2. AGENDA
▸ Les 1 – History, Current State of Art, North Sea
▸ Les 2 – Site Conditions
▸ Les 3 – The Turbine
▸ Les 4 – Actuator Disk Theory and Energy Yield
▸ Les 5 – Structure Design and Load Calculations
▸ Les 6 – Structure Design and Load Calculations
▸ Les 7 – Park Design
▸ Les 8 – Vessels
▸ Les 9 – Installation and Comissioning
▸ Les 10 – Operations and Maintenance
3. What you’ll Learn...
▸ Basic park lay-out
●
Wake Losses
●
Turbine Configuration
▸ Electrical Infrastructure
●
Cable System Turbine
●
Transmission Station
●
Cable System to Land
●
Land Connection
4. Basic Park Lay-Out
Met Mast
Transformer station
HV cable
Turbine
Land
Connection
MV cable
5. Turbine Placement
▸ Flow Blockage
▸ Wind Speed Loss
▸ Turbulance Increase
▸ Power Loss
Increased Loss
Row0
Row1
Row2
6. Turbine Distance
a = ambient
Flow Recovery
Optimum roughly at 6D
(More info: lookup “Jensen’s Far Wake Model”)
7. Turbine Distance
▸ Flow Blockage (for 6 D)
▸ Wind Speed Loss (α = 10-20%)
▸ Power Loss (β = 5-10%)
Increased Loss
Urow=U0⋅(1−α)
row
Prow=P0⋅(1−β)
row
Row0
Row1
Row2
6D
D
15. Cable Arrangement
Transformer Station Cable Failure Disconnected Turbine
▸ More Turbines per Line → Cheaper!
▸ When Cable Failure Occurs → More Turbines Down!
▸ Design for Cost/Risk Optimum!
16. Transformer Station (ACAC)
▸ Lillgrund (Sweden)
▸ 7 km from Shore (= Near-Shore)
▸ 33 kV AC → 130 kV AC
▸ High Voltage → Less Losses
▸ 120 MVAr (Volt Ampere reactive)
▸ ‘120 MW’
Lillgrund
17. Transformer Station (ACDC)
▸ Merkur (Germany)
▸ 60 km from Shore (= Far-Shore)
▸ 33 kV AC → 320 kV DC
▸ Higer Voltage → Lesser Losses
▸ 800 MW
▸ 2 Stations Required (Expensive!)
Dolwin Alpha Installation
by Thialf (Herema)
60 km
18. Transformer Station Comparision
▸ HVAC station
●
Low Transfomer Costs (1 Needed)
●
High Transmission Costs
●
Capped Transmission Length
▸ HVDC station
●
High Transformer Costs (2 Needed)
●
Low Transmission Costs
●
Infinite Transmission Length
▸ Break-Even Distance ~100 km
19. High Voltage Cables (Transformer to Land)
▸ LXPE Cable (HVAC)
▸ ~130 kV
▸ 3 x 300-1000 mm2
▸ HVDC Cable
▸ ~300+ kV
▸ 2 x 1000+ mm2
20. Land Connection
▸ Connection to Grid
▸ Voltage Needs to Accord
▸ Holland
●
Main Line 380 kV
●
4 HV Connection Points
21. Example: ACAC Connection
▸ What are the Maximum Power Losses in this System?
▸ Lillgrund (Sweden)
▸ 48 x Siemens SWT 2.3-93 (110 MW, 33 kV)
▸ 10 km from Land Connection (380 kV)
22. Example: ACAC Connection
▸ AC connection
●
Transformer losses (5% per transformer)
●
Resistive Losses
●
Capacitive Losses
23. Example: ACAC Connection
▸ AC connection
●
Transformer losses (5% per transformer)
●
Resistive Losses
●
Capacitive Losses
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
24. Example: ACAC Connection
▸ ACAC station (Transformer)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
Pel=η⋅Pturbine
Pel=0.95⋅110=105MW
Pel=Vinflow⋅Iinflow=V outflow⋅Ioutflow
1.05⋅108
=3.3⋅104
⋅Iinflow>Iinflow=3182 A
Vinflow⋅Iinflow=V outflow⋅Ioutflow
3.3⋅104
⋅3182=1.3⋅105
⋅Ioutflow>Ioutflow=808 A
25. Example: ACAC Connection
▸ XPLE Cable
●
Resistive Losses
●
Capacitive Losses
●
V=130 kV
●
A=808 A
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
26. Example: ACAC Connection
▸ XPLE Cable
●
Resistive Losses
●
Capacitive Losses
●
V=130 kV
●
A=808 A
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
27. Example: ACAC Connection
▸ XPLE Cable (Resistive Losses)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
PΩ=RAC⋅I2
PΩ=Ohmic Losses[W /m]
RAC=AC Resistance[Ω/m]
I=Current[ A]
28. Example: ACAC Connection
▸ XPLE Cable (Resistive Losses)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
PΩ=RAC⋅I2
PΩ=
0.0405
3
⋅808
2
PΩ=8813W /km
Presistive=PΩ⋅Lcable=79.3kW
29. Example: ACAC Connection
▸ XPLE Cable (Capacitive Losses)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
Wd=2⋅π⋅f⋅C⋅V 2
⋅tan(δ)
Wd=Dielectriclosses[W /m]
f =Frequency[Hz]
C=CableCapacitance[F/m]
V =Voltage[V ]
tan(δ)=Dissipation Factor[ii]=3⋅10−4
31. Example: ACAC Connection
▸ XPLE Cable (Capacitive Losses)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
Pland=Pel−Presistive−Pcapacitive=113.9MW
32. Example: ACAC Connection
▸ XPLE Cable (Capacitive Losses)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
Pland =Pel−Presistive−Pcapacitive=109.9 MW
33. Example: ACAC Connection
▸ ACAC Station (Transformer)
48x Turbine
110 MW
33 kV
50 hz
ACAC Station
33kV > 130 kV
50 hz
5% loss
XPLE cable
9 km
ACAC Station
130kV > 380 kV
50 hz
5% loss
Pnet =η⋅Pland
Pnet=0.95⋅109.9=104.4 MW
34. ACDC Connection
▸ Very Similar to ACAC Connection
▸ 1 Positive Carrier for DC Instead of 3 for AC
▸ No Capacitive Losses
35. Homework
▸ Design the turbine layout for your park (slide 5 till 11)
▸ Design cable Pattern (slide 13 till 15)
▸ Decide AC or DC cable transmission (slide 16 till 18)
▸ Estimate your total tranmission losses (slide 19 till 34)