• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 제2회 학술대회 논문집 일렉트렛트 및 응용기술전문연구회
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• pp.68-72
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• 2000

In order to estimate spatial charging process in the corona charging which has been used to make polymer electret, the electrical properties of polypropylene film were obtained from Thermally Stimulated Current (TSC) measurements after corona charging between knife electrode and cylinder electrode with the voltages of -5, -6, -7 and -8[kV], respectively. And then the electrostatic contour and the electric field vector were also simulated by using Finite Element Method (FEM). The edge effect around edge of knife electrode affected the electrostatic contour on surface of specimen and the electric field concentration inside specimen. The uneven charging state in the electret due to the mistake on design could be calculated and so the optimal design of corona charging device which is appropriate to various materials is come to be practicable.

• 한국초전도ㆍ저온공학회논문지
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• 제20권1호
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• pp.23-27
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• 2018

As the wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air, there are advantages compared with the wired counterparts, such as convenient, safety and fearless transmission of power. From this reason, the WPT systems have started to be applied to the wireless charging for various power applications such as train, underwater ship, electric vehicle. This study aims for the effect and characteristics of different inserted resonance coil between Tx and Rx coils for charging system of superconducting magnetic levitation (MAGLEV) train. The transfer efficiency and effect are evaluated with helix type, rectangular type copper resonance coil, and HTS resonance coil under bulb and HTS magnet load, respectively. The input power is adapted with radio frequency (RF) power of 370 kHz below 500 W.

• 반도체디스플레이기술학회지
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• 제13권3호
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• pp.39-43
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• 2014

The effect of electrode charging on the ion energy distribution (IED) was investigated in the dual-frequency capacitively coupled plasma source which was powered of 100 MHz RF at the top electrode and 400 kHz bias on the bottom electrode. The charging property was analyzed with the distortion of the measured current and voltage waveforms. The capacitance and the resistance of electrode sheath can change the property of ion and electron charging on the electrode so it is sensitive to the plasma density which is controlled by the main power. The ion energy distribution was estimated by equivalent circuit model, being compared with the measured distribution obtained from the ion energy analyzer. Results show that the low frequency bias power changes effectively the low energy population of ion in the energy distribution.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.373-378
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• 1999

In order to analyse the degradation mechanism of polymer materials for outdoor condition, FRP laminate was exposed to high temperature and ultraviolet rays. Then, thedegradation process was evaluated by comparing contact angle, surface potential decay, and polarity effect respectively. Especially, the analysis of surface degradation phenomena by corona charging method showed the exact correlation with the result of chemical properties. Therefore we can confirm that the application of corona charging method on the identification of degradation process is very useful. If this method is usedin degradation studies on the polymer surface, it will be more effective on the surface analysis of polymer insulators. With corona charging method and chemical spectrum analysis, it was possible concretely to define degradation process on the polymer surface exposed at the situation of different environmental conditions.

• Journal of Electrical Engineering and Technology
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• 제13권2호
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• pp.742-751
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• 2018

Electric vehicles (EV) are emerging as the future transportation vehicle reflecting their potential safe environmental advantages. Vehicle to Grid (V2G) system describes the hybrid system in which the EV can communicate with the utility grid and the energy flows with insignificant effect between the utility grid and the EV. The paper presents an optimal power control and energy management strategy for Plug-In Electric Vehicle (PEV) charging stations using Wind-PV-FC-Battery renewable energy sources. The energy management optimization is structured and solved using Multi-Objective Particle Swarm Optimization (MOPSO) to determine and distribute at each time step the charging power among all accessible vehicles. The Model-Based Predictive (MPC) control strategy is used to plan PEV charging energy to increase the utilization of the wind, the FC and solar energy, decrease power taken from the power grid, and fulfil the charging power requirement of all vehicles. Desired features for EV battery chargers such as the near unity power factor with negligible harmonics for the ac source, well-regulated charging current for the battery, maximum output power, high efficiency, and high reliability are fully confirmed by the proposed solution.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.519-522
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• 2001

