Comparison Between Different Laminated Aluminum Busbars Expansion Joints in Terms of Mechanical Performance and Relative Costs

Laminated aluminum expansion joints are an integral part of any busbar system and are commonly used in potline and substation DC circuits. These elements not only transfer electrical current from one rigid conductor to the next, but also deform to absorb thermal expansion in a controlled manner, therefore avoiding the generation of excessive thermomechanical stresses elsewhere in the system. Different geometries and construction techniques have been proposed throughout the years to accomplish a given specific task, such as accommodating longitudinal displacements from long conductors, for instance. It was found that, in practice, different designs respond differently to combinations of axial and transverse displacements. The objective of this work is to compare different laminated aluminum busbars expansion joints in terms of their capacity to accept imposed displacements as well as fabrication and installation costs. Three distinct topologies were assessed by means of both empirical testing and numerical modeling and the different findings are discussed. Recommendations are made for further developments.