Analysis on Electric Field Based on Three Dimensional Atmospheric Electric Field Apparatus

Xing, Hong-yan,He, Gui-xian,Ji, Xin-yuan The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.4

As a key component of lighting location system (LLS) for lightning warning, the atmospheric electric field measuring is required to have high accuracy. The Conventional methods of the existent electric field measurement meter can only detect the vertical component of the atmospheric electric field, which cannot acquire the realistic electric field in the thunderstorm. This paper proposed a three dimensional (3D) electric field system for atmospheric electric field measurement, which is capable of three orthogonal directions in X, Y, Z, measuring. By analyzing the relationship between the electric field and the relative permittivity of ground surface, the permittivity is calculated, and an efficiency 3D measurement model is derived. On this basis, a three-dimensional electric field sensor and a permittivity sensor are adopted to detect the spatial electric field. Moreover, the elevation and azimuth of the detected target are calculated, which reveal the location information of the target. Experimental results show that the proposed 3D electric field meter has satisfactory sensitivity to the three components of electric field. Additionally, several observation results in the fair and thunderstorm weather have been presented.

Analysis on Electric Field Based on Three Dimensional Atmospheric Electric Field Apparatus

Hong-yan Xing,Gui-xian He,Xin-yuan Ji 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.4

As a key component of lighting location system (LLS) for lightning warning, the atmospheric electric field measuring is required to have high accuracy. The Conventional methods of the existent electric field measurement meter can only detect the vertical component of the atmospheric electric field, which cannot acquire the realistic electric field in the thunderstorm. This paper proposed a three dimensional (3D) electric field system for atmospheric electric field measurement, which is capable of three orthogonal directions in X, Y, Z, measuring. By analyzing the relationship between the electric field and the relative permittivity of ground surface, the permittivity is calculated, and an efficiency 3D measurement model is derived. On this basis, a three-dimensional electric field sensor and a permittivity sensor are adopted to detect the spatial electric field. Moreover, the elevation and azimuth of the detected target are calculated, which reveal the location information of the target. Experimental results show that the proposed 3D electric field meter has satisfactory sensitivity to the three components of electric field. Additionally, several observation results in the fair and thunderstorm weather have been presented.

PMMA 함량이 외부전장 하에서 결정화되는 PEO/PMMA 블렌드물의 결정화에 미치는 영향

김영호,홍성돈,김갑진 한국섬유공학회 2003 한국섬유공학회지 Vol.40 No.5

The effects of an external electric field and poly(methyl methacrylate) (PMMA) content on the crystallization of poly(ethylene oxide)(PEO)/PMMA blends were investigated using a polarizing microscope equipped with a hot stage and an external electric field supplier. The crystallization of PEO was strongly affected by the external electric field; i.e., the induction period increased and the crystallization rate decreased with the strength of the electric field. Since the magnitude of electric field effect was enormous, it was difficult to estimate the exact extent of the influence of the electric field on the crystallization of PEO, especially when the applied voltage was over 40 kV/cm. Blending PMMA with PEO decreased the crystallization rate of PEO and the influence of the electric field. Thus, it was possible to investigate the influence of the electric field over a wide range. The total crystallization rate of PEO in PEO/PMMA blends decreased as the strength of the external electric field increased. Because of the electro-inactivity of PMMA, the influence became progressively smaller as PMMA content increased. At higher PMMA contents, stronger electric field was needed to affect crystallization rates significantly.

Low temperature hydrogen production by ethanol steam reforming over Pt-supported catalysts assisted by electric field

( Shuhei Ogo ),( Saori Sakurai ),( Naoya Tsunashima ),( Ryo Manabe ),( Yasushi Sekine ) 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

Catalytic ethanol steam reforming was investigated over Pt/CeO2 catalyst in an electric field at low temperature, and the effect of the electric field and controlling factors for the activity and selectivity were examined. With imposing the electric field, ethanol steam reforming proceeded at low temperature as 423K, at which temperature a conventional catalytic reaction hardly proceeded. Moreover, in the reaction with electric field, CH3CHO selectivity was low and CO+CO2 selectivity was higher than that in the conventional catalytic reaction, which indicated that steam reforming of acetaldehyde was promoted by imposing the electric field. The supported platinum worked as an active site and has great impact on the activity and selectivity for the ethanol steam reforming in the electric field. Conversion of ethanol and H2 yield drastically increased with imposing the electric field, and apparent activation energies for three elementary reactions (ethanol dehydrogenation, acetaldehyde decomposition, and acetaldehyde steam reforming) were lowered by the electric field. In-situ DRIFTS measurements revealed that the adsorbed ethanol forms reactive acetate species by imposing the electric field even at low temperature, which improved hydrogen selectivity. This process can produce hydrogen from bio-ethanol using less energy at low temperature, such as 423K with a high efficiency.

