http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Qingquan Lei (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Hu Kai,Li Guochang,Gu Zhenlu,Zhang Fan,Wei Yanhui,Lei Qingquan 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3
The insulation performance of air gap can be improved by inserting insulation barriers into the high voltage box with limited space. The influence of the barrier dimension, barrier thickness, barrier position and surface state of epoxy resin barrier on the AC breakdown characteristics of the “rod electrode-insulation barrier-ground electrode” system are discussed in the work. An equal-size model of the insulation system is established to analyze the influence of the insulation barrier on electric field and the discharge mechanism. The experimental results indicate that the breakdown voltage is improved significantly by enlarging the barrier dimension, up to twice as much. In contrast, the barrier thickness has little effect on the breakdown voltage because the discharge is mainly along the barrier surface. Besides, the breakdown voltage can be increased by reducing the distance between insulation barrier and rod electrode, this is because of the blocking effect of insulation barrier on the corona layer around the electrode, which can hinder the development of charges to the ground electrode, thus delaying the discharge process. The breakdown voltage increases with the barrier surface roughness because of the prolongation of discharge path and the distortion of local electric field. The breakdown voltage decreases with the rise of temperature, it decreases to 37.5 kV when temperature rose to 60 °C. Due to the increase of free charges mobility, the corresponding surface resistivity decreases from 16.2 × 1014 Ω at 20 °C to 3.14 × 1014 Ω at 60 °C. This work can provide support for the reasonable design of insulation barriers in engineering application.
-
Effect of branched alumina on thermal conductivity of epoxy resin
Yu Long,Lirui Shi,Qingyu Wang,Haitao Qu,Chuncheng Hao,Qingquan Lei 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-
Composites prepared by using epoxy resin (EP) as matrix had limited practical applications owing to theirpoor thermal conductivity. The thermal conductivity of composites can be enhanced by doping inorganicfillers. However, it could not be significantly enhanced owing to the saturation of inorganic fillers. In thisstudy, we prepared branched alumina (b-Al2O3) by using high-temperature sintering and doped it as afiller to obtain b-Al2O3/EP composites. The results shown that the thermal conductivity of the EP compositeswith 70 wt% b-Al2O3 was 1.13 Wm1K1, which was seven times higher than that of pure EP. Thiscould be attributed to the overlapping of b-Al2O3 for the formation of a continuous mesh structure thatresults in thermal conduction channels inside the EP, which reduced the interfacial thermal resistanceand improved the thermal conductivity of the composite. The resistivity of b-Al2O3/EP was 9.64 1014Xm and that of pure EP was 2.08 1014 Xm. The dielectric constant of the b-Al2O3/EP compositesincreased with the increase in b-Al2O3 content, while the dielectric loss factor decreases. This was significantfor the application of EP composites in the field of electrical insulation.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
