Detection of Potential Induced Degradation in c-Si PV Panels Using Electrical Impedance Spectroscopy

Impedance spectroscopy (IS) is an established characterization and diagnostic method for different electrical and chemical research areas such as batteries and fuel cells, but not yet widely adopted for photovoltaics (PV). This work, for the first time, investigates an IS based method for detecting potential-induced degradation (PID) in c-Si PV panels. The method has been experimentally tested on a set of panels that were confirmed to be affected by PID by using traditional current-voltage (I-V) characterization methods, as well as electroluminescence (EL) imaging. The results confirm the effectiveness of the new approach to identify PID in PV panels.</p

A Photovoltaic Module Diagnostic Setup for Lock-in Electroluminescence Imaging

Electroluminescence (EL) imaging and infrared (IRT) thermography techniques have become indispensable tools in recent years for health diagnostic of photovoltaic modules in solar industry application. We propose a diagnostic setup, which performs lock-in EL for accurate analysis of different types of faults occurring in a solar module. The setup is built around a high-speed SWIR camera, which can acquire images at very short integration time (1μs) and high frame rate (301 fps). In addition, a state-of-the-art imaging chamber allows for introducing controlled levels of ambient light noise for developing new light noise removal methods, rotation of panel frame in 3 axes plane for developing perspective distortion correction techniques. The paper also gives an insight of different system and communication delays that affects the performance of overall EL lock-in imaging system integration. The purpose of the diagnostic setup is to support research in PV failure quantification through EL imaging, which can also be useful for aerial drone imaging of PV plants.</p

Development of outdoor luminescence imaging for drone-based PV array inspection

This work has the goal to perform outdoor defect detection imaging that will be used in a fast, accurate and automatic drone-based survey system for PV power plants. The imaging development focuses on techniques that do not require electrical contact, permitting automatic drone inspections to be perform quicker and with less manpower. The final inspection method will combine several techniques such as, infrared (IR), electroluminescence (EL), photoluminescence (PL), and visual imaging. Solar plant inspection in the future can be restricted only by imaging speed requirements, allowing an entire new perspective in large-scale PV inspection

Outdoor Electroluminescence Acquisition Using a Movable Testbed

The experimentation with a movable outdoor electroluminescence (EL) testbed is performed in this work. For EL inspections of PV power plants, the fastest scenario will include the use of unmanned aerial vehicle (UAV) performing image acquisition in continuous motion. With this motivation, we investigate the EL image quality of an acquisition in motion and the extent of image processing required to correct scene displacement. The results show processed EL images with a high level of information even when acquired at 1 m/s camera speed and at frame rate of 120 fps.</p