Integrated Bus Bar Shield Blocks Contactor Magnetic Fields
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Solution Overview
Problem
Current sensors in electric vehicles, such as hybrid and plug-in hybrid electric vehicles, face inaccuracies in current measurements due to magnetic fields generated by contactors, which interfere with the sensor readings.
Innovation Solution
A current sensor shield is integrated into the electric vehicle's componentry, specifically extending from a bus bar to block magnetic fields from the contactor, forming a continuous structure with the bus bar and comprising copper, which effectively impedes magnetic field interference by covering at least three sides of the contactor's coil or being housed within the contactor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a current sensor shield is added to block magnetic fields from the contactor, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The current sensor shield is merged with the bus bar structure, forming a single integrated component. The bus bar is configured with a shield portion that directly blocks magnetic fields from the contactor toward the current sensor, eliminating the need for a separate shield component while maintaining measurement accuracy.
Solution Approach 2:
The bus bar serves dual functions: it provides electrical connection between components and simultaneously acts as a magnetic field shield through its integrated shield portion. This multi-functional design protects the current sensor from magnetic interference while maintaining the bus bar's primary electrical function.
2Manufacturing precision
If a current sensor shield is integrated as a continuous structure with the bus bar, then manufacturing precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The shield and bus bar are formed as a single continuous structure, ensuring perfect alignment between the shield portion and the bus bar. This integration eliminates alignment issues that would arise from assembling separate components, while the entire structure can be manufactured in one piece using appropriate fabrication processes.
3Measurement precision
If the current sensor shield is positioned to block magnetic fields effectively, then measurement precision is improved, but volume of the component increases
Solution Approach 1:
The shield portion is strategically positioned only where magnetic field interference occurs between the contactor and current sensor. Rather than providing complete 360-degree shielding, the shield is localized to the specific region where magnetic fields from the contactor would affect the sensor, minimizing unnecessary material while maintaining effectiveness.
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
The current sensor shield significantly reduces measurement errors by blocking magnetic fields, ensuring accurate current sensing without compromising packaging or weight, thereby enhancing the reliability of state of charge determinations in electric vehicles.
Implementation Method 1
a current sensor shield that blocks magnetic fields of a contactor from influencing a current sensor
Data Source
AI summary
An example electric vehicle component includes a current sensor shield that blocks magnetic fields of a contactor from influencing a current sensor. An example method of improving current sensor measurements includes blocking magnetic fields moving from a contactor toward the current sensor.