Recently, the battery charging technology and reducing technology of harmonics on AC input line are rising importantly according to increasing electrical facilities that it has been replaced battery with emergency power. In this study, I proposed that an auto-charging circuit of battery has low cost with simple-construction circuit, relative, harmonics reduction with diode tap-change method, high reliability of system for using characteristics of thyristor switching. In case of this circuit, convenience and reliability of maintenance of battery power units were more improved. 1 think that it is resulted in effect of prevention to shortening of battery life from over-charging and over-discharging and decrease of harmonics obstacle on AC input line.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.516-517
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• 2008

The ethylene-propylene (EP) rubbers mixed with one to one ratio is used as an insulation material in the nuclear power plant. It was investigated the effect of the amount of reinforcing agent. moisture absorption and heat treatment on the Ethylene-Propylene(EP) rubbers. The level of degradation was measured by the amount of discharging and. charging currents. When $\gamma$ rays were radiated on the EP rubbers with more charging material, the amount of discharging and charging currents was depended on the amount of reinforcing agent It was verified that the discharging and charging currents irradiated by $\gamma$ rays were higher than those that was not irradiated.

• 한국ITS학회 논문지
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• 제21권6호
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• pp.211-224
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• 2022

본 연구는 EV 충전 인프라 구축에 따라 이용자들이 인프라에 대하여 실질적으로 개선되었다는 효능감을 느끼고 있는지 검증을 통해 제주지역 EV 충전 인프라 구축정책에 대한 효과성을 분석하는 것이 목적이다. 연구 결과로는 충전기에 대한 '설치의 충분성', '이용의 신속성', '관련 정보 파악의 용이성', '고장 충전기의 신속 고객서비스 대응'과 같은 세부 만족 요인이 EV 충전 인프라 개선 효능감에 영향을 주는 것으로 나타났다. 아울러 이용자의 '주택유형'에 따른 'EV 충전 이용 만족'이 'EV 충전 인프라 개선 효능감'에 유의미한 영향을 미치는 것으로 확인되었다. 공동주택 거주 전기차 이용자들의 효능감 제고를 위한 충전 인프라 구축 필요성도 도출되었으며, 전반적인 정책 효과성은 높은 것으로 확인되었다. 본 연구는 제주지역 사례를 통해 전기차 충전 인프라 구축정책의 효과성을 검증하는데 기여할 수 있다.

• Macromolecular Research
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• 제8권1호
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• pp.6-11
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• 2000

In this study, we examined the charging behavior of chopped carbon fibers during electro-flocking process, which is one of the key processes of the novel technique for fabricating conductive polymer composite films. Short carbon fibers (CF) during electroflocking were electrically charged by the combined effect of contact charging, corona charging and tribocharging. The specific charge built on CF surface was measured by using Faraday cup method. Specific charge increased not only with increasing electric field strength and potential impressed to mesh electrode as expected from theoretical considerations in literature, but with decreasing mesh opening size due to the improved contact charging condition. However, CF length was found unexpectedly to influence the amount of CF specific charge due to the agglomerated nature of CF flocks leading to the change in charging conditions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.169-171
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• 1993

In order to estimate space charging process in the corona charging apparatus which has been used to make polymer electret cell, the electrical properties of 30[${\mu}m$] thick polypropylene film were obtained from TSC measurement after corona charging between copper knife electrode and aluminum cylinder electrode with the voltage of -8, -7, -6, -5 (kV). And, the electrostatic contour and the electric field vector were calculated using Finite Element Method with the electrical properties obtained from TSC spectra analysis. The edge effect around the edge of knife electrode affects electrostatic contour on the surface of specimen and the electric field concentration inside the polymer. As a result the uneven charging state in the electret cell due to the mistake of design was calculated, and the optimal design of corona charging apparatus opprobriate to various specimen was come to be practicable.