• 제목/요약/키워드: auxiliary transformer

검색결과 116건 처리시간 0.024초

태양광 발전 시스템을 위한 무접점 전원장치 (A Contact-less Power Supply for Photovoltaic Power Generation System)

  • 이현관;공영수;김윤호;이기식;강성인;정봉근;김은수
    • 전력전자학회논문지
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    • 제11권3호
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    • pp.216-223
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    • 2006
  • 태양광 발전 시스템을 위한 무접점 변압기 적용 고효율 Full-bridge LLC 공진컨버터를 제안하였다. 제안된 LLC 공진컨버터는 직렬 커패시터와의 직렬공진을 위해 무접점 변압기의 누설인덕턴스와 자화인덕턴스를 이용하였다. 제안된 LLC 공진컨버터는 공진주파수 보다 높은 스위칭영역에서 연속 공진전류로 동작하는 기존 직렬공진 컨버터와는 달리 공진주파수 아래의 좁은 주파수 범위에서 불연속 공진전류로 동작한다. 이러한 불연속모드 공진전류 때문에 제안된 컨버터는 어떤 보조회로 없이 무접점 변압기 1차측 주스위칭 소자의 영 전압 스위칭(ZVS)과 2차측 다이오드의 영 전류 스위칭(ZCS)을 얻을 수 있고, 높은 전압이득특성을 갖는다. 본 논문에서는 무접점 변압기 적용 Full-bridge LLC 공진컨버터를 이용한 무접점 전원장치에 대한 이론적 해석 및 시뮬레이션을 통해 150W급 시제품을 제작하여 태양광 발전 전원시스템에 적용 실험한 결과를 서술했다.

국부적 자속 포화 현상을 이용한 리엑터 및 변압기의 공극 등가 모델에 관한 연구 (Study on Transformer and Inductor Using Equivalent Air gap to Partial Flux Saturation)

  • 박성준;이상훈;김정훈
    • 한국산업융합학회 논문집
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    • 제17권3호
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    • pp.103-112
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    • 2014
  • BY the Transformers and reactors, the input electrical energy is converted into magnetic energy. At the end through the magnetic energy was passed at the output parameter. Specially At the flyback transformer or a reactor airgap were designed to contain more magnetic energy. But that work is very difficult for the optimal design. It is that Contradictions are between the length of the Air-gap, Winding inductance, DC bias. As to e Several conflicting conditions in order to determine the optimum Air-gap has a lot of experience and trial & error is necessary. The approach proposed in this paper, the auxiliary winding on the core attached to part of primary core, that by applying a DC voltage has a dramatic effect like Core with designed Air-gap. This inventiveness and advantage is to regulate arbitrarily the Saturation Flux Quantity by the input signal to secondary winding. Accordingly obtained the biggest effect is that increasing limits of the saturation current destined by the material and shape of the conventional core. In other words, that can decreas the size of the transformer and reactor, While maintaining the current saturation capacity. This paper, prove its effect as using the local flux saturation in transformers and reactors for research by the computer program using the finite element method (FEM) simulation, followed by actual experiment to verify

V2G 시스템을 위한 보조 LC 회로를 가진 고효율 양방향 공진형 컨버터 (A High Efficiency Bidirectional Resonant Converter With Auxilary LC Circuit for V2G System)

  • 트란덕홍;최우진
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2016년도 전력전자학술대회 논문집
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    • pp.323-324
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    • 2016
  • In this paper a high efficiency bidirectional resonant converterfor Vehicle-to-Grid applications (V2G) is proposed.The proposed converter has adopted an LC auxiliary circuit in the third winding of the transformer. With the proposed method full softswitching can be ensured in all switches over a wide range of loadsand the secondary ringing can be removed with no additional snubber or clamp circuitry.In addition, since the proposed resonant converter is able to operate at an almost constant resonant frequencyregardless of the load, CC/CV charge of the battery can be simply implemented with high efficiency. A 3.3 kW bidirectional converter for On-Board Charger of Electric Vehicle is implemented to verify the validity of the proposed method. The experimental results show the high efficiency characteristics of the proposed converter over the wide range of load in both charge and discharge mode. The maximum efficiency of the proposed system was 98.13 % at 2.3 kW during the constant voltage mode charge operation.

