Flexible Arc Suppression Method Based on SOGI-FLL-PCI Controller and Fault Status Identification for Distribution Networks

Active arc suppression device is proposed for arc suppression of single-line-to-ground fault in distribution networks. Different from the passive Peterson coil, it needs a reliable fault status identification method to realize the secure exit of the device as ground-fault arc is extinguished. To improve the self-healing ability of the distribution network, this paper proposes a flexible arc suppression method based on double closed-loop control and fault status identification, which directly controls the neutral point voltage of distribution network. The reignition of fault arc can be suppressed by flexible arc suppression device (FASD). Through actively reducing the neutral point voltage, the ground-fault resistance is calculated to identify fault status after FASD is put into operation. The purpose of the reliable exit of FASD can be achieved. In the meantime, a double closed-loop controller based on second-order generalized integrator frequency-locked loop and proportional complex integral is designed, which can adaptively track the grid frequency and effectively limit the ground-fault current and voltage. The simulation results verify that the method can realize quick suppression of fault arc and reliable exit of FASD under different types of SLG fault.