Turin-Milan high-speed railway-line, 2x25 kV 50 Hz AC electrified. EMC problems in earthing of exposed conductive parts

The EMC problems have been investigated in earthing of exposed conductive parts along a high-speed railway track, the 2times25 kV AC electrified connection between Turin and Milan. As powering is AC, basically no corrosion danger deriving from internal stray currents is to be expected; nevertheless the external ones cannot be ignored. The game is to earth (or bond equipotential) enough in order to protect livestock, but still maintaining sufficiently high impedance towards stray currents. The approach has been first to apply the relevant standards, then to integrate them with additional theoretic guidelines/instruments reflecting the peculiarities/constraints of the studied case, and finally to transform them into practical solutions. The results are represented by several different typological solutions, depending on the circumstances, validated on site by means of touch voltage measurements