Analysis of Electrodynamic Forces in Switching Devices for Railway Applications

Nowadays, the railway transport field imposes stringent technological limitations in terms of safety requirements and cost savings, which ask for an accurate design for all the devices installed onboard the trains. Switching devices for railway applications have to be optimized in size, weight, and cost; their accurate design allows to reduce the development costs and time. Moreover, the evaluation of electromagnetic forces acting on the current-carrying parts of switching devices is crucial for their proper operation and sizing, especially referring to movable conductors. This paper provides two methods, namely, an analytical and a numerical one, to evaluate the electrodynamic forces in switching devices with complex-shape circuits. The analytical method is a predesign tool able to evaluate in a fast way the electrodynamic forces on the current-carrying conductors. The numerical tool is a verification model that evaluates the forces generated by currents and flux densities by using a 3-D finite-element method. These methods are here applied to fully analyze a so-called earthing switch for railway application. Numerical results are reported to prove the effectiveness of the proposed methods.