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arXiv 2207.07589stat.MLcs.LGstat.AP
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一种用于发电相关天气预报统计后处理的两步机器学习方法

A two-step machine learning approach to statistical post-processing of weather forecasts for power generation

Faculty of Informatics, University of Debrecen(德布勒森大学信息学院)

Ágnes Baran, Sándor Baran

AI总结:

针对风能、太阳能发电依赖的气象变量预报存在偏差和离散度不足的问题,提出两步机器学习集合预报校准法,经匈牙利气象局数据验证,48小时内预报性能优于现有方法,适配多气象变量和预测分布。

摘要:

截至2021年底,可再生能源在全球电力装机容量中的占比达到38.3%,新增装机以风能和太阳能为主,全球增速分别为12.7%和18.5%。然而,风能和光伏能源都具有高度波动性,给电网运营商的规划带来困难,因此对相应气象变量的准确预测是可靠电力预测的关键。\n天气预报领域最先进的方法是集合预报方法,它为概率预报提供了可能;但集合预报往往离散度不足,且存在系统性偏差。因此,这类预报需要某种形式的统计后处理,其中参数化模型可提供目标气象变量的完整预测分布。\n我们提出了一种通用的基于机器学习的两步集合天气预报校准方法:第一步生成改进的点预报,随后将这些点预报与各类集合统计量一同作为神经网络的输入特征,用于估计预测分布的参数。\n在两项基于匈牙利气象局业务集合预报系统的100米风速和全球水平辐照度预报的案例研究中,我们将该新方法的预测性能与原始集合预报的预报技巧、以及最先进的参数化方法进行了对比。两项案例研究均证实,至少在48小时的预报时效内,统计后处理能显著提升原始集合在所有考量预报时效下的预测性能。所提出的两步法的各变体在预报技巧上均优于对比方法,且该新方法适用于不同的气象变量以及多种预测分布类型。

英文摘要:

By the end of 2021, the renewable energy share of the global electricity capacity reached 38.3% and the new installations are dominated by wind and solar energy, showing global increases of 12.7% and 18.5%, respectively. However, both wind and photovoltaic energy sources are highly volatile making planning difficult for grid operators, so accurate forecasts of the corresponding weather variables are essential for reliable electricity predictions. The most advanced approach in weather prediction is the ensemble method, which opens the door for probabilistic forecasting; though ensemble forecast are often underdispersive and subject to systematic bias. Hence, they require some form of statistical post-processing, where parametric models provide full predictive distributions of the weather variables at hand. We propose a general two-step machine learning-based approach to calibrating ensemble weather forecasts, where in the first step improved point forecasts are generated, which are then together with various ensemble statistics serve as input features of the neural network estimating the parameters of the predictive distribution. In two case studies based of 100m wind speed and global horizontal irradiance forecasts of the operational ensemble pre diction system of the Hungarian Meteorological Service, the predictive performance of this novel method is compared with the forecast skill of the raw ensemble and the state-of-the-art parametric approaches. Both case studies confirm that at least up to 48h statistical post-processing substantially improves the predictive performance of the raw ensemble for all considered forecast horizons. The investigated variants of the proposed two-step method outperform in skill their competitors and the suggested new approach is well applicable for different weather quantities and for a fair range of predictive distributions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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