Fatigue Life Assessment of Wind Turbine Load Time Series Based on Measurements with Different Sampling Rates

The flexible design of the rotor and the tower coupled with load based control strategies, increase the need for a load monitoring system. These measurement systems require reliability, availability as well as low latency and high measurement sampling rates to cope with the aeroelastic issues of a load based control system. This work aims to quantify the influence of the strain measurement sampling rates and down-sampling methods on a Structural Health Monitoring (SHM) system for wind turbines. To evaluate these influences, fatigue and spectral analysis were performed on the measurements from elongation sensors which were installed in the rotor blade and tower. The primary results from the analysis showed differences of up to 0.3% in the equivalent fatigue load, which could be seen by comparing datasets recorded with the same sampling rates but down sampled with different methods.