Delivering energy through the world’s longest submarine HV AC cable

N.G. van LuijkLead Electrical Engineer

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Introduction Video

The Martin Linge Field

Martin Linge Overview

Jacket

• Kvaerner Verdal

Platform• Technip /• Samsung• Apply (LQ)

SURF• Subsea 7 • ABB

Onshore• Siemens• Veidekke

FSO• KNOT Offshore

Partners (a subsidiary of Knutsen NYK Offshore Tankers)

Drilling Rig• Maersk Drilling

Concept selection

Maximise power from shore

Inclusion of floating storage and offloading vessel (FSO)

Minimise maintenance cost

No subsea compensation No reactive or harmonic compensation offshore

Space constraint on platform

AC power over DC power No reactive or harmonic compensation offshore

Evaluation – power from shore

Economical advantages Beneficial to Environment Improved electrical efficiency

Martin Linge concept start

Gas turbines

Onshore compensation facility• Main functions:

– To control the voltage offshore – To keep reactive exchange to the grid

to a minimum

• High availability required – Ensure minimum down time (99.9% avail.)

• An important link in the chain: – Decouples the offshore platform from grid

disturbances and vice versa– A crucial facility in order to operate the Martin Linge platform– Loss off any onshore component does not affect the offshore production

• Simplicity over complexity– Avoidance of complex control schemes

Voltage control

Offshore voltage is controlledonshore using fast acting SVCs(40 ms) and slow acting tap changer (3 sec. per tap) in parallel using independent controllers

Voltage performance

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Over voltage protection

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• Significant over voltages in the 100 kV system can be observed after subsea cable energisation at the offshore bus bar (up to 130%).

• Faults at the subsea cable or at the onshore GIS feeders lead to the maximum over voltages within the 100 kV system.

• The maximal overvoltage amplitudes can be observed at the offshore end of the subsea cable and at the offshore switchgear.

Challenges

Load

• Changes duringlife of field

• Start ~45MW• End ~30MW

Harmonics

• Offshore VSDs• Static converters

50Hz to 60Hz• Grid

Grid

• Dynamic configuration

• Future improvements

Submarine cable

• Long lead item – 2 years• Total Length 161.5 km• First km is 500 mm2

• Remainder is 300 mm2

• Highest load under no load condition• Two sections – one subsea joint• Separate onshore section 630 mm2 (1.5 km)

Cable frequency response

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Without Skin Effect

With Skin Effect

Grid Impedance Envelope

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Frequency Response of Complete System

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As seen from Onshore 100kV Bus As seen from Offshore 100kV Bus

Impact of 2nd harmonic

• During energisation of offshore transformers the voltage drop exceeds 20% with point on wave switching.

• Higher knee-point would reduce voltage drop.

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System losses16

note: The jump in losses is caused by an increased power factor from 0.9 to 0.94

• No load losses just under 4 MW• Normal losses during operation between

89.4% and 90.6%

Cable Energisation17

Light blue=screen currentDark blue=conductor current

Zero Sequence Current of 1436A peak

Blue=Ph1 current Red=Ph2 current Yellow=Ph3 current

Current during cable energisation958A peak (inrush) and 416Arms at 82kV

Balancing power from shore• Power from shore is expensive

- Copper is expensive (but so are gas turbines)- Reactive compensation facility is required- No heat recovery offshore

• Power from shore requires in depth studies- Lower short circuit power to gas turbines- Voltage regulation required- Transient and sub-transient behaviour- System resonance

• Many benefits are not easily represented in financial gains- Improved voltage response- Greater availability with less rotating equipment- Reduced operational and maintenance requirements- Improved working environment offshore (noise and vibration)- Less weight and space- Improved system efficiency

Summary – lessons learned• Having multiple contractors involved in

one system requires a greater effort on

interfaces from end client

• Performance requirements are key in

ensuring competitive power from shore

studies by equipment manufacturers

• Invest in conceptual and pre-project definition

• Establish a good working relationship with grid company

• Be prepared for numerous data requests from contractors. Providing

quality data results in simulations close to actual system behaviour.

• Keep neighbours involved

November 2013

Substation under construction

Substation completed

Power cable pulling

Disclaimer and copyright reservation

• The TOTAL GROUP is defined as TOTAL S.A. and its affiliates and shall include the party making the presentation

• Disclaimer– This presentation may include forward-looking statements within the meaning of the Private

Securities Litigation Reform Act of 1995 with respect to the financial condition, results of operations, business, strategy and plans of TOTAL GROUP that are subject to risk factors and uncertainties caused by changes in, without limitation, technological development and innovation, supply sources, legal framework, market conditions, political or economic events

– TOTAL GROUP does not assume any obligation to update publicly any forward-looking statement, whether as a result of new information, future events or otherwise. Further information on factors which could affect the company’s financial results is provided in documents filed by TOTAL GROUP with the French Autorité des Marchés Financiers and the US Securities and Exchange Commission

– Accordingly, no reliance may be placed on the accuracy or correctness of any such statements• Copyright

– All rights are reserved and any material in this presentation may not be reproduced without the express written permission of the TOTAL GROUP

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