Fault detection and classification for TCSC compensated transmission lines using wavelet energy

Abstract

The installation of Thyristor Controlled Series Capacitor (TCSC) in a transmission line affects both steady-state and transient components of the current and voltage signals. As a result the traditional algorithms based on steady-state components find difficulty in accomplishing fast and reliable detection and classification of faults in such lines. This paper presents a fast and reliable fault detection and classification technique for a TCSC compensated line by employing the effective time-frequency analysis based on discrete wavelet transform (DWT) on the measured three-phase current signals. In this work, the features (detail coefficients of level-1, cD1) of currents signals are extracted by DWT using ‘db4’ mother wavelet. The fault detection and classification task is accomplished using the spectral energy (SE) of cD1. The extraction of the new efficient feature; the spectral energy of cD1 is the main contribution of the proposed work. The performance of the proposed fault detection and classification scheme is tested for a wide variety of fault scenarios by generating data on a 400 kV double circuit TCSC compensated transmission line through EMTDC/PSCAD software. The results clearly show that using the proposed method fast and reliable detection and classification of faults on TCSC compensated transmission lines can be accomplished.