Defect detection system for silicon solar panels under all-day irradiation

Area of Science:

• Materials Science
• Renewable Energy Engineering
• Photovoltaics

Background:

• Conventional electroluminescence (EL) defect detection for silicon solar panels requires darkroom conditions, limiting practical application.
• Existing methods struggle with performance under varying sunlight irradiance and weather conditions.

Purpose of the Study:

• To design and validate a novel defect detection system for solar panels operable under direct sunlight across all weather conditions.
• To develop an image processing algorithm for enhanced defect visualization under high irradiance.

Main Methods:

• A modulated current source was used to electrify solar panels.
• High frame rate InGaAs detectors captured image data, transmitted via CameraLink.
• A defect display algorithm model was developed using acquired image data.

Main Results:

• The system effectively collected solar panel defect information under sunlight irradiance ranging from 0.2 to 1300 W/m².
• An image saliency enhancement algorithm was proposed based on modulated phase differences between defective and non-defective points.
• The algorithm effectively reduced background interference and improved defect contrast under high irradiance.

Conclusions:

• The developed system offers a practical solution for outdoor solar panel defect detection.
• The proposed enhancement algorithm significantly improves defect visibility in challenging lighting conditions, crucial for quality control and maintenance.