基于可解释机器学习的水电站耗水率估算方法

    Interpretable machine learning-based method for estimating water consumption rate in hydropower plants

    • 摘要: 耗水率的精确估算直接关系水电及梯级发电调度计划的准确性和可操作性。针对水电站水头-耗水率曲线随着电站长期运行与实际结果发生严重偏差,导致耗水率的准确估算极其困难的问题,提出了一种基于可解释机器学习数据驱动模型的耗水率估算方法。首先,采用Pearson相关性分析方法对历史水电长序列实际运行数据进行分析,挖掘运行数据中的时序特征,确定库水位、水头、发电流量等影响耗水率的影响因子;然后,基于以挖掘的因子作为输入、以处理非线性关系为优势的支持向量回归方法(SVR),构建耗水率预测模型;最后,引入SHAP可解释性算法计算各输入因子的贡献值,根据贡献值对预测模型进行迭代校正。以长江流域某水电站进行模拟仿真,实例结果表明:所提方法预测耗水率的RMSEMAE分别为0.061 8 m3/kWh和0.041 2 m3/kWh,相较于传统插值法的0.21 m3/kWh和0.18 m3/kWh分别降低约70%和77%;NSE为0.972 5,相较于传统插值法的0.75提升约30%,有效克服了运行条件变化导致的耗水率偏差问题,同时使模型结构和预测结果的可解释性更强。研究成果可为水电站耗水率特性分析与预测提供参考。

       

      Abstract: Accurate estimation of the water consumption rate is directly related to the precision and operability of hydropower and cascade power generation scheduling plans.For addressing the issue that the head-water consumption rate curve of hydropower stations often deviates significantly from actual results over long-term operation, making accurate estimation extremely challenging, this study proposes a data-driven interpretable machine learning-based method for estimating the water consumption rate.First, the Pearson correlation analysis method is employed to analyze long-term historical operational data of hydropower stations, extracting temporal features from the operational data and identifying influencing factors such as reservoir water level, head, and discharge flow.Then, a water consumption rate prediction model is constructed using Support Vector Regression (SVR), which excels in handling nonlinear relationships, with the identified factors as inputs.Finally, the SHAP interpretability algorithm is introduced to calculate the contribution values of each input factor, and the prediction model is iteratively calibrated based on these contribution values.A simulation was conducted using a hydropower station in the Changjiang River Basin as a case study.The results show that the proposed method achieves RMSE and MAE values of 0.061 8 m3/kWh and 0.041 2 m3/kWh, respectively, representing reductions of approximately 70% and 77% compared to the 0.21 m3/kWh and 0.18 m3/kWh obtained by the traditional interpolation method.The Nash-Sutcliffe efficiency (NSE) reached 0.972 5, an improvement of about 30% over the 0.75 of the traditional interpolation method.This approach effectively overcomes the deviation in water consumption rate caused by changes in operational conditions while enhancing the interpretability of both the model structure and prediction outcomes.The research findings provide a valuable reference for the analysis and prediction of water consumption rate characteristics in hydropower stations.

       

    /

    返回文章
    返回