전극 형태와 전극 간 거리에 따른 전기적 특성 분석

김태희 ( Tae-hee Kim ),이순형 ( Soon-hyung Lee ),황미용 ( Mi-yong Hwang ),최용성 ( Yong-sung Choi ) 한국전기전자재료학회 2023 전기전자재료학회논문지 Vol.36 No.4

In this paper, in order to analyze high electrical insulation and cooling performance using mineral oil, the liquid insulating oil was changed in electrode shape and distance between electrodes to compare and analyze electrical characteristics according to equal electric field, quasi-equivalent electric field, and unequal electric field. As a result, the breakdown voltages were 36,875 V and 36,875 V in the form of sphere-sphere and plate-plate electrodes with equal electric fields. The breakdown voltage was 31,475 V in the sphere-plate electrode type, which is a quasi-equilibrium field, and the breakdown voltage was 28,592 V, 27,050 V, and 22,750 V in the needle-needle, sphere-needle, and needle-plate electrode types, which are unequal fields. Through this, it is possible to know the difference in breakdown voltage according to the type of electric field. The more equal the field, the higher the breakdown voltage, and the more unequal field, the lower the breakdown voltage. The difference in insulation breakdown voltage could be seen depending on the type of electric field, the insulation breakdown voltage was higher for the more equal electric field, and the insulation breakdown voltage was lower for the more unequal electric field. Also, it was confirmed that the closer the distance between the electrodes, the higher the insulation breakdown voltage, the higher the insulation breakdown current, and the insulation breakdown voltage and the insulation breakdown current were proportional.

Electric Deformation of a Bubble in a Uniform Electric Field

Kwon, Young Chul,Kwon, Jeong Tae,Cho, Hye Jung,Kim, Dae Hoon,Lee, Sang Heon 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.3

Theoretical and numerical analyses have been carried out to investigate the electric deformation of a spherical free bubble in a uniform electric field. In the limit of small deformation, the steady-state deformation of a free bubble in an electric field has been considered. The electric field strength and the electric normal stress at the bubble interface and free energy and volume change of a bubble have been investigated. In addition. the bubble shape and the electric potential in an electric field have been calculated numerically. The boundary-fitted orthogonal coordinate system generated numerically has been employed. The electric normal stress is the largest at the equator (θ = π /2) of the bubble. causing the spherical bubble to deform into an elliptical one. As the electric Weber number increases, the bubble volume decreases linearly. The numerical results also show that the bubble is elongated and becomes more extended as the electric field strength increases. The aspect ratio increases upon increasing the electric Weber number.

FALC 공정에서의 전계 분포 전산모사

정찬엽,최덕균,정용재 한국결정성장학회 2003 한국결정성장학회지 Vol.13 No.2

The crystallization behavior of amorphous silicon is affected by direction and intensity of electric field in FALC(Field-Aided Lateral Crystallization). Electric field was calculated in a simplified model using conductivity data of Mo, a-Si, $SiO_2$and boundary conditions for electric potential at the electrodes. The magnitude of electric field intensity in each corner of cathode was much larger than that in the center of patterns, and the electric field direction was 50~60 degree outside to cathode. And electric field intensity at a relatively small pattern was larger than that of a large pattern. FALC(Field-Aided Lateral Crystallization) 공정에서 요구되는 a-Si의 결정화는 인가한 전계(electric field)의 세기와 방향에 의존한다. 본 연구에서는 유한요소법을 적용하여 실제 패턴을 간단하게 모델링한 형상에 각 물질의 전도도를 대입하고, 전안을 가해 그 결과로 발생하는 전계의 분포를 계산하였다. 전계는 (-)극 주위에서 전극의 양쪽 모서리 부근이 가운데 부분보다 더 높게 나타났고 그 방향은 전극과 50~$60^{\circ}$를 이루는 대각선 방향이었다. 또한 예상한대로 크기가 작은 패턴이 큰 패턴보다 더 큰 전계 값을 가지는 것으로 나타났다.

