Wavelet fuzzy based fault location estimation in a three terminal transmission system

This paper presents a wavelet fuzzy based protection scheme for a three terminal transmission system, makes use of current signals at three ends of transmission line which are synchronized with the help of global position system clock. A wavelet based multi resolution analysis is used to find the detailed coefficients of the signals which are utilized to calculate fault index. These fault indices are compared with the threshold value to detect and classify faults on transmission system. The approximate decomposition of current signals is utilized to locate the fault using fuzzy logic from their respective terminals. The proposed algorithm has been tested successfully for various faults at different locations.