Magnetic shielding solutions for the junction zone of high voltage underground power lines

In this paper a comparison among different shielding techniques for the junction zone of high voltage underground power lines is presented. Three technologies are taken into account: flat conductive shield, passive loop and High Magnetic Coupling Passive Loop. The three solutions are simulated using 2D and 3D models in order to evaluate the magnetic flux density at ground level, the shielding factor and the effectiveness of connection between components of the shield. Shielding performances and installation requirements have been compared by highlighting advantages and drawbacks of the three systems and identifying the most suitable solution with reference to the Italian regulatory framework.

► Three magnetic shields for underground power cable are analyzed and compared.
► A novel technology called HMCPL is included in the comparison.
► Each technology is analyzed by means of numerical simulations.
► Results are provided in terms of ‘shielding factor’ and ‘distance of compliance’.
► A final comparison highlights pros and cons of each shielding solution.