폴리에틸렌으로 피복된 전선화염의 전파에 직류전기장이 미치는 영향에 관한 실험적 연구

진영규(Young Kyu Jin),김민국(Min Kuk Kim),박정(Jeong Park),정석호(Suk Ho Chung),김정수(Jeong Soo Kim),배대석(Dae Seok Bae) 한국연소학회 2010 KOSCOSYMPOSIUM논문집 Vol.- No.41

Effect of applied DC electric fields on flame spread over polyethylene-coated electrical wire was experimentally investigated. Flame spread rates over electrical wire with negatively and positively applied DC electric fields in range of 0∼ ±㎸were measured and analyzed. This study aimed at comparison of the results under applied DC electric fields with the previous results under applied AC electric fields, thereby exploring whether various flame shapes can be still obtained even with applied DC electric fields and what the main reason is for flame spread acceleration particularly at the end part of the installed electrical wire with applied AC electric fields. It is found that applied DC electric fields do not significantly affect flame spread rates. However the flame shape is mildly altered by the ionic wind effect even for applied DC electric field. The flame spread rate is still relevant to flame shape and slanted direction in spite of mild impact. A possible explanation on flame spread can be given by a thermal balance mechanism and fuel-vapor jet.

Analysis of Electrode Configuration of Underwater Electric Field Sensor on Electric-Field-based Localization for Underwater Robots

Jason Kim,Ingyu Lee,Meungsuk Lee,Ki-Woong Bae,Son-Cheol Yu 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11

This paper addresses the effects of electrode configurations of an underwater electric field sensor (EFS) on the localization of underwater robots when the robots used electric field measurements to estimate their positions. Around an underwater electric landmark that generates a known electric field signature, an underwater robot equipped with an EFS can measure the signature to localize itself by searching for the position that minimizes the difference between the actual measurement and the theoretical calculation that should be measured when the robot is located at the position. The underwater robot’s localization accuracy was analyzed in simulations when the robot was equipped with EFSs with different electrode configurations. In general, the electric field measurement accuracy and the consequent robot localization accuracy were higher when the robot was equipped with the EFS that consists of more electrodes. Depending on the measurement conditions, however, the use EFSs with less electrodes was enough to perform sufficiently accurate localization of the robot. The proposed simulation method would contribute to suggest the optimal electrode configuration of the EFS, and therefore, the robot localization with the electric field measurements would become more energy-efficient with the use of the suggested cheap and small EFS.

폴리에틸렌 피복전선 화염의 전파에 영향을 미치는 직류전기장의 인가 효과에 관한 실험적 연구

진영규(Young Kyu Jin),김민국(Min Kuk Kim),박정(Jeong Park),정석호(Suk Ho Chung),윤진한(Jin Han Yun),길상인(Sang In Keel) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.3

본 연구는 전선화염의 전파특성에 직류전기장이 미치는 영향에 대한 실험적 연구이다. 화염전파는은 0에서 ±7㎸ 범위의 음극과 양극의 전기장을 인가하여 실험되어졌다. 본 연구를 통해 앞선 전선화염 전파에 영향을 미치는 교류전기장 효과에 관한 연구결과와 비교하여 관찰된 다양한 화염 모양 변화의 원인을 알아보고, 화염 전파 속도의 가속특성에 대해서도 논의하고자 한다. 직류전기장의 인가가 전선화염에 미치는 영향은 크지 않지만 이온풍 효과에 따른 미미한 영향은 존재하며, 이것은 온도 균형 메커니즘과 연료 증발기체 분사 효과로 설명 될 수 있다. We experimentally investigated the effect of applied DC electric fields on the flame spread over polyethylene-coated electrical wire. The flame-spread rates over electrical wire with negative and positive DC electric fields from 0 to ±7 ㎸ were measured and analyzed. We compared the results for DC electric fields with previous results for AC electric fields. We explored whether or not various flame shapes could be obtained with DC electric fields and the main reason for the flame-spread acceleration, particularly at the end of the electrical wire, for AC electric fields. We found that DC electric fields do not significantly affect the flame-spread rates. However, the flame shape is mildly altered by the ionic wind effect even for DC electric fields. The flame-spread rate is relevant to the flame shape and the slanted direction in spite of the mild impact. A possible explanation for the flame spread is given by a thermal-balance mechanism and fuel-vapor jet.