Power fluctuations from large offshore wind farms

Transcription

1 Power fluctuations from large offshore wind farms Poul Sørensen Wind Energy Systems (VES) Wind Energy Division Project was funded by Energinet.dk PSO

2 Geographical spreading 2

3 Wind turbine sites in Denmark Horns Rev 3 Risø DTU, Technical University of Denmark Energinet.dk advisory meeting on control

4 Validation available data February 2005 January 2006 January 2006 May Horns Rev Horns Rev 160 MW Nysted 165,6 MW 72 WT WT Wind Turbines Wind Trubines Mast acquisition made through the control system, with 1Hz sampling frequency; - wind speed, power, power set point and yaw position used - 2-hour segments were selected, with normal operation hour segments (92,5 days) in Horns Rev and 1989 (165,75 days) in Nysted - wind speeds from 1 to 19 m/s (Horns Rev) and from 1 to 24 m/s (Nysted) 4

5 Validation ramp rates The ramp rate * (load following) is defined as the change in the mean value from one period to another and specifies the ramp rate requiremet that the wind farm power fluctuation causes to other power plants P ramp ( n) = Pmean ( n+ 1) Pmean ( n) Three time scales were investigated: 10 min, 30 min and 1 min * This definition specifies the ramping of the wind farm power. Thus, negative ramp rate means decreasing wind power and requires positive ramping of other power plants. The result were binned according to the initial power P mean (n), because the statistics will depend strongly on the initial power. A power bin size of 0.1 p.u. has been selected. Duration curves are obtained by sorting the ramping in each power bin. 5

6 Validation ramp duration curves Horns Rev duration curves, p.u. 1 min 10 min 30 min Nysted duration curves, p.u. 6

7 Validation 99% percentiles ramp 10 min 30 min 1 min 7

8 Validation reserve requirements The reserve requirement * (regulation) is defined as the difference between the initial mean value and the minimum value in the next period. P ( n) = P ( n) P ( n + 1) res mean min P ramp ( n) = Pmean ( n + 1) Pmean ( n) Three time scales were investigated: 10 min, 30 min and 1 min * with this definition, positive reserves means decreasing wind power that requires positive reserve from other power plants The result were binned according to the initial power P mean (n), because the statistics will depend strongly on the initial power. A power bin size of 0.1 p.u. has been selected. Duration curves are obtained by sorting the ramping in each power bin. 8

9 Validation reserves duration curves Horns Rev duration curves, p.u. 1 min 10 min 30 min Nysted duration curves, p.u. 9

10 Validation 1% percentiles reserves 10 min period 30 min period 1 min period 10

11 Future potential offshore sites 11

12 Climate model resolution 12

13 Simulated wind speeds - smoothing Wind speed (m/s) Turbine (A1) Wind Farm Weather model :00 02:00 04:00 06:00 08:00 10:00 12:00 Time 13

14 Wind farm (aggreg.) power curve Power (pu) Simulated farm Input turbine Wind speed (m/s) 14 Risø DTU, Technical University of Denmark Energinet.dk advisory meeting on control

15 Study cases Djursland Anholt O Djursland Anholt P Horns Rev B Horns Rev A Horns Rev 2 Horns Rev 15

16 Study cases - wind farms data Name Symbol Wind turbine power Total power Annual mean wind speed Horns Rev HR MW 160 MW 9.6 m/s *) Horns Rev 2 HR MW 209 MW 10.4 m/s *) Horns Rev A HRA MW 200 MW 10.6 m/s *) Horns Rev B HRB MW 200 MW 10.5 m/s *) Djursland Anholt O DAO MW 200 MW 9.0 m/s *) Djursland Anholt P DAP MW 200 MW 9.0 m/s *) 16

17 Simulated wind speeds (wf averages) Wind speed (m/s) HR1 HR2 HRA HRB DAO DAP / / / / / Time 17

18 Power fluctuations the 2 cases Horns Rev B Horns Rev A Horns Rev 2 Djursland Anholt O Djursland Anholt P Power (MW) HRB HRA HR2 HR1 Horns Rev / / / / / Time Horns Rev B Horns Rev A Horns Rev 2 Horns Rev Djursland Anholt O Djursland Anholt P Power (MW) DAP DAO HR2 HR / / / / / Time 18

19 Conclusions Efficient simulation tool for simulation of wind power fluctuations in power system region Calibration to sites should be looked more into, especially for onshore applications Applications planning of offshore sites control development 19