电压暂降分类识别是合理选择电能质量治理方案的前提。提出一种基于改进S变换的电压暂降识别方法。首先根据电压暂降特征频率范围自适应确定改进S变换的调节因子，计算所得模时频矩阵作为电压暂降标准模板；再比较待测试暂降的改进S变换模矩阵特定频段与各标准模板之间的相似度，实现扰动分类。在比较相似度值的过程中，为凸显不同暂降类型的相似性及差异性，采用分频逐行计算相似度值，从而实现异类模板差异最大化。该方法充分挖掘各类暂降的特征差异，通过简单的相似度计算对扰动进行分类，无需添加辅助分类器。仿真和大量实测数据研究表明，该方法分类过程简单，抗干扰能力强。%Classification of voltage sags is the precondition for choosing the right power quality management measures. This paper proposes a new voltage sag identification method based on the module matrix of generalized S-transform. It firstly determines the regulatory factor of improving the S-transform by the main frequency constituents of sags and then calculates the modulus matrixes of the S-transform to form the standard templates. The sags are classified through the analysis of the similarity between the specific region of the matrix of the test sags and the standard templates. In the process of similarity calculation, for enlarging the similarities and differences among standard templates, the idea of calculating similarities at different frequencies is proposed, thus making the differences maximized. This method sufficiently excavates the characteristic differences among sags;no extra classification process is needed. Simulation and actual data analysis show that this method is easy to be implemented and has high accuracy and noise robustness. This work is supported by National Natural Science Foundation of China (No. 51077095).
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