Segmented Rogowski Coil Manufacturing for Precision Current Sensing
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Solution Overview
Problem
Current sensing devices, including Rogowski coils, face challenges in manufacturing due to complex coil configurations, leading to high costs and potential errors, while also requiring improved electrical performance and scalability.
Innovation Solution
The development of a current sensing inductive device with segmented winding elements and form-less air coils, which can be manufactured using a method involving continuous winding over bobbin elements with a return conductor, allowing for adjustable configuration and tunability to achieve desired performance and cost tradeoffs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional Rogowski coils are manufactured using complex winding configurations, then measurement precision and electrical performance are improved, but manufacturing cost and labor intensity increase significantly
Solution Approach 1:
The Rogowski coil is divided into multiple discrete segments, each containing a portion of the total windings. These segments can be manufactured independently using standardized processes and then assembled together to form the complete coil. This segmentation enables modular manufacturing, reduces complexity of individual manufacturing steps, and maintains the overall measurement precision through proper segment configuration and assembly.
2Speed
If Rogowski coils use air cores instead of magnetically permeable cores, then response speed to fast-changing currents is improved, but inductance decreases
Solution Approach 1:
The patent optimizes the geometric parameters of the air core segments, including the winding density, segment dimensions, and spatial arrangement. By carefully controlling these parameters, the design achieves sufficient inductance for accurate measurement while maintaining the fast response characteristics inherent to air-core construction. The parameter optimization allows the air-core coil to compensate for the lower inductance through enhanced geometric configuration.
3Measurement precision
If the number of coil segments is increased to improve measurement precision, then device complexity and manufacturing cost increase
Solution Approach 1:
The patent employs multiple identical or near-identical coil segments that replicate the same winding pattern and structural design. This copying approach allows for standardized manufacturing of each segment, reducing overall device complexity through repetition of proven designs. The segments can be mass-produced using the same tooling and processes, then assembled in various configurations to achieve the desired measurement precision without increasing individual segment 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 results in a low-cost, precise, and scalable current sensing solution that offers improved electrical performance and reliability, with the ability to tune the device's output for specific applications by varying the number of segments or coils, and their positioning.
Implementation Method 1
The voltage that is induced in the coil is proportional to the rate of change of current in the conductor such that the output of the Rogowski coil is indicative to the amount of current passing through the conductor.
Data Source
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AI summary
A low-cost and high-precision current sensing device and methods for use and manufacturing. In one embodiment, the current sensing apparatus comprises a Rogowski-type coil which is manufactured in segments so as to facilitate the manufacturing process. In an exemplary embodiment, the current sensing apparatus segments comprise a number of bobbin elements that are wound and subsequently formed into complex geometric shapes such as torus-like shapes. In an alternative embodiment, bonded windings are utilized which allow the segments to be formed without a bobbin or former. In yet another alternative embodiment, the aforementioned current sensing devices are stacked in groups of two or more. Methods of manufacturing and using the aforementioned current sensing apparatus are also disclosed.