Epoxy/MICA 복합체의 MICA 충진함량 변화에 대한 기계적, 전기적 특성연구

박재준(Jae-Jun Park) 대한전기학회 2013 전기학회논문지 Vol.62 No.2

This paper reported a study on the thermal, mechanical and electrical insulation properties of epoxy/mica composites. To investigate the effect of mica content, glass transition temperature, mechanical properties such as tensile and flexural strength, and insulation breakdown properties for epoxy composites with various contents of mica. The effect of insulation thickness on insulation breakdown property was also studied. It was observed that tensile and flexural strength decreased with increasing mica content, while elastic modulus increased as the mica content increased. AC insulation breakdown strength for all epoxy/mica composites was higher than that of neat epoxy and that of the system with 20 wt% mica was 14.4% improved. As was expected, insulation breakdown strength at 30℃ was far higher than that at 130℃, and it was also found that insulation breakdown strength was inversely proportion to insulation thickness.

표면처리된 나노알루미나가 첨가된 에폭시/멀티-알루미나 콤포지트의 교류절연파괴 특성

박재준(Jae-Jun Park) 대한전기학회 2016 전기학회논문지 Vol.65 No.9

The aim of this study is to improve of properties for electrical AC insulation breakdown strength using epoxy/micro-nano alumina composites with adding glycerol diglycidyl ether (GDE:1,3,5g). This paper deals with the effects of GDE addition for epoxy/micro alumina contents (40,50,60wt%)+surface modified nano alumina(1_phr) composites. 14 kinds specimen were prepared with containing epoxy resins, epoxy micro composites and epoxy nano-micro alumina mixture composites. Average particle size of nano and micro alumina used were 30nm and 1~2㎛, respectively. The micro alumina used were alpha phase with Heterogeneous and nano alumina were gamma phase particles of spherical shape. The electrical AC insulation breakdown strength was evaluated by sphere to sphere electrode system and raising velocity 1㎸/s. The AC breakdown strength decreased insulation properties of multi-composites according to increasing micro alumina and GDE addition contents.

인버터 서지와 온도스트레스 하에서 PAI/Nano Silica 에나멜와이어의 가속절연수명 평가

박재준(Jae-Jun Park) 대한전기학회 2016 전기학회논문지 Vol.65 No.10

AC and DC insulation breakdown voltage was studied for magnet wire coated with double layers of high flexural PAI layer and high anti-corona PAI/nanosilica (15 wt%) layer. The specimens were prepared at various drying temperatures (T/D): 220℃, 240℃, and 260℃, respectively. The increase effects of nanosilica on AC and DC insulation breakdown voltage were not so significant compared to that of magnet wire coil coated with original PAI. And the AC and DC insulation breakdown voltage was improved by decreasing diameter of winding coil. As T/D temperature increased, AC and DC insulation breakdown voltage decreased.

지환식 에폭시/표면개질된 마이크로-나노실리카 콤포지트의 유전특성

박재준(Jae-Jun Park) 대한전기학회 2016 전기학회논문지 Vol.65 No.11

The surface of nanosilica and microsilica was modified in order to develop a high voltage insulation material for outdoor application. The modified silicas were well dispersed in an aliphatic cyclic epoxy resin. Dielectric properties were studied for 8 kinds of specimens: 1 kind of neat epoxy, 3 kinds of epoxy/microsilica composites, and 4 kinds of epoxy/microsilica/nanosilica composites. Complex dielectric constants were measured in the range of 10-2~1.2 Hz at room temperature.

고압중전기기용 절연신소재 EMNC와 EMNSC의 특성연구

박재준(Jae-Jun Park) 대한전기학회 2012 전기학회논문지 Vol.61 No.10

In order to develop an new electric insulation material for heavy electric equipments, epoxy/micro/nano composite (EMNC) was prepared by mixing micro-silica with nano layered silicate, where the nano layered silicate was synthesized by our electric field dispersion method, EMNSC was prepared by treating the EMNC with a silane coupling agent. Thermal properties such as glass transition temperature (Tg) and thermal expansion coefficient, and DMA characteristics were studied, and mechanicla properties such as tensile and flexural tests were performed. AC electrical insulation strength was also tested. All properties of EMNSC were modified by treating EMNC with silane coupling agent and it was confirmed that our new developed composites could be used in the heavy electric equipments.

에폭시/층상실리케이트 나노콤포지트의 주파수 가속열화에 따른 부분방전 저항성

박재준(Park Jae-Jun) 대한전기학회 2013 전기학회논문지 Vol.62 No.12

Frequency accelerated partial discharge resistance (PDR) aging of epoxy/layered silicate nanocomposite with 1.5wt % additions of layered silicate was investigated in comparison with that of epoxy without layered silicate in terms of PD(partial discharge) erosion depth. It was found that the change in the erosion depth is far smaller in specimens with layered silicate than those without layered silicate nano particles. Frequency acceleration can be done from 60Hz to 1000Hz. But the depth of erosion is less proportional to frequency. Acceleration factor is almost 2 times between 500Hz and 1000Hz, but it is much less than about 8.3 times between 60Hz and 500Hz. This superior PD resistance is caused by the presence of nanofillers, anano-effect due to closely packed nanofillers, and strong chemical bonds at layered silicate nanofillers /resin interfaces.

