Dual-Glass PV Module Connection Box with Aluminum Alloy Casing
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Solution Overview
Problem
Current double-glass photovoltaic modules face issues with foreign objects causing hot-spot effects, leading to diode failure and reduced service life, and the connection box design makes replacement difficult and costly, with risks of bus bar damage and inefficient welding.
Innovation Solution
A double-glass photovoltaic module design featuring a frame with a notch for a connection box that includes a surface mount thin sheet diode and a conductive block, with a bus bar running through a threading hole and partitioned chamber for secure electrical connections, preventing diode melting and facilitating easy replacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the connection box uses a plastic base material, then the manufacturing cost is reduced, but the service life cannot reach 40 years like the glass module
Solution Approach 1:
The connection box uses an aluminum alloy casing instead of plastic material, providing both durability to match the 40-year service life of the glass module and cost-effectiveness. The aluminum alloy offers superior corrosion resistance and structural strength compared to plastic, while maintaining manufacturing feasibility.
2Reliability
If the diode and bus bar are immersed in solidified potting glue, then the connection box has favorable sealing, but replacement becomes difficult and risky
Solution Approach 1:
The connection box is designed with a separable structure where the aluminum alloy casing can be opened to access internal components. The diode is mounted on the inner wall of the casing, and the bus bar connects to the diode through a threaded connection, allowing individual component replacement without damaging other parts or requiring removal of potting glue from the entire assembly.
Solution Approach 2:
The diode is extracted from the traditional immersed design and mounted separately on the inner wall of the aluminum alloy casing. This allows the diode to be accessed, removed, and replaced independently while maintaining the sealing integrity of the overall connection box structure.
3Device complexity
If the bus bar is located exactly above the leading leg of the diode, then the connection box structure is compact, but the diode may be welded off or false-welded during bus bar welding
Solution Approach 1:
The connection box provides localized heat dissipation pathways specifically at the diode and bus bar connection areas. The aluminum alloy casing acts as a heat sink, and the design ensures that welding operations do not transfer excessive heat to the diode's leading leg, preventing welding damage while maintaining compact structure.
4Object-affected harmful factors
If foreign objects fall or stick to the front of the module, then the hot-spot effect occurs, but the diode protection function becomes invalid before warranty period ends
Solution Approach 1:
The connection box design enables easy maintenance and replacement of the diode by the system operator. When the diode shows signs of failure or the module experiences hot-spot effects, the diode can be quickly accessed and replaced through the separable aluminum alloy casing structure, extending the effective service life and maintaining protection functionality throughout the module's 40-year lifespan.
Data Source
Figure 1~2
Figure 3~5
Figure 6
AI summary
A double-glass photovoltaic module includes: a body (1), where the body (1) includes a first glass layer (11), a first encapsulation layer (12), a cell group layer (13), a second encapsulation layer (14), and a second glass layer (15) that are sequentially disposed in a laminated manner, the cell group layer (13) extracts a current by using a bus bar (131), and the bus bar (131) is led out between the first glass layer (11) and the second glass layer (15) and from an edge of the body (1); a frame (6), encapsulated at a periphery of the body (1) by a sealant and having a notch (60); and a connection box (4), disposed at the notch (60),and sealed and connected to the body (1) the frame (6), and the bus bar (131) is electrically connected to the connection box (4).