Development of a 12MW Floating Offshore Wind Turbine

Transcription

1 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 1 Development of a 12MW Floating Offshore Wind Turbine Hyunkyoung SHIN School of Naval Architecture & Ocean Engineering, University of Ulsan, Korea EERA DeepWind 2017, JAN. 18, 2017, Trondheim, Norway

2 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 2 Outline Introduction UOU 12MW FOWT model Modified Control System Numerical Simulation Design Load Cases Novel Offshore Floater Conclusion

3 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 3 1. Introduction

4 Ulsan, Korea Seoul Ulsan Wikipedia 2014 Light through Darkness

5 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 5 Growth in Size of Wind Turbine Turbines have grown larger and taller to maximize energy capture Source :

6 Critical Needs for FOWTs - Responsible and Sustainable Ocean Economy

7 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 7 Why do we need FOWT? Stronger & Better wind Solution for noise & insufficient space Solution for energy shortage in future Why Floating Offshore Wind Turbine?

8 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 8 Objective (Motive) Target Novel Offshore Floater 12MW FOWT Superconducting Generator Flexible shaft & Carbon Sparcap

9 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 9 Reason why we use a superconducting generator The heavy top head causes the high mechanical stress and high cost of foundation and tower. EESG EESG EESG 1,000 ton EESG Active volume(m 3 ) P G =B r K s πr 2 l ω p Field of rotor(t) Source : Changwon National University, CAPTA

10 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 10 Suggestion of a new technology for the 12 MW Problems of the HTS wind power generator Power supply for DC magnet Slip-ring repairing Huge volume of cryostat High mechanical torque on narrow & small space Current leads loss Source : Changwon National University, CAPTA

11 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 11 Modularized generator for the 12MW Stator body Stator teeth Rotor body Stator coil HTS one pole module Flux pump exciter The modularization of the generator enables a smaller cryogenic volume, an easier repair, assembly, and maintenance of the HTS field coil. Modularization will be suitable for commercial mass production and will increase the operational availability of HTS generators in the wind turbine. Source : Changwon National University, CAPTA

12 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 12 Detailed design for composite flexible shaft Analysis for ultimate & fatigue strength Total Mass : ton M.S. Glass composite shaft 0.22 (First-ply failure) Glass composite shaft Carbon composite pad-up Carbon composite pad-up Metal flanged part 0.56 (First-ply failure) 0.88 (Von-mises stress) Global buckling 46.2 Source : Korea Institute of Materials Science(KIMS) Metal flanged part Global buckling

13 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 13 Detailed design for new support structure Bending load case Case My (MNm) Mz (MNm) x z y Source : Korea Institute of Materials Science(KIMS)

14 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 14 UOU 12MW Wind Turbine Model Design Process Blade mass (42,739 kg) 3⁰ UOU 12MW Wind Turbine NREL 5MW Wind Turbine Upscaling process SCSG/Flexible Shaft/Carbon Sparcap Blade (CFRP) Tower Control Platform Hub mass (169,440 kg) Rotor Axis Wind UOU 12MW Wind Turbine 5⁰ Yaw Bearing C.M m 3.04 m 2.71 m Nacelle mass (400,000 kg) Correction for Floating type Negative damping issue Tower 3P issue m Yaw Axis m Load Analysis IEC IEC IEC m

15 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 15 Design Summary Rating 5 MW 12 MW Rotor Orientation Upwind, 3 Blades Upwind, 3 Blades Control Variable Speed, Collective Pitch Variable Speed, Collective Pitch Drivetrain High Speed, Multiple-Stage Gearbox Low Speed, Direct Drive (SCSG) Rotor, Hub Diameter 126 m, 3 m m, 4.64 m Hub Height 90 m m Cut-In, Rated, Cut-Out Wind Speed 3 m/s, 11.4 m/s, 25 m/s 3 m/s, 11.2 m/s, 25 m/s Cut-In, Rated Rotor Speed 6.9 rpm, 12.1 rpm 3.03 rpm, 8.25 rpm Overhang, Shaft Tilt, Pre-cone 5 m, 5, m, 5, 3 Rotor Mass 110,000 kg 297,660 kg Nacelle Mass 240,000 kg 400,000 kg (Target) Tower Mass (for offshore) 249,718 kg 782,096 kg

16 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan UOU 12MW FOWT Model

17 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 17 Scaling Laws for 12MW power production P = C p 1 2 ρav3 Scale ratio = λ = 12MW 5MW = Blade length : NREL 5MW(61.5m) -> UOU 12MW(95.28 m) Same geometry(airfoil) with NREL 5MW blade Source : EWEA, Wind energy the facts: a guide to the technology, economics and future of wind power, 2009.

