Current Sensor Element Voltage Contact Arrangement

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Solution Overview

Problem

Conventional shunt current sensors face limitations due to the high temperature coefficient of conductor materials, which affects measurement accuracy and reliability, especially when measuring high currents in electric vehicles, as they contribute to temperature-dependent measurement errors alongside the resistance material.

Innovation Solution

Incorporating a third voltage measurement contact, arranged further away from the resistance material than the second contact, allows for the calculation of resistance solely based on the resistance material's properties, effectively eliminating the influence of the conductor material's temperature coefficient, thereby reducing measurement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If conventional shunt current sensors use conductor materials with high temperature coefficients, then electrical conductivity is improved, but measurement accuracy deteriorates due to temperature-dependent measurement errors

Engineering Contradiction:
Improveelectrical conductivityVSAvoidmeasurement accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The sensor is divided into functionally separate components: current-carrying conductor elements and voltage-measuring elements. The voltage measurement contacts are positioned to measure only across the resistance material, excluding the conductor material from the measurement path. This segmentation allows the conductor to have high conductivity while the measurement remains temperature-stable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The influence of the conductor material's temperature coefficient is extracted and excluded from the measurement. By positioning voltage contacts to measure only the voltage drop across the resistance material (not including the conductor material), the harmful temperature-dependent variations in the conductor are taken out of the measurement equation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If voltage measurement contacts are placed on conductor material, then ease of connection is improved, but measurement precision deteriorates due to temperature coefficient contributions

Engineering Contradiction:
Improveease of connectionVSAvoidmeasurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The resistance material serves as an intermediary element between the current path and the voltage measurement. The voltage measurement contacts are positioned to measure across this intermediary, which has a stable, low temperature coefficient. This intermediary isolates the measurement from the temperature-sensitive conductor material while maintaining electrical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Different regions of the sensor have different functional qualities: the conductor material region provides high conductivity for current flow, while the resistance material region provides stable resistance for measurement. The voltage contacts are positioned to interact only with the resistance material region, giving that local region the quality of measurement stability while the conductor region maintains its conductivity quality.

Inventive Principle:
Principle #3Local quality

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 enhances the accuracy and reliability of current measurements by isolating the resistance material's temperature coefficient, achieving near-optimal measurement performance without the need for additional temperature sensing elements.

Implementation Method 1

a first temperature coefficient... a second temperature coefficient which is higher than the first temperature coefficient

Methodology Applied
Scientific EffectTemperature coefficient of resistivity: Electrical Resistance

Implementation Method 2

The output signal is the potential difference between two contacts on both sides of the resistance material 906

Methodology Applied
Scientific EffectOhm's law: Ohm's Law

Data Source

PatentEP3958002B1Current sensor element, current sensor unit, and method of measuring a current
Publication Date: 2024.03.13 TE CONNECTIVITY GERMANY GMBH
  • EP3958002B1 patent drawingFigure 1~2
  • EP3958002B1 patent drawingFigure 3~4
  • EP3958002B1 patent drawingFigure 5~6

AI summary

The present invention relates to a current sensor element, a current sensor unit, and a method of measuring an electrical current. A current sensor element (100) comprises at least one resistance section (106) comprising a resistance material having a first specific electrical conductivity and a first temperature coefficient; a first electrically conductive connection section (102) connected to a first end of the resistance section (106), and a second electrically conductive connection section (104) connected to a second end of the resistance section (106), wherein the first and second connection sections (102, 104) each have a second specific electrical conductivity which is higher than the first electrical conductivity of the resistance material, and a second temperature coefficient which is higher than the first temperature coefficient, and wherein the first and second connection sections (102, 104) are connectable to feed a current (I) to be measured through the resistance section (106). The first electrically conductive connection section (102) comprises a first voltage measurement contact (116), wherein the second electrically conductive connection section (104) comprises a second voltage measurement contact (118) and at least one third voltage measurement contact (120), wherein the first, second, and third voltage measurement contacts (116, 118, 120) are arranged in a way that the resistance between the first and the second measurement contact (116, 118) is smaller than the resistance between the first and the third measurement contact (116, 120).