Segmented Solar Cell Connector Reduces Thermal Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cell connectors for solar cells experience high mechanical stress due to thermal expansion and deformation, which can lead to damage and inefficiency in electrical conductivity, particularly at contact points between cells.
Innovation Solution
A cell connector with a variable cross-section and textured design, featuring a smaller cross-section at contact areas and elongated recesses to reduce mechanical stress, allowing for flexible connection and efficient current flow without continuous mechanical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cell connector has a constant cross-section for electrical connection, then electrical conductivity is maintained, but mechanical stress increases at contact points during thermal expansion and deformation
Solution Approach 1:
The cell connector is divided into multiple cross-sections with different properties: contact areas with smaller cross-sections for reduced stress, and transit areas with larger cross-sections for maintaining electrical conductivity. This segmentation allows the connector to simultaneously achieve low mechanical stress at contact points and high electrical conductivity in transit areas.
Solution Approach 2:
Different regions of the cell connector are assigned different cross-sectional properties tailored to their specific functions. Contact areas have reduced cross-sections optimized for minimizing mechanical stress, while transit areas have increased cross-sections optimized for electrical current flow. This local differentiation resolves the contradiction between stress reduction and conductivity maintenance.
2Stress or pressure
If the cell connector cross-section is reduced at contact areas to lower mechanical stress, then stress on power sources decreases, but electrical conductivity may be compromised
Solution Approach 1:
The connector is segmented into contact areas with smaller cross-sections and transit areas with larger cross-sections. The transit areas compensate for the reduced cross-section at contact points by providing sufficient conductive path area, ensuring that overall electrical conductivity is maintained while mechanical stress at contact points is reduced.
Solution Approach 2:
The solution moves the electrical conductivity function from the contact area dimension to the transit area dimension. By providing larger cross-sections in transit areas, the electrical current is routed through regions optimized for conduction, while contact areas are optimized for mechanical stress reduction. This dimensional separation of functions resolves the contradiction.
3Reliability
If continuous contact areas are used for electrical connection, then electrical conductivity is maximized, but mechanical stress and shadowing effects increase
Solution Approach 1:
The continuous contact area is segmented into discrete contact regions separated by transit areas. This segmentation eliminates the shadowing effect by reducing the physical footprint at contact points while maintaining electrical conductivity through the separated transit areas. The segmented design also reduces mechanical stress by avoiding large continuous contact zones.
Solution Approach 2:
The harmful functions (mechanical stress and shadowing) are extracted from the contact areas by reducing their cross-sectional size. The electrical conductivity function is then extracted and relocated to the transit areas, which are specifically designed with larger cross-sections for optimal current flow. This functional extraction and relocation resolves the contradiction between conductivity and harmful effects.
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 solution effectively reduces mechanical stress on solar cells, enabling the use of thinner materials and lead-free solders, while maintaining high electrical conductivity and flexibility, thus improving the reliability and cost-effectiveness of solar cell connections.
Implementation Method 1
The mechanical stresses are caused by differences in thermal expansion during production and operation of the modules and by deformation of the modules.
Data Source
Figure 1~3
Figure 4~6a
Figure 6b~7
AI summary
The present invention relates to a cell connector (ZV) for electrically contacting planar power sources, wherein the cell connector can be electrically contacted with the power source only in certain regions. The cell connector comprises at least one electrically conductive layer, which is designed as transitional region and is in contact with the power source via contact regions that are only a fraction of the overall region of the transition region.