dynamic response of wind turbines in fault and - ntnu jiang.pdf · dynamic response of wind...

2

Zhiyu Jiang, Department of Marine Technology & Centre for Ships and Ocean Structures

Dynamic response of wind turbines in fault and shutdown conditions

Zhiyu Jiang

Deptartment of Marine Technology, NTNU Centre for Ships and Ocean Structures, NTNU May 28, 2013, CeSOS conference http://www.newscientist.com/blogs/onepercent/2011/12/why-did-a-wind-turbine-self-co.html

3


Why do we study the fault cases?

It is required by the design standards, but not well-defined!

4


Occurence and severity

[Ireson et al., 1996, p. 6.18] [Vijayaraghavan, 2003, p. 13]

Probability of failure Likely failure rate Ranking

Very high >15% 9-10 High 5-10% 7-8 Moderate 2-5% 4-6 Low 0.1-2% 2-3 Remote <0.1% 1

Effect Ranking

Hazardous without warning

10

High 7

Low 5

Very minor 2

None 1

Occurence Severity

5


Wind turbine faults Fault specification Component Effect O S

Dirt on blades Blade surface Decreased

efficiency 10 3

Biased sensor output Pitch sensor Unbalanced rotation 3 6

Pump leakage Pitch actuator Changed dynamics 3 8

Pump blockage Pitch actuator

Out of control

2 9

Yaw position error Yaw sensor Power offset

Bearing wear Drivetrain Decreased efficiency

3 3

Rotor speed error RPM sensor Speed offset

Grid fault Electrical networks Gearbox impact

6


Pitch actuator fault―valve blockage

7


Control and protection of wind turbines

Emergency shutdown

Pitch regulated: Pitch the blade as fast as possible

Stall regulated: aero/mech. brake

Operational control (pitch and torque)

Fault detected?

Supervisory control

Yes

Condition monitoring (subsystem: gearbox,

pitch mechanism, rotor...)

Operational wind speed?

Fault controllable?

No

Yes

Yes

Shutdown

No

No

Other accomodation

methods

8


Turbines studied

9


Load cases

• LC1: normal operation • LC2: grid loss and shut down • LC3: blade blockage and shutdown • LC4: blade runaway and shutdown

UW (m/s) HS (m) TP (s) TI 8 2.5 9.9 0, 0.15 11.2 3.2 10.0 0, 0.15 14 3.6 10.3 0, 0.15 17 4.2 10.5 0, 0.15 20 4.8 10.8 0, 0.15

Environmental conditions for the spar-type wind turbine:

10


Simulation tool

Hawc2 -structural modeling: multi-body formulation -wind loads: Blade Element Momentum and unsteady features -wave loads: Morison’s formula, buoyancy and heave forces -mooring loads: linearized forces and moments -controlled actions: external DLLs

11


Simulation flow chart

12


What happens during three blades shutdown?

A pitching blade

Thru

st, k

N

Time, s

13


What happens if one blade is seized? A seized blade

Tow

er T

orsi

on

Mom

ent,

kNm

Time, s

14


LC1, grid loss and shutdown, land-based UW=17 m/s, TI=0.2, tf=400 s, td=0.1 s, Pr=8 deg/s

15


LC3, blade blockage and shutdown, spar-type

200 250 300 350 400 450 500 550 600

-15

-10

-5

0

5

10

15

Time [s]

Yaw

mot

ion

[deg

]

Initial time of shut down

200 250 300 350 400 450 500 550 600

0.5

1

1.5

2

2.5x 10

4

Time [s]

Equ

ival

ent m

ain

shaf

t ben

ding

mom

ent [

kNm

]


UW =11.2 m/s, HS=3.2 m, TP=10.0 s, TI=0, tf=400 s, td=0.1

200 250 300 350 400 450 500 550 600-1

-0.5

0

0.5

1

1.5

x 105

Time [s]

Tow

er-b

otto

m fo

re-a

ft be

ndin

g m

omen

t [kN

m]


200 250 300 350 400 450 500 550 600

-4

-2

0

2

4

6

Time [s]

Pla

tform

pitc

h m

otio

n [d

eg]


16


Extreme response─azimuthal dependence

0 60 120 180 240 300 360

1.9

2

2.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

x 104

Blade2 azimuth [deg]E

quiv

alen

t mai

n-sh

aft m

omen

t [kN

m]

Uw=11.2 m/s, H=0.2 m, T=10 sUw=11.2 m/s, Hs=2.5 m, Tp=10 s

Land-based Spar-type

-140000

-120000

-100000

-80000

-60000

-40000

-20000

00 50 100 150 200 250 300 350

Max

tow

er-b

otto

m b

endi

ng m

omen

t [kN

m]

Blade 2 azimuth [deg]

Uw=14 m/s, TI=0, td=0.1 s , Pr=8°/s

LC3, blade blockage and shutdown

Uw=11.2 m/s, TI=0, td=0.1 s , Pr=8°/s

17


Comparison─ land-based wind turbine

LC1: normal operation LC2: grid loss and shut down LC3: blade blockage and shutdown LC4: blade runaway and shutdown

