Detection and Classification of Double Line to Ground Faults in a 138 kV Six Phase Transmission Line Using Hilbert Huang Transform

In this paper, Hilbert Huang transform based technique is introduced to detect and classify double line to ground faults in a 138 kV, 60 Hz, 68 km long six phase transmission line. Hilbert Huang transform is used to extract the hidden features contained in fault current signal in the form of Hilbert coefficients. The proposed technique does not requires the communication link between the two terminals of six phase transmission line since the fault current signals are recorded at the first terminal only i.e. at bus-1. For the justification of the proposed technique, wide variety of fault test studies were carried out in MATLAB/ Simscape power system toolbox for different types of three phase to ground faults by varying fault type, fault location, fault inception time, fault resistance and ground resistance. Test results shows that the Hilbert Huang transform based proposed technique effectively detects/ classifies the double line to ground faults