An Analytical Model for the Total Contact Resistance of Cross-Contacted Stranded Conductors

When stranded conductors are contacted in clamping points of terminals, a complex network of wire-wire and wire-bus bar contacts emerges. As the contact forces in terminals have been reduced further and further during their development, it is becoming increasingly important to understand these contact situations so that design recommendations can be deduced in order to keep the total contact resistance as low as possible. For this reason, an analytical model has been derived that predicts the total contact resistance of stranded conductors in cross-contact-based solely on the configuration of the individual wires, the normal force as well as surface and material-dependent factors. One key feature is a convenient simplification of the resulting resistance network, so that the model can be generalized to various wire distributions. This was successfully verified using numerical simulations. After its derivation, the analytical model was used to make insightful predictions about the impact of different wire configurations on their total resistance. In particular, it was found that these relationships are significantly influenced by the surface condition. Finally, the model was validated using experimental tests, which demonstrated a very good agreement to the analytically predicted curves.