GRID

WAVE ENERGY CENTER

Technologies for connection of offshore

renewable power plants to the electrical system

Ana Díez

1oth may 2012

GRID

1. Introduction

3. Equipment/Layout/Configurations

2. Project references

4. Grid integration: FACTS and HVDC transmission

Agenda

1. Introduction

3. Equipment/Layout/Configurations

2. Project references

4. Grid integration: FACTS and HVDC transmission

Agenda

Actividades Principales

Barrow – Irish sea, UK

Contract Value: £9 M

Client & Operator: Barrow Offshore Wind Ltd. (Centrica & DONG Energy)

Completion Date: September 2006

Project Scope: 90 MW Offshore Wind Park with 30 Wind Turbine Generators (Vestas V90/3.0 MW)

Data: 20 m depth, 27 km HV sea cable

Alstom Grid Scope of Works:

− Electrical connection modelling and system studies

− Grid connection at Heysham − Module supply and fitout

• 132 kV & 33 kV GIS switchgear including protection

• Power transformer

• Relay and control panel suite room

• LVAC and DC plant room, refuge, mess and workshop modules

• Capacitor bank modules (2x 5 MVAr)

Robin Rigg – Irish Sea UK

Alstom Grid Scope of Works:

2 Separate platforms – Connected in 4 groups at

33kV to Offshore 132/33kV S/S

− Onshore 132kV Substation

− Offshore 132/33kV Substation

Contract Value: £15.2 M

Client & Operator: E.ON UK Solway Offshore Ltd. and E.ON UK Offshore Resources Ltd.

Completion Date: Spring 2009

Project Scope: 180 MW Offshore Wind Park total 60 Wind Turbine (Vestas V90/3.0 MW)

30 m depth, 12 km from the coast

Alpha Ventus - Germany

Contract Value: 7 M€

Client & Operator: DOTI GmbH (EON Climate&Renewables, Vattenfall Europe New Energy GmbH, EWE AG)

Completion Date: September 2008

Project Scope: 60 MW Offshore Wind Park with 12x5MW Wind Turbines

30m depth/45 km from coast

Alstoms Grid Scope of Works:

− 110/30kV substation on platform

− Turn-key delivery of topside including

• Protection and Control

• 110 kV & 30 kV GIS Switchgear

• 1 Hermetic Power transformer

• Cabling. Shunt reactors

• Auxiliary equipment /Diesel Generators

• Fire protection

• Commissioning

Offshore substation. Loading.

Offshore substation. Overview.

Client & operator: Wetfeet Offshore Windenergy GmbH

Forecasted completion date: September 2012

Project scope: 400 MW offshore wind farm with 80 wind turbine generators (AREVA Multibrid M5000)

Distance: 125 km from the coast

Contract scope (ALSTOM Grid scope in liaison with partner):

− Turnkey delivery of a self-floating and self-installing offshore substation platform including

• 155/33 kV power transformer (4x 120 MVA) • 170 kV & 33 kV GIS switchgear • Substation protection & control, • PACiS solution • Cabling on platform • AC/DC equipment • Emergency diesel generators • Boat landing and helicopter landing deck • Self-contained platform with large working deck • Erection & commissioning of substation (onshore and

offshore) • Manufacturing and fit-out of the hull including

substructure • Permanent accommodation facilities for up to 37

people • Onshore erection and offshore installation

2009 - Global Tech 1 - Germany

1. Introduction

3. Equipment/Layout/Configurations

2. Project references

4. Grid integration: FACTS and HVDC transmission

Agenda

Offshore substation main equipment

High voltage

switchgear (GIS)

Power step-up

Transformer HV/MV

Medium voltage

switchgear (GIS)

Power Transformers

Environmental, technical challenges:

− Weight and dimensions

− Corrosion protection:

• Cataphoretic painting

- Maintenance reduction

• Hermetic transformers: Expansion radiators instead of conservator and de-hydrating breather

• OLTC with vacuum chambers

• Integrated condition monitoring

High voltage substation

Environmental criteria:

− Footprint − Transformer connection by cable

Technical criteria

− Well proven/highly reliabe − Voltage level: 145, 170 or 220 kV − Integrated Protection&Control

system

Cost criteria:

− Configuration: Compromise high availability vs. investment cost

Offshore substation configuration

1. Introduction

3. Equipment/Layout/Configurations

2. Project references

4. Grid integration: FACTS and HVDC transmission

Agenda

Grid integration

- HVAC

- HVAC + FACTS

- HVDC

Selection criteria:

- Technical feasibility of HVAC (distance to the coast)

- Economics

- Grid Codes

Grid code compliance: Shunt compensation by STATCOM STATCOM to Duneill Wind Farm site in Ireland

13 pcs– 850 kW wind turbines ->

P = 11.05 MW

3x 2MVar SVC MaxSine modules in container -> Q= 6 MVar

for Grid Code

compliance

HVDC transmission

HVDC Benefits

20

Station

Cost

DC

Converter

Stations

AC

Stations

DC

AC

Break Even

Distance

Transmission

Distance

• Higher efficiency

• Increased power system reliability and security

• Improved power system transient and dynamic stability

• Limited short circuit level contribution

• Distance break-even point (HVDC vs. HVAC) Underground >30-60 km Submarine >100 km (additional DC platform)

InverterRectifier

F F

Receiving

End

Idc

Vdc

HVDC Connections - Offshore generation

DC cable

VSC VSC

Station 1

U AC

Network

Network

2

Offshore

generators

HVAC

platform

HVDC

platform

Onshore HVDC

station

Station 2

First projects of its kind have:

- Steep learning curves with fast transfer to new projects

- Harsh operational conditions need

• Increased corrosion protection for all systems

• Learning from other industries (Oil & Gas,

automotive,…)

- Weather dependent restricted access need

• Minimized offshore installation & service time

• Integrated service concepts with wind farm operators

- Future wind farms need offshore substations with

Innovations in technical design such as

-Self-floating Self-installing platforms and

-Integrated designs

Summary

ALSTOMs participation in OCEAN LIDER project

http://www.oceanlider.com

www.alstom.com

Typical Layout: Radial configuration (most common)

Ring configuration