2MW baseline wind turbine: model development and verification (WP1) The University of Tokyo & Hitachi, Ltd.

Transcription

1 2MW baseline wind turbine: model development and verification (WP1) The University of Tokyo & Hitachi, Ltd. Downwind turbine technology, IEA Wind Task 40 First Progress Meeting, Tokyo, Japan 11 Dec,

2 Outline Motivation Objectives Baseline model development Load cases for simulations Schedule 2

3 Motivation Lack a representative downwind turbine model for research and assessment Design Load Cases for the parked condition may not be suitable for downwind turbines (e.g. for passive yaw system) Fatigue loads of downwind turbines may differ from upwind turbines (e.g. due to tower shadow) Examples of widely known reference upwind turbines NREL 5-MW reference wind turbine LEANWIND 8 MW reference turbine (LW) DTU 10 MW reference wind turbine 3

4 Objectives Develop a baseline model of downwind turbine Define load cases for the verification of the model using multiple simulation tools (e.g. FAST, Bladed and so on) Compare downwind and upwind configurations 4

5 Baseline model development Model name: UT80-2 MW Downwind and Upwind Turbines Specifications Rating Configuration Size & Mass Controls Aerodynamics -blade length, twist angle -airfoils -tower & nacelle drag Structure dynamics -mass, size of blades and tower -stiffness of blades and tower -drivetrain properties. Control & electrical system -pitch, torque, yaw controller -generator model Based on -method used for NREL-5MW & DTU 10 MW models - publicly available info. of 2 MW models 5

6 UT80-2 MW Specifications Rated power Rotor configuration Rotor diameter Hub height Drivetrain Cut-in, rated, cut-out wind speed Cut-in, rated rotor speed Rated tip speed Cone and Tilt 5, 8 Overhang 4.02 m Rotor mass (hub included) Tower mass, Nacelle mass 2 MW Horizontal axis, Downwind, 3 Blades 80 m 80 m High-speed, multi stage gearbox (ratio: 98) 4 m/s, 12 m/s, 25 m/s 6.7 rpm, 17.5 rpm 73.3 m/s kg kg, kg 6

7 Proposed simulation cases for the analysis and verification of the model Inspired by Description of Load Cases for OC4, Phase II 7

8 General setup (example) Setup parameters are defined considering Bladed and FAST as simulation tools but they are equally applicable for any other (& similar) wind turbine simulation tool Parameter Value Time step for data output Δ 0.05 s Time step for wind data Δ 0.05 s Gravity g 9.8m s Simulation time for deterministic load cases (after transients) Simulation time for stochastic load cases (after transient) 600 s 600 s 6 For all load cases 8

9 Load cases set 1 (example) Identify general characteristics, e.g. natural frequencies Simulations are run: in the absence of air, with generator locked, at azimuth angle 0 degree 1. System ID (generator locked) Load case Description DOFs Sim. length Wind condition Output (for comparison) 1. 1 Eigen analysis All N/A No air Natural frequencies 1.2 Static equilibrium All N/A No air Static-equilibrium position and loads NOT same as the DLCs of IEC or GL guideline 9

10 Load cases set 2 (example) Analyze system for both steady and unsteady wind 2. Full system dynamics (fully flexible system) Load case Description 2. 1 Deterministic, below rated ( ) 2.2 Stochastic, at rated Ω 17.5 rpm 2.3 Stochastic, above rated, Ω 17.5 rpm, pitch = year extreme wind, Ω 0 rpm pitch = 90 DOF s Sim. length Wind condition All 60 s Steady, uniform, no shear, 8 m/s All All All 10 min 6 10 min 6 10 min 6 NTM, 12 m/s, % & 2m/s, Mann model NTM, 18 m/s, % & 2.7m/s, Mann model EWM, 50 m/s, % & 5.5m/s, Mann model Output (for comparison) Time series Time series, PSDs Time series, PSDs Time series, PSDs, 10

11 Load cases set 3 (example) Verify tower shade models Compare active and passive yaw scenarios 2. Full system dynamics (fully flexible system) Load case Description DOFs Sim. length Wind condition Output (for comparison) year extreme wind, Ω 0 rpm pitch = 90 All 10 min 6 EWM, 50 m/s, % & 5.5m/s, Mann model Time series, PSDs, 3.2 Stochastic, at rated Ω 17.5 rpm All 10 min 6 NTM, 12 m/s, % & 2m/s, Mann model Time series, PSDs Load cases specifically for downwind configuration Effect of tower shadow on the fatigue load (operation) Passive yaw system for the extreme wind condition (Parked) 11

12 Comparison of turbine configurations Wind VS Wind Downwind Upwind Images: Kress, PhD. Thesis ETH (2016) 12

13 Schedule of WP1 1.1 Baseline model development 1.2 Verification 1.3 Comparison of DWT and UWT 2017/ / /12 Report Model Verification. Comparison Final 13

14 Thank you for your attention 14