TERNA CRNA GORA

HVDC MON.ITA Project

Rome , 27 th January 2014

MON.ITA Project

In Montenegro, connection point will be the new 400/110 kV substation in Lastva

The new planned 400 kV Lastva substation will be built as “in-out” substation, by cutting the

existing 400 kV line Trebinje-Podgorica 2 and realizing a new 400 kV connection

The new planned 400 kV Lastva-Plevlija 2 overhead line will be realized

HVDC link and associated grid infrastructures

2

Stazione 1

Scheme of the link

MON.ITA Project

Nominal voltage: VDC = 500 kV

Nominal power: PDC = 1000 MW

Configuration: bipolar with marine electrodes

Conversion technology: LCC (line-commuted converter)

Power flow: Bidirectional

Cable type: MI (mass impregnated)

3

Layout of project infrastructures in Italy and Montenegro

MON.ITA Project

Part in DC cableItalian side ~16 km

Existing

substation

Pljevlja 2

In-out 400 kV from SE

Lastva in existing

Podgorica II - Trebinje~35 km

Lastva Grbaljska

Mrcevo Polije

Terrestrial cables

Cepagatti

converter

station

New Overhead line

400kV

Lastva - Pljevlja II

~160 km

Marine

connection~393 km

Marine cables

4

AC Filters Storage

Controlbuilding

Valves hall DC Building

MON.ITA project

General layout of converter station

5

Terrestrial cable route

MON.ITA project

Proposal of TERNA – out of DSP corridor

1°solution – inside DSP corridor

2°solution* – inside DSP corridor

Final solution* – inside DSP corridor

FINAL ROUTE

6

UNDERGROUND CABLE (Cu 1x1900 mm2)cable diameter ̴12 cm

No. Constituents

1 Conductor , round centre wire and concentric layers of “key-stone”

2 Conductor screen, carbon black paper

3Insulation, water washed wood pulp HVDC cable paper impregnated

compund

4 Insulation screen, carbon black paper and metallized paper

5 Lead sheath, alloy

6 Inner sheath, polyethylene

7 Transversal reinforcement

8 Longitudinal reinforcement

9 Outer sheath, polyethylene

Power cable section

MON.ITA project

7

Marine cable route and profile

Bathymetric profile

MON.ITA project

Tracciato.wmv

8

OPTICAL CABLEcable diameter ̴4 cm

MV CABLE (Cu 630 mm2)cable diameter ̴8 cm

HVDC CABLE (Al 1900 mm2)CABLE DIAMETER ̴14 cm

No. Constituents

1 optical fibers

2 core

3 retain

4 protective tapes

5 Copper case

6 Polyethylene case

7 Galvanized steel wires

8 Filling

9 Galvanized steel wires

10 External bandage

Sections of marine cables

MON.ITA project

9

Sea trial

CIGRE Electra n. 171 recommends carrying out this test when

laying conditions and/or cable designs differ considerably from

previously established practice (in order to verify the

performance of cable in conditions of mechanical and

environmental stresses).

The test is carried out on a sample of cable sufficiently long to

reproduce the laying conditions and includes both a factory

joint and a repair joint.

The cable sample is laid at the maximum sea depth the cable

will reach in real laying conditions and then recovered and

subject to electrical tests and visual examination

MON.ITA project

10

SA.CO.I - main tasks and short historyIn December 1967, the Sardinia – Corsica – Italian Mainland direct current interconnection (200kV – 200 MW), called

SACOI, entered into operation, connecting the Codrongianos (Sardinia) converter stations with S.Dalmazio (middle

Tuscany), in order to initially perform large energy transfers from the new Sardinia (Sulcis) coal power plants

towards the Italian Mainland.

This use almost immediately underwent some changes, actually allowing to compensate for production shortages

in the island, both referring to load/production imbalance periods and to particular emergency conditions and to

regulate frequency in AC sardinian grid.

The two converter stations were connected to the 220 kVac grids and

the converter was equipped with two esaphase bridges with mercury arc valves