HVDC CABLES FOR HIGH PERFORMANCE TRANSMISSION LINES Experience, developments and future applications

Davide Pietribiasi - PRYSMIAN GROUP

HVDC International Workshop – Tutorial

28th March 2017

Agenda

1. Prysmian Group – An Overview

2. HVDC Systems – State-of-the-art Experience

3. HVDC Systems – Recent Developments a) New 700 kV Paper Cables b) New 600 kV XLPE Cables c) New 600 kV P-Laser Cables

4. Choice of a DC power transmission system

5. Research to Excellence

1. Prysmian Group - An Overview

4

Almost 140 years of history

88 plants

Over 20,000 employees

7.36 billion sales in 2015

17 R&D centres

50 countries

HQ + HQ R&D

Plant

Plant + R&D centre

Office

Prysmian Group - 2017

5

Prysmian PowerLink – Unique Capabilities

• Responsible for global submarine cable business

• HQ located in Milan, Italy

• Worldwide presence (Regional Offices)

• Undisputed market leader (Market share and capability)

• Unique track record (over 10,000 km Submarine Cables)

• Medium Voltage, HVAC and HVDC solutions

• Extruded and Paper insulation technologies

• Voltage levels up to 700 kV

• High manufacturing capacity (Multiple submarine & land factories)

• EPC Contractor capability (Realization of turn-key projects)

PRYSMIAN POWERLINK AT A GLANCE

Arco Felice (Italy)

Pikkala (Finland)

Drammen (Norway)

MANUFACTURING PLANTS

6

The Prysmian Fleet

• Best of class vessels and equipment providing extended project versatility

• Wide ranging track record and global experience

• Deep water installation capability up to 3,000 m

• Shallow water and near shore installation solutions

CABLE LAY AND INSTALLATION VESSELS

HYDROPLOW

VERTICAL INJECTOR HEAVY DUTY PLOUGH

JETTING MACHINES

IN-HOUSE CABLE PROTECTION

Giulio Verne

Cable Enterprise

Ulisse

2. HVDC System – State-of-the-art Experience

8

Prysmian Global Experience - HVDC Submarine Cable Systems

MI and Extruded Cables

MI Cables only

Extruded Cables only

DISTRIBUTION OF PROJECTS

COUNTRY EXTRUDED MI

GERMANY 2,750 0

ITALY 73 964

UNITED KINGDOM 526 1,419

USA 185 106

DENMARK 406 107

NETHERLANDS 390 0

SPAIN 136 245

NORWAY 48 470

GREECE 109 84

AUSTRALIA 0 295

SOUTH KOREA 0 192

PHILIPPINES 66 0

FRANCE 0 176

FINLAND 67 10

TOTAL Prysmian HV submarine

power cables (extruded/MI)

in operation/projects

in progress worldwide

5,031 4,266

9

Skagerrak 4 HVDC Interconnection – in operation

Main features

525 kV MI cable - 1600 mm² Cu conductor

700MW - Use of MI with VSC converters

N.2 jointing teams working simultaneously

10

SA.PE.I (Sardinia-Peninsula Italiana) – in operation

Main features

500 kV MI cable – 1000/1150 mm² Al

Rated power 1000 MW (bipolar configuration, 2x500MW)

Submarine Route 2x425 km, Land Route 2x15 km

Max water depth 1650 m

Cable type and size Paper, MI

Pole 1 in service since Dec 2008, pole 2 in service since Oct 2010

11

The Western Link HVDC Project

Main features

Largest Cable Contract ever awarded

Highest Voltage DC System ever (600 kV with PPL insulation)

Highest Power of any long length DC system (2250 MW continuous, 2400 MW 6 hour overload)

Overall route length approx. 422 km (37 km underground, 385 km submarine)

12

North Sea Link HVDC Interconnector – ongoing

Main features

At 740Km it is the longest ever HVDC Link with subsea / land cables

Prysmian has been awarded Lot 2 and Lot 3, route length 2 x 470Km

Proven Prysmian mass impregnated paper cable, nominal DC voltage ±515 kV

2.5Km land cables to the UK converter station, converter is based on VSC

13

INELFE Spain-France Interconnection – in operation

Main features

320 kV Extruded cable – 2500mm² Cu

Rated power: 2000 MW (2 symmetrical monopole systems, 2x2x500MW)

Long lengths from 1267 m to 2190 m

14

German HVDC Projects – in operation

Project

Voltage

(kV)

