Hotspot Detection Method in Large Capacity Photovoltaic (PV) Farm

Abstract

The obligation to use low carbon emissions power plants encourages the increased utilization of renewable energy generation. Among the whole renewable energy plants, photovoltaic (PV) is a modular plant that is easy to implement, which the utilization reaches 100GW in the year 2017. By the increasing use of PV globally, the health of PV modules needs to be a concern because, during the operation, PV modules can experience various faults. Almost 50% of the overall fault is the hotspot which is very hard to detect on a wide area PV farm. For example, a 30 MW PV generation with an area of 60 hectares and composed of 126000 modules (consists of millions of cell), the existing hotspot detection methods takes up to 210 days. The long time and not continuous detection lets the hotspot to degrade and burn the modules. To prevent catastrophic failure due to hotspot, a detection method that can detect the fault quickly is needed. The proposed method, thermal imaging using a fish-eye lens could be used in this case as it has a very wide angle of view, which allows monitoring all of the PV modules in one detection period.

A Review of Models for Photovoltaic Crack and Hotspot Prediction

“…One of the issues of this detection method is that it is difficult to apply in large-scale farms. An example of this has been given by [36], where conventional hotspot detection methods using IR would take up to 210 days for a 30 MW PV farm because these methods cannot detect faults fast and continuously. That faults are detected continuously is especially important in this case, as it is crucial for predicting defects at an early stage, so that the necessary action can be taken to avoid or minize the impact on performance.…”

“…That faults are detected continuously is especially important in this case, as it is crucial for predicting defects at an early stage, so that the necessary action can be taken to avoid or minize the impact on performance. As a result, the authors [36] proposed the use of a detection system using a fish eye lens, which can simultaneously monitor 10 rows of PV modules that are 100 m long.…”

Solar cell micro crack detection technique using electromechanical impedance and finite element analysis

“…One of the issues of this detection method is that it is difficult to apply in large-scale farms. 11 That faults are detected continuously is especially important in this case, as it is crucial for predicting defects at an early stage, so that the necessary action can be taken to avoid or minimize the impact on performance. For this purpose, the electromechanical impedance (EMI) technique, which is based on highfrequency excitation (in few hundred kHz frequency range), is best suited for incipient damage detection.…”

“…One of the issues of this detection method is that it is difficult to apply in large-scale farms. 11…”

Defects Impact on PV System GHG Mitigation Potential and Climate Change

“…These hotspots affect the PV systems in the short term and long term, which includes performance, efficiency, health, and reliability of PV systems [8,14]. The literature suggests that almost 50% of the overall fault is the hotspot [15]. However, PV system overheating may arise due to aging, cracks, snail tracks, etc., as well other than hotspots [3].…”