Photovoltaic (PV) hot-spots are considered as one of the main reliability issues for PV modules.Although PV modules are capable to tolerate over-temperature, the hot-spots can lead to accelerated aging and, sometimes, to sudden failure with possible risk to fire. The commonpractise for mitigating this phenomenon is the adoption of the conventional bypass diode circuit, yet, this method does not guarantee a decrease in the temperature of hot-spotted solar cell. Therefore, in this paper, we present the development of a new current limiter circuit that is capable of mitigating the current flow of PV modules affected by mismatch conditions including partial shading and hot-spotting phenomenon. The foundation of the proposed circuit is fundamentally based on an input buffer which allows high impedance input voltages, and an operational amplifier circuit which controls the current flow of an integrated MOSFETs.Hence, to allow the control of the amount of current passing though mismatched PV substrings, and therefore, increase the output power generation. Detailed circuit simulations and multiple experiments are presented to evidence the capability of the circuit. In contrast, the average dissipated power of the circuit is limited to 0.53 W.

Faults in photovoltaic (PV) modules, which might result in energy loss and reliability problems are often difficult to avoid, and certainty need to be detected. One of the major reliability problems affecting PV modules is hot-spotting, where a cell or group of cells heats up significantly compared to adjacent solar cells, hence decreasing the optimum power generated. In this article, we propose a fault detection of PV hot-spots based on the analysis of 2580 PV modules affected by different types of hot-spots, where these PV modules are operated under various environmental conditions, distributed across the UK. The fault detection model comprises a fuzzy inference system (FIS) using Mamdani-type fuzzy controller including three input parameters, namely, percentage of power loss (PPL), short circuit current (Isc), and open circuit voltage (Voc). In order to test the effectiveness of the proposed algorithm, extensive simulation and experimental-based tests have been carried out; while the average obtained accuracy is equal to 96.7%.

Photovoltaic (PV) systems can be affected by different types of defects, faults, and mismatching conditions. A severe problem in PV systems has arisen in the last couple of years, known as potential-induced degradation (PID). During the early installation stage of the PV system, the PID may not be noticed because it appears over time (months or years). As time passes, it becomes more apparent since the output power may drop dramatically. We studied PV modules over the course of three years that were affected by PID. An electroluminescent and thermal imaging technique helped discover the PID. PID appeared in PV modules after being in different fields for 4–8 months, resulting in a 27–39% drop in power. An anti-PID box was fitted during the second year of the PV operation to recover the PID. Accordingly, it has stabilized the power degradation, but it could not restore the performance of the affected PID modules as compared with healthy/non-PID modules.

The potential-induced degradation (PID) of photovoltaic (PV) modules is one of the most extreme types of degradation in PV modules, where PID-affected modules can result in an almost 25% power reduction. Understanding how module defects impact PID is key to reducing the issue. Therefore, this work investigates the impact of an anti-PID inverter on PV modules throughout three years of field operating conditions. We used electroluminescence (EL), ultraviolet fluorescence (UVF), and thermography imaging to explore the varieties of an anti-PID inverter connected to a PV string. It was discovered that a PV string with an anti-PID inverter could improve the output power of the modules by 5.8%. In addition, the performance ratio (PR) was equal to 91.2% and 87.8%, respectively, for PV strings with and without an anti-PID inverter.

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