Multi-physics analysis of plug-in connector taking into account daily change

With the aim to research the influence of daily load current and daily temperature change on thermal and mechanical characters of plug-in connector, a 3D electrical-thermal-mechanical coupled FEM model based on matrix coupling and load transmitting has been developed. The power losses obtained from the current conduction analysis are used as heat source in the thermal-mechanical analysis to get the temperature, stress and displacement field distributions of enclosed bus connector. The calculated results with steady current temperature rise test results of 110 kV enclosed bus bar verify the effective of the calculation model. The influence of daily load current and daily temperature on connector temperature rise and relative displacement are analyzed based on calculation model. Calculated results show that daily temperature change has less influence compared with daily load currents due to the existence of the enclosed bus thermal time constant. The insert depth of connector can be changed under the action of alternating thermal load which induced by daily change of current and environmental temperature, leading the connector degradation and overheating fault may be induced.