Investigation of sag behaviour for aluminium conductor steel reinforced considering tensile stress distribution

Abstract

Sag calculation plays an important role in overhead line design. Since the tensile stress of aluminium conductor steel reinforced (ACSR) is required for the sag calculation, an analysis on sag behaviour when considering the tensile stress distribution can be very useful to improve the accuracy of sag results. First, this paper analyses the ACSR tensile stress distribution arising from the temperature maldistribution through proposing a new calculation formula. A finite-element analysis (FEA) model of ACSR is conducted for the solution of the new formula. By using the results, the error and limitations of the existing sag calculation methods for ACSR are discussed. As the critical point of sag calculation, knee-point temperature is solved iteratively involving the tensile stress maldistribution phenomenon in aluminium wires. Based on this iterative solution, an improved analytical method for the ACSR sag calculation considering the creep effect is presented and also compared with the hybrid sag method. The results show that these two methods are basically coincident without the consideration of creep effect, while there are non-negligible differences between them as the creep strain is involved. Compared with the existing analytical methods, the improved sag calculation method proposed in this paper can be applied in more extensive situations.

Calculation Methods of High-Voltage Direct Current (HVDC) Line Sag Considering Meteorology

“…The different physical parameters of different layers also result in different temperatures in the inner and outer strands [15]. The use of finite element simulation analysis to analyze the temperature distribution of aluminum stranded wire has a good effect, but such studies often overlook the influence of radial thermal expansion [16]. Therefore, some scholars divide the conductor temperature into different layers, that is, by analyzing the temperature of each layer of the conductor and calculating the layer stress, sag, and critical temperature of the conductor, but they ignore the temperature difference caused by convective heat dissipation at different positions on the same layer [17].…”

Holding Force Characteristics of Preformed Helical Fitting Based on Finite Element Method

“…Guo D.M. et al [26] established a finite element model of ACSR to obtain the temperature distribution. Rocha PHC.et al [27] combined theory and experimental methods to study contributions on fatigue of contacting wires of overhead conductors.…”

Estimação dos parâmetros de linhas aéreas de transmissão de energia elétrica por meio de medições temporais.

“…Outros fatores que podem contribuir para a imprecisão dos cálculos incluem o envelhecimento da linha, fatores climáticos, condutividade do solo e características elétricas dos cabos e torres, como condutividade e isolamento. Exemplos dessas situações podem ser encontradas em (SEMLYEN, 2003;KUROKAWA et al, 2006;GUO et al, 2021), onde hipóteses simplificadoras são adotadas nos cálculos. Ao considerar frequência, permeabilidade do solo e temperatura ambiente como constantes, os parâmetros calculados se mostram distantes dos parâmetros estimados por algoritmos que fazem uso de medições, como corrente e tensão da linha de transmissão.…”