Back-Contact Cell Assembly Layout for Hidden Bus Bar Insulation
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Solution Overview
Problem
The exposure of bus bars in back contact cell modules affects the aesthetics and reduces the light-receiving area, leading to poor power generation efficiency and increased production difficulty due to high accuracy requirements and risks of short circuits.
Innovation Solution
The bus bar is positioned on the backlight surface of cell pieces, hidden from the light-receiving surface, with insulation bars covering and extending beyond the bus bar to ensure electrical connections without perforation or block replacement, allowing for improved assembly efficiency and reduced short-circuit risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the bus bar is mounted in a middle position of the rear side of the cell piece with an insulation bar, then the bus bar can be hidden and aesthetics improved, but the production difficulty increases due to high requirements for perforation accuracy and arrangement position accuracy
Solution Approach 1:
The insulation bar is divided into multiple segments corresponding to different cell pieces, with each segment having insulation holes positioned to match the bus bar and ribbon connections. This segmentation allows independent positioning and assembly of each insulation segment, reducing the overall accuracy requirements compared to a single continuous insulation bar.
Solution Approach 2:
The patent introduces auxiliary positioning structures including positioning blocks on the insulation bar that engage with corresponding positioning grooves on the cell pieces, and positioning ribs on the bus bar. These intermediary positioning elements serve as mediators to align and fix the relative positions of the insulation bar, bus bar, and cell pieces, significantly reducing the difficulty of achieving precise positioning during assembly.
2Reliability
If the insulation bar is perforated or insulation blocks are provided intermittently to enable bus bar contact with ribbons, then electrical connection is achieved, but position offset easily occurs during lamination causing short circuits
Solution Approach 1:
The insulation bar is pre-formed with insulation holes positioned at specific locations before the lamination process. The positioning blocks and grooves are also pre-configured on the insulation bar and cell pieces respectively. This preliminary preparation of positioning features ensures that when lamination occurs, the components align automatically without requiring high precision during the lamination process itself, preventing position offset and short circuits.
Solution Approach 2:
The patent designs the insulation bar with extended portions that protrude beyond the bus bar in the first direction, creating a cushioning effect. These extended portions provide a tolerance zone that absorbs potential position offsets during assembly, preventing the bus bar from making unintended contact with ribbons of reverse polarity and avoiding short circuits.
3Productivity
If the bus bar is exposed on the rear side, then the structure is simple, but the light-receiving area is reduced and power generation efficiency deteriorates
Solution Approach 1:
The patent moves the bus bar from the traditional planar position on the rear surface to a three-dimensional arrangement where it is positioned on the side of the insulation bar, extending in the second direction (width direction) while cell pieces are arranged in the first direction (length direction). This dimensional reorganization allows the bus bar to be hidden from the light-receiving surface while maintaining electrical connectivity, thus preserving light-receiving area without significantly increasing structural complexity.
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 increases the effective light-receiving area, enhances assembly conversion efficiency, and improves the aesthetic appeal of the cell module while reducing production complexity and short-circuit risks, ensuring higher reliability and universality across different module configurations.
Implementation Method 1
an insulation bar is provided between the bus bar and the cell piece
Implementation Method 2
By virtue of a photovoltaic effect of a semiconductor p-n junction, sunlight can be converted into electric energy
Data Source
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AI summary
The present disclosure relates to the technical field of solar cells. Disclosed are a back contact cell module and a system. The assembly includes a cell string, an insulation bar, and a bus bar; the cell string includes a first cell piece and a second cell piece, which are adjacent to each other; the insulation bar is provided on a backlight surface of the first cell piece; a second ribbon is connected to the second cell piece and the bus bar, respectively; and the insulation bar blocks the second ribbon and the first cell piece.