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보조 사이리스터의 턴-오프 회로를 간소화한 HVDC 사이리스터 밸브 시험용 합성시험회로 (A Synthetic Test Circuit for HVDC Thyristor Valve Test with Simplified Turn-Off Circuit of Auxiliary Thyristor)

  • 정재헌;구법진;조한제;노의철;한병문;정용호;백승택
    • 전력전자학회논문지
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    • 제19권5호
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    • pp.475-480
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    • 2014
  • This study proposes a new synthetic test circuit (STC) for HVDC thyristor valve tests. The conventional STC with a 2-phase chopper requires a 3-phase transformer, a 3-phase diode rectifier, and an IGBT to facilitate the off state of an auxiliary thyristor. In the proposed STC, these three components are replaced with one diode and one resistor, which result in the simplified implementation of the hardware of the STC. Simulation and experimental results demonstrate the validity of the proposed scheme.

기계적 접점을 이용한 FCL의 동작 특성 (Operational Characteristics of the FCL Using the Mechanical Contact in the Power System)

  • 정병익;최효상
    • 전기학회논문지
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    • 제65권5호
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    • pp.878-882
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    • 2016
  • These days, SFCLs are being developed in order to limit fault current. However, the superconducting elements that limit the fault current have such problems as capacity increase and require auxiliary devices including cooling device. If devices that comprise the current power network can withstand fault current for at least one cycle, it is possible to limit the fault current with current limiting elements by bypassing it on the fault line. In this study, the fault current limiter was configured with current transformer, vacuum interrupter, and current limiting element. Through the experience, it was confirmed that the fault current was limited within one cycle. The superconducting element, as a current limiting element, limited the fault current by 80 % within one cycle from fault occurrence, and the passive element limited it more than 95 %. Also, through the comparison between resistance curve and power consumption curve, it was confirmed that the current limiting element using a passive element was more stable than the superconducting element that required capacity increase and other auxiliary devices. It was considered that the FCL proposed in this study could limit fault current stably within one cycle from fault occurrence by using the existing power technologies such as fault current detection and solenoid valve operating circuit.

Common-Mode Voltage Elimination with an Auxiliary Half-Bridge Circuit for Five-Level Active NPC Inverters

  • Le, Quoc Anh;Park, Do-Hyeon;Lee, Dong-Choon
    • Journal of Power Electronics
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    • 제17권4호
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    • pp.923-932
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    • 2017
  • This paper proposes a novel scheme which can compensate the common-mode voltage (CMV) for five-level active neutralpoint clamped (5L-ANPC) inverters, which is based on modifying the space vector pulse width modulation (SVPWM) and adding an auxiliary leg to the inverter. For the modified SVPWM, only the 55 voltage vectors producing low CMV values among the 125 possible voltage vectors are utilized, which varies over the three voltage levels of $-V_{dc}/12$, 0 V, and $V_{dc}/12$. In addition, the compensating voltage, which is injected into the 5L-ANPC inverter system to cancel the remaining CVM through a common-mode transformer (CMT) is generated by the additional NPC leg. By the proposed method, the CMV of the inverter is fully eliminated, while the utilization of the DC-link voltage is not decreased at all. Furthermore, all of the DC-link and flying capacitor voltages of the inverter are well controlled. Simulation and experimental results have verified the validity of the proposed scheme.

