融合双注意力机制与多尺度特征的轨道交通牵引负荷预测

Rail Transit Traction Load Forecasting Integrating Dual Attention Mechanism and Multi-scale Features

  • 摘要:
    目的 城市轨道交通牵引负荷具有强时序相关性及高频波动性,且受多维气象因素耦合及随机客流冲击影响显著,传统预测方法难以兼顾预测精度与鲁棒性。为解决该问题,有必要研究一种能够有效捕捉负荷复杂演变规律的高精度预测模型,以辅助牵引供电系统的优化调度与智能运维。
    方法 基于武汉某地铁线路实测数据,解析了牵引负荷的时空演变特性,揭示了全线网负荷相对于单个变电所的对冲平滑效应,量化了气温非线性驱动、季节性演变及日历效应等关键影响机制。提出一种融合双注意力机制与多尺度特征的改进LSTM(长短期记忆)神经网络预测模型,构建嵌套式预测框架;引入双注意力机制动态加权时间步与外部特征,以强化对关键致因变量的提取能力;设计并行的细粒度与粗粒度LSTM子网络,分别捕捉负荷的瞬时高频波动与长期趋势特征,并通过自适应权重进行多尺度融合;利用历史时序数据集对模型进行训练与验证。
    结果及结论 所提改进LSTM预测模型在测试集上的MAPE(平均绝对百分比误差)降至2.75%,拟合优度R2达到0.99。该模型在高温突变及节假日等复杂工况下表现出优异的泛化能力,能够为城市轨道交通牵引供电系统的节能运行与精细化管理提供高精度的决策依据。

     

    Abstract:
    Objective The traction load of urban rail transit features strong temporal correlation and high-frequency volatility, and is significantly influenced by the coupling of multi-dimensional meteorological factors and the impact of random passenger flows. Traditional forecasting methods struggle to balance prediction accuracy and robustness. To solve this problem, it is necessary to study a high-precision forecasting model that can effectively capture the complex evolution patterns of the load, facilitating the optimal dispatching and intelligent operation and maintenance of the traction power supply system.
    Method Based on the measured data of a metro line in Wuhan, the spatio-temporal evolution characteristics of the traction load are analyzed, the offsetting and smoothing effect of the entire network-wide load relative to a single substation is revealed, and key influence mechanisms such as non-linear temperature driving, seasonal evolution, and calendar effects are quantified. An improved LSTM (long- and short-term memory) neural network forecasting model integrating a dual attention mechanism and multi-scale features is proposed, constructing a nested forecasting framework. A dual attention mechanism is introduced to dynamically weight time steps and external features to enhance the extraction ability of key causal variables. Parallel fine-grained and coarse-grained LSTM sub-networks are designed to capture the instantaneous high-frequency volatility and long-term trend characteristics of the load, respectively, and multi-scalar fusion is performed through adaptive weights. The model is trained and validated using historical time-series datasets.
    Result & Conclusion  The MAPE (mean absolute percentage error) of the proposed improved LSTM forecasting model on the test sets decreased to 2.75%, and the goodness of fit R2 reached 0.99. The model demonstrates excellent generalization ability under complex working conditions such as sudden high-temperature and holidays, providing a high-precision decision-making basis for the energy-saving operation and refined management of urban rail transit traction power supply systems.

     

/

返回文章
返回