AVATAR Deliverable D1.3 Comparison of the

INNWIND and AVATAR Research Wind Turbines

Ainara Irisarri Ruiz (CENER)

Helge Aagaard Madsen, David Robert Verelst (DTU) Alessandro Croce, Luca Sartori, Marco Stefano Lunghini (PoliMi)

Marion Reijerkerk, Henk-Jan Kooijman, Martin Stettner (GE)

April 2, 2015

Agreement n.: FP7-ENERGY-2013-1/ n 608396 Duration: November 2013 to November 2017 Coordinator: ECN Wind Energy, Petten, The Netherlands

Supported by:

Page 2 of 48 WP no.: 1.3

Document Information

Document Name: D1.3 Comparison of the INNWIND and AVATAR Research Wind Turbines

Confidentiality Class XX

Document Number: D1.3

Editor: Martin Stettner (GE)

Contributing authors: Ainara Irisarri Ruiz (CENER)

Helge Aagaard Madsen, David Robert Verelst (DTU)

Alessandro Croce, Luca Sartori, Marco Stefano

Lunghini (PoliMi)

Marion Reijerkerk, Martin Stettner (GE)

Review: G. Sieros (CRES)

Date: 02/04/2015

WP: WP1 - Integration and Evaluation of 10MW Rotor

Task: Task1.3 Evaluation of the AVATAR and the INNWIND.EU RWT

Page 3 of 48 WP no.: 1.3

Table of contents

1. Introduction 6

2. AVATARr2 vs. INNWIND Model 6

3. System Simulation 9

Design Load Cases 9

System Simulation Tools 10

CENER: Bladed 10

PoliMi: Cp-Lambda 10

DTU: HAWC2 13

4. Component Loads 14

Coordinate System and Plot Color Scheme Conventions 14

Load Predictions and Limits 14

Blade and Blade Loads 15

Blade Properties 15

Sectional Extreme Loads (MXS, MYS) 18

Root Extreme Loads (MXB, MYB, MXYB, MZS) 20

Tip Deflection (XB, YS, ZS) 22

Rotor and Shaft Loads 24

Thrust (FXN) 24

Torque (MXN) 27

Low Speed Shaft Bending Moment (MXYR) 28

Tower Loads 29

Tower Top Extreme Loads (MZK, MXYK) 29

Tower Bottom Extreme and Fatigue Loads (MXYF, MYF) 31

Stability 34

Power 42

Annual Energy Production 45

5. Summary 46

Bibliography 48

Page 4 of 48 WP no.: 1.3

Figures

Figure 1: Difference in Uncoupled Blade Frequencies (Structural), DTU vs. PoliMi (in % of

PoliMi frequency, and in % of Operating Rotor Speed [1P]) ......................................................16

Figure 2: Difference in Uncoupled Blade Frequencies (Structural), AVATARr2 vs. INNWIND ..16

Figure 3: Changes in Uncoupled Blade Frequencies (Structural) from Standstill to Operating

RPM ..........................................................................................................................................17

Figure 4: Uncoupled Blade Frequencies (Aeroelastic) [Hz] vs. Wind Speed [m/s] .....................17

Figure 5: Uncoupled Blade Damping (Aeroelastic) [Hz] vs. Wind Speed [m/s] .........................18

Figure 6: MYS - Blade Flapwise Bending Moment [kNm] vs. Radius [m]....................................19

Figure 7: MXS - Blade Edgewise Bending Moment [kNm] vs. Radius [m] ...................................19

Figure 8: MXB - Blade Root In-plane Bending Moment Extreme Load Hierarchy [kNm] ...........20

Figure 9: MYB - Blade Root Out-of-plane Bending Moment Extreme Load Hierarchy [kNm] .....21

Figure 10: MXYB - Blade Root Resultant Bending Moment Extreme Load Hierarchy [kNm] .......21

Figure 11: MZS - Blade Root Pitching Moment Extreme Load Hierarchy [kNm] .........................22

Figure 12: XB - Blade Tip Out-of-plane Deflection Hierarchy [m] ..............................................23

Figure 13: YS - Blade Tip Edgewise Deflection Hierarchy [m] ....................................................23

Figure 14: ZS - Blade Tip Twist Hierarchy [] .............................................................................24

Figure 15: FXN - RotorThrust [kN] vs. Hub Height Wind Speed [m/s] .......................................25

Figure 16: FXN - Rotor Thrust Extreme Load Hierarchy [kN] .....................................................26

Figure 17: MXN - Rotor Torque Extreme Load Hierarchy [kNm] ................................................27

Figure 18: MXYR - Main Shaft Resultant Bending Moment Extreme Load Hierarchy [kNm] ......28

Figure 19: MZK - Tower Top Torsion Extreme Load Hierarchy [kNm] ........................................29

