Page 16 - North American Clean Energy March April 2015

wind power

Quality engineered
components, such

as slip rings, can
dramatically reduce
turbine downtime and

related maintenance
costs
Component Considerations

Improving wind turbine reliability

By Russell J. Tallyen

GIVEN THAT MAINTENANCE FOR WIND TURBINES involves the replacement of costly • Choosing a reliable gearbox
Carbon brush considerations
parts, along with time-consuming and dangerous ascents of turbines up to 100 meters Gearboxes are the components that fail most
Selecting the correct brush grade might tall, there’s a constant focus within the industry on improving reliability. After all, the often within wind turbine power generation

seem like a minor consideration, however, more durable, dependable, and eicient the components in a turbine are, the less likely systems. Choosing the most appropriate and
it’s an important step in turbine upkeep. repairs or unplanned upkeep will be required.
reliable gearbox for a turbine is, therefore,
The brush grade required depends on
Although it’s impossible to predict all of the necessary maintenance that might be a signiicant key to reducing downtime.
the service conditions of each turbine. needed in any component throughout its expected lifetime, taking a few extra steps Because of this, performing adequate
Each grade contains a different material
when building and maintaining turbines can substantially reduce the risk of unsched- scheduled maintenance on the box—such
composition and impregnation, which is uled downtime—not to mention the associated costs of lost power generation.
as ensuring proper lubrication for the
designed to optimize service life.
environmental conditions of the turbine—is
Understanding the system
an important step that’s not to be missed
Brushes are primarily made from graphite,
though the percentage of graphite can he system of power generation within a wind turbine is fairly simple. Wind turns the when it comes to ensuring reliability.
vary; some grades include copper, for blades of a turbine, which in turn rotates a slow-moving crankshaft. he motion of this Wind turbines are often placed in some
instance, or other metals as abrasive or shaft is, then, ampliied by a gearbox before it’s applied to a rapidly spinning generator. of the harshest conditions on the planet.
cleaning materials in service conditions his generator produces the power, which is applied to the slip ring, and drawn of by Ofshore wind farms, for example, must

where brush ilm build-up is likely. carbon brushes in a brush holder (mounted near the slip ring). he resulting power is contend with the high salinity of sea air.
Similarly, impregnations, or chemical taken to the grid.
hen, there’s the wind farms in desert
compounds that are introduced into
Operating time is key to efective power generation by wind turbines. Since wind is conditions, which must contend with dry air
the graphite during production, help to
optimize brush ilm, protecting the turbine not constant, turbine operators strive to keep turbines spinning more than 98% of the that contains abrasive sand, as well as high
time during adequate wind events. For this to be possible, all of the components of the temperatures and low wind speeds. Proper
components.
turbine must be working properly.
maintenance is especially important in these
Monitoring environmental conditions, such When something fails or simply doesn’t work up to par, however, time becomes a cases, as harsh environmental conditions

as humidity, temperature, and salinity—via major factor. Not only can turbine downtime cost in terms of power losses, but there’s wear down turbine components much
consultations with an application engineer, also the maintenance time to consider—and the danger involved in repairing or replac- faster than laboratory service conditions
can help turbine operators ind the ideal ing components at height. When these considerations are factored in, it becomes clear might indicate, especially if not properly
brush grade for each turbine installation.
that long component service life is critical to efective turbine performance and power maintained.

generation.

• Selecting the correct brush grade
he carbon brushes, resting on the slip

ring in a nacelle, might not seem all that
THE NEW FACE of WIND POWER
signiicant. Carbon brushes are the least
expensive component in a turbine system,
and one of the easiest to replace. However,

they are responsible for creating a brush
ilm on the ring, and they must be replaced
the most frequently.
A suitable carbon brush can last up to
SAFE
three years, helping to extend the service
HIGH PERFORMANCE life of other components, such as the
slip ring. But, any unsuitable brushes
LOW COST
can lead to drastically increased costs

FIND OUT MORE AT: and unnecessary downtime. When an
SheerWindunsuitable grade of brush for a turbine’s
.com
operating conditions is used, or worn

16 nacleanenergy.com
MARCH/APRIL 2015