Single-ring network tie-line three-power supply structure feeder automatic protection method

The invention discloses a single-ring network tie-line three-power supply structure feeder automatic protection method, which is realized based on a single-ring network three-power supply two-active-one-standby mode. When single line fault happens to the single-ring network tie-line three-power supply structure, a feeder automatic protection control device controls cutoff of a switching station outgoing circuit breaker, power cutoff is realized, a distribution automatic terminal exchanges operation information, switches at two ends of a fault region are cut off, fault isolation is carried out, and finally, the distribution automatic terminal controls on and off of a power incoming circuit breaker, a tie switch and a load switch, and power supply for a non-fault region is realized. when fault happens to any section, the switch of the corresponding section is opened, the tie switch is closed, the load is transferred to a corresponding feeder, transferring is completed, and the method can be applied to a region with high reliability requirements, a region with medium and small capacity, a region with concentrated single power supply users, and a region with huge dual-ring network transformation difficulty.