Single-ended transient positional protection of transmission lines using mathematical morphology

This paper presents a novel single-ended transient positional protection (SCTPP) scheme developed using the combined scheme with multi-filter units of mathematical morphology (MFUMM) and multi-resolution morphological gradient (MMG). Multi-filter units can effectively and gradually suppress a variety of random and pulsed noises existing in fault-generated transient signals which can be detected by using multi-resolution morphological gradient. The fault can be located accurately according to relative traveling times and polarities of transient signals. A typical 500-kV extremely high voltage (EHV) transmission system has been simulated by PSCAD/EMTDC to evaluate the scheme. The simulation results show that this scheme is capable of locating accurately under various types of faults occurring at different positions on power lines. Meanwhile, it should be indicated that this algorithm has less computational complexity than multi-resolution wavelet transform, which makes it possible to put into practice