Rogowski Current Sensor Asymmetric Superposed Coils Crosstalk
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Solution Overview
Problem
Rogowski current sensors on printed circuit boards have low gain and are prone to crosstalk issues, making them inadequate for certain applications, such as protecting electricity distribution installations and accurately detecting short-circuit currents.
Innovation Solution
A current sensor design featuring a Rogowski winding with two superposed coils wound around a substrate, where the first coil has a longer quadrilateral contour and the second coil has a shorter, wider contour, with staggered through-holes and rectilinear portions, enhancing immunity to electromagnetic disturbances and improving measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single Rogowski coil is used on a printed circuit board, then the manufacturing is simple and inexpensive, but the gain is low and crosstalk susceptibility is high
Solution Approach 1:
The patent combines two Rogowski coils into a single integrated sensor structure on the printed circuit board. The first and second coils are superimposed and electrically connected in series, merging their functions to achieve higher gain while maintaining PCB manufacturing simplicity. This resolving combination allows the sensor to overcome the low gain limitation of single-coil designs without sacrificing ease of manufacture.
Solution Approach 2:
The patent implements a nested configuration where the second coil is positioned within the contour of the first coil, with the second contour line contained inside the first contour line. This nesting arrangement allows both coils to occupy overlapping spatial regions on the PCB, maximizing the use of available space while achieving the desired series connection for enhanced gain.
2Device complexity
If a single Rogowski coil is used on a printed circuit board, then the structure is simple, but the sensor is susceptible to crosstalk
Solution Approach 1:
The patent combines two Rogowski coils into a single integrated sensor structure on the printed circuit board. The first and second coils are superimposed and electrically connected in series, merging their functions to achieve higher gain while maintaining PCB manufacturing simplicity. This resolving combination allows the sensor to overcome the low gain limitation of single-coil designs without sacrificing ease of manufacture.
Solution Approach 2:
The patent introduces asymmetry in the coil dimensions, where the first contour line defines a quadrilateral with greater length but smaller width, while the second contour line defines a quadrilateral with smaller length but greater width. This asymmetric configuration optimizes the magnetic coupling characteristics and reduces crosstalk susceptibility while maintaining structural simplicity.
3Measurement precision
If coil contours are made larger to increase gain, then the measurement sensitivity improves, but the sensor size increases
Solution Approach 1:
The patent implements a nested configuration where the second coil is positioned within the contour of the first coil, with the second contour line contained inside the first contour line. This nesting arrangement allows both coils to occupy overlapping spatial regions on the PCB, maximizing the use of available space while achieving the desired series connection for enhanced gain.
Solution Approach 2:
The patent utilizes the third dimension (vertical stacking) by superimposing the two coils on top of each other on the PCB. This dimensional transition allows the sensor to achieve increased effective area and sensitivity without proportionally increasing the planar footprint, as the coils occupy different vertical layers rather than expanding horizontally.
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 design enhances the gain and immunity to crosstalk, providing improved measurement accuracy and reliability for current sensing applications, particularly in protecting electricity distribution installations.
Implementation Method 1
The current flowing through the electrical conductor induces a voltage across the coil
Data Source
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AI summary
This current sensor (6) comprises: - an insulating substrate (10) having a central opening (12); - a Rogowski coil (14) surrounding the central opening and including a first coil (16) and a second coil (18) superimposed and electrically connected in series, the first coil and the second coil being wound around the substrate according to, respectively, a first contour line (C1) and a second contour line (C2), each contour line delimiting, in the plane of the substrate, a quadrilateral-shaped contour centered around the central opening; in which the quadrilateral-shaped contour delimited by the first contour line (C1) has a length (L1) greater than the length (L2) of the quadrilateral delimited by the second contour line (C2) and a width (f1) less than the width (ℓ2) of the quadrilateral delimited by the second contour line (C2).