Shielded Bus Bar Current Sensor Assembly for Linear 3-Phase Sensing

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Solution Overview

Problem

Existing current sensors in electric vehicles are prone to errors due to separate configurations of bus bars, current sensors, and shields, which can cause structural challenges and inaccuracies in current measurement, and are difficult to optimize relative positions and distances.

Innovation Solution

A current sensor assembly where the bus bar, current sensor, and shield are integrated as a single configuration within a housing, with optimized positions and distances to ensure linear current measurement, reduced vibration, and minimized crosstalk and phase delay effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bus bar, current sensor, and shield are provided as separate configurations, then the current sensor can be independently replaced or adjusted, but measurement errors occur and structural changes are difficult

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidstructural configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bus bar, current sensor, and shield are merged into a single integrated assembly where the current sensor is mounted directly on the bus bar with the shield positioned adjacent to both components. This integration eliminates measurement errors caused by separate configurations while maintaining replaceability of individual components through modular design

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If the bus bar, current sensor, and shield are combined as one configuration, then measurement accuracy improves, but the structure becomes more complex to manufacture

Engineering Contradiction:
Improvecurrent measurement linearityVSAvoidassembly complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The integrated assembly is segmented into distinct modules (bus bar, current sensor, shield) that can be manufactured separately and then assembled together. This allows each component to be optimized for manufacturing while achieving the benefits of integration for measurement precision

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If the current sensor is positioned close to the bus bar, then measurement sensitivity increases, but crosstalk and phase delay effects increase

Engineering Contradiction:
Improvecurrent detection sensitivityVSAvoidcrosstalk and phase delay
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The shield acts as an intermediary component positioned between the bus bar and the current sensor, and also between adjacent bus bars. This shielded configuration reduces crosstalk and phase delay effects while allowing the current sensor to remain positioned close to the bus bar for high measurement sensitivity

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Accurate current detection is achieved with reduced errors from vibration and improved linearity, while optimizing the sensor's position relative to the bus bar and shield to minimize crosstalk and phase delay.

Implementation Method 1

a current sensor unit comprising a printed circuit board and a plurality of current sensors disposed on the printed circuit board to measure the current applied to the plurality of bus bars

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

a plurality of shields which are accommodated inside the housing and open toward a top of the housing

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP4145143B1Current sensor assembly
Publication Date: 2025.08.13 LG MAGNA E POWERTRAIN CO LTD
  • EP4145143B1 patent drawingFigure 1
  • EP4145143B1 patent drawingFigure 2
  • EP4145143B1 patent drawingFigure 3

AI summary

The present invention relates to a current sensor assembly comprising: a housing; a plurality of shields which are accommodated inside the housing and open toward the top of the housing; a plurality of bus bars to which three-phase current is applied and which are arranged spaced apart from each other so as to go past the plurality of shields, respectively; and a current sensor unit which includes a printed circuit board and a plurality of current sensors disposed on the printed circuit board to measure the current applied to the bus bars, wherein the shields, the bus bars, and the current sensor unit are configured to be accommodated inside the housing, and the current sensors are spaced apart from the bus bars and disposed in the inner spaces of the shields.