Ice detection system
In many cases, an ice detection system is required for the operation of wind power plants in order to avoid personal injury and property damage due to falling ice (the so-called ice throw) from the rotor blades. There are different methods to detect ice formation on the rotor blade. Particularly in northern regions and in the Alpine regions there are strict conditions with regard to ice detection systems on wind energy installations. Especially in Austria, a further tightening of the conditions is expected soon (as of mid-2014). It is assumed that redundant systems must be installed.
Ice detection system certified
In order to meet these requirements, certification of commercially available systems is necessary. One of the best known certification bodies is the DNV GL (until 12 September 2013: „Germanischer Llyod“). For economical reasons a reliable detection of ice formation is necessary. In the case of misdetections (no ice on the rotor blade, in spite of an alarm), the resulting loss of yield quickly amounts to several thousand euros. The reliability and availability of the offered systems are considered critically. As a result of the ever-decreasing feed-in tariff (in Germany, see „Renewable Energies Act (EEG)“, in particular the amendment „EEG 2012“), the operators are under increasing pressure and are looking for new solutions the failures due to incorrectly detected ice formation minimize.
Various ice detection systems:
- Measured variable used for detection of ice attack
- Operating parameters (eg: power, pitch angle, (outside) temperature)
- Ice-proportional sizes (eg: change in the electrical resistance of ice-circulating conductors or the oscillation behavior of the rotor blades)
- Location of the ice detection system
- On the gondola
- In the rotor blades
- measurement methods
- Electrical sensors
- Fiber optic sensors
Suppliers on the market in addition to fos4X are:
- Bosch Igus
- Labkotec Ice Detector
- Moog Insensys
The „Rotor Ice Control“ solution offered by fos4X is based solely on fiber optic measurement technology. The sensors are installed directly in the rotor blades and the measuring system is installed in the hub. There are therefore no electrical components and lines installed in the rotor blade, so the ice detection system is not endangered by lightning strike. The measuring technology and the sensors are designed for the life span of a WKA (> 20 years). The system is suitable for retro-fit – as a stand-alone solution or by being integrated into existing control cabinets.