Electrothermal modelling of the railroads catenaries

Feeding catenaries sometimes induces mechanical problems because of high temperature gradients, particularly for power supply voltage of continues tensions from 750 to 3000 V, contrary to the supplies in alternative tensions used of the order of 25 000 V. One of the major reasons of these problems comes from both high temperatures reached in operating configurations and surrounding conditions. The authors of this study have developed a simple nodal method allowing to estimate the temperatures reached in the volume of the contact wires taking into account the surrounding conditions of thermal exchanges with the atmosphere, so by radiation that convection. The exchanges of the external surface of the wire with the external air are there developed in an original way by taking into account the incidence of the wind with regard to the axis of the catenaries.