태양광 시스템에서의 Arc Fault Detector 개발을 위한 DC 모의 아크 주입 기법

Abstract

UL 1699B (1st version, Underwriters Laboratories, U.S.A.) was issued with the title of “Standards for Safety: Photovoltaic DC Arc Fault Circuit Protection” in 2018. Complying the standard, we need to go through the long and rigorous work to prove the reliability of AFD, whether it satisfies the test standard. Definitely, one of the key issues has been the unwanted trip caused by harmonic frequencies from a site dependent photovoltaic inverter. Avoiding the intense work dedicated to DC arc fault production, the generation process of simulated DC arc signal has been developed as one simple method to help the research staffs working in the laboratories of arc fault detection. In order to produce the load current of the photovoltaic system that changes according to the amount of insolation, the DC arc is generated at 4.5A, 5.5A, 6.5A, and 7.5A in the laboratory according to UL1699B. The DC arc signal datas are each compare with real DC arc signal from the DWT and FFT process, were injected to the photovoltaic circuit through the D/A process. In this paper, the test result obtained from the 50 kW photovoltaic system explains the validity of simulated DC arc signal that is compatible with a real DC arc fault event.