Micro Rain RADAR MRR | MRR-PRO Dome
The Micro Rain Radar MRR at 24 GHz is a unique meteorological radar profiler for Doppler spectra of hydrometeors in height ranges 15 m … 6000 m. The high resolution in time and height enables the MRR to monitor the genesis of frozen hydrometeors, the melting zone (bright band) and the formation of rain drops. With the derived rain rate the MRR offers a calibration of weather radar. The MRR has been adapted even for monitoring of avalanches and volcanos.
Details
METEK offers a modified version of the Micro Rain Radar MRR-PRO called MRR-PRO Dome, specially designed for installations on ships, platforms or wind turbines or for operation under other extreme conditions. The Dome provides enforced protection of all the radar components against the humid and salty environment typically found at offshore locations or against the aggressive conditions experienced in the vicinity of volcanos. The MRR inside the Dome is a normal MRR-PRO with the same technical specifications that can be found here https://metek.de/product/mrr-pro/.
Erosion safe-mode control for wind turbines
A further important application of the METEK MRR-PRO Dome has been identified using the MRR-PRO Dome version for nowcasting of precipitation for control of wind turbines. The concept behind this idea is described in a paper from Tilg et al., 2020: https://doi.org/10.5194/wes-5-977-2020.
The serious leading edge erosion on modern wind turbine blades with a high tip speed are assumed to be mainly caused by a limited number of heavy rain and hail events every year. The MRR-PRO Dome can identify these precipitation events with a forecast time of 2-5 minutes. This allows to generate a warning and to enable the wind turbine control system to take actions like reducing the rotor speed or stopping the turbine for some minutes. More background information about the wind turbine erosion problem and the financial consequences of the problem can be found in a paper by Beck et al., 2018: https://doi.org/10.5194/wes-3-729-2018.
The illustrated precipitation event in the attached plot (13.12.2019, paper from Tilg et al., 2020: https://doi.org/10.5194/wes-5-977-2020) clearly indicates such slope of rainfall characteristics providing a delay of several minutes between upper and lower measuring heights in regard of the onset of precipitation. Such time delay is sufficient for the wind turbine control system to swap into a erosion safe mode by reducing the rotational speed.
Research projects about erosion:
- DURALEDGE – Durable leading edges for high tip speed wind turbine blades
https://www.duraledge.dk/ - EROSION – Wind Turbine Blade Erosion: Reducing the largest uncertainties
https://www.rain-erosion.dk/