• 제목/요약/키워드: low/high frequency surge current

검색결과 14건 처리시간 0.025초

뇌서지에 의한 플라이백 컨버터의 서지전류 경로 분석 (Analysis of Surge Current Path of Flyback Converter by Lightning Surge)

  • 박준우;이강희;김진호;홍성수;원재선;김종해
    • 전력전자학회논문지
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    • 제18권2호
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    • pp.178-183
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    • 2013
  • The study of lightning surge have been conducted on information and communications equipment and power system. However, the research on SMPS itself is an inactive field. This paper analyzes surge current path of flyback converter with the combination wave generator by lightning surge. Also, this paper discloses that there exists the surge current with high-frequency component besides the low-frequency component based on the standard surge current. This high-frequency surge current is the major reason to damage the semiconductor devices such as FET and IC. To confirm the validity of the proposed issue, the analysis and experimental results are presented.

고주파수 PWM제어를 이용한 ABS의 맥동 저감에 관한 연구 (A Study on Falling Pressure Surge of ABS Using High Frequency PWM Control)

  • 이용주;김병우;박호
    • 한국공작기계학회논문집
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    • 제12권3호
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    • pp.38-44
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    • 2003
  • The solenoid valve in ABS hydraulic modulator is a two directional on-off valve and is controlled by around 100Hz high speed pulse width modulation. When the valve is switched from open state to closed state, noise and vibration due to pressure surge phenomena in the hydraulic line and wheel cylinder are made. In this study, we identify Pressure surge phenomenon in the braking process of a ABS, and investigate the way to reduce the phenomenon. For the purpose of theoretical analysis on the pressure surge in the closed state hydraulic line, characteristic curve method based on wave equation was utilized. To reduce the surge, high frequency control of 20kHz was attempted. The result showed that the surge pressure of 50% was reduced compared to one observed in the low frequency control. Duty variation of high frequency can control current of solenoid valve and prevent sudden change of displacement.

정보통신기기용 과도전압 차단장치의 개발에 관한 연구 (A Study on the Development of a Transient Voltage Blocking Device for Info-communication Facilities)

  • 한주순
    • Journal of Advanced Marine Engineering and Technology
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    • 제23권2호
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    • pp.159-167
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    • 1999
  • This paper presents a new transient voltage blocking device(TOBD)which low power and high frequency bandwidth to protect info-communication facilities from transient voltages. Conventional protection devices have some problems such as low frequency bandwidth low ener-gy capacity and high remnant voltage. in order to improve these limitations a hybrid type TOBD which consists of a gas tube avalanche diodes and junction type field effect transistor (JFETs) is developed. The TOBD differs from the conventional protection devices in configuration and JFETs are used as an active non-linear element and a high speed switching diode with low capacitance limited high current. Therefore the avalanche diode with low energy capacity are protected from the high current and the TOBD has a very small input capacitance. From the performance test using combination surge generator which can produce $1.2/50{\mu}m$ 4.2 kV/max, $8/20{\mu}m$ 2.1 kAmax it is confirmed that the proposed TOBD has an excellent protection per-formance in tight clamping voltage and limiting current characteristics.

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바리스터와 LC필터를 사용한 2단 서지보호장치 (Two-Stage Surge Protection Device with Varistor and LC Filter.)

  • 이복희;김지훈;이경옥
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.279-281
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    • 1996
  • This paper deals with the two stage surge protection device by using varistor and LC low pass filter. Recently varistor alone has been used with overvoltage protection devices for the AC power mains and has same problems associated with high remnant voltage and noise. In this work, in order to improve the cutoff performance of surge protection device, the lightning surge protection device having two stage hybrid circuit for an AC single phase mains was designed and fabricated. Operation characteristics and surge clamping performance of the surge protection device in an $8/20{\mu}s$ surge current are investigated. As a consequence, it is found that the proposed two stage surge protective device for AC power mains has a variety of advantages such as a smaller clamping voltage, high frequency noise reduction and large clamping capacity.

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광대역 과도전압 차단장치의 설계 및 제작 (Design and Fabrication of Wide-band Transient Voltage Blocking Device)

  • 송재용;이종혁;길경석
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 1999년도 춘계종합학술대회
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    • pp.330-334
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    • 1999
  • This paper presents a new transient voltage blocking device (TBD) for commucation facilities with low power and high frequency bandwidth. Conventional protection devices have some problems such as low frequency bandwidth, low energy capacity and high remnant voltage. In order to improve these limitations, the new TBD, which consists of a gas tube, avalanche diodes and junction type field effect transistors (JFETs), was designed and fabricated JFETs were used as an active non-linear element and a high speed switching diode with low capacitance limits high current. Therefore the avalanche diodes with low energy capacity are protected from the high current, and the TBD has a very small input capacitance. From the performance test using surge generator, which can produce 1.2/50${\mu}\textrm{s}$ 4.2 k$V_{max}$, 8/20${\mu}\textrm{s}$ 2.1 kA$\sub$max/, it is confirmed that the proposed TBD has an excellent protection performance in tight clamping voltage and limiting current characteristics.

