Segmented Bus Bar Current Sensor for Positional Deviation
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Solution Overview
Problem
Existing current sensors face challenges in maintaining detection accuracy due to changes in current density caused by assembly errors or positional deviations of the sensor unit relative to the bus bar.
Innovation Solution
The current sensor design includes a bus bar configured by stacking a first and second bus bar with a gap between them, which reduces current density changes in the width direction, thereby improving detection accuracy robustness against positional deviations of the sensor unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor unit is positioned close to the bus bar to improve detection sensitivity, then detection precision is improved, but detection accuracy deteriorates due to current density changes caused by positional deviations
Solution Approach 1:
The bus bar is divided into multiple bus bar segments arranged in the width direction, with gaps between adjacent segments. This segmentation creates multiple current paths that distribute the current flow, reducing the impact of sensor unit positional deviations on current density changes and thereby improving detection stability while maintaining accuracy.
2Reliability
If the bus bar width is increased to reduce current density changes, then detection stability is improved, but device complexity increases
Solution Approach 1:
Instead of increasing the overall bus bar width, the invention segments the bus bar into multiple narrower segments with gaps between them. This achieves the effect of reduced current density changes (improving stability) without requiring a larger overall structure, thereby avoiding increased device complexity.
Solution Approach 2:
The invention transitions from a single solid bus bar structure to a segmented structure with gaps in the width direction. This dimensional change allows current to flow through multiple paths, effectively distributing current density without increasing the overall footprint or complexity of the bus bar assembly.
3Reliability
If the gap between bus bar segments is increased to reduce current density changes, then detection stability is improved, but manufacturing precision requirements worsen
Solution Approach 1:
The invention optimizes the gap width as a critical parameter, setting it to a specific range (0.1mm to 5mm) that balances multiple objectives: reducing current density changes for stability while remaining manufacturable with standard tolerances. This parameter optimization resolves the contradiction between stability and manufacturing precision.
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 effectively reduces changes in detection accuracy even when the sensor unit is deviated in the width direction, enhancing the sensor's robustness and reliability.
Implementation Method 1
a sensor unit that outputs a detection signal based on a magnetic field generated according to the alternating current flowing through the bus bar
Data Source
AI summary
A current sensor includes: a bus bar defining a longitudinal direction along one direction and in which an alternating current flows along the longitudinal direction; a sensor unit that outputs a detection signal based on a magnetic field generated according to the alternating current flowing through the bus bar; and a sensor housing in which the bus bar and the sensor unit are arranged. The bus bar is configured by a first bus bar and a second bus bar stacked in an arrangement direction of the bus bar and the sensor unit. The bus bar includes a covered portion covered with the sensor housing and a fastening portion exposed from the sensor housing. The first bus bar and the second bus bar are arranged in a state in which a gap is defined between the first bus bar and the second bus bar in the covered portion.