Busbar Current Sensing Layout for Stronger Magnetic Field Detection

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Solution Overview

Problem

Current sensing arrangements in electric systems face challenges due to magnetic fields canceling out or being weakened by adjacent busbars, particularly in DC systems, leading to low signal-to-noise ratios and potential disturbances in current measurement.

Innovation Solution

A current sensing arrangement with a parallel busbar carrying current in the opposite direction to the load current, superimposing magnetic fields to reinforce detection, using meandering patterns and Hall sensors to enhance signal detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If parallel busbars are arranged to form a low-inductance arrangement, then inductance is reduced, but magnetic fields cancel each other out weakening the detectable signal

Engineering Contradiction:
ImproveinductanceVSAvoidsignal strength for current detection
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The busbar system is segmented into a first busbar and a second busbar, with only specific sections (first section of first busbar and second section of second busbar) arranged in parallel to form the low-inductance arrangement. Other sections are positioned separately, preventing complete magnetic field cancellation while maintaining low inductance in the critical measurement region.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The busbars are configured with different spatial arrangements in different regions: in the first region, they are arranged in parallel close proximity to achieve low inductance and magnetic field superposition for detection; in other regions, they are positioned at different locations to avoid complete field cancellation. This local differentiation optimizes both inductance reduction and signal detection.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If current sensor is placed near busbar to detect magnetic field, then detection sensitivity is improved, but magnetic field is weakened or disturbed by adjacent busbar

Engineering Contradiction:
Improvecurrent detection sensitivityVSAvoidmagnetic field weakening by adjacent busbar
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A non-conductive support structure is introduced as an intermediary element to hold the current sensor in close proximity to the busbar for sensitive detection, while electrically isolating the sensor from the busbar. This allows the sensor to detect the magnetic field generated by the busbar current without being affected by electrical interference or heat, and without the sensor itself interfering with the magnetic field distribution.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If multiple busbars are arranged in parallel for DC power supply, then power transmission capability is improved, but magnetic fields cancel out reducing signal-to-noise ratio

Engineering Contradiction:
ImproveDC power transmission capabilityVSAvoidsignal-to-noise ratio for current measurement
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The DC power supply system uses multiple busbars with segmented spatial arrangement: in the first region, busbars are arranged in parallel close together to provide high power transmission capability and generate strong magnetic field for detection; in other regions, they are positioned at different locations to prevent complete magnetic field cancellation, thereby maintaining adequate signal-to-noise ratio for current measurement throughout the system.

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 configuration creates a sensitive current sensing arrangement with a high signal-to-noise ratio, effectively detecting amplified magnetic fields and preventing disturbances, allowing efficient current measurement in low-inductance systems.

Implementation Method 1

detect a magnetic field generated on the longitudinal section

Methodology Applied
Scientific EffectMagnetic field generation: Magnetic Field

Implementation Method 2

a Hall sensor, particularly a differential Hall sensor, can be arranged in the current sensing arrangement

Methodology Applied
Scientific EffectHall effect: Hall Effect

Implementation Method 3

a magnetic field generated on the longitudinal section by the further busbar can superimpose on the magnetic field of the busbar, thereby reinforcing it

Methodology Applied
Scientific EffectMagnetic field superposition: Magnetic Field

Data Source

PatentEP4134681B1Current detecting device
Publication Date: 2026.04.22 ROBERT BOSCH GMBH
  • EP4134681B1 patent drawingFigure 1
  • EP4134681B1 patent drawingFigure 2~3
  • EP4134681B1 patent drawingFigure 4~5

AI summary

The invention relates to a current sensing arrangement. The current sensing arrangement comprises at least one electrically conductive busbar. The electrically conductive busbar is designed to carry a load current. A longitudinal section is formed in the busbar for detecting the load current flowing in the busbar. The current sensing arrangement also comprises at least one current sensor, which is arranged and configured to detect a magnetic field generated on the longitudinal section and to generate a current signal representing the load current as a function of the magnetic field. According to the invention, the current sensing arrangement of the type mentioned above comprises a further busbar. The further busbar is configured to carry a current, in particular direct current, with a current direction opposite to that of the load current.The additional power rail running parallel to the power rail is guided in the area of ​​the longitudinal section to the power rail in such a way that a magnetic field generated on the longitudinal section by the additional power rail can superimpose on the magnetic field of the power rail in a field-enhancing manner.