Authors: Aixiang Zeng; Xiao'an Qin; Yuanyuan Wang; Hui Pan
Addresses: School of Physics and Electronic Science, Changsha University of Science and Technology, 960, 2nd Section, Wanjiali South RD, Changsha, Hunan, 410004, China. ' Wuhan Power Supply Company, 14F, Gaoke Plaza, Guandong Science and Technology Industry Park, Wuhan, Hubei, 430074, China. ' School of Electrical and Information Engineering, Changsha University of Science and Technology, 960, 2nd Section, Wanjiali South RD, Changsha, Hunan, 410004, China. ' School of Electrical and Information Engineering, Changsha University of Science and Technology, 960, 2nd Section, Wanjiali South RD, Changsha, Hunan, 410004, China
Abstract: Traditional double-terminal travelling wave protection schemes are unable to satisfy the requirement of power systems stability and economy. In order to solve these problems for extra high voltage (EHV) transmission lines protection, a novel non-unit transient protection based on HHT energy spectrum is developed. The travelling-wave characteristics between internal faults and external faults are analysed. The main difference is that the travelling wave high frequency components energy caused by the internal faults is larger than that caused by the external faults due to the influences of line trap and bus-to-ground capacitance. Intrinsic mode functions (IMF) of travelling wave are extracted by the empirical mode decomposition (EMD). And then Hilbert-Huang transform (HHT) is utilised to calculate the corresponding instantaneous frequency of each IMF component to obtain energy spectrum. Finally, the energy spectrum is applied to distinguish the internal and external fault. EMTP simulation results show that, under different fault conditions, the novel scheme can distinguish reliably the internal faults from external faults and protect the whole transmission line with high sensitivity.
Keywords: EHV transmission lines; extra high voltage; non-unit transient protection; Hilbert-Huang transform; HHT energy spectrum; travelling waves; fault protection; wave protection; power systems stability; power systems economy; simulation; internal faults; external faults.
International Journal of Advanced Mechatronic Systems, 2012 Vol.4 No.1, pp.18 - 24
Available online: 16 Feb 2012 *Full-text access for editors Access for subscribers Purchase this article Comment on this article