| 摘要 |
The invention relates to a method and a device (1) for the online-detection of a deterioration in the state of an insulation in an electric machine (2). A stepped voltage is applied to the winding(s) (3) of the machine (2) with the aid of a converter (41), and the current (i) induced in this manner, and/or the time derivative (di/dt) thereof, is acquired as a measurement signal with the aid of at least one sensor (6, 7, 8) and is then oversampled with a frequency higher than the frequencies characteristic for settling. The signal obtained by said oversampling is then evaluated with regard to parameters of the settling process such as overshooting (Ah) and/or natural frequency (1/??) and/or a damping constant, in order to detect any deterioration in the insulation. |