Uw [m/s]

18


Comparison─ land-based wind turbine

LC1: normal operation LC2: grid loss and shut down LC3: blade blockage and shutdown LC4: blade runaway and shutdown

19


Comparison─ spar-type wind turbine

Load Case1 2 3 4 5 6

Tow

er-b

otto

m b

endi

ng m

omen

t (kN

m)

0

5e+4

1e+5

2e+5

2e+5

3e+5

3e+5Normal operationGrid loss and emergency shutdownBlade sieze and emergency shutdownBlade runaway and emergency shutdown50-yr environment and parked (standing-still)

Load Case1 2 3 4 5 6M

ain

shaf

t equ

ival

ent b

endi

ng m

omen

t (kN

m)

0

10000

20000

30000

40000Normal operationGrid loss and emergency shutdownBlade sieze and emergency shutdownBlade runaway and emergency shutdown50-yr environment and parked (standing-still)

Load Case1 2 3 4 5 6

Yaw

mot

ion

resp

onse

(deg

)

0

5

10

15

20

25

30 Normal operationGrid loss and emergency shutdownBlade sieze and emergency shutdownBlade runaway and emergency shutdown50-yr environment and parked (standing-still)

parked case

Operational cases

Normal operationGrid loss and emergency shutdownBlade sieze and emergency shutdownBlade runaway and emergency shutdown50-yr environment and parked (standing-still)(standing still)

20


Conclusion

• Emergency shutdown gives rise to large resonant responses for both turbines.

• When the pitch system fault and emergency shutdown occur in sequence, the response extremes exhibit a cyclic variation.

• Large tower-bottom bending moment (land), main-shaft bending moment, tower-top bending moment and yaw motion (spar) are observed in the fault and shutdown cases.

21


Key references [1] International Electrotechnical Commission. IEC 61400-3 Wind Turbine—Part 3: Design Requirements for Offshore Wind Turbines (3rd edn). IEC: Geneva, Switzerland, 2009. [2] International Electrotechnical Commission. IEC 61400-1 Wind Turbine Part 1: Design Requirements (3rd edn). IEC: Geneva, Switzerland, 2007. [3] Det Norske Veritas. Design of Offshore Wind Turbine Structures, DNV-OS-J101, 2010. [4] Germanischer Lloyd Industrial Services GmbH. Guideline for the Certification of Wind Turbines. Hamburg, Germany, 2010. [5] Arabian-Hoseynabadi H, Oraee H, Tavner P. Failure Modes and Effects Analysis (FMEA) for wind turbines. International Journal of Electrical Power and Energy Systems. 2010;32:817-24. [6] Esbensen T, Sloth C. Fault Diagnosis and Fault-Tolerant Control of Wind Turbines. Master Thesis, Department of Electronic Systems, Aalborg University, Aalborg, Denmark, 2009. [7] Odgaard PF, Stoustrup J, Kinnaert M. Fault tolerant control of wind turbines a benchmark model. Preprints of the 7th IFAC Symposium on Fault Detection, Supervision and Safety of Technical Processes, Barcelona, Spain, June 2009. [8] Johnson KE, Fleming PA. Development, implementation, and testing of fault detection strategies on the National Wind Technology Center's controls advanced research turbines. Mechatronics. 2011; 21:728-36 [9] Odgaard PF, Johnson KE. Wind turbine fault detection and fault tolerant control-a second challenge. 2012. [10] Hameed Z, Hong Y, Cho Y, Ahn S, Song C. Condition monitoring and fault detection of wind turbines and related algorithms: A review. Renewable and Sustainable Energy Reviews. 2009;13:1-39. [11] Blanke M, Kinnaert M, Lunze J, Staroswiecki M. Diagnosis and fault-tolerant control (2nd edn). Springer, Berlin, Germany, 2006. [12] Bossanyi EA, Jamieson P, Blade pitch system modelling for wind turbines. 1999 European Wind Energy Conference, Nice, France, March1999; 893-896. [13] Johnson KE, Fingersh L, Wright A. Control advanced research turbine: lessons learned during advanced controls testing. Technical Report NREL/TP-500-38130, National Renewable Energy Laboratory, Golden, CO, USA, 2005. [14] Chen W, Ding SX, Sari A, Naik A, Khan A, Yin S. Observer-based FDI Schemes for Wind Turbine Benchmark. Preprints of the 18th IFAC World Congress, Milano, Italy, September 2011; 7073-7078. [15] Laouti N, Sheibat-Othman N, Othman S. Support vector machines for fault detection in wind turbines. Preprints of the 18th IFAC World Congress, Milano, Italy, September 2011; 7067-7072. •.

22


Wind Energy

Thanks!

[email protected]

dynamic response of wind turbines in fault and - ntnu jiang.pdf · dynamic response of wind...

Documents