Wind turbines and their individual components need to be

tested to make sure they can withstand extreme

environmental conditions:

1. Mechanical environmental factors: shocks and

impacts, low frequency vibrations from waves (in the

case of offshore turbines), accelerations due to

emergency stops, strong blasts of winds and storms.

2. Climatic environmental factors: extreme

temperatures, salt, rain, pressure, humidity, ice, solar

radiation.

The need of reliable turbines and optimized operation

and maintenance (O&M) strategies, is even more

pronounced for remote wind farms where interventions

may be very costly.

At locations with harsh environments (extreme winds,

waves, temperatures, snow, …), repair works may be

postponed because of adverse weather conditions. This

negatively affects the wind turbine availability and its

business case. Avoiding unplanned reparations is crucial

in these cases.

In order to reduce these O&M costs two approaches can

be defined:

1. Improving component reliability

2. Reducing costs to perform maintenance

This poster will focus on the first approach and has a

direct link with the activities of the OWI-Lab test facility.

Improving Reliability in the Wind Turbine Industry

Pieter Jan Jordaens ; Sirris ; Belgium

www.owi-lab.be

Abstract

In General

The wind turbine industry is rapidly expanding in remote

areas where wind turbines need to work under extreme

conditions. Operating temperatures can vary from -40°C

tot +60°C depending on the location (Inner Mongolia,

Finland, Canada, India,...).

Another trend is building turbines offshore or high in the

mountains were maintenance tasks are difficult. High

reliability for every component is key for these machines

to avoid expensive maintenance tasks in these locations.

Advanced reliability testing is paramount in this evolving

industry.

Testing & Test Infrastructure

Project Partners OWI-LAB

Large Climate Chamber

Improving Product Reliability

Conclusion

OWI-lab’s large climate chamber will be available to test

different wind turbine components up to 150 ton:

Mechanical components

(gearboxes, yaw & pitch systems,...)

Electrical components

(transformers, switch gears,...)

Electro-mechanical equipment

(generators, hybrid gearboxes,...)

Power electronics

(convertors, ...)

Hydraulic components

(hydraulic gearboxes, oil filters,...)

Cooling and heating systems

The test chamber can handle components with maximum

dimensions up to 10m x 7m x 8m (Length x Width x

Height) and is located nearby a breakbulk quay to handle

the large and heavy objects. A specialized trailer is

foreseen to mount the test specimens and to move them

into the climate chamber were they can be tested in a

temperature range from -60°C to +60°C. Special cable

penetration holes are foreseen to connect electrical wiring

inside the chamber. High power to feed drives and other

electrical components for system testing can be foreseen

by mobile generators up to 1MVA. Larger power capacity

is possible by connecting multiple power units and mobile

transformers deliver appropriate voltages for system

testing of broad range of components.

Reliability means: ‘the ability of a system to perform a

required function, under given environmental and

operating conditions and for a stated period of time’ .

It is a competitive differentiator and therefore deserves

enough attention. In order to confirm that a product will

meet established reliability goals design verification tests

and environmental tests need to be performed.

Ideally, testing is done throughout the product

development cycle, from the first prototype to the

beginning of serial production. Testing allows to assure

that the component or turbine meets all of its

specifications (verification), to validate models, and to

confirm it’s robustness and reliability.

Wind turbines consist of different mechanical, hydraulic

and electrical components. Obviously different system

tests need to be developed and performed for all these

components in their specific working conditions:

Wind turbine field testing

Nacelle and drivetrain testing

Drivetrain component testing

Sub component testing (i.e. bearings, individual gears)

Blade testing

Tower & foundations testing

The trend towards bigger multi-MW wind turbines leads

to a need for specialized test equipment and

infrastructure which can handle these large weights and

dimensions. Also larger torques, power, cooling

capacity,… are needed to test these machines and it’s

components. Different companies and knowledge

centers are currently investing in specific test stands.

Besides that, new test methodologies and certification

procedures are introduced in the industry in order to

make sure that wind energy for remote areas gets it’s

reliability boost.

.

Extreme Temperature Testing

Climatic environmental tests, in particular temperature

testing is one of the essential tests for wind turbine

components. Differences in temperatures and extreme

temperature values can have their impact on:

Differential thermal expansion of

(sub)components and materials

Lubricants become more or less

viscous which effects the oil flow

in bearings and raceways

Metals can become brittle at

very low temperatures

Cooling system can experience overheating problems

during extreme heat

Cold start problems and effect on production time

One specific extreme temperature test which is needed

for certification of gearboxes is a cold start test. Usually

on- and offshore turbines are designed to operate in a

temperature range of -10°C to +40°C but in some

locations low temperatures can reach -40°C. A proper

cold start procedure, starting up the turbine after idling in

cold conditions, has a big influence on the reliability and

productivity of these turbines. Manufactures rightly take

this at heart and develop and test this procedures

thoroughly.

WWW.OWI-LAB.BE

Reliability is key for remote located wind turbines

Extreme environmental scenario’s have to be tested

Trend in wind energy R&D: advanced testing becomes

more and more important to reduce the time-to-market

of turbine components, ensure reliability to clients and to

obtain certification.

(Extreme) temperature testing is needed for the

validation of certain components

OWI-lab invested in a large climate chamber in order to

support manufacturers in the testing process

Risø National Laboratory blade test ; RWTH’s "Center for Wind Power Drives (CWD) ;

FAG bearing test stand ; ZF Wind Power Antwerpen NV gearbox test stand

Clemson University 15MW and 7.5MW drivetrain test stand – Renk test systems

Cold start test ZF Wind Power Antwerpen NV

OWI-Lab large climate chamber test stand

Remote located wind turbines in harsh environmental conditions: arctic wind turbine and offshore wind turbine