PV Device Luminescence Imaging for Field Defect Detection
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Solution Overview
Problem
Current methods for detecting defects in photovoltaic (PV) devices are often limited to laboratory-scale testing, require expensive equipment, or necessitate electrical connection to an external power source, making them impractical for field use and maintenance.
Innovation Solution
A method and system that uses a non-solar light source to illuminate one portion of a PV device's surface, inducing luminescence in a non-illuminated portion, allowing for defect detection without external power connection or physical manipulation, using a detector to collect and analyze luminescence data to create composite representations of the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electroluminescence imaging methods are used to detect defects in PV devices, then defect detection capability is improved, but the requirement for external power connection and device disconnection increases
Solution Approach 1:
The PV device itself serves as the light source by utilizing sunlight to generate electrical current, which then produces electroluminescence. This eliminates the need for external power sources or biasing equipment, allowing defect detection while the device operates normally in the field.
Solution Approach 2:
The patent uses the PV device's own generated current as an intermediary to produce electroluminescence. The sunlight acts as the initial energy source, which is converted to electrical current by the PV device, and this current then generates the electroluminescence signal for defect detection, eliminating the need for direct external power connection.
2Device complexity
If photoluminescence imaging is used to illuminate and image the same section of PV cell, then imaging is simplified, but the ability to detect disconnects caused by cracks and breakage is reduced
Solution Approach 1:
The imaging system divides the PV device into illuminated regions and non-illuminated regions. By illuminating only certain areas and detecting electroluminescence from adjacent non-illuminated areas, the system can identify disconnects and cracks that would be missed in uniform illumination photoluminescence imaging.
Solution Approach 2:
The patent applies localized illumination to specific regions of the PV device rather than uniform illumination. This creates local variations in electrical current generation, allowing the electroluminescence imaging to reveal defects such as cracks and disconnects that affect current flow between illuminated and non-illuminated regions.
3Measurement precision
If specialized lasers and filters are used for defect detection, then measurement precision is improved, but equipment cost and complexity increase
Solution Approach 1:
The system uses standard imaging equipment such as cameras and light sources that can serve multiple purposes. The same camera used for capturing images can detect electroluminescence signals, and standard light sources can provide the necessary illumination, eliminating the need for specialized expensive equipment.
Solution Approach 2:
The patent replaces expensive specialized lasers and filters with more affordable standard imaging components. While these standard components may have shorter operational lifetimes or lower performance specifications, they provide sufficient functionality for field-based defect detection at a fraction of the cost of specialized equipment.
4Measurement precision
If laboratory-scale testing methods are used, then measurement precision is improved, but scalability to field conditions is reduced
Solution Approach 1:
The PV device uses its own operational characteristics (sunlight absorption and current generation) to produce the electroluminescence signal needed for testing. This allows the same testing methodology to work both in controlled laboratory settings and in actual field conditions where the device operates normally.
Solution Approach 2:
The system captures images at different time points or under different illumination conditions to monitor defect development over time. This periodic imaging approach allows for tracking degradation and defect propagation while maintaining the same testing protocol across different environments from laboratory to field.
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
Enables quicker, safer, and more cost-effective defect detection in PV devices, allowing for field-based maintenance and performance assessment without disrupting normal operation, effectively identifying defects such as cracks and corrosion.
Implementation Method 1
illuminating, using a non-solar light source, a first portion of a surface of a photovoltaic (PV) device
Implementation Method 2
The first portion of the surface and the second portion of the surface are electrically connected
Implementation Method 3
collecting, using a detector, a first set of measurements relating to at least one of the presence or absence of luminescence from a second portion of the surface
Data Source
AI summary
The present disclosure relates to optical methods and systems for detecting defects in photovoltaic (PV) devices such as PV cells, PV panels, PV modules, and PV arrays.