Active photovoltaic string arc fault detection method and system

Abstract

The invention provides an active photovoltaic string arc fault detection method and system. The method comprises steps of an active signal injection step, actively generating a high-frequency signal,and actively outputting the high-frequency signal at a photovoltaic string side; a current signal acquisition step, measuring and recording a current signal on a direct current bus on the photovoltaicstring side, and acquiring the current signal information on the direct current bus on the photovoltaic string side; and an arc fault judgment step, carrying out wavelet transformation machining according to the current signal information on the direct current bus on the side of the photovoltaic string side, analyzing signal characteristics after wavelet transformation machining, comparing the signal characteristics after wavelet transformation machining with input high-frequency signals, determining whether the photovoltaic string has an arc fault or not, and obtaining the arc fault detection result information of the active photovoltaic string. The method is advantaged in that detection is carried out on the photovoltaic string side, and influence of inverter noise and different operation conditions on detection is fundamentally eliminated.

Description

technical field [0001] The present invention relates to the technical field of arc fault detection, in particular to an active photovoltaic string arc fault detection method and system. Background technique [0002] In recent years, with the improvement of my country's environmental protection requirements and the advancement of renewable energy power generation technology, the scale of clean energy utilization has been enlarged and developed rapidly. For example, as of 2019, the cumulative installed capacity of photovoltaic power generation in my country has reached 204GW, ranking first in the world. However, due to arc faults in photovoltaic strings, frequent fire accidents in photovoltaic power stations have resulted in huge economic losses and serious personal safety hazards, which have attracted the attention of the industry. At present, there are two main detection technologies for arc faults in photovoltaic strings: one is based on the detection method of physical pr...

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Problems solved by technology

However, it cannot adapt to the joint action of multiple environmental factors, and cannot guarantee high reliability when it involves changes in multiple influencing factors

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