MITIGATING POTENTIAL-INDUCED DEGRADATION (PID) IN SOLAR PANELS THROUGH GROUNDING: DIAGNOSTIC AND OPTIMIZATION APPROACHES

Аннотация

; This paper explores diagnostic and optimization approaches to mitigate Potential-Induced Degradation (PID) in photovoltaic (PV) modules through effective grounding techniques. PID is a critical issue in solar energy systems that leads to significant power losses due to high-voltage stress and leakage currents. The study analyzes the underlying mechanisms of PID, evaluates common diagnostic tools used for early detection, and examines various grounding strategies to reduce or eliminate its effects. Experimental results and comparative assessments highlight the effectiveness of isovalent impurity doping and optimized grounding configurations. The findings offer practical insights for improving the long-term performance and reliability of solar panels in high-voltage applications. Keywords: PID, solar panel, grounding, IV-curve, insulation resistance, thermographic monitoring, power loss 1. Introduction Photovoltaic (PV) systems, which convert solar energy into electrical energy, are becoming increasingly popular as stable and environmentally friendly sources of power. However, their long-term efficiency is affected by various degradation processes, among which Potential-Induced Degradation (PID) plays a particularly significant role. PID mainly arises due to the electrical potential difference associated with the grounding of PV panels. If the grounding system is improperly designed or entirely absent, the risk of PID increases significantly. This degradation leads to a noticeable decline in PV system performance and shortens the overall operational lifespan of the system. This paper explores the origins of PID, the role of grounding systems in its prevention, diagnostic methods, and practical measures for optimization based on experimental findings. 2. Methods 2.1. PV Panels Used The study utilized monocrystalline photovoltaic (PV) panels. Each panel had a rated power of 320 W and was manufactured by SunTech, model STP320. The panels consisted of 72 cells and were provided with standard test condition (STC) parameters. 2.2. Grounding Configurations. Two grounding configurations were selected for testing: https://scientific-jl.com/wsrj 4 4 Volume-40_Issue-2_June-2025 World scientific research journal Grounded System – PV panels were connected to a central grounding system. This configuration reduced the potential difference across the panel surfaces. Grounding served to eliminate excess voltages and protect the semiconductor structure. Isolated System – Panels were either ungrounded or electrically isolated during testing. In this scenario, the risk of PID occurrence was significantly higher. 2.3. Electrical Network Configuration. The system included an inverter capable of handling up to 1000 V, equipped with Maximum Power Point Tracking (MPPT) functionality to maximize PV system efficiency. The DC side of the system was grounded, and voltage monitoring was carried out continuously. 2.4. Diagnostic Instruments To detect and analyze PID, the following instruments were employed: Multimeters and voltmeters – for voltage and current measurements. IV curve tracer – to obtain the voltage-current characteristics of the PV panel. Thermal imaging camera – to detect potential thermal hotspots on the panel surface. Insulation resistance tester – to assess the effectiveness of the grounding system. 2.5. Experimental Conditions The tests were conducted outdoors under direct sunlight, with ambient temperatures ranging between 25°C and 35°C. The testing period lasted 72 hours, with measurements taken every 12 hours. Weather conditions included moderate humidity and clear air. 2.6. Measurements and Monitoring Panel output voltage and current were recorded regularly. Insulation resistance and grounding resistance were measured. Thermal images were captured to identify potential thermal damage zones. PID impact on efficiency was evaluated through IV curve analysis. 2.7. Mathematical Model and Equations The mathematical model describing the voltage associated with Potential- Induced Degradation (PID) is presented as follows: 𝑉 = 𝑉 − 𝑉 1. 𝑃𝑂𝐷 𝑝 𝑦 This model accounts for the influence of surface potential differences, insulation resistance, and leakage current pathways that contribute to PID formation in PV systems. By analyzing the relationship between these parameters, the model helps quantify the risk and severity of PID under various grounding and environmental conditions. https://scientific-jl.com/wsrj 4 5 Volume-40_Issue-2_June-2025 World scientific research journal 3. Results 3.1. Output Power of PV Panels During the experiment, the output power of two different PV systems — grounded and ungrounded — was compared. The table below presents the average results obtained over the 72-hour observation period: System Type Average Output Power (W) Power Loss (%) Grounded 312 W 2.5 % Ungrounded 297 W 7.2 % These results indicate that the ungrounded system experienced a significantly higher PID effect, resulting in approximately 5