Enamelled rectangular magnet wires used in driving motor for electric vehicle need to test their partial discharge initial voltage (PDIV). However, the current IEC and national standards have no normative parameter on the PDIV test condition, and domestic motor manufacturers have different requirements on the PDIV performance. In order to obtain accurate PDIV data, the testing principle of instrument for measuring partial discharge was studied. The influence of test methods on the PDIV results of polyamide-imide and polyimide enamelled rectangular magnet wires under different voltage increase rate, determination threshold, and fitting length of wires was analyzed. The results indicate that if 10 V/s and 10 pC are taken as test condition and the fitting length of wires is more than 90 mm, the PDIV results are the closest to the theoretical value. If higher rising rate and higher threshold are used, the measured PDIV results will be higher, and the stability of test results will decrease.
| 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 |