Scientific and Technological Challenges in Offshore Vertical Axis Wind Turbines

7-9 September 2016, Technical University of Delft, The Netherlands

I. Bayati and M. Belloli

Politecnico di Milano

Department of Mechanical Engineering

VODCAVAWT Open Data for Code Assessement

x = 0:.01:8*pi;s = x.*sin(x);c = x.*cos(x);plot3(s,c,x)

Ilmas Bayati, PhD.

Presentation overview

• Participants

• PoliMi Wind Tunnel Facility

• The PoliMi Vertical Axis Wind Turbine with IPC

• Structural design

• Mechatronic design

• Control Hardware/Software features

• PoliMi’s Proposal

• Open discussion on main topics

Ilmas Bayati, PhD.

VODCA Participants

Institution Country Type Contact Person Email

Politecnico di Milano Italy Academia Bayati ilmasandrea.bayati@polimi.it

DELFT UniversityThe

NetherlandsAcademia Ferreira C.J.SimaoFerreira@tudelft.nl

Cranfield UniversityUnited

KindomAcademia Collu maurizio.collu@cranfield.ac.uk

EOLFI France Industry Paillard benoit.paillard@eolfi.com

Nenuphar France Industry Kluczewska-Bordierjoanna.kluczewska-bordier@nenuphar-

wind.com

DTU Denmark Academia Paulsen uwpa@dtu.dk

Sandia National

LaboratoriesUnited States Government Griffith dgriffi@sandia.gov

INNOSEA/ECN France Industry/Academia Gilloteaux jean-christophe.gilloteaux@ec-nantes.fr

VUB Belgium Academia Runacres mark.runacres@vub.ac.be

Others ? ? ? ? ?

Ilmas Bayati, PhD.

PoliMi Wind Tunnel

Facility Overview

Two different

test sections for

different applications

BOUNDARY LAYER TEST SECTION

LOW TURBULENCE TEST SECTION1.5 MW

Closed - circuit

Wind Tunnel

Ilmas Bayati, PhD.

Wind Tunnel Facility

13.8x3.8m, 16m/s,

Boundary Layer Section:- turbulence < 2%

- with turbulence generators = 25%

- 13m turntable

4x3.8m, 55m/s,

Low Turbulence Section:- turbulence <0.1%

- open jet / closed test section

36 m

Ilmas Bayati, PhD.

Low Turbulence Test Section

13.8x3.8m, 16m/s,

Boundary Layer Section:- turbulence < 2%

- with turbulence generators = 25%

- 13m turntable

4x3.8m, 55m/s,

Low Turbulence Section:- turbulence <0.1%

- open jet / closed test section

Ilmas Bayati, PhD.

Wind Quality Assessment

(Open Jet Config)

Top View

Measuring line (mide height, z=0)

Ilmas Bayati, PhD.

PoliMi IPC-VAWT

In-house designReference machine for VOCA project:

VAWT Open data for Code Assessment

Airfoil NACA0021

Chord C 0.25 m

Height H 2.7 m

Radius R 1.5 m, 1.0 m

Blades N 3

Solidity σ 0.25, 0.375

Ilmas Bayati, PhD.

PoliMi IPC-VAWT

Design of structural parts & assembly issues

Design parameters

Angular speed: 300 rpm

Radius: 1.5 m

Ilmas Bayati, PhD.

PoliMi IPC-VAWT

Blades

Airfoil (NACA 0012,15,18,21)

Support Beam dimensionAero-Structural optimization

NACAAirfoil

S (mm)2a_max

(mm)

0012 30 23

0014 37.5 29

0018 45 34

0021 52.5 40

C=0.25 m

Assuming hinged kinematic configuration

First natural bending frequency, n=1

Genetic Algorithm Optimization

Carbon fiber/composite sandwitch structural rib

Ilmas Bayati, PhD.

Roller bearings

SKF 61911-2RS1

Motor-blade

coupling shaft

PoliMi IPC-VAWT

Individual Pitch Control unit

Motor-blade

Intermediate

coupling shaft

Elastic joint

GIFLEX GE-T 14 SG

Maxon motor-reducer

EC-4pole 30,

brushless, 200W

Encoder MR

Gearhead GP32

Blade structural

beam carbon fiber

2 Uni-directional

+ 2 Balanced

Ilmas Bayati, PhD.

