Offshore Switchgear

Medium Voltage Switchgears for Offshore

Mario Haim R&D Director Medium Voltage Switchgears

Our Offshore References

e r o

Horns Rev 2 (14) Meerwind (32)

h s f f o s s l n e o n i a t a p c i 0 l 0 p 5 p 1 a n y a r h ma t e i r r o P M in Beatrice (6)

Dan Tysk (24)

Nordsee Ost (145)

Robin Rigg (24)

Veja Mate (34)

Walney I+II (20)

Rödsand (16)

Ormonde (90)

Baltic II (30)

West of Duddon Sands (18)

Alpha Ventus (28)

Riffgat (12)

Barrow (12)

Greater Gabbard (420)

Cote D'Albatre (16)

Gunfleet Sands (10)

With WS market leader in ≥5 MW offshore Windturbines Schneider Electric - Infrastructure – Mario Haim – 2012

Thornton Banks (85)

Global Tech (370)

Borkum West II (38)

With GHA market leader in offshore substations 2

Offer for any MV offshore application

GMA

Schneider Electric - Infrastructure – Mario Haim – 2012

WS

WI

GHA

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Agenda ●Market trend ●Wind park layout & Short circuit level ●Requirements ●Overvoltages & Insulation coordination ●Preferred Solution Schneider Electric - Infrastructure – Mario Haim – 2012

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Main areas for Wind Offshore in Europe Moray Firth

Firth of Forfh

Dogger Bank North Sea Baltic Sea

Hornsea Irish Sea

32 GW 18 GW

East Anglia

Bristol Channel Hastings

5 GW 5 GW

25 GW 10 GW

Isle of Wight Le Treport Fecamp Courseuilles Saint‐ Brieuc

Saint‐Nazaire

6 GW 6 GW

*Capacity to be intalled until 2030 *Capacity to be intalled until 2020 Schneider Electric - Infrastructure – Mario Haim – 2012

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Carbon Trust Carbon Trust has brought together 8 offshore wind developers in a joint industry project to work towards reducing the cost of offshore wind by at least 10% by 2015. ●DONG Energy ●EON, ●Mainstream Renewable Power, ●RWE Innogy, ●Scottish Power Renewables, ●SSE Renewables (formerly Airtricity), ●Statkraft, ●Statoil, ●http://www.carbontrust.com/our-clients/o/offshore-wind-accelerator

Schneider Electric - Infrastructure – Mario Haim – 2012

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Market trend

Clear recommendation:

Go to 66 kV system voltage in tower to reduce costs

Schneider Electric - Infrastructure – Mario Haim – 2012

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66 kV in tower + substation

-tower switchgear at 66 kV -platform switchgear at 66 kV -transformer at 66 kV -cable at 66 kV Schneider Electric - Infrastructure – Mario Haim – 2012

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Agenda ●Market trend ●Wind park layout & Short circuit level ●Requirements ●Overvoltages & Insulation coordination ●Preferred Solution Schneider Electric - Infrastructure – Mario Haim – 2012

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Source: http://www.carbontrust.com/our-clients/o/offshore-wind-accelerator Schneider Electric - Infrastructure – Mario Haim – 2012

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4 types of wind turbines Induction (asynchronous) generator Vestas (Neg Micon), Siemens (Bonus) Strong points: robust and simple Weak points: low efficiency (fixed speed), flicker, no control of reactive power

G

GENERATOR INDUCTION COUPLING

CAPACITOR BANK

8% of manufactured No converter Ageing technology

Doubly-Fed induction generator Vestas, General Electric, Gamesa, Nordex Strong points: variable speed (wide range), control of reactive power Weak points: produces harmonics (but only 25% of the power goes through the converter) G DC BUS L1

L2

CONVERTER Schneider Electric - Infrastructure – Mario Haim – 2012

42% of manufactured 25% power through converter Main Onshore technology

Induction (asynchronous) generator with slip control Vestas (for US market), Gamesa (for US market), Suzlon Strong points: variable speed (limited range), low harmonics Weak points: low efficiency, no control of reactive power G Control R

R

INDUCTION COUPLING

CAPACITOR BANK

20% of manufactured No converter Ageing technology

Variable speed induction or synchronous generator Enercon, Multibrid, General Electric, Siemens, Clipper, Vestas Strong points: total variable speed, control of reactive power, fast answers to bad electrical conditions coming from the grid Weak points: expensive, huge size, produces harmonics (100% of the power goes through the converter) L2 30% of manufactured

L1 G CONVERTER

100% power through converter Main offshore technology 11

Wind park layout & grid model for 66 kV simulation

●Based on the defined network architecture the model was created ●For this model a static simulation (short circuit level) and dynamic simulation (transient recovery voltage) had been done Schneider Electric - Infrastructure – Mario Haim – 2012

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Voltage / Power-Factor 33 kV vs. 66 kV

Schneider Electric - Infrastructure – Mario Haim – 2012

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Static network simulation: Short circuit level • The thermic short circuit inside the 66 kV network architecture can be between 11,33 kA and 18,04 kA & 29,07 kAp and 46,24 kAp peak value for short circuit • Inside the tower the maximum thermal short circuit level is between 10,94 kA and 17,13 kA & the peak value between 27,86 kAp and 43,17 kAp

A 25 kA System at 66 kV is fully sufficient Schneider Electric - Infrastructure – Mario Haim – 2012

