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Lee, Taeyeong,Kim, Hokyeong,Lee, Nayoung,Chin, Taehoon,Bu, Hanyoung,Cho, Younghoon The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.3
This paper evaluates the dv/dt performances of the motor input terminal fed by a gallium nitride (GaN) field effect transistor (FET) matrix converter for variable frequency drive applications. To limit the high dv/dt caused by the fast switching operation of GaN devices, a dv/dt filter is employed. With the dv/dt filter, the input terminal voltage can meet the standards suggested by National Electrical Manufacturers Association. On the other hand, when a GaN FET matrix converter and an electric motor are connected by a long cable, the parasitic impedance of the cable varies. This impedance mismatch results in voltage reflection (VR), and this VR causes a large surge voltage with severe ringing at the motor input terminal. Even in this case, the dv/dt filter effectively restricts the dv/dt of the voltage applied to the electric motor. Frequency response results are obtained through the transfer functions of the filter according to the applied position. Experiments are carried out using a 220 V/60 Hz induction motor and a GaN FET-based matrix converter prototype. The dv/dt filter performance with two positions and cable lengths of 5 m and 25 m is evaluated by comparing the obtained experimental results with the frequency response.
Highly isolated switching mode power supply for solid-state transformers in railway vehicles
Lee, Yejun,Bu, Hanyoung,Lee, Dohong,Cho, Younghoon The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.4
This paper discusses an isolated switching mode power supply (SMPS) with an AC 30 kV<sub>rms</sub> insulation capability for application to the solid-state transformers (SSTs) in railway vehicles. The insulation capability of the SMPS should be higher than AC 25 kV<sub>rms</sub> for application at the SSTs in railway vehicles. The proposed highly isolated SMPS is superior to commercial isolated power supplies with low insulation capability, which is normally less than 20 kV. The input side of the proposed isolated SMPS is physically separated from its output side by a specially designed miniature high-frequency (HF) transformer to obtain high insulation capability. The core of the miniature HF transformer is separated by insulation material. The primary and secondary coils are wound around each separated core. A CLLC resonant converter that consists of a primary resonant capacitor (C), two inductors (LL), and a secondary resonant capacitor (C) is applied as the proposed isolated SMPS topology to improve the output voltage regulation performance, which varies due to a large leakage inductance derived from the airgap of the proposed miniature HF transformer. Experiments are carried out to verify the CLLC resonant converter of the proposed isolated SMPS. Electrostatic finite element method (FEM) simulations and high potential (HiPot) tests are carried out to verify the AC 30 kV<sub>rms</sub> insulation capability of the proposed isolated SMPS. The electrostatic FEM simulations demonstrate the DC 42.43 kV insulation capability, and the HiPot tests verify the insulation capability from AC 5 kV<sub>rms</sub> to AC 30 kV<sub>rms</sub>.
설계인증 BIM적용을 위한 평가 및 운영 체계에 대한 기본연구
이한영(Hanyoung Lee),김준갑(Jungab Kim),최중식(Jungsik Choi),원서경(Seokyung Won) (사)한국CDE학회 2022 한국CDE학회 논문집 Vol.27 No.4
BIM technology is one of the important 4th industrial technologies that can improve productivity in the design and construction stages. Various studies are being conducted to utilize BIM technology in the design, construction, and maintenance stages. However, research related to design certification is still insufficient. In this study, a study was conducted for the evaluation and operation of various design certifications using BIM technology. Among the design certifications, the certifications to be analyzed were selected according to the priority analysis result. Acquisition process for each selected certification was derived, and detailed analysis of the major evaluation items of the derived process was carried out, and a checklist template for BIM application was prepared according to the result. In this study, the evaluation and operation framework for the application of BIM technology for design certification is established, and it will be used for future operation guidelines and checklist research.
Bu, Hanyoung,Lee, Yejun,Cho, Younghoon,Kim, Myung-Yong,Lee, Eunsoo,Park, Jin-Hyuk The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.8
This paper proposes a neutral section passing strategy for preventing the inrush current of an electric railway vehicle (ERV) with a solid-state transformer (SST). This inrush current is not generated when the ERV passes the neutral section by maintaining a dc-link voltage at a constant level that is higher than the peak voltage of an electric railway feeder using regenerative energy from the ERV. Depending on the position of the ERV, the control strategies and modes are changed. When the ERV passes the neutral section, the regenerative energy from the ERV charges the dc-link voltage. A dc-ac converter that operates a traction motor takes charge of the dc-link voltage control in the regeneration operation. Simulation results show that the proposed strategy can protect the SST from inrush current when the ERV passes the neutral section. Experiments have been carried out with a scaled-down prototype. Experimental results verify the performance of the proposed neutral section passing strategy.
이한영(Hanyoung Lee) 대한전기학회 2009 정보 및 제어 심포지엄 논문집 Vol.2009 No.10
범용 발포 폴리에티렌 은박매트를 사용하여 침입자 감지센서를 구현하였다. 발포 폴리에티렌 상하 은박면 사이의 정전용량이 침입자에 의해 가해지는 압력에 의하여 변화되는 것을 감지하는 방식을 사용하였다. 센서는 외부의 습도, 진동, 온도변화, 정압의 영향을 받지 않아 이동 및 매설이 가능하고 10㎏ 이상의 침입자가 들어오는 것을0.4~4㎡ 면적에서 감지되는 것을 실험적으로 보여주었다.
이한영(Hanyoung Lee) 대한전기학회 2010 정보 및 제어 심포지엄 논문집 Vol.2010 No.10
산란광을 이용한 차량용 우적감지 센서는 광도파관을 이용하는 일반 우적감지 센서와는 달리 수신되는 신호가 극히 미약하므로 이를 신호 대 잡음비를 저하시키지 않으면서 고감도로 수신할 필요가 있다. 제안하는 산란광을 이용한 우적감지 센서용 광송수신 장치는 간섭필터를 사용하여 주변광의 영향을 최소화 하였으며 전기적 신호 증폭단계에서 반송파 주파수를 이용한 변조방법과 확장디지털 신호 변환법을 사용하여 신호 대 잡음비를 최대로 유지하였다. 스프레이어를 이용한 가상강우 환경에서 제작된 광송수신 장치를 장착한 산란광 감지방식 우적감지 센서는 빗방울 감지시 불필요한 궤환이나 혼신 없이 차량용 우적감지 센서로 이용할 수 있는 가능성을 보여 주었다.