Confluence detection method and system for combiner box, solar power station

Abstract

The invention provides a convergence detecting method and system for a convergence box. During zero value judgment, current values of adjacent input ends or similar input ends are utilized for mutual verification, during mean value judgment, the number of solar battery pack strings actually connected to the input ends of the convergence box of the grade are taken into consideration for mean value judgment, during high-value out-of-limit and low-value out-of-limit judgment, change rates of the current values of the adjacent input ends or the similar input ends are mutually verified, and the fault judgment accuracy of the convergence box in a photovoltaic array is improved. The invention further provides a solar power station.

Description

technical field [0001] The invention relates to the field of solar power generation, in particular to a confluence detection method and system for a combiner box, and a solar power station. Background technique [0002] With the increasing shortage of energy, the development and utilization of renewable green energy has attracted more and more attention, especially the utilization of solar energy has been favored by the world. As a clean, safe, sustainable and reliable energy source, solar photovoltaic system is rapidly expanding its application in energy and industrial technology development. In recent years, the development and application of photovoltaic cells and large-area photovoltaic module devices as solar energy conversion media have attracted widespread attention. The wide application of solar panels represented by monocrystalline silicon, polycrystalline silicon, and amorphous silicon thin films in commercial and residential buildings and other facilities has sho...

AI Technical Summary

Problems solved by technology

[0007] The disadvantage of this method is: for the morning and evening of every day, affected by light or shadow, it is very likely that some solar cell strings still generate electricity, but the current of the solar cell strings is small, while some components no longer generate electricity.

[0008] It can be seen that the existing fuse alarm judgment logic will introduce daily false positives

[0009] 2. Current low value cross limit method

[0011] The disadvantage of this method is that for multi-level confluence monitoring, the current value of each input terminal in the combiner box may be the sum of the currents of the multiple strings of battery components connected to the previous multi-level combiner box.

This kind of alarm signal due to changes in natural conditions will lead to a high false alarm rate

[0012] 3. Current high value over-limit method

However, first of all, this technical solution only takes into account the rate of change of one current, and does not take into account the current changes of the solar battery strings caused by the above-mentioned building shading and other conditions, and the fault false detection rate is still high; secondly, In the case of multi-level combiner boxes, this technical solution is only applicable to the current collection and detection between the output terminal of the last level combiner box and the inverter, but not for individual solar battery strings or upper level combiner boxes. The failure of the box is detected, so that the technician only knows that a failure has occurred, but does not know where the failure occurred

[0018] Regardless of any of the above detection methods, the current value or rate of change of a single input terminal or output terminal of the combiner box is measured in the time domain or frequency domain. The comparison of environmental factors cannot be ruled out, and the fault false alarm rate is high

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