Study of the pitch behaviour of large‐scale wind turbines based on statistic evaluation

Abstract Pitch control is a basic function of large‐scale wind turbines to improve energy capture efficiency. Pitch system is also a component system with a high failure rate due to the complex pitch behaviour. It is helpful to the practical design and control if a clear pitch behaviour is obtained. However, pitch behaviour is affected by the structure of wind turbines, control strategies, wind resource characteristics, and so on. So, there is still a lack of sufficient understanding. In this study, the pitch behaviour of a 2 MW wind turbine is investigated based on SCADA data. Four key evaluation indicators describing pitch behaviour are proposed, which include pitch status, pitch time consumption, pitch angle peak, and mean pitch angle. Moreover, the SCADA data extraction algorithm for pitch behaviour investigation is also given. Then, the pitch behaviour is investigated based on statistical evaluation. Some valuable conclusions have been given. For example, for the investigated wind turbine, the time proportions for the four states (non‐pitch, increasing pitch, pausing pitch, and decreasing pitch) are 85.80%, 5.97%, 1.45%, and 6.78%, respectively. The pitch cycles, pitch angle peak, and mean pitch angle increase with the increase of the standard deviation of wind speed