基于解析小波变换的变压器绕组模态参数识别

摘要

Modal parameters of power transformer winding are closely related to vibration feature, dynamic optimal design and fault diagnosis of the winding structure. Considering the difficulty of obtaining the accurate modal parameters of the power transformer winding, an axial excitation experiment of a 10 kV power transformer was made in the paper. The complex wavelet transform was introduced and applied to the analysis of the measured vibration signal. Then, algorithm of Crazy Climber was employed to extract the wavelet ridge, and the first three natural frequencies and the damping ratio of the transformer winding were obtained. The results from this method were found to be in good agreement with those calculated by the identification method of Poly MAX in frequency domain. It shows that the proposed method is correct and effective. Furthermore, it is shown that the proposed method has strong anti-interference feature and can be applied effectively to the identification of the modal parameters of transformer winding.%　　电力变压器绕组的模态参数与绕组结构振动特性、动力特性优化设计及振动故障诊断密切相关，考虑到传统的模态识别方法在获取变压器绕组这类非线性系统参数时的局限性，在对某10 kV实体变压器绕组进行轴向激振实验的基础上，引入复小波变换法对测试得到的振动信号进行分析，同时使用Crazy Climber算法提取小波脊线，得到变压器绕组的前三阶固有频率及其对应的阻尼比。计算结果与目前通用的频域识别方法Poly Max法识别结果的良好吻合说明计算结果的正确性。此外，计算结果表明基于小波变换的模态参数识别方法具有较强的抗干扰性能力，适合于分析变压器绕组这类复杂结果的模态参数。