Structural optimization based design of jacket type sub-structures for 10 MW offshore wind turbines
Structural optimization based design of jacket type sub-structures for 10 MW offshore wind turbines
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DOI：
10.1016/j.oceaneng.2018.12.023
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发表时间：
2019-01
影响因子：
5
通讯作者：
A. Natarajan;M. Stolpe;W. N. Wandji
中科院分区：
文献类型：
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作者：
A. Natarajan;M. Stolpe;W. N. Wandji
10 兆瓦装机容量的风力涡轮机的海上支撑结构的设计是一个挑战，因为在运行过程中，低转子速度可能会产生共振问题。本文通过探索子结构的频率约束空间，验证了不考虑转子励磁的低成本设计的可行性，描述了一台10 MW汽轮机50 m水深的导管架子结构的优化设计。概念设计采用两级优化框架。外部设计问题，即导管架总体尺寸的确定，采用了一种无导数的优化方法。采用稳健有效的序列二次规划方法解决了构件尺寸确定的内在问题。在满足频率约束、塔顶位移约束和杆件极限应力约束的情况下，创新性地选择了结构的基本固有频率最小为优化目标。在使用完全耦合的气动-流体-弹性模拟验证所有极限状态和疲劳极限状态的过程中，对所得到的设计进行了修改。最终的设计是一个低质量的四腿导管架，完全符合所有设计极限状态的海上结构标准要求，同时不受转子励磁的影响，因此最适合长时间使用。
The design of offshore support structures for wind turbines of 10 MW capacity presents a challenge due to potential resonance problems from the low rotor speeds during operation. The present work delineates the optimization based design of jacket type sub-structures at 50 m water depths for a 10 MW turbine by exploring the frequency constraint space of the sub-structure and confirming feasibility of a cost effective design away from rotor excitation. The conceptual design is made using a two-level optimization framework. The outer design problem, i.e. overall jacket dimensioning, is solved by a derivative free optimization method. The inner problem which consists of member sizing is solved using a robust and efficient Sequential Quadratic Programming method. The objective of the optimization is innovatively chosen as to minimize the fundamental natural frequency of the structure, while subject to frequency constraints, tower top displacement constraints and member ultimate stress constraints. The resulting design is modified during the process of verifying that all ultimate and fatigue limit states are met using fully coupled aero-hydro-elastic simulations. The final design is a low mass four-legged jacket that fully complies with offshore structural standard requirements for all design limit states, while not being affected by rotor excitation, thus being best suited for long operating life.