基于全局自注意力机制和局部多尺度特征通道融合的锂电池健康状态预测

State-of-health Estimation for Lithium-ion Batteries Based on Global Self-attention Mechanism and Local Multi-scale Feature Channel Fusion

  • 摘要: 准确预测锂电池的健康状态对于降低由电池性能衰退所引起的风险和损失至关重要。然而,电池内部复杂的电化学机理和特定于用户的使用工况为这一任务带来了挑战。现有的基于模态分解的预测方法大多因不能同时处理电池短期容量增生和长期性能衰退的多尺度信息而使其预测精度受限。为此,提出一种基于全局自注意力机制和局部多尺度特征通道融合的锂电池健康状态预测方法。该方法首先利用完全集合经验模态分解技术获得电池性能衰退的多尺度信息,然后使用基于Softmax函数的全局自注意力机制从中捕获电池长期退化特征,同时采用多种卷积核的深度可分离卷积神经网络提取短期多尺度信息。通过包含不同权重参数的残差连接方式自适应融合这些长短期特征,实现精确的电池健康状态预测。在NASA和CALCE数据集上的试验结果表明,该方法不但取得了高于主流模型的预测精度,而且具有较强的泛化能力。

     

    Abstract: Accurate state-of-health(SOH) estimation of lithium-ion batteries is crucial for reducing risks and losses. However, the complex electrochemical mechanisms within the battery and the user-specific operating conditions pose significant challenges to this task. Current prediction methods based on modal decomposition often fall short in accuracy because they cannot simultaneously handle the multi-scale information related to both short-term capacity growth and long-term performance degradation specific to batteries. To address these limitations, a novel method for predicting battery SOH based on global multi-head self-attention mechanism and local multi-channel feature fusion is proposed. First, complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN) is utilized to obtain multi-scale information on battery performance degradation. Then, a global self-attention mechanism based on the Softmax function is employed to capture long-term degradation features of the battery, while using various depthwise separable convolutional neural networks to extract short-term multi-channel and multi-scale information. By adaptively fusing these long-term and short-term features through residual connections with weight parameters, precise battery SOH prediction is achieved. Experimental results based on NASA and CALCE battery datasets demonstrate that the proposed method not only achieves higher prediction accuracy compared to mainstream model architectures, but also exhibits stronger generalization capability.

     

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