining the AC current based on said difference or gradient.