Automated Photovoltaic Strip Assembly for Cascaded Solar Panels

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Solution Overview

Problem

The manual fabrication of solar panels is time-consuming and error-prone, making it costly to mass-produce reliable solar panels with cascaded cell arrangements, which require precise and consistent division and alignment of solar cells into strips for proper electrical and physical connections.

Innovation Solution

An automated electro-mechanical system that arranges photovoltaic structure strips into a cascaded formation using suction cups and actuators to lift and position the strips, ensuring precise overlap and electrical contact without damaging the strips, and utilizes conductive paste for bonding busbars to reduce series resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual fabrication methods are used to assemble solar panels, then flexibility and adaptability are maintained, but production time increases and error rates rise making mass production costly

Engineering Contradiction:
Improveproduction speedVSAvoidautomation system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The solar cells are divided into strips that can be separately handled and assembled. This segmentation enables automated manipulation of individual strips while maintaining the overall panel structure, resolving the contradiction between automation and complexity by breaking down the assembly process into manageable units

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A conductive paste is introduced as an intermediary material to bond the strips together. This intermediary simplifies the automation process by providing a standardized bonding mechanism that automated systems can apply consistently, reducing errors while maintaining production flexibility

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If solar cells are divided into strips and cascaded to form strings, then series resistance decreases and fill-factor improves, but precise alignment becomes difficult to achieve consistently in high volumes

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidstrip alignment precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The overlapping configuration of strips is designed to be self-aligning, where the physical geometry of adjacent strips naturally guides their relative positioning. This self-service alignment mechanism reduces the precision requirements for automated placement while ensuring consistent electrical connections between strips

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The strips are pre-configured with overlapping edges and conductive contacts positioned in advance. This preliminary arrangement ensures that when strips are assembled, the critical alignment points are already prepared, making the actual assembly process more tolerant of variations and easier to automate with consistent precision

Inventive Principle:
Principle #10Preliminary action

3Productivity

If automated systems use mechanical arms to pick and place strips, then productivity increases, but damage to the strips may occur

Engineering Contradiction:
Improveassembly throughputVSAvoidstrip damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Suction cups are used to grasp and manipulate the solar cell strips during automated assembly. This pneumatic gripping method provides gentle, distributed contact force that secures the strips for transport and placement without causing mechanical damage, enabling high-speed automation while protecting the fragile photovoltaic structures

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 system enables efficient and precise automation of cascaded solar panel assembly, reducing production costs and increasing reliability by minimizing damage to the solar cells and improving the fill-factor of the panels through reduced series resistance.

Implementation Method 1

a first cell-lifting mechanism with a set of suction cups that can hold onto a strip by applying a suction force on a surface of the strip

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

utilizes conductive paste for bonding busbars to reduce series resistance

Methodology Applied
Scientific EffectConduction: Conduction (electrical)

Data Source

PatentEP3227926B1Systems and methods for cascading photovoltaic structures
Publication Date: 2020.02.05 TESLA INC
  • EP3227926B1 patent drawingFigure 1A
  • EP3227926B1 patent drawingFigure 1B
  • EP3227926B1 patent drawingFigure 1C

AI summary

A string-forming system is described. The string-forming system may include at least a first cell-lifting mechanism and a second cell-lifting mechanism that can automatically arrange a set of strips of a photovoltaic structure into a cascaded formation. During operation, a controller can cause the first cell-lifting mechanism to lift a first strip from a first platform, and can cause the second cell-lifting mechanism to lift, from the first platform, a second strip that may follow the first strip on the first platform. The controller may then activate a first shifting actuator of the first cell-lifting mechanism or a second shifting actuator of the second cell-lifting mechanism to place a leading edge of the second strip above a trailing edge of the first strip.