Fault trajectories and location estimations for distance protection using two new simplified phasor analysers

• Published in: Australian journal of electrical & electronics engineering Vol. 10; no. 3; pp. 331 - 343
• Main Authors: Patra, JP, Dash, PK, Krishnanand, KR
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group LLC 2013
• Subjects: Algorithms; Analysis; Electric power systems; Electric power transmission; Signal processing
• ISSN: 1448-837X
• DOI: 10.7158/E12-031.2013.10.3

The paper presents two new computationally simple algorithms for the protection of power transmission lines during fault conditions. The first method is based on the minimisation of a weighted forgetting factor based error cost function by the use of a fast Gauss-Newton method approach. Further a Hessian matrix approximation is used to produce a fast recursive algorithm, which is immune to random noise, waveform distortion due to DC offsets and increases the speed of convergence and accuracy. The algorithm models the typical time-varying signal and the accompanied distortions due to harmonics and random noise in a manner that will be suitable for real-time apparent impedance estimation. The second approach is based on a phase corrected wavelet transform known as fast discrete S-transform, which unlike the conventional one, uses frequency selection and frequency localised band pass filtering techniques to reduce the computational overhead and makes it suitable for on-line implementation in computing the fault location on an overhead transmission line. Both the proposed schemes are evaluated for the protection of a transmission line in a meshed power system network for a variety of fault types, fault locations, fault resistances, and significant noise in the signal using computer simulation studies.