Power

BorWin2 300 kV 800 MW

HelWin1 320 kV 864 MW

HelWin2 250 kV 576 MW

SylWin1 320 kV 690 MW

BorWin3 320 kV 900 MW

DolWin3 320 kV 900 MW

HVDC Submarine & Land

Connections in the German

North Sea

~ 2000 km HVDC extruded cables, of which ~ 650 km land cables, with more than 900 joints

15

Cobra Cable HVDC Interconnection – ongoing

Main features

Rated power: 700 MW (symmetrical monopole configuration, 2x350MW)

Submarine section • 320 kV kV Extruded cable – 2500mm² Al • Largest submarine aluminium cross section • route length 310 km • max. burial depth 13 m

Land section • 320 kV kV Extruded cable – 2500mm² Al • route length 21 km

Global OPEX evaluation (i.e. cable losses)

NL Onshore Offshore DK Onshore Contractorland cable installation

- HVDC Converter + Sub contractors - HVDC Converter- Civil works

Civil contractor

16

HVDC cable systems: Challenges & Trends

CHALLENGES AND

TRENDS

• Higher Rating with lower

CAPEX:

• Higher voltages

• Higher operating

temperatures

• Minimum losses (lower OPEX)

• Reliability

• Fully tested solutions

• Monitoring systems

• Repairs

• Industry vs. Market Demand

• Longer distances, deeper

waters

Submarine Power Cable Projects Worldwide

3. HVDC System – Recent Developments

18

NOTES: Submarine cables may have different armouring design mainly depending on water depth. Rating depends on ambient and installation parameters

XLPE

±600 kV

3,000 MW @ 70 degC

VSC (LCC up to 250 kV)

Need degassing to reduce

chemical by-products

(cause of space charges)

P-Laser

±600 kV

3,500 MW @ 90 degC

Both LCC and VSC

No post-insulation

treatment, fully

recyclable insulation

MI paper

±525 kV

2,400 MW @ 55 degC

Both LCC and VSC

Need impregnation

MI-PPL

±700 kV

3,400 MW @ 80 degC

Both LCC and VSC

Need impregnation

Prysmian HVDC Cable Technologies

19

New 700 kV Paper Cables

High Performance HVDC MI-PPL Cable Maximum transmissible power could be increased of about 30 % with respect to the traditional paper insulated paper, due to the maximum conductor working temperature of up to 80-85 °C.

IMPULSE BREAKDOWN STRENGTH: 20-25 % higher than traditional paper

DC BREAKDOWN STRENGTH AT LOAD CYCLES:

40 % higher than traditional paper

20

New 600 kV XLPE Cables

Tests on full size cable

Type test according Cigré TB 496

Maximum dc voltage 1110 kV

21

New 600 kV P-Laser Cables

Tests on full size cable

Type test according Cigré TB 496

Maximum dc voltage 1110 kV

22

MAIN FEATURES

Qualified up to 600 kVdc

Suitable for higher voltages

(test in progress)

Higher power and lower cost (ca. 10%)

Outstanding technical performance

(operation up to 90 °C)

No by-products

(as no chemical reaction)

Higher material integrity for DC

(no space charges)

Shorter production time

(ca. 30% as no degassing)

Longer extrusion length (t0 ca.+100%)

Fully recyclable

THE MAJOR STEPS OF THE DEVELOPMENT

OF THIS INSULATION ARE THE FOLLOWING:

2000-2005 development of the compound

and of the process and prequalification tests

2006 first medium voltage cable in service

2013 first high voltage cable installed in service

2016 completion of 525 kVdc Type Test

2017 completion of 600 kVdc Type Test

High Performance Thermoplastic Elastomer (HPTE) insulation

23

VARIOUS OPTIONS INVESTIGATED:

Commercial compounds

In-house compounds

Development and Qualification of Extruded insulation for HVDC

TT 525 kV XLPE Cigré TB 496

Internal tests on full size prototype XLPE

Internal tests on full size prototype P-LASER

TT 600 kV XLPE Cigré TB 496

TT 525 kV P-LASER Cigré TB 496

Internal tests on full size 600 kV prototype XLPE

R&D work PHASE 1 Ranking among more than 20 options

R&D work PHASE 2 Development tests on 6 «best candidates»

PQ Qualifications programs for XLPE and P-LASER, up to 600 kV for underground and submarine applications

