Safe Signals for the Wind Energy in the Windfair Newsletter

There are also new developments as for example the magnetic incremental encoder which works without direct contact with a magnetic wheel. The sensor is completely sealed and works within harsh environments without wear and tear. Another example is the classical incremental encoder RHI90 which passed the offshore requirements with a special housing to withstand salt water corrosion, a higher protection grade and an enhanced electro-magnetic immunity.
Finally there are the safety encoders fulfilling SIL3 requirements with the new P+F frequency and safety monitor. This combination serves to detect a stand-still situation as well as a pre-programmed maximum speed to deliver safe output signals for a control system.

Acceleration sensors for the condition monitoring

After many years of experience in the heavy duty mobile equipment world with inclination sensors, the same technology was now used to develop acceleration sensors. In this case it is possible to measure forces starting with a frequency as little as 0,1 Hz in a range of +/- 2g. There are single and double axis versions available. The devices are extremely robust and capable to work reliably at temperatures as low as -40 degrees Celsius. The housing is completely sealed and conforms to the GL regulations. Therefore, forces in the nacelle could be precisely measured for further evaluation of the signals by a condition monitoring system. The sensor is also secured against manipulation. There are developments in the pipeline with special features to provide customer specific executions for certain manufacturers of wind turbines.

Online corrosion measurement for offshore foundations

Where ever steel constructions are exposed to corrosion driving environments like salt water, damages to the material could result in a loss of stability. Pepperl+Fuchs has created a unique instrument which is capable to measure those processes continuously and to send the results to a condition monitoring system for example. This is possible by means of a special sensing device which consists of the same material as the construction to be observed. This makes sure that the identical behaviour concerning corrosion takes place at the sensor. The internal program uses three different principles to evaluate the signals. This enables the device to securely detect not only the general corrosion process of the surface of the material but also the so localized corrosion. Via the integrated interface the data could be transferred to a condition monitoring system for further evaluation and documentation.


Robotic guidance for the manufacturing of rotor blades

The steady increase of quantities and the enhanced requirements in terms of quality and costs generate the pressure to introduce higher degrees of automation in the manufacturing process of rotor blades. Thus, we see the introduction of robots in the painting stations for example.
The P+F daughter company VMT has developed a vision based system which allows the exact guidance of the robots. Laser line scanners are taking precise three dimensional measurements of the shape of the actual blade to be compared with the CAD model. Deviations of the real blade from the model but also tolerances of the mechanical construction are calculated to generate corrected data for the robots. The precise guidance of the robots is therefore guaranteed.

This is only a small extract of the complete product range of Pepperl+Fuchs. The inductive proximity switches, frequency converters, distance measuring systems and fill level sensors are additional products which are applied in wind turbines. P+F offers more than 20.000 products and makes them available all over the world with its numerous subsidiaries and representatives.