A fault diagnosis method for photovoltaic strings under non-uniform irradiance

Abstract

The present invention is a fault diagnosis method for photovoltaic strings under non-uniform irradiance. In the case of inconsistent irradiance in photovoltaic strings caused by changeable weather, firstly, the irradiance sensors and temperature sensors arranged at multiple points are used to measure The environmental parameters of photovoltaic modules in different locations, using the equivalent circuit model of photovoltaic cells to theoretically estimate photovoltaic current, voltage and output power. At the same time, measure the actual photovoltaic current, voltage and output power at the combiner box of the photovoltaic string. Then, the fault coding is carried out for the open circuit fault and the short circuit fault, and the theoretical output power function about the fault coding is obtained. Finally, the absolute value of the difference between the theoretical output power of the photovoltaic string and the actual output power is used as the optimization target, and the objective function is optimized by using the enhanced firework algorithm with fast mining and reconnaissance performance, so as to realize the fault diagnosis and location of the photovoltaic string. The invention enables the operation and maintenance staff of the photovoltaic power station to arrange maintenance for the failed photovoltaic modules in time.

Description

technical field [0001] The invention relates to a photovoltaic string fault diagnosis method, in particular to a photovoltaic string fault diagnosis method under non-uniform irradiance. Background technique [0002] With the depletion of traditional energy sources such as fossil fuels and the increasingly prominent environmental pollution problems, human needs for new energy sources are becoming more and more urgent. Solar energy has the advantages of cleanness, environmental protection, safety, reliability, and sustainable development, and is an ideal renewable new energy source. At present, photovoltaic power generation is an effective technology for converting solar energy into electrical energy, which can effectively alleviate the energy crisis and improve environmental pollution problems. As an important part of the photovoltaic power generation system, the photovoltaic array can theoretically have an average lifespan of 20 to 30 years. Problems such as circuit failur...

AI Technical Summary

Problems solved by technology

On-line detection generally includes photovoltaic array fault detection methods based on mathematical models and intelligent photovoltaic array fault diagnosis systems. The shortcomings of low diagnostic accuracy and high fault false alarm rate have increased the work intensity of on-site operation and maintenance personnel, and even serious fault false alarms have occurred, directly affecting the efficiency, safety and stability of photovoltaic power generation systems

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