海洋风电支撑结构的随机性动力优化设计

Probabilistic dynamic optimization design for support structure of offshore wind turbines

研究了海上风电三脚架支撑结构的随机性优化分析。与陆上风电相比,海上风电支撑结构成本较大,而支撑结构受到复杂载荷作用,且其海上维修、安装费用较大,在设计中必须要考虑支撑结构在海洋环境下的安全可靠性。因此采用了随机性动力优化设计的方法一方面降低了成本,另一方面充分考虑了海上风电工作过程中由于随机性因素引起的安全性问题。首先考虑了风、浪、流及地震载荷作用,对海上风电支撑结构进行了整体动力分析,确定结构随机性优化的响应约束条件。然后通过实验设计的方法简化设计变量,通过代理模型的方法构造变量与响应之间的数学模型。最后在代理模型基础上采用全局优化算法对海上风电支撑结构进行随机性优化。优化后的三脚架支撑结构在满足强度与刚度设计要求下即节省了一定的成本又提高了结构的可靠性。研究算例表明,所提出的海上风电支撑结构的随机性动力优化分析研究具有可行性。

Probabilistic dynamic optimization design for a tripod supporting structure of offshore wind turbines was studied. Compared with onshore wind turbines, the cost of supporting structures of offshore wind turbines was higher and their repairing and installation costs induced by dynamic environmental loads were also larger, so the reliability of supporting structures of offshore wind turbines had to be taken into account. The method of probabilistic dynamic optimization design was adopted to reduce costs and fully consider safety issues due to uncertainties. Firstly, based on simulations of dynamic environmental loads, the global dynamic responses of an offshore wind turbine were analyzed and therefore the response probabilistic constraint conditions were identified. Then, design variables were simplified with the design of experiment (DOE) method and relationships between variables and responses were constructed with approximation models. Last, global optimization algorithms were adopted based on approximation models for probabilistic dynamic optimization design of a tripod supporting structure. Optimized results not only satisfied strength and stiffness requirements but also had a lower cost and a better reliability. The results of examples showed that the proposed method is feasible.