Q2-14 Q3-14 Q4-14 Q1-15 Q2-15 Q3-15 Q4-15 Q1-16 Q2-16 Q3-16 Q4-16 Q1-17 Q2-17 Q3-17

TT 600 kV P-LASER Cigré TB 496

Q4-17

a

4. Choice of a DC power transmission system

25

Choice of submarine power transmission system

26

Prysmian Technologies to increase transmissible power

NOTE: Assumed data: ambient temperature 15°C; burial depth 1,5 m; spacing between cables 20 m; soil thermal resistivity 0,8 m K /W

1000

1500

2000

2500

3000

3500

4000

4500

5000

1000 1500 2000 2500 3000

Tra

nsm

itte

d p

ow

er

per

bip

ole

(M

W)

Conductor cross section (mm² Cu)

PPL-MI 800 kV

PLASER 600 kV

PPL-MI 600 kV

XLPE 600 kV

PLASER 525 kV

XLPE 525 kV

Paper-MI 525 kV

@ 525 kV: XLPE cables give a +12 to + 15% average power increase over MI cables HPTE cables give a +20 to +25% average power increase over MI cables

27

Case study 1 – Submarine system 525 kV DC

Reference case: a 500 kV submarine project in Europe. Transmitted power: 1000MW Land part approx. 25 km Submarine part approx. 400 km

Solution for 600 MW Supply cost Installation cost TRL

MI

1x1900 mm2 Al (sub) 100 100

9

1x1900 mm2 Cu (land) 100 100

XLPE

1x1200 mm2 Al (sub) 90 90

6

1x1200 mm2 Cu (land) 80 95

HPTE

1x1000 mm2 Al (sub) 85 90

6

1x1000 mm2 Cu (land) 70 95

9Technology in operation

since > 5 years

8System already sold

and in operation

7 System PQT + TT

6PQT or TT of

all individual components

5Internal qualification,

full size

4Internal qualification,

models

3Test on parts,

ageing on materials

2Material candidates

selection

1 Definition of technology

28

Study Case 525 kV

2500 mm2 Cu XLPE

525 kV 2000 mm2 Cu

HPTE

525 kV 2500 mm2 Cu

HPTE

525 kV 2500 mm2 Cu

HPTE

Trench Type Base Case Trench

(1.7x0.9 m) Base Case Trench

(1.7x0.9 m) Minimised Trench

(1.7x0.4 m) Base Case Trench

(1.7x0.9 m)

Maximum Power(*)

1.6 GW 1.6 GW 1.6 GW 1.9 GW

Conductor Temperature

70°C 90°C 90°C 90°C

Same cable size Same power Reduced trench: -50%

Same cable size Same trench Higher power: +20%

Same power Same trench Reduced cable size: -20%

Case study 2 – Land system 525 kV DC – Middle East*

(*) Soil Temperature = 30 degC - Thermal Resistivity = 1,2 K.m/W

5. Research of Excellence

30

WATER DEPTH > 3,000 M

On going developments and tests confirm

the feasibility of HV submarine power cables

at water depth up to 3000 m and beyond.

Present and Future Innovations

Solutions for future HVDC

concepts

Larger conductors, up to 3500-4000 mm2

31

Challenges in Deep Water Projects

32

DIAGNOSTIC AND MONITORING SYSTEMS - PryMON

Real-time monitoring of distributed assets

Management of several types of data

Single web interface

Interface through mobile devices

PryMON

Enhanced Monitoring

TO MEASURE PARTIAL DISCHARGE

Partial discharge, temperature and current monitoring

Galvanic isolated sensors

Accurate PD acquisition

Reliable and advanced diagnosis

Remote monitoring

Installation without service interruption

PryCam

33

Partial Discharge: HVAC vs HVDC PryCam Gate

PD on HVAC PD on HVDC

PD patterns synchronized with AC PD patterns NOT synchronized with AC

Thousands of PDs per minute Typical acquisition time: 2-5min / measure

Few pulses per minute Typical acq time: 30min+ / measure

NEW Pry-Cam Gate - System description Pry-Cam Gate is a small electronic unit able to measure pulse timings with very high resolution (90 ps). The Gate employes two PD sensors placed accross the component to monitor. By comparing the time of arrival of the pulses to the sensors, it is possible to discriminate pulses coming from outside the component (noise) from pulses originating inside (real PDs). The basic idea is quite simple*: if a pulse comes from ouside it have to travel the monitored segment for oll the lengt, so it will take the full time to pass between the two sensors. A PD originating from the inside will take allway a shorter time. *A patent on Gate technology has been filed by Prysmian in 2016

Thank you