18 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 18 12MW Carbon blades 61.5 (m) 5MW glass blade : 17.7 ton (m) 12MW glass blade : 62.6 ton (Too heavy) (m) 12MW carbon (sparcap) blade : 42.7 ton 0⁰ Stiffness [Gpa] Density [kg/m 3 ] Blade Weight [ton] Center of Gravity [m] Scale-up blade properties(deflection) EI 12 = L 4 12 EI 5 L 5 CFRP (Carbon Sparcap) 31.8 L 12 GFRP Source : Korea Institute of Materials Science(KIMS) L 5 w 5 w 12 N.F. [Hz] 1 st Flapwise 2 nd Flapwise 1 st Edgewise 2 nd Edgewise 12MW Blade (5MW) (12MW)

19 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 19 How the blade compares to existing ones 97.6m UOU Carbon(sparcap) blade DTU U O U Source : C. Bak, The DTU 10-MW Reference Wind Turbine, 2015(DTU) 97.6 m 100

20 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 20 Hub height Nacelle target mass: 400 ton, Hub mass: ton (scale-up) Hub height : Rotor radius + Extreme wave height (half) with 50-year occurrence S.F. of / = m 7MW offshore wind turbine(shi) Rotor radius Margin Wave height 86 m 111 m Source : Statoil hywind (Statoil.com) (cf / = 113 m) Source :

21 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 21 Scale-up tower properties Scale up using offshore tower from OC4 definition(5mw : Height : 78.2 m, Weight : ton) 12MW Material : steel, Height : m, Weight : ton (scale-up) [cf. UPWIND report 2011 : 983 ton (10MW), 2,780 ton (20MW)] T 12 Beam deflection δ = TL3 3EI δ 12 δ 5 = L 12 L 5 T 12 T 5 = 12 MW 5 MW T 5 δ 12 EI 12 2 EI 5 = 12L 12 5L 5 2 T = C t 1 2 ρav2 δ 5 Scale-up tower properties L 5 L 12 EI 12 2 = 12L 12 EI 2 5 5L 5 (Beam deflection) (5MW) (12MW)

22 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 22 Scale-up platform properties Ratio of W 12 (1480ton) to W 5 (600ton) OC4 semi-submersible displaced volume 13,917m 3 (5MW) 34,336m 3 (12MW) Scale up properties ρgv 12 ρgv 5 = Weight of wind turbine 12 Weight of wind turbine 5 (Buoyancy force) Novel offshore floater without mooring lines W 5 B 5 W 12 B 12 OC4 DeepCWind semi-submersible (5MW) OC4 DeepCWind semisubmersible (12MW) UOU 12MW FOWT

23 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan Modified Control System

24 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 24 Wind Turbine Power Curve Region II Power, P Torque Control Variable speed, Constant pitch, Target : Cp = Cp_max Maximize the optimum power P = C p 1 2 ρav3 Region III Pitch Control Constant speed, Variable pitch, Target : P = P_rated Maintain the rated power V cut-in Torque control V rated Pitch control V cut-out Wind Speed, V Source :

25 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 25 Maximum Cp and Optimal TSR(Tip Speed Ratio) Max. Cp = at TSR of (cf. NREL 5MW Max. Cp = at TSR of 7.55) Cp TSR curve Modification of the AeroTwst : Node Rnodes AeroTwst DRNodes Chord Airfoil Table [-] [m] [ ] [m] [m] [-] Cylinder1.dat Cylinder1.dat Cylinder2.dat DU40_A17.dat DU35_A17.dat DU35_A17.dat DU30_A17.dat DU25_A17.dat DU25_A17.dat DU21_A17.dat DU21_A17.dat NC64_A17.dat NC64_A17.dat NC64_A17.dat NC64_A17.dat NC64_A17.dat NC64_A17.dat Aerodynamic properties

26 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 26 Torque Scheduling for 12MW Region 1 Region 2 Region 3 Region 1.5 Region = V=5m/s =

27 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 27 Simulation Study(Pitch gain-tuned) Steady wind(12m/s), Regular wave(h = 2m / T = 10s)

28 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 28 Simulation Study(Pitch gain-tuned Controller) NTM(23m/s), JONSWAP spectrum(hs = 3.2m / Tp = 9.6s)

29 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 29 Steady state analysis 29

30 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 30 Campbell diagram (3P Issue) Tower resonance Need to redesign tower properties

31 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 31 Natural frequency of the tower f n = 1 2π 3E(πr 3 t) = C ρ 2πrt l + M tophead l 3 r 3 l 3 D1.5 l 1.5 Target Tower Length Rotor 3P-Excitation : Tower 1 st Side to Side Natural Frequency : % margin % margin No margin Source :

32 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 32 Campbell diagram(after) Tower Length (to avoid 3P!!) m m (-4.35m)

33 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan Numerical Simulation

34 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 34 Design process for a floating offshore wind turbine 1. Initial design 2. Land based design 3. Check the platform without RNA 4. Tower redesign Control redesign 6. Optimization to make a costeffective design 5. Source: IEC Fully Coupled Analysis - Ultimate strength(50-yr) - Fatigue strength(20-yr)

35 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 35 Flow Diagram of UOU + FAST v8 Pre-processors Simulators Post-processors Airfoil Data Files TurbSim Wind Turbulence CATIA Modeling Control & Elec. System Turbine Configuration WT_perf Performance UOU In-house Code BModes Beam Eigenanalysis Wind Data Files Hydrodynamic Coefficient Beam Properties Mode Shapes FAST Aero-Hydro- Servo-Elastic Includes: ElastoDyn AeroDyn ServoDyn HydroDyn MoorDyn Time-Domain Performance, Response, & Loads Linearized Models Origin Long-term distribution Crunch Statistics MBC3 Multi-Blade Transformation

