Interpretation of wind turbine performance decline with age based on SCADA data analysis

The performance of wind turbines depends non-trivially on environmental conditions and working parameters and it is therefore complicated to interpret it reliably. Nevertheless, this is fundamental in order to formulate actions for the improvement of wind turbine efficiency. Basing on this, the objective of the present study is developing appropriate SCADA data analysis methods for the long-term investigation of wind turbine performance and interpreting meaningful real-world test cases. Data have been provided by the companies ENGIE Italia and Lucky Wind. The test cases cover different technologies: four Vestas V100 with hydraulic pitch actuation and six Senvion MM92 with electric pitch actuation. The keystone of this work is a deeper exploitation, with respect to the state of the art, of the measurement channels contained in the SCADA-collected data sets. In particular, operation curves related to the blade pitch have been analysed using the method of bins and it arises that the pitch manifold pressure and the pitch motor currents are important quantities to monitor for, respectively, hydraulic and electric pitch control technology. The comparative test case analysis supports the hypothesis that the hydraulic blade pitch is a critical component which is likely associated to the most noticeable performance worsening in time.