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Novel Buck Mode Three-Level Direct AC Converter with a High Frequency Link

  • Li, Lei;Guan, Yue;Gong, Kunshan;Li, Guangqiang;Guo, Jian
    • Journal of Power Electronics
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    • 제18권2호
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    • pp.407-417
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    • 2018
  • A novel family of Buck mode three-level direct ac converters with a high frequency link is proposed. These converters can transfer an unsteady high ac voltage with distortion into a regulated sinusoidal voltage with a low THD at the same frequency. The circuit configuration is constituted of a three-level converter, high frequency transformer, cycloconverter, as well as input and output filters. The topological family includes forward, push-pull, half-bridge, and full-bridge modes. In order to achieve a reliable three-level ac-ac conversion, and to overcome the surge voltage and surge current of the cycloconverter, a phase-shifted control strategy is introduced in this paper. A prototype is presented with experimental results to demonstrate that the proposed converters have five advantages including high frequency electrical isolation, lower voltage stress of the power switches, bi-directional power flow, low THD of the output voltage, and a higher input power factor.

정보통신기기용 과도이상전압 고속도차단장치의 설계 및 제작 (Design and Fabrication of a High Speed Blocking Device of Transient Overvoltages for info-communication Facilities)

  • 길경석
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권1호
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    • pp.51-56
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    • 1999
  • This paper presents a new transient overvoltage blocking device (TOBD) for info-communication facilities with low power and high frequency bandwidth. Conventional protection devices have some problems such as low frequency bandwidth, low energy capacity and high remnant voltage. In order to improve these limitations, thehybrid type TOBD, which consists of a gas tube, avalanche diodes and junction typefield effect transistors (JFETs), was designed and fabricated. The TOBD differs from the conventional protection devices in configuration, and JFETs were used as an active non-linear element and a high speed switching diode with low capacitance limits high current. Therefore the avalanche dilde with low energy capacity are protected fromthe high current, and the TOBD has a very small input capacitance. From the performance test using combination surge generator, which can produce $1.2/50\mus\;4.2kV_{max}\; 8/20\mus\; 2.1kA_{max}$, it is confirmed that proposed TOBD has an excellent protection performance in tight clamping voltage and limiting current characteristics.

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낙뢰 보호용 접지시스템 평가를 위한 고주파 접지임피던스 측정시스템의 설계 및 제작 (Design and Fabrication of High Frequency Ground Impedance Measuring System for Assessment of Grounding System for Lightning Protection)

  • 길형준;송길목;김영석;김종민;김영진
    • 한국안전학회지
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    • 제31권3호
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    • pp.47-52
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    • 2016
  • This paper describes the design and fabrication of high frequency ground impedance measuring system for assessment of grounding system for Lightning protection. The ground impedance measuring system has been designed and fabricated which makes it possible to assess the ground impedance by frequency ranges from 100 Hz to 1 MHz. The effective grounding systems having a very low impedance to electromagnetic disturbance such as lightning surges and noises in microelectronics and high-technology branches are strongly required. In order to analyze the dynamic characteristic of grounding system impedances in lightning and surge protection grounding systems, it is highly desirable to assess the ground impedances as a measure of performance of grounding system in which lightning and switching surge currents with fast rise time and high frequency flow. The measuring system is based on the variable frequency power supply and consists of signal circuit part, main control part, data acquisition and processing unit, and voltage and current probe system. The ground impedance measuring system can be used to assess grounding system during occurrence of lightning.

변압기 2차측 LLC 직렬공진컨버터 적용 승압형 DC/DC 컨버터 (The Secondary LLC Series Resonant Converter for the Boost DC/DC Converter)

  • 이현관;차인수;이기식;정봉근;강성인;김은수
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제55권8호
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    • pp.423-429
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    • 2006
  • Recently, the high frequency isolated boost DC/DC converter has been widely used for the PCS (Power Conditioning System) system because of its small size and low cost. However, the high frequency isolated boost DC/DC converters applied the conventional voltage-fed converter and current-fed converter have the problems such as the high conduction losses and the surge voltage due to the high circulating current and the leakage inductance, respectively. To overcome this problems, in this paper the secondary LLC resonant converter is proposed, and the experimental results of the secondary LLC series resonant converter for boost DC/DC converter are verified on the simulation based on the theoretical analysis and the 700W experimental prototype.

매설지선 접지임피던스의 주파수 의존성 (Frequency Dependance of Ground Impedances of the Counterpoises)

  • 최영철;최종혁;김동규;이규선;양순만;이수봉;이복희;안창환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.1489_1490
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    • 2009
  • Ground impedance is changed according to frequency of the current injected into the grounding system. Because the lightning surge gives a broad frequency spectrum from some ten Hz to a few MHz, frequency dependance of ground impedance must be evaluated. In this paper, we have constructed 10m, 30m, 50m counterpoise and evaluated frequency dependance of ground impedance. Also we have evaluated frequency dependance of ground impedance according to current injection point. As a result, long counterpoises have low ground resistance, but ground impedances of those are significantly increased in the range of high frequency. In the case that currents are injected into the center of counterpoise, the ground impedance is most lower than any other injection point. Also, additory ground rod of 1.8m long affect ground impedance decrease.

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