Arc Fault Detection and Localization in Photovoltaic Systems Using Parallel Capacitors

Arc faults threaten the safety operation of photovoltaics (PV) systems. An arc fault detection and localization approach using parallel capacitors is proposed. Five capacitors are paralleled with the branches of a PV system. Series and parallel arc faults are tested in the system. The amplitudes and polarities of the capacitor currents are obtained, and discrete wavelet transformation (DWT) is applied to the capacitor currents. The results indicate that the distributions of absolute amplitudes, polarities and spectrums of capacitor currents are unique under different fault types and locations, which can be used to detect and localize arc faults in PV systems.