The invention belongs to the technical field of power
system power distribution network
relay protection, and provides an
active fault property discrimination method based on injection disturbance current
response characteristics, which comprises the following steps: step 1, when an inter-phase fault occurs in a
system, three-phase
tripping of a fault line outlet
circuit breaker occurs, and according to three-phase current and
voltage change conditions before and after the fault, determining whether the fault occurs or not; determining two phases with increased
line current and reduced
voltage as fault phases; 2, delaying for 200ms after the
circuit breaker trips, and controlling the action of a split-phase switch; according to the method, disturbance current signals are injected through an external power supply, the disturbance signals have obvious difference in
response characteristics during permanent faults and instantaneous faults, the reliability and superiority of the method under different working conditions are verified through
simulation, the method makes up for the defects of an active injection type method during fault property recognition
processing, and the method has the advantages of high reliability and high reliability. The method is not influenced by injection time and fault duration, fault property discrimination can be realized only through one-time injection, and the method is simple in operation, small in calculation amount and high in reliability.