Comprehensive aging assessment of pitch systems combining SCADA and failure data

Abstract

Due to the recent rapid development of the wind energy industry, many wind turbines that have been operational over long periods will face degradation caused by aging effects; hence, an appropriate aging assessment method for wind turbines and their components is essential for optimizing the asset management and maintenance strategy of a wind farm. An aging assessment method is proposed for wind‐turbine electric‐pitch systems by introducing four individual aging indicators based on the examination of supervisory control and data acquisition (SCADA) and failure data, i.e. function, energy‐consumption, temperature, and reliability indicators. To obtain a reliable comprehensive assessment, an information‐fusion method has been developed based on a given reference value; the weighting factors in the information fusion were calculated based on the reference value, while reliability and robustness were verified using the SCADA and failure data from a wind farm over three years.

Discussion of Wind Turbine Performance Based on SCADA Data and Multiple Test Case Analysis

“…The manifestations of wind turbine under-performance associated to blade pitch aging or, more in general, rotor issues which have been observed in this work are coherent with the findings in [30] and are:…”

“…Inspired by the analysis in [30], which at present is the unique study in the literature expressly devoted to blade pitch aging assessment, in this work an analysis is replicated for the three test cases at disposal. In [30], it is argued that the aging of the blade pitch likely manifests as diminished efficiency in the capability of maintaining the rated power above rated speed.…”

“…Inspired by the analysis in [30], which at present is the unique study in the literature expressly devoted to blade pitch aging assessment, in this work an analysis is replicated for the three test cases at disposal. In [30], it is argued that the aging of the blade pitch likely manifests as diminished efficiency in the capability of maintaining the rated power above rated speed. Therefore, in this study, a space-time comparison of the standard deviation of the power extracted above rated speed is performed, and it is inquired whether meaningful trends are visible.…”

“…In order to corroborate the above interpretation, the standard deviation of the power measurements collected above rated speed is computed, because in [30] it is indicated as a symptom of blade pitch system aging. The results are reported in Table 7: an increasing trend is visible for T2 and T4, but it is higher for T2, which, correspondingly, has undergone more performance decline and more blade pitch pressure decrease.…”

Wind Turbine Performance Decline with Age

“…This hypothesis should be analyzed more in deep through the study of a vast statistics of case studies and a deeper comprehension of the behaviour of the blade pitch. For example, in [12], an attempt is formulated at assessing the ageing of the electrical blade pitch component by taking into account indicators partially similar to those formulated in [7]: power coefficient C p , power stability above rated speed, pitch motor energy consumption and heating, failure rates. It would be interesting to do a similar study for hydraulic blade pitch cases.…”