Offshore wind turbines are seen as the key to the expansion of wind energy. However, even the most advanced turbines are not safe from damage. Rotor blades are among the most heavily stressed components. Failure rates for offshore wind turbines are generally four times higher than for onshore turbines. This is where BLADEcontrol® from weidmüller offers significant added value for turbine operation, because the failure of offshore wind turbines in particular is especially serious, as they produce large amounts of electricity almost continuously and repair work is always very cost-intensive due to their accessibility.
The BLADEcontrol® Condition Monitoring System (CMS) is able to recognise critical damage to rotor blades at an early stage before a failure occurs. The CMS uses highly sensitive sensor technology to detect even the smallest changes to rotor blades and their structure. In addition to providing the hardware and software, Weidmüller Monitoring Systems also offers a monitoring service. The service includes data-based 24-hour monitoring of the rotor blade status.
In this case, our experts from the monitoring team recognised a noticeable vibration deviation on one rotor blade compared to the other two blades at an early stage. A detailed analysis of the measurement data led to the clear identification of the cause of the damage, a crack on the surface of the rotor blade. After reporting the event to the operator and a subsequent visual inspection, the crack was confirmed as the cause of the measurement deviation. The CMS was used to monitor the further development of the longitudinal crack until the defined threshold value was reached. When this value was reached, the customer was informed directly.
The Weidmüller online portal WebVis clearly shows the deviating vibration behaviour of the affected blade (green).
In close consultation with our monitoring team, the customer decided to shut down the system and plan and carry out a repair. By recognising the damage at an early stage, a possible breakage of the rotor blade and thus a long-term failure of the entire turbine could be avoided. Subsequent events, such as imbalances occurring in the turbine, increased vibration behaviour of the rotor blades, parts breaking off and the resulting environmental pollution, were also reliably averted. The advantage for our customer was a significant reduction in repair costs for the installed blade compared to a complete rotor blade replacement. In addition to the savings in repair costs, the early detection of damage also prevented increased yield losses due to long downtimes.
For an offshore turbine in the 12 MW class, the loss of revenue per day amounts to approx. 18.000 euros. In the case described above, the downtime could be reduced by 50 to 70 days due to preventive damage detection - compared to a potential blade loss - depending on the availability of crane vessels
The use of BLADEcontrol® has been proven to make maintenance more predictable and avoid expensive repairs. This leads to an increase in energy yield and a reduction in operating costs over the entire service life of the turbines. Around 5,450 onshore and 450 offshore wind turbines are currently equipped with the BLADEcontrol® system.
Dr Daniel Schingnitz, Head of Sales and Marketing at Weidmüller Monitoring Systems GmbH, says: ‘With over 24.200 machine years of experience, we are the experts in the field of rotor blade monitoring. The algorithms and the system around BLADEcontrol® are continuously being developed and supplemented with new measurement data. Our customers, including the world's largest manufacturers and operators of wind turbines, have been convinced by our range of solutions for 20 years.’
Would you like to get to know the experts behind our rotor blade monitoring? Then get in touch with us. We will be happy to advise you on your individual requirements.
Our BLADEcontrol® system is continuously being developed and customised to meet our customers' requirements. Would you like to get to know the experts behind our rotor blade monitoring? Then get in touch with us. We will be happy to advise you on your individual requirements.
Dr. Daniel Schingnitz