• 제목/요약/키워드: Inductive circuit

검색결과 183건 처리시간 0.024초

Influence of Discharge Conditions on the Ignitability of Lycopodium Streams Due to a Single Capacitance Discharge Spark

  • Park, K. S.;M. Yamaguma;T. Kodama;J. H. Joung;Kim, T. Y.;M. Nifuku;M. Takeuchi
    • KIEE International Transactions on Electrophysics and Applications
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    • 제3C권3호
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    • pp.99-105
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    • 2003
  • The influence of discharge conditions, including the resistance of the sparking circuit, the shape of the electrodes and the width of the falling dust on the ignitability of lycopodium streams were investigated. Discharge characteristics and the ignition phenomena were also explored. When a 100 ㏀ resistor was connected in series with the sparking circuit, the lowest level of minimum ignition energy (MIE) was attained for lycopodium streams. Simultaneously, the area where flammable gas generated increased and the duration of flammable gas generation decreased. That is, the ignita-bility of lycopodium streams depended strongly on the discharge power and discharge duration. Electrodes with sharp tips gave smaller MIEs than those with round tips in a capacitive-inductive sparking circuit, while shape made no difference in a capacitive-resistive circuit. Streams that were too narrow required a considerable amount of energy for ignition.

Numerical analysis on the critical current evaluation and the correction of no-insulation HTS coil

  • Bonghyun Cho;Jiho Lee
    • 한국초전도ㆍ저온공학회논문지
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    • 제25권1호
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    • pp.16-20
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    • 2023
  • The International Electrotechnical Commission (IEC) 61788-26:2020 provides guidelines for measuring the critical current of Rare-earth barium copper oxide (REBCO) tapes using two methods: linear ramp and step-hold methods. The critical current measurement criterion, 1 or 0.1 μV/cm of electric field from IEC 61788-26 has been normally applied to REBCO coils or magnets. No-insulation (NI) winding technique has many advantages in aspects of electrical and thermal stability and mechanical integrity. However, the leak current from the NI REBCO coil can cause distortion in critical current measurement due to the characteristic resistance which causes the radial current flow paths. In this paper, we simulated the NI REBCO coil by applying both linear ramp and step-hold methods based on a simplified equivalent circuit model. Using the circuit analysis, we analyzed and evaluated both methods. By using the equivalent circuit model, we can evaluate the critical current of the NI REBCO coil, resulting in an estimation error within 0.1%. We also evaluate the accuracy of critical current measurement using both the linear ramp and step-hold methods. The accuracy of the linear ramp method is influenced by the inductive voltage, whereas the accuracy of the step-hold method depends on the duration of the hold-time. An adequate hold time, typically 5 to 10 times the time constant (τ), makes the step-hold method more accurate than the linear ramp method.

부성저항을 이용한 능동 대역 통과 여파기 (An Active Bandpass Filter Using Negative Resistance Circiuts)

  • 신상문;권태운;최재하
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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    • pp.229-232
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    • 2000
  • In this study, An active band grass filter for 2.14GHz have been designed with MMIC using negative resistance circuit. The negative resistance element was realized with a common-drain FET with series inductive feedback. The designed active filter showed an insertion loss of 0dB at 2.14GHz and a 3-dB bandwidth of 125MHz.

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인버터에어컨에 능동역률개선회로 적용에 관한 연구 (A Study On The Application Of Active Power Factor Correction Circuit In Inverter Airconditioner)

  • 김태덕;배영돈;박윤서
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.306-308
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    • 1996
  • The demands of minimizing the reactive power and reducing the current harmonics are increasing nowdays. The inverter airconditioner needs high inductive power and it operates with wide load ranges. Conventionally, an huge LC passive filter is used in airconditioner to improve the power factor and to reduce current harmonics which doesn't give good results. In this paper, a design of active power factor correction(APFC)circuit for inverter airconditioner is described. To improve the P.F and reduce the current THD, average current controlled APFC is designed and tested. The problems of APFC implementation, their solution and testing results are described.

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Investigation on the Commercialization Issues of Resistive Type Superconducting Fault Current Limiters for Electric Networks

  • Park, Tae-Gun;Lee, Sang-Hwa;Lee, Bang-Wook
    • Progress in Superconductivity
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    • 제11권1호
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    • pp.19-24
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    • 2009
  • Among the various types of fault current limiters, superconducting fault current limiters could be the most preferable choice for high voltage electric power systems owing to the remarkable current limiting characteristics of superconductors. But, there have been no commercial superconducting fault current limiters which were installed into actual electric power systems until these days due to some remained technical and economical problems. Thus, in order to promote the development and application of the superconducting fault current limiters into real field, it is essential to understand the power utilities’ requirements for their networks and also suitable test method and some specifications should be prepared. This paper focuses on the matters of test requirements and standardization issues that should be prepared for commercialization of superconducting fault current limiters. The unique current limiting characteristics of superconducting fault current limiters were investigated and related other standards including circuit breakers, transformers, reactors, power fuse, and fused circuit breakers were compared to setup the basis of novel specification of superconducting fault current limiters. Furthermore, required essential test procedures for superconducting fault current limiters were suggested.

