PCB Rogowski Coil Layout for Compact High-Precision Current Sensing

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Solution Overview

Problem

Current current detection systems, reliant on current transformers and meters, face challenges in miniaturization due to large sizes and integration limitations, particularly with Rogowski coils, which struggle to maintain a usable quality factor when reduced in size, impacting precision and portability in electrical equipment.

Innovation Solution

A current detection system utilizing a printed circuit board with multiple Rogowski coils and amplification apparatuses, including active inductance circuits, to reduce size while maintaining precision, by concentrically mounting Rogowski coils with current-carrying conductors and employing active inductance circuits for direct current component suppression, allowing for integration into electrical equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the size of Rogowski coil is reduced to enable integration into electrical equipment, then portability and integration capability are improved, but the quality factor decreases leading to reduced measurement precision

Engineering Contradiction:
Improvesize of current detection systemVSAvoidquality factor
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent changes the electrical parameters of the Rogowski coil by optimizing the winding structure, turn density, and geometric dimensions to maintain a high quality factor despite size reduction. This allows the coil to achieve both compactness and measurement precision through parameter optimization rather than simply scaling down the traditional design.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different structural characteristics to different parts of the Rogowski coil, such as varying winding densities in different sections or using different core materials in specific regions, to optimize both the quality factor and size. This localized optimization allows maintaining high precision in critical measurement zones while reducing overall device volume.

Inventive Principle:
Principle #3Local quality

2Reliability

If traditional current transformers and meters are used for current detection, then measurement reliability is maintained, but device size becomes excessively large preventing integration

Engineering Contradiction:
Improvedetection accuracyVSAvoidsize of detection system
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent integrates the Rogowski coil, amplification circuit, and signal processing functions into a single compact detection system. By merging these previously separate components into one integrated unit, the system achieves both small size for equipment integration and maintained reliability through coordinated design of all functional elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces traditional mechanical current transformers with an electronic-based Rogowski coil system combined with electronic amplification and processing circuits. This substitution enables miniaturization while maintaining measurement reliability through electronic signal conditioning and digital processing capabilities.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 effectively reduces the size of current detection systems while ensuring high precision and stability, enabling integration into compact electrical equipment without compromising detection accuracy, thus addressing the limitations of traditional systems.

Implementation Method 1

N Rogowski coils are concentrically mounted on the printed circuit board with N current-carrying conductors respectively

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

each of the N groups of amplification apparatuses includes at least one amplification apparatus... employing active inductance circuits for direct current component suppression

Methodology Applied
Scientific EffectInductive reactance: Inductor

Data Source

PatentEP3889620B1Current detection system, current detection method, and detection apparatus
Publication Date: 2024.01.24 HUAWEI DIGITAL POWER TECH CO LTD
  • EP3889620B1 patent drawingFigure 1~3
  • EP3889620B1 patent drawingFigure 4~6
  • EP3889620B1 patent drawingFigure 7

AI summary

A current detection system (1400), a current detection method, and a detection apparatus (1500) are provided. The current detection system (1400) includes a printed circuit board and N groups of amplification apparatuses (200, 310, 320, 330, 720, 730). Each group of amplification apparatuses (200, 310, 320, 330, 720, 730) of the N groups of amplification apparatuses (200, 310, 320, 330, 720, 730) includes at least one amplification apparatus (200, 310, 320, 330, 720, 730), where N is a positive integer greater than or equal to 1. N Rogowski coils (111, 112, 113, 230, 300, 710) are mounted on the printed circuit board. The nth Rogowski coil (111, 112, 113, 230, 300, 710) in the N Rogowski coils (111, 112, 113, 230, 300, 710) is capable of being mounted concentric with the nth current-carrying conductor (121, 122, 123) in N current-carrying conductors (121, 122, 123), and the nth current-carrying conductor (121, 122, 123) is perpendicular to a plane of the nth Rogowski coil (111, 112, 113, 230, 300, 710). An output end (231, 232) of the nth Rogowski coil (111, 112, 113, 230, 300, 710) is connected to an input end (211, 212) of the first amplification apparatus (200, 310, 320, 330, 720, 730) in the nth group of amplification apparatus (200, 310, 320, 330, 720, 730) in the N groups of amplification apparatuses (200, 310, 320, 330, 720, 730). It is convenient to integrate the foregoing current detection system (1400) into electrical equipment. In addition, if each group of amplification apparatus (200, 310, 320, 330, 720, 730) includes a plurality of amplification apparatuses (200, 310, 320, 330, 720, 730), the current detection system (1400) may be used in different electrical equipment.