Current Transformer Parallel Branches for Compact High-Current Sensing

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Solution Overview

Problem

Conventional current transformers have limitations in size and weight due to their single primary winding design, which restricts their ability to handle high current ratings efficiently and compactly.

Innovation Solution

A current transformer with multiple primary winding branches configured in parallel, allowing the primary current to be divided among them based on impedance, with each branch connected to a secondary winding that induces a proportional secondary current, reducing the number of turns required in the secondary winding and thereby minimizing the size and weight of the transformer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single primary winding is used in conventional current transformers, then the structure is simple, but the size and weight increase when handling high current ratings

Engineering Contradiction:
Improvewinding structureVSAvoidtransformer weight
Core Design Contradiction:
Device complexityVSWeight of stationary object

Solution Approach 1:

The primary winding is divided into multiple parallel branches, each carrying a portion of the total primary current. This segmentation allows the magnetic flux in each branch to be reduced proportionally, enabling the use of fewer secondary winding turns and smaller core cross-sectional area, thereby reducing the overall transformer size and weight while maintaining the same current transformation capability

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single primary winding is used in conventional current transformers, then the design is straightforward, but the volume increases for high current applications

Engineering Contradiction:
Improvewinding structureVSAvoidtransformer volume
Core Design Contradiction:
Device complexityVSVolume of stationary object

Solution Approach 1:

The primary winding is segmented into multiple parallel branches, which reduces the current magnitude in each branch. This allows for a smaller core cross-sectional area and fewer secondary winding turns, significantly reducing the transformer volume for high current applications

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new structural dimension by arranging multiple primary winding branches in parallel, transforming the single-path current flow into a multi-path configuration. This dimensional change in the winding structure enables more efficient space utilization and reduces the overall transformer volume

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Weight of stationary object

If multiple primary winding branches are used, then the transformer size and weight are reduced, but the winding structure becomes more complex

Engineering Contradiction:
Improvetransformer weightVSAvoidwinding structure
Core Design Contradiction:
Weight of stationary objectVSDevice complexity

Solution Approach 1:

The primary winding is divided into multiple parallel branches with simplified connection structures. Each branch is designed with uniform or systematically varied parameters, making the complexity manageable through modular design principles while achieving significant weight reduction

Inventive Principle:
Principle #1Segmentation

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 design enables the current transformer to be more compact and lightweight, capable of handling higher current ratings and reducing the size and weight significantly compared to conventional transformers, making it more suitable for applications requiring high current handling and space efficiency.

Implementation Method 1

secondary windings having a plurality of turns configured to induce a secondary current from at least one of the one or more of the primary winding branches

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3613066B1Current transformer with current branches on primary conductor
Publication Date: 2024.12.11 NARAYAN POWERTECH PVT LTD
  • EP3613066B1 patent drawingFigure 1
  • EP3613066B1 patent drawingFigure 2
  • EP3613066B1 patent drawingFigure 3

AI summary

Embodiments described herein comprise a current transformer having a primary winding with multiple primary parallel branches that divide the primary current, and a secondary winding which is placed in any one, or more, branches. The current thus divided in the primary branches produces an alternating magnetic flux which induces alternating current in the secondary winding for an end user application. The invention disclosed herein reduces the weight and size of the current transformer drastically compared to the existing conventional current transformers.