Turbine Measurements

Performance testing

The power curve of a wind turbine is the most important system characteristic to describe the performance of a wind turbine. Based on power curves, the annual production of wind turbines is assessed. Thus, power curves are an important factor in the financial model of a wind project. The power curve of a turbine serves as a reference and as a sales argument. Furthermore, the power curve is needed in the certification process.

Among others the following task are part of this service:

a. Performance Testing for Type Test
b. Site Calibration
c. Performance Verification
d. Performance Test of Small Wind Turbines

Load measurements

Modern wind turbines are increasing continuously in dimension and rated power. Slim design and use of new component parts are adequate methods for reducing loads but make the calculation of precise computer-aided simulation data more complicated. Therefore the determination of the true loads on wind turbines by measurements is of high importance for construction and design improvement. The load measurement is not only needed within the certification process, but is even more important to obtain a true picture of the actual loads on the components, and thus increase confidence in the construction and the product. Critical components and effects, which are difficult or impossible to simulate (e.g. vibrations) can be identified and improved.

Not only restricted to the signals given by the applicable standards, special measurements to identify critical components can be undertaken. This is done not only on the wind turbine as a system but also in the sense of component testing.
Small wind turbines can be tested in the field or on the Kaiser-Wilhelm-Koog-test site. Apart from performance testing, duration tests and structural tests are carried out on small turbines, mainly for the purpose of certification, but also as a general test. The general installation permission for the test site facilitates a fast and effective testing of small turbines.

Among others the following task are part of this service:

a. Load Measurements
b. Test of turbine behaviour and safety test
c. Special Measurements
d. Component testing
e. Small wind turbine

Electrical measurements

Electrical measurements are mainly necessary to obtain permission to connect a wind turbine to the grid. The results of the measurements prove that the required values and pre-requisites are met and fulfilled by the turbine operator. The grid parameters which will be checked and measured are parameters which occur during normal operation of the wind turbine, such as harmonics, flicker and switching operations, and parameters, which occur during special conditions, e.g. during grid faults. Depending on the applicable grid code, this means that the turbine needs to have a grid protection system installed, whose release values will be checked. A grid code can also require certain behaviour during grid failure, a so called fault ride through behaviour. This means that the wind turbine stays connected during the grid fault and thus, supports the grid. The grid operators require this behaviour to be proved and certified. In many grids, a certificate of the grid values leads to higher feed-in tariffs (e.g. Germany, Spain).

Among others the following task are part of this service:

a. Power quality measurement
b. Grid protection measurement
c. Fault Ride Though
d. Electro-magnetic compatibility
e. Grid Monitoring
f. Small wind turbines

Acoustical measurement

Noise evaluations of turbines and wind farms are needed for permitting reasons as well as for certification reasons. Noise impact measurements are mainly done to avoid complains of people living next to wind farms and to keep permissions valid.

Many different components have impact on the noise level of a wind turbine. The blades, the gear boxes and also the towers influence not only the overall noise level, but also, caused by resonances, the emission of single tones, so called tonality. A noise measurement is capable to identify different noise sources of the wind turbine and thus, gives hints to reduce the noise level.

A lower noise level of a turbine type leads to better noise propagation results in the wind farm planning process and is often the decisive factor for realization of wind projects, especially in highly populated areas like Europe.

a. Noise measurement for type test
b. Noise impact measurement