132 kV DT connections for “Parma Vigheffio – S.Quirico” Line no. 607

Construction of underground 132 kV DT connections for the no. 607 C.P. S.P.I.P. “Parma Vigheffio – S.Quirico” line.

Introduction

The 132 kV branch lines which feed the Line in-Line out SPIP Primary Substation extend entirely within the Municipality of Parma.
The buried portion of the line starts from the HV terminals installed on the dedicated support bars and runs for approximately 2000 m; it will be installed by laying two underground three-cable bundles in a single trench of approximate width 1300 mm.
Part of the route will pass through agricultural land up to Provincial Highway no. 72, which is crossed, thence proceeding along Via Franklin for approximately 700 m. The next section continues along Via Forlanini for about 470 m until the intersection with Via della Lupa.
The underground cable branch lines then continue along Via della Lupa for approximately 420 m and then enter the new SPIP Primary Substation via its access road, terminating at the dedicated HV stalls resting on tank foundation bases.

Power cable

The new underground power lines shall consist of 170 kV single core XLPE insulated aluminium cables with PE outer sheath (101/31) with the following parameters:

• Short circuit Current: 31.5 kA
• Maximum operating voltage Um: 170 kV
• Nominal cross section: 1,600 sq.mm in aluminium
• Current: 1,000 A
• Insulation: Cross-linked polyethylene extrusion (XLPE)
• Protective outer sheath: Extruded polyethylene (PE)

Technical characteristics of the work

The circuit will be composed of two 150 kV three-conductor extruded cable sets with the following lengths:

• “Terna DX”, outward from the SPIP Primary Substation: 1950 m
• “Terna SX”, outward from the SPIP Primary Substation: 1925 m

“Terna DX”, outward from the SPIP Primary Substation

• Length: approx. 1950 m
• Power cable: XLPE ARE4H1H5E 150 kV 1x 1600 mm²
• Ground cable: RG7R 0.6/1 kV 1x 240 mm²
• Cable arrangement:
  • in culvert, with trefoil cable arrangement at a variable laying depth (0.6 m – 0.8 m)
  • directly laid in the trench, with trefoil cable arrangement at a depth of 1.50 m (installation level)
  • in duct, with trefoil cable arrangement at a depth of 1.50 m (installation level)
  • By variable-depth remote controlled drilling.
• Metal shields: Metal cable shields connected according to the “Cross Bonding” diagram (see ANNEX 950.8.1656).
• Splices: “GMS 1170” sectioned splices.
• Number of routes: 3 routes.
• Sheath cut-out boxes: “18/45X” cassettes.
• Terminations: External terminals, type “TES 1170 AD”
• Grounding boxes: “SC3P” unipolar boxes.
• TLC connections: One 48 F.O. cable

“Terna SX”, outward from the SPIP Primary Substation

• Length: approx. 1925 m
• Power cable: XLPE ARE4H1H5E 150 kV 1x 1600 mm²
• Cable arrangement:
  • in culvert, with trefoil cable arrangement at a variable laying depth (0.6 m – 0.8 m).
  • directly laid in the trench, with trefoil cable arrangement at a depth of 1.50 m (installation level).
  • in duct, with trefoil cable arrangement at a depth of 1.50 m (installation level)
  • By variable-depth remote controlled drilling.
• Metal shields: Metal cable shields connected according to the “Cross Bonding” diagram (see ANNEX 950.8.1656).
• Splices: “GMS 1170” sectioned splices.
• Number of routes: 3 routes.
• Sheath cut-out boxes: “18/45X” cassettes.
• Terminations: External terminals, type “TES 1170 AD”
• Grounding boxes: “SC3P” unipolar boxes.
• TLC connections: One 48 F.O. cable