36 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 36 UOU in-house code Hydrodynamic coefficients need for numerical simulation in hydro part Diffraction problem Radiation problem + = Motion equation UOU in-house code 3D panel method(bem) Element : 1024 Output 1. Added mass coefficients 2. Radiation Damping coefficients 3. Wave Excitation Forces/Moments

37 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 37 12MW Stability analysis Wave direction Transverse Stability (Roll) Floating Platform Geometry 5MW 12MW Elevation of main column above SWL Elevation of offset columns above SWL Spacing between offset columns Length of upper columns Length of base columns Depth to top of base columns below SWL Diameter of main column Diameter of offset (upper) columns Diameter of base columns Diameter of pontoons and cross braces Longitudinal Stability (Pitch) GZ (mm) MW Reference 12MW Modified GZ (mm) MW Reference 12MW Modified degree degree

38 Heave RAO (m/m) Pitch RAO (deg/m) Surge RAO (m/m) EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 38 RAO results in regular wave 3 Surge Angular frequency (rad/s) Pitch Heave Angular frequency (rad/s) Angular frequency (rad/s)

39 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan Design Load Cases(DLCs)

40 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 40 Design Load Cases IEC : International Standards DLC DLC1.1 (NSS) DLC1.3 (NSS) DLC1.6 (SSS) DLC6.1 (ESS) Significant Wave height Peak Period Wind Model 3.2 m 9.6 s NTM 3.2 m 9.6 s ETM 9.72 m s NTM m 15.1 s EWM50 Preliminary study for ultimate strength analysis - DLC1.1 - DLC1.3 - DLC1.6 - DLC6.1

41 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 41 DLC1.1(NSS/NTM) Normal Sea State : H s = 3.2m / T p = 9.6s Normal Turbulence Model : I ref = 0.14(B)

42 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 42 DLC1.3(NSS/ETM) Normal Sea State : H s = 3.2m / T p = 9.6s Extreme Turbulence Model : I ref = 0.14(B)

43 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 43 DLC1.6(SSS/NTM) Severe Sea State : H s = 9.72m / T p = 13.98s Normal Turbulence Model : I ref = 0.14(B)

44 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 44 DLC6.1(ESS/EWM50) Extreme Sea State : H s = 11.32m / T p = 15.1s Extreme Wind Speed Model : I ref = 0.14(B)

45 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 45 Summary Maximum Units DLC Rotpwr 15, kw DLC 1.6 (17 m/s) GenPwr 15, kw DLC 1.6 (17 m/s) RotSpeed rpm DLC 1.6 (17 m/s) OoPDefl m DLC 1.3 (11 m/s) TTDspFA 1.34 m DLC 1.6 (11 m/s) TTDspSS 0.88 m DLC 6.1 (-30 deg) TwrBsMyt 618, knm DLC 1.6 (11 m/s) PtfmSurge m DLC 6.1 (+60 deg) PtfmHeave 7.61 m DLC 1.6 (3 m/s) PtfmPitch 6.17 deg DLC 1.6 (11.2 m/s)

46 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 46 Long-term distribution IEC Annex F Statistical extrapolation of loads for ultimate strength analysis Extrapolation of out-of-plane tip deflection Extrapolation of in-plane tip deflection 50-year recurrence = year recurrence = m m Out of plane tip Deflection Extreme value m (safety factor 1.25) In plane tip Deflection Extreme value m (safety factor 1.25)

47 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan Novel Offshore Floater

48 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 48 Wave Energy Propulsion without foil with foil

49 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 49 Wave Energy Propulsion

50 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 50 Wave Energy Propulsion

51 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 51 Passive/Active mode Multiplying Gear-Box Crankshaft Cluch Generator Passive Mode Reduction Gear-Box Crankshaft Cluch Motor Active mode

52 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 52 Novel Stationkeeping(passive mode) Period : 2.43s, Wave Length : 9.18m, Wave Height : 0.075m, Frequency : 0.412Hz, L w a v e / D f l o a t e r : Wave propagating direction

53 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan Conclusion

54 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 54 Conclusion Preliminary design of a UOU 12MW floating offshore wind turbine is made by being scaled up from NREL 5MW wind turbine and OC4 semi-submersible. An innovative floater without mooring systems for the UOU 12MW FOWT is suggested. In order to reduce the top head mass, SCSG, Flexible shaft and CFRP blades are adopted in UOU 12MW FOWT. To avoid the negative damping of FOWTs, controller was modified. Tower length was changed to avoid the 3P excitation. Long term analysis of the UOU 12MW FOWT was performed. Later, IEC rule should be considered for the UOU 12MW FOWT.

55 EERA DeepWind 2017, JAN. 18, 2017, Norway Ocean Engineering Wide Tank Lab., Univ. of Ulsan 55 THANK YOU! ACKNOWLEDGMENTS This work was supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP) and the Ministry of Trade, Industry & Energy(MOTIE) of the Republic of Korea (No and No ).