Although wind turbines have been around for decades, recent research has been focused on what occurs in wind turbines under abnormal wind conditions. It is understood anecdotally that high gusts and turbulent winds can add to the chance of breakdown of wind turbine equipment and lead to an increase in O&M and capital costs. Why is it that ridgeline or downwind turbines see higher O&M costs? Most of the focus has, understandably, been on the effect these winds have on blades and tower structures but the entire drivetrain sees an impact from these transient events. Although there is not a one-size fix-all solution to these problems, there are options for the wind industry to help reduce the damage to wind turbine components to help extend turbine life. A better understanding of how these turbulent loads impact component life and turbine costs is needed. The primary focus of this webinar is to help educate and increase the awareness level in the wind industry of what is taking place in wind turbines during transient aerodynamic events and identify a loads based solution to reduce the effects of these events. Watch this webinar to learn: • What are the types of wind events that can damage drivetrains • What is the current research saying about the roles of sheer winds and turbulence • What are the effects to the drivetrain when the turbine is subjected to significant wind or other operating events

1. Transient
Winds
and
Their
Effect
on
Drivetrain
Loads

2. Before We Start
q This
webinar
will
be
available
at
www.windpowerengineering.com
&
via
email
q Q&A
at
the
end
of
the
presenta:on
q Hashtag
for
this
webinar:
#WindWebinar

3. Moderator Presenter
Nic Abraham
Windpower Engineering
& Development
Doug Herr
AeroTorque

5. • Increasing
awareness
of
how
transient
aerodynamic
events
affect
wind
turbine
drivetrains.
• Introducing
new
research
data
on
how
to
control
these
impacts.
• Growing
the
understanding
of
the
speed
of
these
events
and
how
current
systems
cannot
stop
them
from
occurring.
• Understanding
how
an
asymmetric
approach
to
torque
control
can
enhance
the
system.

6. • What
are
the
types
of
wind
events
that
can
damage
drivetrains?
• What
is
the
current
research
saying
about
the
roles
of
sheer
winds
and
turbulence?
• What
are
the
effects
to
the
drivetrain
when
the
turbine
is
subjected
to
significant
wind
or
other
operaAng
events?

7. • AeroTorque
was
spun
out
of
PT
Tech
Inc.
in
March
of
2013.
• PT
Tech
has
spent
the
last
36
years
working
to
reduce
transient
torque
loads
in
many
different
types
of
equipment.
• Both
companies
are
under
EBO
Group,
an
100%
employee
owned
company.

8. Our
mission
is
to
extend
the
usable
life
of
the
drivetrain
by
proacAvely
working
with
owners
and
strategic
partners
and
to
build
a
stronger,
more
sustainable
financial
model
for
the
wind
industry
fleets.

10. per
IEC
61400-­‐1
•
Extreme
operaAng
gust
(EOG)
•
Extreme
direcAon
change
(EDC)
•
Extreme
coherent
gust
(ECG)
•
Extreme
coherent
gust
with
direcAon
change
(ECD)
•
Extreme
wind
shear
(EWS)

11. Shear
winds
have
the
following
characterisAcs:
• Are
usually
caused
by
nearby
topography,
oen
cliffs
or
ridges
• Cause
the
wind
to
flow
verAcally
up
the
face
of
the
turbine,
rather
than
through
the
blade
sweep
• Can
load
the
blades
unevenly

12. Turbulent
winds
have
the
following
characterisAcs:
• Are
non-­‐linear
winds,
flowing
without
a
pa]ern
• Can
be
caused
by
surrounding
roughness
and
structures
• Can
also
cause
a
reducAon
in
power
producAon
• Will
load
the
blades
unevenly
• Can
even
be
caused
by
nearby
turbines

13. Liing
force
has
an
opposite
effect
on
the
wind,
pushing
it
tangenAally,
causing
spin
in
the
opposite
direcAon
Source:
WE
Handbook-­‐
2-­‐
Aerodynamics.
Wind
Turbine
Blade
Aerodynamics
(2009):
1-­‐10.
Gurit
Wind
Energy
Handbook.
Gurit
Holding
AG,
14
Dec.
2009.
Web.
1
Oct.
2014.

14. “Horn’s
Rev”
turbulence
Photo: Va)enfall/Christian Steiness

15. Texas
Tech
and
NREL
research
with
dual-­‐doppler
systems
show
the
downwind
effect
at
80
meters
Schroeder, John. Improving Wind Farm Efficiency Using Advanced Doppler
Radar Technologies. Lubbock, TX: Texs Tech U, 2013. Print.

17. Rotor
inerAa
Generator
inerAa

19. Photo courtesy: Aaron Greco/Argonne National Laboratory

21. Gaining
producAon
at
lower
wind
speeds
can
improve
the
operaAng
profits
at
lower
wind
sites.

22. Significantly
more
wind
must
be
deflected
with
larger
blades

23. The
WOPR
number
provides
a
raAo
of
the
maximum
accessible
wind
power
the
blades
must
withstand
compared
to
the
maximum
power
the
turbine
can
extract
from
the
wind.
WOPR
=
(Cut-­‐out
Speed
÷
Rated
power
speed)3
Example:
Cut-­‐out
speed
=
25mps
Rated
power
wind
speed
=
15mps,
WOPR
number
is
(25
÷
15)3
=
(1.667)3
=
4.6
The
blades
could
produce
4.6
;mes
the
power,
if
the
generator
could
harness
it.
Reduce
cut-­‐in
to
12mps
with
larger
rotor
=
(25/12)
3
=
9
WOPR
Nine
:mes
the
poten:al
power!
Generator
iner:a
can
momentarily
cause
higher
loading!

24. To
improve
the
economics
and
increase
producAon,
rotor
sizes
have
moved
from
89
meters
to
117
meters
since
2005,
a
growth
of
31%.
ROTOR
DIAMETER
IN
METERS
89.34
92.29
90.9
93.25
95.32
98.91
105.7
111.35
117.03
140
120
100
80
60
40
20
0
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
AVERAGE
SIZE
YEAR

29. A
control
system
can
only
react
as
fast
as
the
mechanical
system
that
it
controls.
Can
a
control
system
react
fast
to
prevent
a
torque
reversal?
Sense
the
Wind
speed
IniAate
blade
pitch
Stop
pitching
How
quickly
can
it
respond
to
a
gust
or
an
emergency
stop
command?

38. • As
turbines
have
and
conAnue
to
grow
in
size,
potenAal
transient
loading
from
wind
events
has
increased
• Current
control
systems
cannot
react
fast
enough
to
stop
damage
• Asymmetric
torque
control
miAgates
sudden
reverse
loads,
as
well
as
higher
freqency
loads
• The
addiAon
of
an
asymmetric
torque
device
in
exisAng
turbines
is
a
major
step
in
extending
the
life
of
drive
components
and
reducing
O&M
costs

40. Questions?
Nic Abraham
Windpower Engineering & Development
nsharpley@wtwhmedia.com
Twitter: @WPE_Nic
Doug Herr
AeroTorque
dherr@aerotorque.com
Phone: 330.590.8105
Twitter: @AeroTorque

41. Thank You
q This
webinar
will
be
available
at
www.windpowerengineering.com
&
email
q Tweet
with
hashtag
#WindWebinar
q Connect
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Windpower
Engineering
&
Development
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