Resistance-calculation-based fault diagnosis method for photovoltaic string

Abstract

The invention, which belongs to the field of photovoltaic power generation, provides a resistance-calculation-based fault diagnosis method for a photovoltaic string. The method comprises: step one, data point sampling is carried out by means of voltage modulation, series and parallel resistors of the string are calculated, and relevant data are uploaded to a data analysis platform; step two, datachanging rules and features of the series and parallel resistors are extracted, a fault type determination and degree assessment model is established, and then comparison and analysis are carried outon the series and parallel resistors of the string, so that fault type determination and degree assessment of the string are carried out; step three, according to a fault diagnosis result, a fault report is issued and the operation and maintenance are guided; and step four, the relevant data are stored into a database and the fault diagnosis model is optimized regularly. Therefore, on-line automatic diagnosis of the fault of the photovoltaic power station string is realized; shutdown during the diagnosis process is avoided; and the influence on the power generation state of the power station is reduced. And subjectivity and instability of the manual inspection are eliminated; the fault is processed quickly, accurately, and efficiently; the labor cost is lowered; and the operation and maintenance efficiency is improved.

Description

technical field [0001] The invention relates to a photovoltaic string fault diagnosis method based on resistance calculation, which belongs to the field of photovoltaic power generation. Background technique [0002] In recent years, my country's photovoltaic industry has developed rapidly, and its installed capacity has increased significantly. With the passage of time, the photovoltaic industry is bound to gradually enter the post-photovoltaic era in which the goal is to ensure the stable and efficient operation of power stations, and the daily operation and maintenance of photovoltaic power stations is the main task. Since the average lifespan of existing photovoltaic power plants is about 25 years, and photovoltaic systems usually operate unattended, system failures will reduce output power and affect the normal operation of the entire system. [0003] In practical applications, various faults may occur in the photovoltaic power plant system, among which the related fau...

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Problems solved by technology

[0007] The main purpose of the present invention is to provide a photovoltaic string fault diagnosis method based on resistance calculation to solve the problems of inaccurate diagnosis, low diagnostic efficiency, and large fluctuations in power generation status in fault diagnosis of photovoltaic strings

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