The effects of repetitive pulse voltage on the surface potential of the inverter-fed motor rotor bar insulation with different length of extension part and fixed metal plate were discussed under different rise times. Then the changing mechanism of the insulation surface potential was discussed combined with charge relaxation theory and finite element simulation. The results show that the surface potential peak-to-peak value of bar decreases with the increase of repetitive pulse rise time. When the pulse rise time reaches 800 ns, the potential peak-to-peak value at the end of the conductive armor tape is close to twice of the applied voltage peak-to-peak value. Under working conditions, when the insulation surface temperature exceeds 150℃, white smoke will be generated and accompanied by partial discharge phenomenon. It is analyzed that the jump voltage with short rise time is an important parameter affecting the electrical and thermal properties of bar. Finally, according to the experimental and simulation results, some reasonable improvement suggestions are proposed for the insulation design of inverter-fed motor bars.
| 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 |