| 摘要 |
The invention is related to a method for classifying the status of the winding clamping (100) of a power transformer which is immersed in an oil (14) filled transformer tank (12), wherein the power transformer comprises at least one transformer coil (16, 18, 20) with at least one clamped (102 ‡” 104) electrical winding (106) arranged on a transformer core (22), the method comprising the following steps:
€¢ applying a mechanical force impulse (24) on an impact area (28, 30, 32, 34) of the transformer tank (12), so that the at least winding (106) is mechanically excited to vibration and a voltage is induced (40, 42, 44, 52) within the at least one winding (106) therewith,
€¢ measuring the induced voltage (40, 42, 44, 52) of the at least one winding (106) for a period of time during vibration, transferring (58) those measurement data from the time domain into the frequency domain and providing a respective dataset comprising the measurement data in the frequency domain (58),
€¢ searching for local maxima (88, 90, 92) within the measurement data in the frequency domain of the dataset,
€¢ classifying the status of the winding clamping (100) of the at least one winding (106) as defective in case that there is no distinct maximum (74) within the local maxima,
€¢ classifying the status of the winding clamping (100) of the at least one winding (106) as at least possibly sufficient in case that there is exactly one distinct maximum (74) within the local maxima. |
