Fault Arc Suppression Method With Elimination of Line Voltage Drop Influence for Flexible Distribution Networks Connected via Power Electronics

Single phase-to-ground (SPG) faults constitute the prevalent type of electrical failure in live distribution networks, posing critical threats including electrocution hazards, electrical fires, and widespread power supply disruptions. Power electronic converter can suppress the fault current and voltage, sustaining this suppression effect throughout the fault arc persistence period until arc extinction. However, not only does it consume additional resources, but the effect is also significantly affected by the line impedance voltage drop. This article analyzes the causes of line voltage drop and proposes an SPG fault arc suppression method for flexible distribution networks. The line voltage drop caused by the load currents of faulty feeder is eliminated by transferring the load currents via the employed flexible interconnection device during simultaneous fault arc suppression. The line voltage drop caused by the zero-sequence currents output from the device for fault arc suppression during simultaneous load current transfer is also eliminated, by only adopting the device arms connected to nonfaulty phase of the faulty feeder to output the zero-sequence currents. Extensive simulation study and experimental validation demonstrate that the fault current and voltage can be suppressed efficiently with a suppression rate of more than 98% in the case of different operating conditions.