Investigations on the Behavior of Connectors in High Current Systems

The initial contact resistance of overlapped bolted and clamped connectors for overhead transmission lines and busbar connectors (b-link) for gas-insulated switchgear is assessed experimentally. The parameters influencing the initial contact resistance are investigated. Furthermore, the behavior of the contact resistance of bolted copper joint when loaded by AC current was measured with changing mechanical contact devices shape and material. Also, the effect of current cycle on the behavior of contact resistance of clamped and b-link connectors was investigated experimentally. The thermal network method is used for calculating the temperature rise of the connector when loaded by a current. The method is based on substitution of the connector geometry by a circuit consisting of thermal resistances, capacitances and heat sources. The temperature rise is determined using the network simulation program PSPICE with the corresponding thermal model libraries. The validity of the obtained results has been checked by comparing the computed values with those measured experimentally. The agreement was found satisfactory.