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Implementation of Effective Wireless Power Transmission Circuit for Low Power System

  • Lho, Young Hwan
    • 전기전자학회논문지
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    • 제22권3호
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    • pp.846-849
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    • 2018
  • Wireless power transfer (WPT) is the technology that enables the power to transmit electromagnetic field to an electrical load without the use of wires. There are two kinds of magnetic resonant coupling and inductive coupling ways transmitting from the source to the output load. Compared with microwave method for energy transfer over a long distance, the magnetic resonance method has the advantages of reducing the barrier of electromagnetic wave and enhancing the efficiency of power transmission. In this paper, the wireless power transfer circuit having a resonant frequency of 13.45 MHz for the low power system is studied, and the hardware implementation is accomplished to measure the power transmission efficiency for the distance between the transmitter and the receiver.

콘버어터의 전원 고조파분을 저감시키기 위한 SHE PWM 방식의 적응 (Application of SHE PWM Scheme for Reducing The Source Harmonic Components of Converter)

  • Chung, Dong-Hwa
    • 대한전자공학회논문지
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    • 제27권9호
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    • pp.1427-1435
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    • 1990
  • This paper proposes the Selected Harmonic Elimination Pluse Width Modulation (SHE PW) scheme toreduce the ahrmonic components of source line current. To eliminate the low order harmonics which affects the source dominatly, we apply the Fourier series analysis to line current waveforms and then find out the switching patterns using the SHE PWM scheme. In addition to the analysis of harmonic effects, the three phase filter circuit is used to reduce high order harmonics. For the experimental realization, the converter circuit with power Transistor(PTR) is designed and the Pulse Time Control(PTC) is applied. The line current and the load voltage are measured under the condition of three phase application, highly inductive load.

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지연보상 동기복조방법에 의한 소프트웨어 레졸버-디지털 변환기 (Software-Based Resolver-to-Digital Converter by Synchronous Demodulation Method including Lag Compensator)

  • 김윤현
    • 전기학회논문지
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    • 제62권6호
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    • pp.756-761
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    • 2013
  • This paper propose the new demodulation method that can detect resolver signal's peak at the time of position estimation when the position information is required during current controller period. The proposed method is performed in a synchronous demodulation way with exciting signal and also cover a capability which can compensate the lag element of exciting signal caused by the resolver's inductive component and filter circuit. This paper carried out the experiment to investigate the validity and performance of the suggested method by using the test board made up of DSP and demodulation circuit. The test results show that the proposed method is theoretically clear and work completely as expected from making sure of sampling resolver signal's peak at the time of position estimation. In addition, Software position tracking algorithm is executed with the demodulated signals generated by the suggested method and an exact position can be estimated.

개선된 자기소호회로와 아크전압 억제회로를 사용한 유도성 부하의 직류차단 특성 실험 (Experiment on DC Circuit Breaker for Inductive Load by Improved Magnetic Arc-extinguisher and Arc-attenuation Circuit)

  • 이성민;유태식;김효성
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2012년도 전력전자학술대회 논문집
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    • pp.417-418
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    • 2012
  • 최근 들어 디지털 제품의 급증으로 인해 직류를 사용하는 부하가 증가하고, 태양광, 풍력발전 등의 직류를 생산하는 신재생에너지원의 발달로 인하여 부하에 직류를 직접 공급 할 수 있게 되었다. 직류배전은 가전기기 내부의 전력 변환단계를 줄임으로써 교류배전에 비해 에너지 변환 효율을 높일 수 있는 장점이 있다. 하지만 직류는 교류와 다르게 고장 전류의 차단이 어렵다. 본 논문은 유도성 부하에서 효과적인 직류차단을 위한 자기소호회로와 아크전압 억제회로를 제안하고 실험을 통하여 그 효과를 검증하였다.

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저항 점 용접의 1차 동저항 특성에 관한 연구 (Characterization of Primary Dynamic Resistance in Resistance Spot Welding)

  • 조용준;이세헌;신현일;배경민
    • Journal of Welding and Joining
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    • 제17권2호
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    • pp.97-103
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    • 1999
  • The dynamic resistance monitoring in primary circuit is one of the important issues. Because in-process and real time quality assurance of resistance spot weld is needed to increase the product reliability. In this study, new dynamic resistance detecting method is proposed as a practical manner of weld quality assurance using instantaneous current and voltage measured at the primary circuit. and also, various patterns of primary dynamic resistance curve are characterized with the macro photograph and the weldability lobe curve. It is found that the primary dynamic resistance patterns are basically similar to those of the secondary, but there is evident advantage such as no extra devices are needed to obtain the quality information and eventually real time feedback control will be possible.

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