Summary

The paper analyses ampacity of a busbar connection assembly between tubular aluminium busbars. These connections are made of stranded aluminium conductors bolted with clamp joints on the tubes. The assembly is installed in high voltage substations to provide a transverse connection between lines up to 4000 A. The purpose of the paper is to present coupled electromagnetic and thermal simulations, which were made according to dynamic line rating in operation. Increasing maximum permissible line current according to weather conditions affect all components in the system. The problem represents a complex task, which requires taking various weather and material parameters into consideration. The model was prepared as a real design of contemporary installed parts in substations of transmission system. The finite element analysis of the model involved all the major factors affecting its thermal balance – Joule heating including skin and proximity effects, solar radiation gain, convective and radiative cooling and the effect of electrical contacts. The solution includes strong coupling of electromagnetic and thermal fields for solving a highly temperature dependent problem. The results were compared with an analytical solution and a computational fluid dynamics model to determine the effect of the influences of complex geometry on simplified heat transfer correlation formulas. The current load was adjusted according to three factors. The first ultimate limiting factor was represented by the maximum permissible temperature of the assembly of 90 °C. The other two input values – ambient temperature and solar heat radiation – were changed to simulate combinations according to their usual range in the Czech Republic. The results uncovered a considerable margin between the calculated current limit and parameters given by the manufacturer. That confirmed possible new operational. Temperature distribution plots also contributed to a more effective thermal-camera analysis of aging contacts in the assembly.

Additional informations

Publication type ISH Collection
Reference ISH2015_329
Publication year 2015
Publisher ISH
File size 700 KB
Price for non member Free
Price for member Free

Authors

Zachariades Christos, Renforth Lee, Foxall Marc, Seltzer-Grant1 Malcolm

Ampacity of high voltage busbar connections
Ampacity of high voltage busbar connections