A photovoltaic DC arc detection method and system

Abstract

The present invention provides a photovoltaic direct current arc detection method and system, comprising: using a Hall sensor to obtain a current signal of a photovoltaic direct current circuit; extracting time domain characteristics, frequency domain characteristics and wavelet characteristics of the current signal; including: time-frequency change rate and the mean value of the absolute value of the time-frequency change rate; the difference between the high-frequency component and the low-frequency component and the zero-removing standard deviation in the frequency domain; the standard deviation of the wavelet coefficients of each frequency band, the mean absolute value of the wavelet coefficients of the highest frequency band, and the maximum value of the high-frequency component; Domain features, frequency domain features and wavelet features are input into the trained gradient boosting tree model, and whether arcs are generated in the photovoltaic DC circuit are detected according to the classification results of the model. The invention analyzes the characteristics of the DC arc from three levels of time domain, frequency domain and wavelet, and selects a reasonable eigenvalue processing for the characteristics of the DC arc, so that the arc current characteristics can be displayed at multiple levels and angles, and as a training set, it has more The good training effect improves the recognition accuracy of the model.

Description

technical field [0001] The invention belongs to the field of DC arc detection, and more particularly, relates to a photovoltaic DC arc detection method and system. Background technique [0002] With the acceleration of the global electrification process, the demand for electricity continues to rise, and photovoltaic power generation is rapidly popularized, but photovoltaic accidents at home and abroad are also showing an upward trend. Arc is a gas discharge phenomenon that produces high temperatures, high brightness, and radiation. When an arc occurs, if the arc is not extinguished in time, it may cause cable damage, loss of power generation, or even fire. In a photovoltaic system, one of the common types of arcs on the DC side is a series arc, which is commonly found at the MC4 terminal of a photovoltaic system. In order to cut off the branch in time when an arc occurs, an arc detection function needs to be added to the photovoltaic system. [0003] The prior art utilize...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the defects of the prior art, the purpose of the present invention is to provide a photovoltaic DC arc detection method and system, which aims to solve the problems of difficult detection of photovoltaic DC current arc, low accuracy rate, frequent misjudgment, and difficulty in timely detection of arc current.

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