Detecting instant of multiple faults on the transmission line and its types using time-frequency analysis

Abstract

In a complex interconnected network, due to dynamic interaction between the AC networks, at the time of multiple occurrences of faults, the successful relay operation is threatened. For security and reliability of power system network, fast and accurate protection scheme is of great importance. This paper presents a protection scheme for multiple faults detection at bus/line and its type in wide area network. If a fault occurs on a line, followed by another fault at the same/different line, before the clearance of former fault, the proposed scheme is capable to detect such multiple fault events. The protection scheme applies processed signal information for itstime-frequency representation using Smoothed Pseudo Wigner-Ville distribution, followed by Hilbert transform and calculation of indices to interpretate the fault events. It is shown that faulted bus, faulted line, time instant, and types of fault can be easily identifiedwithout involving any high computationally burden. The proposed scheme is validated on the signals simulated on two area Kundur’s model and standard IEEE 39 bus system and verified with real-time signals on RTDS for different fault conditions; fault resistance and fault location on the line. The scheme can be successfully applied on wide area signals available from PMUs for wide area network protection.