Improved performance of stellarator coil design optimization
Improved performance of stellarator coil design optimization
复制标题
仿星器线圈设计优化的改进性能
DOI：
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发表时间：
2020
影响因子：
2.5
通讯作者：
T. Pedersen
中科院分区：
文献类型：
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作者：
J. Lobsien;M. Drevlak;T. Kruger;S. Lazerson;Caoxiang Zhu;T. Pedersen
后续早期的工作，证明了一个改进的数值仿星器线圈设计优化性能使用随机优化(Lobsien等人，核子。Fusion, vol. 58(10), 2018, 106013)，这里证明了对于Wendelstein 7-X测试用例可以进行显着的进一步改进-降低场误差和提高鲁棒性。这可以通过增加样本量和应用全三维扰动来实现，但最重要的是，通过改变应用优化目标的设计顺序来实现：首先进行现场误差优化，线圈形状惩罚只在设计过程的后面步骤添加到目标函数中。与我们之前的工作中发现的最大局部场误差6.08%和平均场误差1.56%相比，这里实现了一个鲁棒、可行的线圈配置，其局部最大场误差为3.66%，平均场误差为0.95%。这些新结果与没有使用FOCUS和ONSET套件进行随机优化的结果进行了比较。讨论了优化空间的局部极小值与线圈形状惩罚之间的关系。
Following up on earlier work which demonstrated an improved numerical stellarator coil design optimization performance by the use of stochastic optimization (Lobsien et al., Nucl. Fusion, vol. 58 (10), 2018, 106013), it is demonstrated here that significant further improvements can be made – lower field errors and improved robustness – for a Wendelstein 7-X test case. This is done by increasing the sample size and applying fully three-dimensional perturbations, but most importantly, by changing the design sequence in which the optimization targets are applied: optimization for field error is conducted first, with coil shape penalties only added to the objective function at a later step in the design process. A robust, feasible coil configuration with a local maximum field error of 3.66 % and an average field error of 0.95 % is achieved here, as compared to a maximum local field error of 6.08 % and average field error of 1.56 % found in our earlier work. These new results are compared to those found without stochastic optimization using the FOCUS and ONSET suites. The relationship between local minima in the optimization space and coil shape penalties is also discussed.