基于高频脉冲传播时差的光伏系统电弧故障定位检测方法

Abstract Series arc faults pose substantial fire risk in photovoltaic (PV) power systems, and accurately localising these faults within a PV array has become a pressing challenge. Current arc fault location methods are based on the electromagnetic pulses generated by arcs and propagation characteristics in space. However, this requires high-speed sampling equipment and precise time synchronisation, and the location accuracy is easily affected by interference. In fact, the array of silicon wafers on multiple PV panels forms a tortuous transmission line. The voltage pulses generated by arcs propagate and attenuate between PV panels. This study presents a wide- frequency impedance model based on the physical structure of the PV panel. The particle swarm optimisation (PSO) algorithm is employed to optimise the model parameters. The propagation and attenuation characteristics of high-frequency pulse voltages in PV panels are analysed through simulation and theoretical analysis. Subsequently, arc fault experiments are conducted on PV systems. The pulse voltage waveforms generated by series arc faults are measured, which corresponded well with the simulation results. Finally, a method for locating series arc faults is proposed. This method only requires the installation of a high-frequency, AC coupling voltage measurement point at the inverter input. By utilising the time difference between the peak values of positive and negative polarity pulse voltages, arc faults can be precisely located. The proposed method is low-cost, simple, reliable, and effective offering a novel approach to series arc fault localisation in PV systems.