Autors: Velkov, M. S., Stefanov, S. B., Gueorgiev, V. T.
Title: Influence of Elevated Temperature on Equipment Installed in Combiner Boxes and Potential-Induced Degradation on the Modules of a Photovoltaic Power Plant
Keywords: DC combiner boxes, elevated temperature, fuses, insulation degradation, overheating, Photovoltaic power plants, potential-induced degradation, reliability of electrical equipment, surge protection dev

Abstract: In this paper, the influence of elevated ambient and internal temperatures on the performance, reliability, and service life of electrical components installed in direct current (DC) combiner boxes of photovoltaic power plants is investigated. The study focuses on key elements such as fuses, DC circuit breakers, surge protection devices (SPDs), and cable insulation, which are particularly sensitive to thermal stress. Through thermographic analysis and on-site temperature monitoring conducted during periods of high solar irradiation, critical temperature values were identified and analyzed. Simulation models and failure analysis were also applied to investigate the main degradation mechanisms accelerated by overheating, including insulation breakdown, contact oxidation, and increased thermal resistance. In parallel with the analysis of thermal impacts, the phenomenon of potential-induced degradation (PID) in photovoltaic modules was also examined. By means of theoretical review and practical observations, the mechanisms of PID occurrence were studied—charge migration under the influence of high system voltage, high humidity, and elevated temperature. Results from simulations and field tests are presented, demonstrating a significant decline in generated power and accelerated module aging. Emphasis is placed on preventive measures, including the selection of PID-resistant modules, optimization of grounding schemes, and the use of regenerative devices (PID-box), aiming to minimize the effects and improve the long-term efficiency of photovoltaic power plants. The obtained results highlight the necessity of adequate ventilation, proper sizing, and material selection already at the design stage. Recommendations are provided for temperature management and PID mitigation in order to enhance safety, operational reliability, and extend the lifespan of equipment and modules under harsh climatic conditions.

References

  1. W. Luo, Y. S. Khoo, P. Hacke, V. Naumann, D. Lausch, S. P. Harvey, J. P. Singh, J. Chai, Y. Wang, J. Wohlgemuth, C. J. Brabec, "Potential-Induced Degradation in Photovoltaic Modules: A Critical Review," Energy & Environmental Science, 2017. doi:10.1039/C6EE02790A
  2. D. C. Jordan, S. R. Kurtz, "Photovoltaic Degradation Rates — An Analytical Review," Progress in Photovoltaics: Research and Applications, 2013. doi:10.1002/pip.1182
  3. J. Wohlgemuth, S. Kurtz, "Reliability Testing Beyond Qualification as a Key Component in Photovoltaic Module Development," Progress in Photovoltaics, 2011. doi:10.1002/pip.1083
  4. P. Hacke, R. Smith, K. Terwilliger, J. Pankow, M. Kempe, S. Kurtz, D. Jordan, "Accelerated Testing and Modeling of Potential-Induced Degradation in PV Modules," IEEE Journal of Photovoltaics, 2015. doi:10.1109/JPHOTOV.2015.2395134
  5. N. Gueorguiev, A. Nachev, Y. Boychev, K. Nesterov, S. Yaneva, "Reliability of Electro-Power Equipment Determined by Data in Its Operation and Storage," Engineering Proceedings, TechSys 2025, vol. 100, no. 1, p. 67, 2025. doi:10.3390/engproc2025100067
  6. D. Dimitrov, H. Hristov, M. Dochev, "Thermal Behavior of Electrical Components in Outdoor Switchgear under Summer Conditions," Electrotechnica & Electronica (E+E), 2022. [Online]. Available: https://eplusejournal.com
  7. D. Zafirova, T. Grigorova, S. Stefanov, "Monitoring of PV Systems Installed in Urban Areas in Bulgaria," Renewable Energy and Power Quality Journal, 2021. doi:10.24084/repqj19.310
  8. D. Atanasov, I. Kolev, D. Ivanov, "Performance Analysis of Photovoltaic Systems with Different Module Technologies under Balkan Climatic Conditions," IEEE International Conference on Renewable Energy Research and Applications (ICRERA), 2020. doi:10.1109/ICRERA49962.2020.9242751
  9. S. Kanev, I. Vasilev, V. Petrov, "Influence of High Temperatures on the Efficiency of PV Systems in Southeastern Europe," Journal of Electrical Engineering, 2019. doi:10.2478/jee-2019-0034
  10. G. Badran, M. Dhimish, "Potential Induced Degradation in Photovoltaic Modules: A Review of the Latest Research and Developments," Solar, 2023. doi:10.3390/solar3020019.

Issue

2025 17th Electrical Engineering Faculty Conference - Energetics and Efficiency, BulEF 2025, 2026, Bulgaria, https://doi.org/10.1109/BulEF66320.2025.11298994

Вид: публикация в международен форум, публикация в реферирано издание, индексирана в Scopus