Figure 20: MXYK - Tower Top Resultant Bending Moment Extreme Load Hierarchy [kNm] .......30

Figure 21: MXYF - Tower Bottom Res. Bending Moment Extreme Load Hierarchy [kNm] ..........31

Figure 22: MYF - Tower Bottom Fore-Aft Bending Moment DELs [kNm], DLC1.2, 0 Yaw ........32

Figure 23: MYF - Tower Bottom Fore-Aft Bending Moment DELs [kNm], DLC1.2, +30 Yaw (left)

and -30 Yaw (right) .................................................................................................................33

Figure 24: Frequency [Hz] and Damping [% critical] of the three lowest damped Modes of the

AVATARr2 Rotor ......................................................................................................................35

Figure 25: Frequency [Hz] and Damping [% critical] of the three lowest damped Modes of the

INNWIND Rotor .......................................................................................................................36

Figure 26: Frequency [Hz] and Damping [% critical] of Tower Modes ......................................37

Figure 27: Frequency [Hz] and Damping [% critical] of First Flap Modes (INNWIND) .............38

Figure 28: Frequency [Hz] and Damping [% critical] of First Flap Modes (AVATAR) ...............39

Figure 29: Frequency [Hz] and Damping [% critical] of First Edge Modes (INNWIND) ............40

Figure 30: Frequency [Hz] and Damping [% critical] of First EdgeModes (AVATAR) ...............41

Figure 31: Hub Axial Force Coefficient vs. Hub Height Wind Speed in steady (left) and turbulent

(right) wind ...............................................................................................................................42

Figure 32: Power Coefficient vs. Wind Speed in steady (left) and turbulent (right) wind ...........43

Figure 33: Steady Power Curve, [MW] vs. [m/s]........................................................................44

Figure 34: Turbulent Power Curve, [MW] vs. [m/s] ..................................................................44

Figure 35: Turbulent Power Curve, 30 Yaw Impact, [MW] vs. [m/s] .....................................45

Page 5 of 48 WP no.: 1.3

Tables

Table 1: Component Property Definitions relevant for DLC modeling ........................................ 6

Table 2: AVATARr2 vs. INNWIND Controller Settings (1/2) ...................................................... 7

Table 3: AVATARr2 vs. INNWIND Controller Settings (2/2) ..................................................... 8

Table 4: AVATARr2 Design Load Cases .....................................................................................11

Table 5: AVATARr2 Load Limits and Predictions (from D1.1) ...................................................14

Table 6: Uncoupled Blade Natural Frequencies (Structural) [Hz]..............................................15

Table 7: Annual Energy Production, Mean over all Seeds [GWh/y] ...........................................45

Table 8: Comparison of Predicted and Rounded Calculated Values ...........................................47

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1. Introduction

This document represents Deliverable D1.3 of the AVATARr2 project, containing comparison of the INNWIND.EU 10 MW/ DTU 10MW RWT research wind turbine (Bak (to be accepted)), referred to as INNWIND machine in this report, and its low induction rotor variant developed in the AVATARr2 project, denoted as AVATARr2 wind turbine or AVATARr2, as described in Deliverable D1.1. (Chaviaropoulos 2014) and D1.2 (Sieros 2015). The comparison is based on system simulations performed by partners CENER, DTU, and Politecnico die Milano (PoliMi) and includes blade properties, key component loads (extreme and fatigue), power curves, and projected Annual Energy Production, AEP.

2. AVATARr2 vs. INNWIND Model

As described in AVATARr2 D1.2 (Sieros 2015) the AVATARr2 research wind turbine is an INNWIND machine (Bak (to be accepted)) with the tower height increased to from 118.4 m to 127.9 m, and the 178.4 m diameter rotor replaced by the 205.76 m AVATARr2 rotor described in AVATARr2 D1.1 e (Chaviaropoulos 2014) and D1.2 (Sieros 2015).

Class Variable Value Comment

Generator Overspeed reference value: 11.52 RPM 120% of rated RPM Generator connection speed: 3 RPM Generator disconnection speed: 6 RPM Stop simulation speed: 2 RPM Pitch Drive Min/Max. pitch angle -5/90 Max pitch rate

start-up

normal operation

normal shutdown

E-stop

runaway

10/sec 10/sec 10/sec 5/sec 5/sec

As in INNWIND INNWIND INNWIND: 2/sec INNWIND

Pitch runaway

Tolerance

Time delay

0 0 sec

Yaw Drive Activation speed Yaw error to activate 10 Average time 30sec Yaw rate 0.25/sec Mechanical Brake

Connection speed 6 RPM

Ramp time 0.74sec Max. continuous service time 10sec Max. braking torque 5225.35 kNm INNWIND

Table 1: Component Property Definitions relevant for DLC modeling

Page 7 of 48 WP no.: 1.3

Apart from a modified tower, changes were necessary in the controller, and some