The main wind turbine design standard IEC61400-1 ed. 4 includes an annual target reliability index for structural components of 3.3. Presently, no standards specify specific reliability requirements for existing wind turbines, to be used in relation to verification of structural integrity for life extension or continued operation. For existing structures in general, both economic and sustainability considerations support differentiation in reliability targets, as it is generally more expensive and requires more resources to improve the reliability. ISO2394 “General Principles on Reliability for Structures” includes tables with differentiated reliability targets depending on the consequences of failure and costs of improving reliability, which are derived using risk-based economic optimization. However, the assumptions behind these tables do not match the specific problem of life extension of wind turbines. In this paper, the risk-based approach is applied to derive specific target reliability levels for life extension of wind turbines, and a target annual reliability index around 3.1 is proposed.

中文翻译：

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基于风险的风力涡轮机结构部件寿命延长目标可靠性水平推导

主要风力发电机设计标准IEC61400-1 ed。4 包括结构部件的年度目标可靠性指标 3.3。目前，没有标准规定现有风力涡轮机的具体可靠性要求，用于验证结构完整性以延长寿命或继续运行。一般而言，对于现有结构，经济和可持续性考虑都支持可靠性目标的差异化，因为它通常更昂贵并且需要更多资源来提高可靠性。ISO2394“结构可靠性的一般原则”包括具有不同可靠性目标的表格，具体取决于失效后果和提高可靠性的成本，这些表格是使用基于风险的经济优化得出的。然而，这些表格背后的假设与风力涡轮机寿命延长的具体问题不符。本文采用基于风险的方法推导出风电机组延寿的具体目标可靠性水平，并提出了3.1左右的目标年度可靠性指标。