A fault diagnosis method and diagnostic equipment

Abstract

The fault diagnosis method and diagnostic equipment provided by the present invention are applied in the technical field of photovoltaic power generation. After obtaining the high-irradiance IV data set and the low-irradiance IV data set of the diagnostic object, the method takes any IV data set as the target IV data Set, filter the target IV data as the inflection point data in the target IV data set, use another IV data set as the reference IV data set, and filter the IV data corresponding to the same voltage value as the target IV data in the reference IV data set, as the reference IV data. If the reference IV data also belongs to the inflection point data, the mismatch type of the diagnostic object is determined according to the change result of the target IV data and the reference IV data following the irradiance. The method analyzes the IV data under different irradiation conditions to determine whether the mismatch fault of the diagnostic object is the front current mismatch or the rear current mismatch, so as to realize the decoupling of the fault determination results of the diagnostic object and improve the accuracy of fault diagnosis.

Description

technical field [0001] The invention relates to the technical field of photovoltaic power generation, in particular to a fault diagnosis method and diagnostic equipment. Background technique [0002] The IV data of photovoltaic modules or strings refers to the current-voltage data of photovoltaic modules or strings during operation. In practical applications, the corresponding IV data set can be obtained by performing IV scan on the photovoltaic module or string through the detection equipment. The data set includes multiple value pairs, each value pair consists of a current value, and the current value The voltage values ​​at the same sampling moment are formed. Since IV data can directly reflect the operating status of photovoltaic modules or strings, IV data is widely used in fault diagnosis of photovoltaic modules or strings. [0003] Most of the diagnostic methods in the prior art draw IV curves based on the test object, that is, the IV data set of the photovoltaic mo...

AI Technical Summary

Problems solved by technology

[0004] The inventors have found that for double-sided modules or strings, the IV data is the superimposed result of the output characteristics of the front and rear modules, and most of the commonly used diagnostic methods are based on the IV data of single-sided modules or strings. However, it only has good adaptability and diagnostic accuracy for single-sided components or strings. For double-sided components or strings, the existing diagnostic methods cannot determine the specific cause of the mismatch fault, that is, it is impossible to determine the cause of the mismatch fault. It is caused by the mismatch of the front current or the mismatch of the back current, which is difficult to meet the actual application requirements.

Images