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一种基于CatBoost优化的光伏阵列故障诊断模型
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作者 彭自然 许怀顺 肖伸平 《电子学报》 EI CAS 2024年第7期2418-2428,共11页
大部分光伏电站地处偏僻、地形复杂的区域,受到外界环境的影响,易发生各种故障.而传统的光伏阵列故障诊断方法存在精度不高以及光伏数据利用率低等问题.针对以上问题,本文先是通过引入Levy飞行策略和步长因子动态调整策略改进麻雀搜索算... 大部分光伏电站地处偏僻、地形复杂的区域,受到外界环境的影响,易发生各种故障.而传统的光伏阵列故障诊断方法存在精度不高以及光伏数据利用率低等问题.针对以上问题,本文先是通过引入Levy飞行策略和步长因子动态调整策略改进麻雀搜索算法(Sparrow Search Algorithm,SSA),降低SSA算法陷入局部最优的风险,提升SSA算法的寻优能力.然后采用改进的Levy步长调整麻雀搜索算法(Levy Adjustment Sparrow Search Algorithm,LASSA)对CatBoost模型关键超参数进行寻优,提出了一种基于CatBoost并以LASSA为优化策略的光伏阵列故障诊断模型LASSA-CatBoost,以实现光伏阵列的短路、开路、老化和阴影遮挡故障的精确诊断.实验结果表明,LASSA-CatBoost模型的故障诊断准确率为99.7%,相较于优化前的CatBoost模型,准确率提高了3.6%.与现有的光伏阵列故障诊断模型相比,LASSA-CatBoost模型的准确性和稳定性更高. 展开更多
关键词 光伏阵列 故障诊断 I-V特性曲线 CatBoost Levy adjustment sparrow search algorithm
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A Mesh Adjustment Scheme for Embedded Boundaries
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作者 J.S.Sachdev C.P.T.Groth 《Communications in Computational Physics》 SCIE 2007年第6期1095-1124,共30页
An adaptive meshing technique and solution method is proposed in which a two-dimensional body-fitted multi-block mesh is locally adjusted to arbitrarily embedded boundaries that are not necessarily aligned with the me... An adaptive meshing technique and solution method is proposed in which a two-dimensional body-fitted multi-block mesh is locally adjusted to arbitrarily embedded boundaries that are not necessarily aligned with the mesh.Not only does this scheme allow for rapid and robust mesh generation involving complex embedded boundaries,it also enables the solution of unsteady flow problems involving bodies and interfaces moving relative to the flow domain.This scheme has been implemented within a block-based adaptive mesh refinement(AMR)numerical framework which can ease computational expense while maintaining a detailed representation of the embedded boundary and providing an accurate resolution of the spatial characteristics of the fluid flow.Rigid body motion and evolving motion due to physical processes are considered.A block-based AMR level set method is used to deal with evolving embedded boundaries.Numerical results for various test problems are presented to verify the validity of the scheme as well as demonstrate the capabilities of the approach for predicting complex two-dimensional inviscid and laminar fluid flows. 展开更多
关键词 Dynamic and stationary embedded boundaries mesh adjustment algorithm blockbased adaptive mesh refinement.
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