Permanent Fault Identification Method Between Phase-to-phase in Distribution Network Based on Parameter Identification

For the problem of automatic reclosing blindly reclosing to permanent faults after the phase-to-phase fault occurs in distribution lines, a method based on parameter identification to identify permanent faults between phase-to-phase in the distribution network is proposed. After the phase-to-phase fault trips, the external variable-frequency voltage signal is injected into the power outage line, and the generated transient voltage and current information are used to construct the parameter network equation, and the internal structure of the network is identified based on the principle of parameter identification. The transient fault loop model is used as the calculation model, the loop equivalent inductance is used as the quantity to be calculated, and the nature of the fault is identified based on the difference between the calculated value of the loop equivalent inductance and the true value. If the difference between the calculated value and the true value is small, it is a transient fault; if the calculated value and the true value arc significantly different, it is a permanent fault.