Photovoltaic Cell String Welding Strips for Crack-Resistant Assembly
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Solution Overview
Problem
Current photovoltaic module designs face issues with solar cell sheets prone to cracking and fragmentation, leading to low yield and high manufacturing costs.
Innovation Solution
The use of welding strips with multiple continuous bending portions to connect adjacent solar cell sheets, acting as buffer joints to release stress and prevent warping, while ensuring proper alignment with bus bars and bonding pads for efficient electrical contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solar cell sheets are connected using conventional rigid welding strips, then electrical contact is achieved, but the solar cell sheets are prone to cracking and fragmentation due to stress and warping
Solution Approach 1:
The welding strip is designed with multiple bending portions that provide flexibility to the connection structure. These bending portions allow the welding strip to deform elastically under stress, preventing stress concentration on the rigid solar cell sheets and avoiding cracking and fragmentation.
Solution Approach 2:
The bending portions in the welding strip act as pre-designed stress absorption zones that cushion mechanical stress before it can reach the solar cell sheets. This beforehand cushioning prevents stress-induced damage to the fragile solar cell sheets during assembly and operation.
2Productivity
If welding strips are used to connect solar cell sheets, then electrical contact is established, but manufacturing yield is low due to cracking and fragmentation issues
Solution Approach 1:
The flexible welding strip with bending portions reduces manufacturing defects by eliminating stress-induced cracking during assembly, thereby improving the overall yield and reliability of photovoltaic module production.
3Ease of manufacture
If rigid connections are used between solar cell sheets, then assembly is simple, but warping occurs due to stress accumulation
Solution Approach 1:
The welding strip incorporates bending portions that provide flexibility while maintaining ease of assembly. The flexible structure naturally accommodates dimensional variations and stress, preventing warping of the solar cell sheets without complicating the assembly process.
Solution Approach 2:
The welding strip transitions from a rigid static connection to a flexible dynamic connection that can adapt to stress and dimensional changes. The bending portions allow the connection to dynamically respond to mechanical stresses, maintaining shape stability of the solar cell sheets.
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 approach improves the reliability and yield of the cell string by preventing warping and ensuring effective electrical contact, thereby reducing manufacturing costs and enhancing the overall efficiency of the photovoltaic module.
Implementation Method 1
the welding strip composed of multiple bending portions arranged continuously is used to connect the adjacent solar cell sheets, the multiple bending portions are used as buffer joints to fully release the stress
Data Source
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AI summary
The embodiments of the present application relate to a photovoltaic module and a method for preparing the photovoltaic. The photovoltaic module includes: a cell string, including multiple solar cell sheets, and adjacent solar cell sheets in the multiple solar cell sheets are connected to each other by multiple welding strips; where each of the multiple solar cell sheets includes a substrate, the substrate has a front surface and a back surface opposite to the front surface, a first passivation layer disposed on the front surface of the substrate, a second passivation layer disposed on the back surface of the substrate, multiple bus bars disposed on a surface of the second passivation layer; the multiple bus bars are disposed at intervals along a first direction and extend along a second direction, and each of the multiple bus bars includes multiple bonding pads disposed at intervals along the second direction; the multiple welding strips, where each of the multiple welding strips is in electrical contact with a corresponding bus bar, each of the multiple welding strips includes multiple bending portions arranged continuously along the second direction; along the second direction, an orthographic projection of a central line of each of the multiple welding strips on a back surface of the solar cell sheet coincides with an orthographic projection of a central line of the corresponding bus bar on the back surface of the solar cell sheet and/or an orthographic projection of a central line of each of the multiple bonding pads on the corresponding bus bar on the back surface of the solar cell sheet. It is conducive to improving the yield and reducing production costs of the cell string.