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Agenda ●Market trend ●Wind park layout & Short circuit level ●Requirements ●Overvoltages & Insulation coordination ●Preferred Solution Schneider Electric - Infrastructure – Mario Haim – 2012

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Key Requirements

Reliability

Safety

Cost efficient

Environment

Offshore Wind Power Schneider Electric - Infrastructure – Mario Haim – 2012

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Reliability General Service-Conditions for MV switchgear according to IEC 62271 ● In principle indoor switchgear according IEC 62271-1 ● Offshore Conditions exceeding the ‘normal’-conditions ● Standard -5….+40°C, 24h average < 35°C ● Ambient air not polluted with corrosive materials like salt etc. ● Relative 24h average humidity not exceeding 95% ● condensation occasionally ● Relative monthly average humidity not exceeding 90%

Schneider Electric - Infrastructure – Mario Haim – 2012

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Reliability Additional Challenges for the switchgear: Harsh environment ● saline atmosphere ● humidity ● Corrosion resistive ● Vibration due to operation of Windmill ● Low temperature operation without external power supply ● Operation starting at deep ambient temperature without any preload (cold start)

Schneider Electric - Infrastructure – Mario Haim – 2012

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Reliability Design responding to additional challenges ● Gas Insulated Switchgear with ● Sealed Pressure System for Electrical active parts ● Hermetical closed gas tanks ● High-voltage parts are contained in a tightly sealed stainless steel tank

● Corrosion resistive components: ● Drive for devices ● Housing ● Connections ● LV-equipment

● Vibration withstand ● Vibration tests with dedicated frequencies

● Low temperature withstand ● Mechanical operations tests at low temperature ● Dielectric performance at low temperature

Schneider Electric - Infrastructure – Mario Haim – 2012

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Safety Design responding to safety requirements

● Optimum safety of operation due to a complete interlocking system ● Degree of protection: IP65 for the primary part ● Personal safety due to Internal Arc withstand: IAC AFLR up to 40 kA ● Switchgear tested and certified according to IEC 62271

Schneider Electric - Infrastructure – Mario Haim – 2012

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Safety for operating personal Internal arc classification according IEC 62271-203 ●Internal arc events could cause effects like pressure increase and burn through of enclosure (no effect on personnel is considered) ●Durations of 0.1 s up to 0.3 s are considered (switch off by protection equipment) ●No test procedure to qualify personnel safety in high voltage standard

Schneider Electric - Infrastructure – Mario Haim – 2012

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Safety is no Option! Internal arc classification according IEC 62271-200 ●Internal arc test as Type Test according t0 IEC 62271-200 Chapter 6.106 safety for personnel as important feature ●Improved safety for the operator (defined areas of access for the user) ●Durations of arcing from 0.1 s up to 1 s are considered and tested (min selectivity) ●All criteria to pass the test have to be fulfilled: ● ● ● ● ●

Doors / covers do not open No fragmentation of enclosure No holes on accessible areas Indicators do not ignite Earthing remains in service

Design for safety according IEC 62271-200 Schneider Electric - Infrastructure – Mario Haim – 2012

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Cost efficient ●Size is Key! ●Less material ●Less weight ●Less space ●Less volume inside the tower ●Less transportation costs

●Predefined interface between MV switchgear and: ●wind turbine ●MV-cable ●control and protection ●Metering ●mechanic Schneider Electric - Infrastructure – Mario Haim – 2012

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Cost efficient ●Switchgear section preinstalled on base frame ●Completely pretested in factory ●Less transport efforts

●Predefined interface ●No erection on site ●Commissioning of protection and control done in factory Schneider Electric - Infrastructure – Mario Haim – 2012

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Environment Environmentally friendly construction

● No gas handling at site ● Space saving due to compact design ● Switching in Vacuum with Vacuum Interrupter ● All materials are fully recyclable ● At end of life time, the SF6 gas will be fed into recycling process hence - no factory-special tool required for gas removal - all gas tanks are equipped with a valve in standard use Schneider Electric - Infrastructure – Mario Haim – 2012

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Agenda ●Market trend ●Wind park layout & Short circuit level ●Requirements ●Overvoltages & Insulation coordination ●Preferred Solution Schneider Electric - Infrastructure – Mario Haim – 2012

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Insulation level based on Ur=72.5 kV

Except of IEC 62271-1 [1]

Usys = 66kV; Δ = ± 10%

Ur = 72.5 kV

[1] IEC 62271-1: High voltage switchgear and controlgear – Part 1: Common specifications, Edition 1.1, IEC 2011 Schneider Electric - Infrastructure – Mario Haim – 2012

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Overvoltages – Insulation Level (BIL) ●Overvoltages mainly due to lightning strike or switching operations (TRV) (IEC 60071-2) ●Lightning strike mainly in overhead-lines ●Switching operations, especially in case of switching inductive or capacitive loads, e.g. cables

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Transient recovery voltage

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Lower Insulation level required With surge arrester installed directly at the switchgear (L=0), the effect of travelling wave can be disregarded. Thus, the second part of the equation will equal to 0: BIL ≥ Ks ·Ures As recommended in [2], Ks = 1.15 should be applied as safety factor for internal insulation coordination: required BIL for the switchgear

BIL = 1.15 x 3.33 x 72,5 kV = 277 kV