An improved method for expressing the transient ground resistance of overhead transmission lines by exponential polynomial. Issue 18 (23rd August 2017)

• Record Type: Journal Article
• Authors: Liu, Xin; Wang, Litong; Yang, Jiawei; Yue, Huiqing
• Is Part Of: IET generation, transmission & distribution. Volume 11:Issue 18(2017)
• Page Start: 4680
• Page End: 4687
• Publication Date: 2017-08-23
• Subjects: power overhead lines -- multiconductor transmission lines -- polynomial approximation -- vectors -- permittivity; overhead transmission lines -- transient ground resistance -- exponential polynomial -- rational approximation -- ground conductivity -- permittivity -- normalise poles -- line geometrical geometry -- conventional vector fitting -- recursive convolution -- multiconductor transmission lines -- lightning induced voltages; Electric power production -- Periodicals; Electric power transmission -- Periodicals; Electric power distribution -- Periodicals; 621.3105
• DOI: 10.1049/iet-gtd.2017.0215
• Languages: English
• ISSNs: 1751-8687

Abstract

Abstract : In this study, a method is proposed for expressing the transient ground resistance of the overhead transmission lines (TLs) by the exponential polynomial. The relation of the poles due to the rational approximation of the ground resistance between the ground conductivity, permittivity and the line geometry is fully discussed. A concept of 'normalise poles' is introduced, which makes it very easy to evaluate the poles according to any ground conductivity, permittivity and line geometrical geometry. A new and easily programmed method is achieved which can overcome the uncertain error caused by the conventional vector fitting method when approximating the ground resistance. Based on this method, a recursive convolution can be achieved for analysing the multi‐conductor TLs system, so good efficiency can be obtained. Several examples are provided to demonstrate the validation of the proposed method for evaluating the transient ground resistance with different ground parameters and line geometry, and an application on calculating the lightning induced voltages of the overhead TLs system is also provided.