Multi-Stable Stochastic Resonance Based Protection Scheme for Parallel Transmission Lines with UPFC

Abstract

This paper presents a multi-stable stochastic resonance (MSR) based on complex wavelet transform (CWT) for protecting a double line transmission system with unified power flow controller (UPFC) in one line. The fault detection at the sending end is recognized by the collective sum technique (CST) using the current signals of all the three-phases with heavy background noise. The noisy signal is processed by parameter compensation and the processed signal is decomposed by CWT with different scale frequencies. The spectral energies of each phase can be used to identify the faulty phases. The CWT is used to compute the spectral energies of each phase current. The proposed scheme has been studied for wide variation of operating parameters and compared with two other fault extraction methods such as EMD-based spectral analysis and wavelet transform with post spectral analysis. The test results of the proposed CWT based MSR algorithm indicates that it can accurately detect and classify the fault with in one cycle from fault inception.