MI Ovest [MiIano West] – Baggio

Construction of the new «MI Ovest – Baggio» underground cable 220 kV power line

Introduction

The route extends from the “Ovest” (Milan) Power Station to the “Baggio” Power Station in the municipality of Settimo Milanese.

The planimetric length of the underground link is approximately 7,500 m and it is mainly laid along the roadside with a trefoil cable arrangement; the design foresees the use of 14 junction triplets so as to constitute 15 cable sections in a cross-bonding configuration.

The main typological solutions that will be adopted are the following:

• Where applicable, under-crossing shall be implemented by supporting subservice plant and standard trefoil laid cable arrangement;
• over-crossing shall be implemented by excavation standard trefoil laid cable arrangement, with a self-supporting structure to be erected where applicable;
• raising/lowering of interfering sub-services and subsequent under/over laying of cable in standard trefoil arrangement
• where applicable, underpass laying of cable in protective conduit implemented via remote controlled drilling

Power cable

The link construction envisages the use of extruded insulation single core cables with nominal rating 127/220 kV and max. voltage (Um) = 245 kV

The cables will have the following constructional characteristics:

• cross-linked polyethylene (XLPE) insulation, longitudinally welded aluminium strip screen, outer sheath in graphitised black linear polyethylene;
• 1200 mm² cross section copper conductor (code RE4H5E 127/220 kV 1 × 1200 mm²).