Busbar Current Sensor Layout for Direct Cooling and Shielding
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Solution Overview
Problem
Current sensors face challenges in efficiently cooling busbars due to increased heat generation from higher motor capacities in electric vehicles, leading to decreased accuracy and product life, while increasing the cross section of the busbar is disadvantageous for size and weight reduction.
Innovation Solution
A current sensor design that positions the busbar close to a cooling device without intervening shields, incorporates a magnetic sensor with optimized sensitivity direction, and utilizes overlapping current paths and heat dissipation structures to enhance cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cross section of the busbar is increased to reduce heat generation, then the heat generation is reduced, but the size and weight of the current sensor increase
Solution Approach 1:
The invention converts the harmful heat generated by the busbar into a beneficial cooling effect by strategically positioning the busbar adjacent to the cooling device. The heat that would otherwise degrade sensor accuracy and reduce product life is now efficiently dissipated, improving overall system reliability while maintaining compact dimensions.
Solution Approach 2:
The invention rearranges the spatial configuration by positioning the busbar in the height direction adjacent to the cooling device, rather than using lateral shielding plates. This dimensional repositioning enables direct thermal coupling between the busbar and cooling device, achieving efficient heat dissipation without increasing the sensor's footprint or weight.
2Measurement precision
If shielding plates are placed between the busbar and the cooling device to shield the magnetic field, then the magnetic field is shielded, but the cooling efficiency is reduced
Solution Approach 1:
The invention segments the functional zones by positioning the magnetic sensor between the busbar and the shielding plate. This spatial segmentation allows the shielding plate to be located where it can effectively block magnetic fields from reaching external components, while the sensor remains in the optimal position for both magnetic field detection and thermal management.
Solution Approach 2:
The invention moves the shielding function to a different spatial arrangement by placing the shielding plate in the height direction rather than laterally between the busbar and cooling device. This dimensional change allows the cooling device to maintain direct thermal contact with the busbar while the shielding plate provides magnetic field protection in a different spatial plane.
3Stability of the object's composition
If the busbar is positioned at the center of the enclosure, then the structure is balanced, but the cooling efficiency is reduced
Solution Approach 1:
The invention intentionally creates an asymmetric configuration by positioning the busbar off-center in the height direction, adjacent to the cooling device. This asymmetric arrangement prioritizes thermal management efficiency over symmetric structural balance, allowing the cooling device to directly dissipate heat from the busbar while the shielding plate and sensor are positioned to maintain functional symmetry in the lateral direction.
4Measurement precision
If the magnetic sensor is positioned to face the busbar, then the measurement accuracy is improved, but the sensitivity to adjacent phase magnetic fields increases
Solution Approach 1:
The invention introduces the shielding plate as an intermediary element positioned between the magnetic sensor and adjacent phase current paths. This shielding plate acts as a magnetic field barrier that blocks interference from adjacent phases from reaching the sensor, while allowing the sensor to maintain its optimal positioning for detecting the magnetic field generated by the busbar.
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 design efficiently cools the busbar, improves measurement accuracy, and reduces the sensor's size, addressing the heat-related issues while maintaining compactness and performance.
Implementation Method 1
the busbar can be efficiently cooled by the cooling device
Implementation Method 2
a cooling device can be installed, and the current sensor can be disposed at a position facing the cooling device to enable cooling of the busbar
Implementation Method 3
a current sensor that measures a current flowing through a busbar on the basis of a magnetic field
Implementation Method 4
at least a pair of shielding plates at positions so as to sandwich the busbar and the current sensor in the thickness direction to shield the magnetic field
Data Source
AI summary
A current sensor capable of efficiently cooling a busbar by using a cooling device includes a busbar, a shield disposed to face the busbar, a magnetic sensor disposed between the shield and the busbar, and an enclosure that integrally encases part of the busbar, the shield, and the magnetic sensor. When a side on which the busbar is disposed in the X-axis direction in which the busbar, the magnetic sensor, and the shield are arranged is defined as an X1 side, the busbar is disposed on the X1 side from the center line of the enclosure, and at least the X1 side of the enclosure is disposed to face the cooling device.