Dual-Material Shunt Resistor Layout for Independent Current Sensing
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Solution Overview
Problem
Current current measurement systems in hybrid and electric vehicles face challenges in ensuring reliable and redundant measurements, particularly at high continuous currents, due to the potential for simultaneous errors in resistance elements made from the same material batches, which can lead to parallel drift and reduced safety levels.
Innovation Solution
The resistor arrangement employs resistance elements made from different materials, such as CuMn10Ni4 and CuMn14Ni2 alloys, with distinct thicknesses and configurations, including plate-shaped connection elements and a narrower strip-shaped intermediate element, to prevent simultaneous errors and improve redundancy, allowing for independent voltage measurements and enhanced plausibility checks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If resistance elements are made from the same material batch to simplify production, then manufacturing precision is improved, but reliability deteriorates due to parallel drift and simultaneous errors
Solution Approach 1:
The patent applies local quality by using different material compositions for resistance elements that are part of the same measuring device. Specifically, the first resistance element uses a first alloy composition while the second resistance element uses a second alloy composition, creating local material differentiation. This ensures that errors or drifts affecting one material batch will not simultaneously affect both resistance elements, thereby maintaining measurement independence and reliability while still allowing for controlled manufacturing variations.
Solution Approach 2:
The patent employs composite materials by combining different alloy compositions for the resistance elements. The first resistance element is made from a first alloy (e.g., CuMn10Ni4) while the second resistance element is made from a second alloy (e.g., CuMn14Ni2). This use of composite material strategies ensures that the resistance elements have different error characteristics, preventing parallel drift and enhancing the reliability of redundant current measurements in safety-critical applications.
2Reliability
If redundant measurement components are added to achieve safety level ASIL C, then reliability is improved, but device complexity and costs increase
Solution Approach 1:
The patent merges multiple measurement functions into a single integrated device. By incorporating both the first and second resistance elements with different material compositions into one measuring device, it achieves redundant current measurement capability without requiring separate Hall effect sensors or multiple discrete components. This integration maintains safety level ASIL C while reducing device complexity and cost compared to using completely different sensor types.
Solution Approach 2:
The measuring device achieves multi-functionality by using the same basic resistance element structure for both measurement channels, but with different material compositions. This universal design allows the device to perform redundant current measurements while maintaining simplicity. The same structural blueprint is used, but material variation provides the necessary measurement independence, eliminating the need for complex multi-type sensor integration.
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 enhances the reliability and independence of current measurements by preventing parallel drift and allowing for better adjustment of resistance values, improving safety and reducing costs by eliminating the need for redundant components and complex Hall effect measurements.
Implementation Method 1
a first resistance element (12) which is electrically connected to the first connection element (10), a second resistance element (13) which is electrically connected to the second connection element (11)
Data Source
AI summary
A resistor arrangement having a first electrically conductive connection element and a second electrically conductive connection element, a first resistance element which is electrically conductively connected to the first connection element, a second resistance element which is electrically conductively connected to the second connection element, an electrically conductive intermediate element arranged between the first resistance element and the second resistance element and connected with these resistance elements in an electrically conductive manner, wherein the connection elements, the resistance elements and the intermediate element are arranged side by side in a row. The connection elements and the intermediate element on the one hand and the resistance elements on the other hand formed of different materials, wherein the material of the first resistance element differs from the material of the second resistance element.