Improving the stability of power transmission lines based on an adaptive single pole auto-reclosure using a two-step strategy

摘要

As more than 80% of single line to ground faults in power transmission lines (PTLs) are transient, single pole auto-reclosure (SPAR) is of considerable importance for increasing the successful SPAR rate, improving power system stability and reducing shocks to the power systems. In this study, a new two-step strategy for ASPAR is presented. In the first step, the fault type (permanent or transient) is determined using the derivative of the first harmonic of the faulty phase voltage. Then in the second step, the extinguishing moment of the secondary arc is detected in the case of transient occurrence, in which the reclosing signal is sent to the side circuit breakers of the PTL after the secondary arc is completely extinguished. The major features of the proposed scheme are: its capability to detect the permanent fault from the transient one, and determine the extinguishing moment of the secondary arc without the need to define a specific threshold level, its independence from the PTL type and its appropriate structure that facilitates its online hardware implementation and makes it more comprehensive. Extensive simulations in the ElectroMagnetic Transient Program-RV, as well as practical data testing, demonstrate the accuracy and precision of the proposed method.