wind farm structures’ impact on harmonic emission and grid interaction
DESCRIPTION
Wind Farm Structures’ Impact on Harmonic Emission and Grid Interaction. Harmonics in Large Offshore Wind Farms Łukasz Kocewiak (DONG Energy) Jesper Hjerrild (DONG Energy), Claus Leth Bak (Aalborg University). Contents. Onshore Wind Farms Karnice Wind Farm Offshore Wind Farms - PowerPoint PPT PresentationTRANSCRIPT
Wind Farm Structures’ Impact on Harmonic Emission and Grid Interaction
Harmonics in LargeOffshore Wind Farms
Łukasz Kocewiak (DONG Energy)Jesper Hjerrild (DONG Energy),Claus Leth Bak (Aalborg University)
Onshore Wind Farms Karnice Wind Farm
Offshore Wind Farms Horns Rev 2 Offshore Wind Farm
Models of Wind Farm ComponentsHarmonic Impedance
Karnice Wind Farm Impedance Plots Horns Rev 2 Impedance Plots Results Comparison
Harmonic Level at Connection PointConclusions
Contents
Analysed Wind Farms
Horns Rev 2 and Karnice Wind FarmWind farms built and owned by
DONG Energy A/STwo different wind farms:
onshore and large offshoreEquipped with the same
SWT-2.3-93 wind turbines
Connected to completely different networksWind turbines are equipped with full-scale converters
Onshore Wind Farm- Karnice Wind Farm
Onshore wind situated in the north part of Poland
The wind farm consists 13SWT-2.3-93 wind turbines
Total capacity is 30 MWKarnice Wind Farm is connected
directly to the distributionnetwork
The biggest offshore windfarm in the world
Situated by the west coastof southern Denmark
The wind farm consists 91SWT-2.3-93 wind turbines
Total capacity is 210 MWHorns Rev 2 is connected to the network by
100 km HVAC submarine and underground cable
Offshore Wind Farm- Horns Rev 2 Offshore Wind Farm
source: Energinet.dk
High and Medium Voltage CablesWind Turbine and Park TransformersShunt ReactorsCapacitor BanksExternal Network
Models of Wind Farm Components
Models of Wind Farm Components- Medium and High Voltage Cables
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
x 104
0
10
20
30
40
Mag
nitu
de |Z
| [
]
Power Cable Impedance
ZT
Z
Z eq
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
x 104
-100
-50
0
50
100A
ngle
Z
[]
Frequency f[Hz]
Lumped Π and T modelsEquivalent Π modelMedium voltage cables
equivalent impedance calculated based on aggregated model
Approximation of the skineffect using correctionfactors
Frequency of interest:50Hz – 3 kHz
Models of Wind Farm Components- Wind Turbine and Park Transformers
Harmonic models based on measurements and dataprovided by manufacturers
Models based on frequencysweep analyzer measurements
Measurements performed using FRAX FSA within the confines of internal research projects
Frequency of interest:50Hz – 3 kHz
Models of Wind Farm Components- External Network
Frequency characteristic at the point of common couplingDifferent short circuit levels, network configurations consideredFrequency of interest: 50Hz – 3 kHz
Harmonic Impedance- Karnice Wind Farm
Harmonic Impedance- Horns Rev 2 Offshore Wind Farm
Results Comparison
Harmonic Level at Connection Point
Large wind farms significantly change impedance at PCC
Voltage THD much lower during wind farm production
11th and 13th voltage harmonics change significantly
Conclusions
Offshore wind farms are mainly connected to the transmission network by long HV cables
Offshore wind farms have much more components which have influence on overall system impedance
Medium voltage cables network is much bigger in offshore wind farms
Large offshore wind farms can operate as a power plant and improve power quality at the point of connection
Every large wind farm has to be analysed separately
Thank You