Research on Adaptive Reclosing Technology for Low-Voltage Distribution Networks

To improve the success rate of auto-reclosing on low-voltage distribution lines, a method for identifying permanent phase-to-phase faults is proposed. A power electronic switch is connected in parallel with the main protection switch of the low-voltage distribution transformer. When a three-phase trip occurs due to a fault in the distribution network, the power electronic switch is briefly connected to the distribution network to detect the transient current of the faulty line. There are significant differences in the magnitude and abrupt change direction of the transient current corresponding to permanent inter-phase faults and transient faults. These differences can be used to distinguish between permanent inter-phase and transient faults. The effectiveness of this method has been verified through theoretical analysis and PSCAD/EMTDC simulation analysis.