Method, device and equipment for identifying battery string faults in photovoltaic systems

Abstract

Embodiments of the present invention provide a method, device, and equipment for identifying battery string failures in a photovoltaic system. The method includes: obtaining at least two sets of I-V values ​​of the first battery string in the photovoltaic system; value, using a predetermined string physical model for fitting processing to obtain at least one characteristic parameter of the first battery string; compare at least one characteristic parameter with a pre-acquired standard characteristic parameter to determine whether the first battery string failure, or curve fitting processing of collected data through the physical model of the string, which can be widely used. The characteristic parameters obtained by comprehensive processing of all the measured data of the battery string are compared with the standard characteristic parameters when there is no fault. Because the test error of individual points causes misjudgment, and does not depend on the judgment of the environment, the scheme will not be affected by the inconsistency of the environment, and effectively improves the processing efficiency and accuracy of string fault identification.

Description

technical field [0001] Embodiments of the present invention relate to optoelectronic technology, and in particular to a method, device and equipment for identifying faults of battery strings in a photovoltaic system. Background technique [0002] A solar cell module is the basic unit of a photoelectric system (or photoelectric device) that implements photoelectric conversion, and can convert sunlight energy into DC power. In actual photovoltaic power station applications, multiple solar cell modules are generally connected in series to form a battery string, and then one or more parallel strings are connected to a grid-connected inverter, through which the DC power is converted into AC power and sent to the AC grid. [0003] The output power characteristics of solar cell modules are determined by factors such as the state of the cell itself, the intensity of external light, and the ambient temperature. When the battery module is working, the output power will decrease due t...

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Problems solved by technology

[0005] Embodiments of the present invention provide a method, device and equipment for identifying battery string faults in a photoelectric system, which are used to solve the problem in the prior art that the slope is discontinuous due to the error of sampling parameters at individual operating points, resulting in misjudgment of faults , and solve the problem of low fault identification accuracy caused by the inconsistent working conditions of the battery strings at different locations in the power station due to the ambient temperature and irradiance

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