大型电动机的内部故障诊断与保护方法

Interior fault diagnosis of large induction motor and protection theory

分析了大型电动机内部故障诊断与保护方法的研究现状和发展趋势 ,讨论了常规的电流幅值检测、对称分量法、Fourier变换和小波变换、人工智能方法、派克相量法、交流电机多回路理论。对称分量法基于理想电机模型 ,原理上只能反映严重的外部故障。小波变换等先进信号处理方法为电动机内部故障信号检测提供了有效的工具。以单个绕组为研究单元的多回路理论突破了传统故障分析中的理想电机假设 ,适合于研究电动机内部故障机理和定量分析。这一理论与先进信号处理方法的结合可望使电动机内部故障的诊断与保护取得新的突破。

The current research state and development tendency of the interior fault diagnosis and protection for large induction motors are analyzed. It includes the conventional over-current detection, the symmetrical component principle, the Fourier transform, the wavelet transform, the Park's vector approach and the multi-loop theory. The symmetrical component principle adopts the ideal motor model and can only theoretically reflect the serious exterior faults. The advanced signal processing methods, such as the wavelet transform, provide the novel techniques for detecting the signals of interior faults. The multi-loop theory, considering the single coil as the elementary cell, breaks through the hypothesis of the ideal motor model in the traditional fault analysis. It is adapted to study the mechanism and quantitative description of the interior faults for induction motors. It is believed that the combination of the theory with the advanced signal processing methods will make new progress in this field.