PoliMi IPC-VAWT

Control features

Encoder Lika

Line-Driver

Hollowed Motor

Motor Power

Ska Rotary

245.60

Slip Ring Moog

AC6373

Controller

Maxon Escon

50/5

1P + NP

detector

Angular velocity

Current (Torque)

Main shaft motor

Main shaft angular

velocity and

position

Homing

Homing

Blade angular speed

Blade motor

(angular loop)

Feedback

Actuation

Signal

Analog

Digital

Digital

Angular velocity

Current (Torque)

Analog2 Proximitors

Omron M8x1

Ilmas Bayati, PhD.

PoliMi IPC-VAWT

Wind Tunnel test capabilities

Experimental modal analysis20 Distributed accelerometers (blades and shaft)

Design

limit

A

1P limit due to: A B

B

𝜆 =𝜔𝑅

𝑉Tips Speed Ratio:

First shaft bending natural freq. 𝐹1 = 19.5 Hz

𝐹1/3P > 2

Experimental IPC

Bandwidth assessment

Max sine wave

amplitude withouth

phase shift for

1P = 2.5 Hz

3P = 5 deg

Radius R [1.5,1.0] m

Solidity σ [0.25, 0.375]

Wind V [4 - 20] m/s

Testing

region

𝜔>2.5 for lower

IPC control bandwidth

or amplitudes

Ilmas Bayati, PhD.

PoliMi IPC-VAWT

Control tasks

𝜗(𝑡) = 𝜗𝑘 +𝜗𝑘+1−𝜗𝑘

ΔT 𝒌

Effective shaft angular position 𝜗 𝑡

𝜑 𝑡 = 10°sin(𝜗 𝑡 )

Riprogrammable

RT-National Instrument

FPGA/PXI controller

IPC law 𝜑(𝜗(t))

Shaft + blades

homing

Host Interface

Ilmas Bayati, PhD.

PoliMi’s Proposal

Validation Activity Management issuesPhase

Preliminary Numerical Vs Numerical

• PoliMi reference VAWT

• Investigating the differences among

different codes

• Fixed Pitch 𝜑 = 0

• Fixed Pitch 𝜑 ≠ 0

• Variable Pitch: IPC simple control laws

(e.g 1P) consistent with PoliMi VAWT

Numerical Vs ExperimentalWind tunnel tests: cases choosen among the ones

investigated in the Phase I

I

II

III

PoliMi will provide the

Person Months for

• Project coordination

• Data processing

• Writing papers

For Phase I, II and III

PoliMi will provide

5 wind tunnel and person days

for the tests

Required N wind tunnel and

person days for the tests.

• N to be defined

• Control laws must be public

Numerical Vs Experimental (Control)Wind tunnel tests: implementation of IPC

advanced control laws, based on the results of

Phase I and Phase II

Ilmas Bayati, PhD.

PoliMi’s Proposal

Validation Activity Time schedulePhase

Preliminary Numerical Vs Numerical

• PoliMi reference VAWT

• Investigating the differences among

different codes

• Fixed Pitch 𝜑 = 0

• Fixed Pitch 𝜑 ≠ 0

• Variable Pitch: IPC simple control laws

(e.g 1P) consistent with PoliMi VAWT

Numerical Vs ExperimentalWind tunnel tests: cases choosen among the ones

investigated in the Phase I

I

II

III Numerical Vs Experimental (Control)Wind tunnel tests and implementation of IPC

advanced control laws, based on the results of

Phase I and Phase II

TBD

TBD

TBD

(IEA task?)

Ilmas Bayati, PhD.

VODCA references

Website:

• https://vodcabench.wordpress.com/: in transition under PoliMi’s official website

• Reference website for sharing data, results, presentations and minutes

References

• Deteailed description of the design and features of PoliMi IPC-VAWT

I.Bayati, M. Belloli, D.Tarsitano, S.Foletti,

“A reference open data IPC Vertical Axis Wind Turbine for code validation purposes”

Under review for publication in Frontiers in Mechanical Engineering, Special Issue in Wind

Power Generation publication expected before December 2016

Ilmas Bayati, PhD.

Thank you!

…the discussion is open