Abstract:

In order to avoid hazards caused by arc faults,the relevant standards,detection methods and products proposed at home and abroad are overviewed,and the advantages and disadvantages of these detection methods and products are analyzed.The interferences of arc fault detection are discussed,which are caused by the system factors such as the time change property of the PV array and the inverter switch noise.Based on MATLAB simulation platform,the DC arc fault characteristics are discussed.The features are extracted by time-frequency transformation method,and the feature quantities are obtained.Finally,a product prototype is developed,which is tested in the application scenario with 375 V voltage.In order to check whether the designed arc fault detection algorithm can better avoid the interference of switching noise,the test is carried out under three conditions:DC/DC arc fault,inverter load arc fault,and inverter load normal startup.The results show that the developed prototype is able to cut faults accurately and quickly.The time required to cut off the faults is about 0.85 s,which meet UL1699B standard.

Key words: photovoltaic system, arc fault, experiment analysis, product development