태양광 발전 시스템을 위한 LLC 직렬공진컨버터 적용 무접점 전원장치 (A Contact-less Power Supply using LLC resonant converter for Photovoltaic Power Generation System)

  • 이현관;이기식;강성인;공영수;김은수;김윤호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.347-350
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    • 2006
  • The high efficiency full-bridge LLC resonant converter using a contact-less transformer is proposed for the photovoltaic power generation system. For the series resonance with a series capacitor, the LLC resonant converter utilizes the leakage inductance and magnetizing inductance of a contact-less transformer. Unlike the conventional series resonant converter operated to the continuous resonant current at above resonance frequency, the proposed converter operates to the discontinuous resonant current at the narrow frequency control range below resonance frequency. Due to the discontinuous mode resonant current, the proposed converter can be achieved the zero voltage switching (ZVS) in the primary switches and the zero current switching (ZCS) in the secondary rectification diodes without any auxiliary circuit. In this paper, the experimental results of the proposed full-bridge LLC resonant converter using a contact-less transfonner are verified on the simulation based on the theoretical analysis and the 150W experimental prototype.

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154 kV 및 345 kV 주변압기 부싱의 내진성능 시험 연구 (The Experimental Study on Seismic Capacity of 154 kV & 345 kV Main Transformer Bushings)

  • 황경민;함경원;김경환
    • 한국지진공학회논문집
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    • 제22권2호
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    • pp.87-94
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    • 2018
  • In this study, seismic performance of bushings and their connection parts was analyzed by performing shaking table tests for various types of bushings widely used as auxiliary equipment of main transformers in domestic substations. As a result of the seismic tests of five types of 154 kV bushings according to the manufacturers, all the bushings secured the structural integrity even at the acceleration of 1.4 g and it was found that leakage of insulating oil didn't occur. Also, the average acceleration amplification rate at the upper part of the bushings was about 2.5 to 3.0 times higher than the lower one. On the other hand, when a representative 345 kV bushing was subjected to the seismic test, the structural integrity was secured even at 1.0 g acceleration similar to the design earthquake load level, but in this test, leakage of insulating oil occurred. However, when a stiffener restricting the connection of the bushing is installed in the same 345 kV bushing, the displacement of the bushing connection is controlled and the stiffener prevent the oil from leaking even at the acceleration of the designed seismic level.

변압기의 가변 턴비 기법을 통해 넓은 전압범위를 만족하는 리튬이온 배터리용 고효율 LLC 공진형 컨버터 (A High Efficiency LLC Resonant Converter with Wide Operation Range using Adaptive Turn Ratio Transformer for a Li-ion Battery)

  • 한형구;최영준;김래영;김주용;조진태
    • 전력전자학회논문지
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    • 제22권4호
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    • pp.305-311
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    • 2017
  • In this paper, the LLC resonant converter battery charger, using adaptive turn ratio scheme, is proposed to achieve high efficiency and wide range output voltage. The LLC converter high frequency transformer has an adaptively changed turn ratio by the auxiliary control circuitry. As a result, the optimal converter design with a large magnetizing inductance is easily achieved to minimize the conduction and the turn-off losses while providing widely regulated voltage gain capability to properly charge the Li-ion battery. The proposed converter operational principle and the optimal design considerations are illustrated in detail. Finally, several simulation results verify the proposed LLC resonant converter's effectiveness.

FB ZVT PWM 컨버터의 환류구간 손실저감을 위한 보조회로 (An auxiliary circuit for reducing loss during free-wheeling interval in FB ZVT PWM converter)

  • 윤창선;김병철;김광헌
    • 전력전자학회논문지
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    • 제5권3호
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    • pp.209-214
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    • 2000
  • 본 논문에서는 FB ZVT PWM DC-DC 컨버터에서 영전압 스위칭에 도달하기 위해 두 개의 보조 스위치 대신에 가포화 인덕터를 사용한다. 기존의 고주파 위상 변위 FB ZVT PWM DC-DC 컨버터는 프리휠링 주기동안 고주파 변압기와 스위칭 소자를 통해 흐르는 순환전류를 갖으며, 이러한 순환전류로 인해 컨버터의 도전손실이 증가한다. 이러한 손실을 줄이기 위해 변압기의 2차측에 도전손실저감회로를 제안한다. 컨버터의 동작원리를 자세하게 설명하고 제안된 회로를 시뮬레이션과 실험을 통해 검증하였다.

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