Analysis of photovoltaic system under over-irradiation conditions in arid climate

Abstract

Photovoltaic systems are sensitive to weather conditions in terms of fluctuation, intermittentness and randomness, which could be affected drastically by the factors such as fast variation from sunlight conditions, environment temperature, cloud shadings under outdoor environmental conditions. The performance of photovoltaic systems could pose greater impact on the security and stability to the power grid especially under extreme irradiance condition. This paper established a mathematical analysis model for photovoltaic system under over-irradiation (OI) condition (>1000 W/m²) combined with the experimental data of a 5.605 kWp monocrystal silicon modules system from 2019 to 2020 in arid climate. The result evaluated the data in aspects of amplitude, frequency, velocity and duration of the performance of the system along with the weather data. The results show that the yield of the system under OI status accounts for 15.09% of the total energy generation, the maximum operating current exceeded the short-circuit current by 26.8% with average duration reaches 272 seconds. Finally, the four typical OI days were chosen from the date and demonstrated that the fuses of the string and inverters in the system would undertake an over-rated status over 12,050 seconds, which raised a challenge to the response time of the inverter and the MPPT algorithm as well as the fuses reliability.