Magnetic field computation for gas insulated lines installed in gallery

The magnetic field generated by double-circuit gas insulated transmission lines (GIL) has been calculated for tunnel installation. This is not an imaginary situation, but it is the foreseeable installation inside the pilot tunnel of the planned new Bolzano-Innsbruck railway galleries between Italy and Austria. The paper analyses the generated magnetic field inside and outside the tunnel, aiming at optimising the phase sequence arrangement. Proximity effects have also been taken into consideration. Furthermore, the results have been compared with a finite element method, giving a really good agreement.