배전용 몰드변압기 적용을 위한 EMNC의 교류절연파괴특성 연구

박재준(Park Jae-Jun) 대한전기학회 2013 전기학회논문지 Vol.62 No.5

A conventional epoxy-microsilica composite (EMC) and an epoxy-microsilica-nanosilicate composite (EMNC) were prepared in order to apply them to mold-type transformers, current transformers (CT) and potential transformers (PT). Nanosilicate was exfoliated in a epoxy resin using our electric field dispersion process and AC insulation breakdown strength at 30∼150℃, glass transition temperature and viscoelasticity were studied. AC insulation breakdown strength of EMNC was higher than that of EMC and that value of EMNC was far higher at high temperature. Glass transition temperature and viscoelasticity property of EMNC was higher than those of EMC at high temperature. These results was due to the even dispersion of nanosilicates among the nanosilicas, which could be observed using transmission electron microscopy (TEM). That is, the nanosilicates interrupt the electron transfer and restrict the mobility of the epoxy chains.

실란처리된 Epoxy/MICA 콤포지트의 열적, 기계적 전기적 특성연구

박재준(Jae-Jun Park) 대한전기학회 2013 전기학회논문지 Vol.62 No.2

In this study, epoxy/mica composite was prepared by mixing with mechanical stirrer together with homogenizer, and the effect of amino-type silane coupling agent was also studied. To reduce the viscosity without any decrement of other properties, 1,4-Butanediol diglycidyl ether (1,4-BDGE) as an aliphatic epoxy reactive diluent was introduced to the epoxy/mica composite in order to use as vanish for high voltage motor and generator stator winding. It was confirmed by scanning electron microscopy (SEM) observation that interfacial characteristics between organic epoxy and inorganic mica was modified by coupling agent treatment so that glass transition temperature increased, and tensile strength and electrical breakdown strength increased. The properties were estimated by Weibull statistical analysis and the ac electrical breakdown strength was 20.2% modified by treating silane coupling agent.

표면개질된 나노알루미나를 혼합한, 에폭시/마이크로-나노알루미나 콤포지트의 열적특성

박재준(Jae-Jun Park) 대한전기학회 2016 전기학회논문지 Vol.65 No.9

The aim of this study is to improve properties both glass transition temperature(Tg) and coefficient of thermal expansion(CTE) using epoxy/micro-nano alumina composites with adding glycerol diglycidyl ether (GDE:1,2,3,5g). This paper deals with the effects of GDE addition for epoxy/micro alumina contents (40, 50, 60wt%)+surface modified nano alumina(1_phr) composites. 20 kinds specimen were prepared with containing micro, nano alumina and GDE as a micro composites(10, 20, 30, 40, 50, 60, 70wt%) or a nano/micro alumina composites(1phr/40, 50, 60wt%). Average particle size of nano and micro alumina used were 30nm and 1~2㎛, respectively. The micro alumina used were alpha phase with Heterogeneous and nano alumina were gamma phase particles of spherical shape. The glass transition temperature and coefficients of thermal expansion was evaluated by DSC and TMA. The glass transition temperature decreased and coefficients of thermal expansion become smaller with filled contents of epoxy/micro alumina composites. On the other hand, Tg and CTE as GDE addition variation(1,2,3,5g) of epoxy/micro-nano alumina composites decreased and increased respectively.

인버터서지용, 유/무기 나노 하이브리드 코일의 온도스트레스에 따른 절연파괴 수명

박재준(Jae-Jun Park) 대한전기학회 2019 전기학회논문지 Vol.68 No.2

The one nano hybrid rectangular coil was fabricated by dispersing SiO₂ in PAI resin using a sol / gel method, and the another nano hybrid rectangular coil was fabricated by adding a flexible agent. To evaluate the dielectric breakdown lifetime, the dielectric breakdown lifetime was measured according to the change of temperature environment (30, 70, 100, 130, 150, 200℃) under an inverter surge (1.5kV/20kHz). Compared to the PAI original coil, the dielectric breakdown lifetime of the nano hybrid rectangular coil at 30℃ was improved by 23.23 times. The dielectric breakdown lifetime of the nano hybrid rectangular coil without the flexible agent was longer than that with the flexible agent at 100℃ or less. However, at 100℃ or higher, the life time of the dielectric breakdown of the rectangular coil added with the flexible agent was further improved.