Offshore Wind Farm Research: Quo Vadis?

Transcription

1 Offshore Wind Farm Research: Quo Vadis? Marta Molinas Wind Seminar

2 Outline Offshore new challenges New Opportunities AC-AC direct conversion Hybrid and Classic HVDC Active Comp. FACTS 2

3 Hybrid and and classic HVDC HVDC Active Active comp. comp. FACTS FACTS Outline Offshore New Challenges 3

4 Offshore new challenges Investment Power density: weight and size Platforms Operation Grid integration Reliability Efficiency 4

5 Hybrid and and classic HVDC HVDC Active Active comp. comp. FACTS FACTS Outline New Opportunities 5

6 Research opportunities Offshore grid topologies DC grids AC grids, Hybrids Series, parallel Operation Modulation Control Energy conversion system Modularity Reduced number of stages New type of semiconductor cto devices 6

7 DC grid 7 C. Meyer, Key components for future offshore DC grids, PhD dissertation, Rheinisch-Westfallischen Technischen Hochschule Aachen, Germany, 2007

8 No Platform 8

9 Hybrid and and classic HVDC HVDC Active Active comp. comp. FACTS FACTS Outline in series DC grid 9

10 AC-AC AC-AC direct direct conversion conversion State t of the art Nacelle DC/DC MF transformer G AC DC DC AC AC DC S. Lundberg, Wind farm configuration and energy efficiency studies - series dc versus ac layouts. Lic. of Eng. thesis, Chalmers University of technology, Goteborg, Sweden,

11 AC-AC AC-AC direct direct conversion conversion Our Idea AC AC Reduced Matrix Converter MF transformer G AC DC AC DC AC DC AC Nacelle A. Mogstad, M. Molinas, Power collection and integration on the electric grid from offshore wind parks, In proc. NORPIE 2008, June 2008, pp

12 AC-AC AC-AC direct direct conversion conversion 12

13 AC-AC AC-AC direct direct conversion conversion Modularity 13

14 AC-AC AC-AC direct direct conversion conversion Series DC farm 14

15 AC-AC AC-AC direct direct conversion conversion Benefits Reduction of size Less stages of conversion No electrolytic l ti capacitor High frequency transformer Efficiency Less stages of conversion Optimized modulation Use of RB-IGBT 15

16 AC-AC AC-AC direct direct conversion conversion Farm study 16

17 AC-AC AC-AC direct direct conversion conversion Powers 17

18 AC-AC AC-AC direct direct conversion conversion Voltages 18

19 AC-AC AC-AC direct direct conversion conversion Pitch control 19

20 Outline Hybrid HVDC 20

21 Hybrid HVDC Hybrid HVDC 21

22 Hybrid HVDC Hybrid HVDC Advantages LCC can handle high power levels VSC is very flexible (independent control of active and reactive power, mitigation of power quality disturbance, feeding islands and passive ac) Lower losses and less cost in Hybrid HVDC compared with VSC HVDC 22

23 Hybrid HVDC Some outputs t 23

24 Hybrid and and classic HVDC HVDC Active Active comp. comp. FACTS FACTS Outline Active compensation FACTS 24

25 Active Active comp. comp. FACTS FACTS Series compensation 25

26 Voltage and Current Plots Active Active comp. comp. FACTS FACTS Magnitu de (pu) Vinja Vinjc Vc1 Source Phase Voltage and Line Current Ia Va1 Converter Phase Voltage and Line Current Ia Magnit tude (pu) Vc2 Va Time (s)

27 Active Active comp. comp. FACTS FACTS Shunt Compensation 27

28 Active Active comp. comp. FACTS FACTS Active filtering 28

29 Active Active comp. comp. FACTS FACTS Effect on Instantaneous Power 29

30 Active Active comp. comp. FACTS FACTS Q compensation w/ Matrix Converter Compact: PM Machine, Conventional Matrix Converter and small input filter to smoothen input current Dual role: It controls the speed of the PMSM as well as the reactive power on thegrid side. Can provide Q compensation alone or in combination with active power Q range strongly depends on the modulation technique of the matrix converter. 30

31 Active Active comp. comp. FACTS FACTS Q Range Indirect SVM P and Q strongly correlated. If P=0,,Q=0 Pure Q compensation not possible Three-Vector-Scheme Decouples P and Q 31

32 Research Needs Grid flexibility Modelling and design tools for farms: integrated modelling (meta models) Offshore grid stability Storage technology 32

33 We ve passed the point of no return for offshore wind it is happening on a big scale 33

34 Thanks for your attention ti 34

35 Hybrid and Control classic HVDC Parameters Generator Turbine Parameter Value Unit Parameter Value Unit S (nominal) 2 MW Nominal Power 2 MW U(nominal) 690 V Rotor diameter 75 m U DC(nominal) 2 kv Nominal speed 18 rpm Rs Ω Cable Ld mh Parameter Value Unit Lq mh RL 9.6 Ohm Flux L H Num poles 20 C 34 uf Inertia 1342 N m s 35

36 Hybrid and Control classic HVDC Coordinated d control 36

37 Hybrid and Control classic HVDC Short circuit it : model used Turbine 1 Turbine 2 Turbine 3 Turbine 4 to 80 Same as V 3 37

38 Control 38

39 Converter losses 39

40 Modelling 40

41 The concept in detail 41

42 Turbine speed 42

43 Onshore values 43

44 Offshore new challenges Proposed AC-AC directtopology conversion P t ti l applications Potential li ti J. Cotrell. A preliminary evaluation of a Multiple generator drive train configuration For wind turbines. National renewable energy laboratory. Colorado

45 AC-AC Proposed direct Topology conversion 10 MW Britannia i conventional high speed PM generators of 660kW each. 45

46 Matrix converter study CMC IMC SMC 46

47 Effect on Reactive Energy 47