Abstract

Induction electric motors are widely used as drives of various mechanisms in power engineering and industry. Their failure can lead to costly repairs, to a reduction in power, or, for example, to a complete shutdown of a power plant unit. One of the reasons for the failure of high-voltage induction motors operating under severe starting conditions is damage to the squirrel-cage rotor winding. Existing methods for monitoring the breakage of the winding bars of such electric motors are ineffective due to the peculiarities of their operating modes. Therefore, monitoring the condition of the bars of high-voltage motors at startup and searching for diagnostic signs is an urgent task. Initially, the studies were carried out with a model of a high-voltage induction motor, developed in the ANSYS software package. To confirm the results obtained for a real motor, research has also been conducted on the developed experimental bench. The recorded signals were processed based on the method of short-time Fourier transform in the MatLab environment. In the course of the study, it was shown that, in the presence of bar breaks, the spectrum of an induction motor exhibits sharply increased amplitudes of harmonic components of the dummy rotor winding at the lower side frequencies of the first orders; this confirms the possibility of using external magnetic field signal at startup to detect the presence of bar breaks in the squirrel-cage rotor winding of high-voltage induction motors with heavy prolonged starts.

中文翻译：

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启动模式下高压电厂电动机转子绕组损坏的诊断信号的实验确定

摘要

感应电动机在电力工程和工业中被广泛用作各种机构的驱动器。它们的故障可能导致维修成本高昂，功率降低或例如完全关闭电厂设备。高压感应电动机在严酷的启动条件下运行失败的原因之一是鼠笼式转子绕组的损坏。由于其操作模式的特殊性，用于监视这种电动机的绕组条的断裂的现有方法是无效的。因此，在启动时监视高压电动机的磁条状态并寻找诊断信号是一项紧迫的任务。最初，研究是使用ANSYS软件包中开发的高压感应电动机模型进行的。为了确认实际电动机获得的结果，还在已开发的实验台上进行了研究。记录的信号是在MatLab环境中基于短时傅立叶变换的方法进行处理的。在研究过程中发现，在出现条形断裂的情况下，感应电动机的频谱在第一阶的下侧频率处显示出虚拟转子绕组的谐波分量的幅度急剧增加；这证实了在启动时使用外部磁场信号检测高压感应电动机的鼠笼式转子绕组中是否存在断条的可能性。记录的信号是在MatLab环境中基于短时傅立叶变换的方法进行处理的。在研究过程中发现，在出现条形断裂的情况下，感应电动机的频谱在第一阶的下侧频率处显示出虚拟转子绕组的谐波分量的幅度急剧增加；这证实了在启动时使用外部磁场信号来检测长时间启动的高压感应电动机的鼠笼式转子绕组中是否存在断条的可能性。记录的信号是在MatLab环境中基于短时傅立叶变换的方法进行处理的。在研究过程中发现，在出现条形断裂的情况下，感应电动机的频谱在第一阶的下侧频率处显示出虚拟转子绕组的谐波分量的幅度急剧增加；这证实了在启动时使用外部磁场信号来检测长时间启动的高压感应电动机的鼠笼式转子绕组中是否存在断条的可能性。感应电动机的频谱在第一阶的下侧频率处显示出虚拟转子绕组的谐波分量的幅度急剧增加；这证实了在启动时使用外部磁场信号来检测长时间启动的高压感应电动机的鼠笼式转子绕组中是否存在断条的可能性。感应电动机的频谱在第一阶的下侧频率处显示出虚拟转子绕组的谐波分量的幅度急剧增加；这证实了在启动时使用外部磁场信号来检测长时间启动的高压感应电动机的鼠笼式转子绕组中是否存在断条的可能性。