Transient Lightning Impulse Performance Analysis for Composite Transmission Line Tower

Abstract

In this paper, the transient impulse performances of a 330-kV composite transmission line tower under direct lightning strokes are comprehensively presented. An equivalent distributed parameter model combined with lumped capacitance elements for the tower is established. The wave impedances of the hybrid model are determined by using analytic equations. The lumped capacitances are calculated by 3-D finite element method (FEM). An accurate model for extended grounding structure (EGS) of the tower base considering the soil ionization is used to simulate its impulse performances. The wave process of the tower is analyzed by using the electromagnetic transient program (EMTP). The proper grounding conductor system is determined for the case of a superior lightning impulse performance considering three diverse grounding configurations. The influence of radius of the grounding conductor is assessed. The numerical electromagnetic field analysis, finite-difference time-domain (FDTD) simulation is applied to verify the validity of the presented hybrid model. Then, the influence of the wave-front time of the lightning current, the soil resistivity, the dimension of the EGS, and their combined effect on the transient impulse performances for the EGS are analyzed and discussed.

Evaluation of a Direct Lightning Strike to the 24 kV Distribution Lines in Thailand

“…Using a composite transmission line tower by double grounding the conductor system [25] Flashover will not happen for negative or positive injected lightning current…”

“…It was demonstrated in Reference [24] that reducing the soil resistivity and permittivity decreases the rate of power outages by 13-32% for usual distributions. A composite transmission line was applied by Reference [25]; the results showed that the best structure is a double-grounding conductor system, as flashover will not happen in this structure with either negative or positive lightning current. It was also found that the radius of the grounding conductors had little effect on improving lightning performance.…”

A distributed modelling method of the transmission tower and transient response analysis of lightning wave process

“…Huangfu et al. considered the coupling between the ground conductors of the composite tower and established a non‐uniform multi‐conductor transmission line model combined with lumped circuit elements, and finally formed a composite transmission line tower model under lightning strike [17, 18]. Ishii et al.…”

“…Usually, the transmission tower model is an effective tool on both the lightning protection level and the lightning protection design of the transmission line. Thus, in recent years, a large number of researchers have carried out modelling studies on transmission towers [5], which can be roughly divided into the single-wave impedance model [6][7][8][9][10][11][12][13][14], frequency-dependent model [15,16] and multi-wave impedance model [17][18][19][20][21][22][23][24][25]. Among them, the multi-wave impedance models are mainly divided into the composite tower equivalent model [17,18], multilayer transmission tower model (MTTM) [19][20][21][22] and Hara model [23][24][25].…”

“…Thus, in recent years, a large number of researchers have carried out modelling studies on transmission towers [5], which can be roughly divided into the single-wave impedance model [6][7][8][9][10][11][12][13][14], frequency-dependent model [15,16] and multi-wave impedance model [17][18][19][20][21][22][23][24][25]. Among them, the multi-wave impedance models are mainly divided into the composite tower equivalent model [17,18], multilayer transmission tower model (MTTM) [19][20][21][22] and Hara model [23][24][25]. Huangfu et al considered the coupling between the ground conductors of the composite tower and established a non-uniform multi-conductor transmission line model com-bined with lumped circuit elements, and finally formed a composite transmission line tower model under lightning strike [17,18].…”