In the partial discharge test and detection of power transformers, multi-source pulse overlap seriously affects the identification of partial discharge signals. In this paper, a clustering separation method of partial discharge signals based on multi-terminal pulse amplitude ratio was proposed. Firstly, the partial discharge test of 220 kV transformer was carried out, and the pulse overlapping phenomena in PRPD and T-F spectra under different test voltages were analyzed. Then, based on the propagation attenuation law of different types of pulses in transformer, a three-dimensional amplitude ratio pulse clustering separation method based on multi-terminal detection of transformer was proposed, and the method was realized by DBSCAN algorithm. Finaly, multi-terminal detection was carried out during the partial discharge test of 220 kV transformer, and the clustering separation and pulse source analysis of the pulse were carried out. The results show that utilizing the multi-terminal amplitude ratio clustering separation method can accurately divide the multi-source overlap pulses during partial discharge process in to interference pulse and two kinds of discharge pulse, and the initial location of the pulse source can be realized according to the amplitude ratio . The multi-terminal pulse amplitude ratio clustering separation method realizes the extraction of transformer partial discharge pulse, and its development and application will be conductive to improve the anti-interference capability and detection accuracy in transformer partial discharge testing.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |