In order to study the influence of different fault currents of power system on the transient temperature rise characteristics of the contact position of the butt-contact

In this paper

a conductive bridge model is used to simulate the surface contact between the fingers and the conductor bar.Based on the A-φ method

a three-dimensional circuit-electromagnetic field finite element calculation model of the butt-contact is established.In this model

the power loss on each part of the contact is calculated with the external circuit constraints

then

the results are transmitted to the finite element model as thermal load.The temperature rise distribution of the butt-contact is obtained based on multi-physics coupling theory.Physical temperature rise test platform of the butt-contact was built

and physical experiments were carried out to verify the validity of the established numerical calculation model.The transient temperature rise characteristics of the butt-contact under the impact of short-circuit fault current and transformer excitation inrush current are analyzed by using the established field-circuit coupling numerical calculation model.The results show that the contact position reacts very quickly to the current load.The maximum instantaneous temperature rise of the contact under transformer excitation inrush current is 71 ℃

and the maximum instantaneous temperature rise of the contact under the impact of the short-circuit current is 270 ℃.The research results can provide reference for the design

manufacture and maintenance of butt-contacts.