Decision Tree Based Fault Classification Scheme for Protection of Series Compensated Transmission Lines

Abstract Series compensation at the midpoint of a transmission line creates problems to conventional protection approaches. A new fault classification technique has been developed for a transmission line with a series capacitor at the midpoint, having different percentages of compensation varying from 25% to 75%. The proposed technique requires three line currents and voltages at each end and computes fundamental phasors of these quantities using a modified version of Full Cycle Discrete Fourier Transform. Using these phasors, the absolute values of three phase impedances are calculated for faulted phase identification. Moreover, the involvement of the ground in the fault is identified using a zero sequence component of the fault current. Using a PSCAD/EMTDC software package, a large test data (28,800) set has been generated with different types of faults and system variables, which includes fault resistances, fault inception angles, fault positions (before and after series capacitor) and variable loading conditions along with wide variations in the source impedances at both ends of a transmission line. The proposed scheme is tested on the said data set and the results are found to be promising. The results indicate that the proposed technique is fast, accurate and robust for a wide variation in system and fault conditions. Submitted: April 3, 2007 · Accepted: October 24, 2007 · Published: November 21, 2007 Recommended Citation Parikh, Urmil B.; Bhalja, Bhavesh R. Jr.; Maheshwari, Rudra Prakash; and Das, Biswarup (2007) "Decision Tree Based Fault Classification Scheme for Protection of Series Compensated Transmission Lines," International Journal of Emerging Electric Power Systems: Vol. 8 : Iss. 6, Article 1. DOI: 10.2202/1553-779X.1630 Available at: http://www.bepress.com/ijeeps/vol8/iss6/art1