• Title/Summary/Keyword: High frequency resonant inverter

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Transcranial Magnetic Stimulation using Cockroft-Walton Circuit and Half Bridge Resonant Inverter (코크로프트-월톤회로와 반파공진인버터를 적용한 경두개 자기자극장치)

  • Kim, Whi-Young;HwangBo, Gak
    • The Journal of the Korea Contents Association
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    • v.10 no.4
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    • pp.257-264
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    • 2010
  • Though existent a transcranial magnetic stimulation makes various treatment and diagnostic sine waveform of fixed stimulation pulse, there is limitation. In this research, because strength, pulse width, pulse pattern required in treatment and diagnostic introduce other Cockroft-Walton circuit and half bridge inverter frequency and voltage variable become new device propose wish to. Have more advantages than existing device. First, do not have high voltage transformer. Second, switching loss can be less, and control output energy precisely. Three, stimulation strengths, pulse width, pulse pattern are various. As a result, sought special quality and an experiment that is improved applying inverter and cockroft - Walton circuit is half bridge inverter that do not use transformer.

The Study on FTPM and PSPM of High Frequency Induction-Heating Iron Load (고주파유도가열 철부하의 FTPM 및 PSPM 제어에 관한 연구)

  • 임영도;김두영
    • The Transactions of the Korean Institute of Power Electronics
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    • v.5 no.2
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    • pp.192-199
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    • 2000
  • This paper describes a Phase-Shift Pulse Modulation(PSPM) and Frequency Trad이ng Pulse Modulation(FTPM) s series resonant high-frequency inverter using IGBT for the power control of high-frequency induction heating u using Neuro-Fuzzy, which is practically applied for 20kHz~500kHz induction-heating and melting power supply in i indust껴aJ fields. The adaptive frequency tracking based on the PSPM(phase-shifting pulse modulation) r regulation scherne is presented in or$\tau$ler to l11lmmlZe svvitching losses. The trially-produced breadboards using N Neuro Fuzzy controller are successfully demonstrated cUld cliscussed.

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Comparison of Output and Radiation Quality of X-rays according to the Full-Wave Rectification Method and Dual-Voltage Rectification Method of an X-ray Generator (X선 고전압장치의 전파 및 배전압 정류방식에 따른 X선 출력 및 선질 비교)

  • Kim, Tae-Gon;Cheon, Min-Woo;Park, Yong-Pil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.23 no.7
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    • pp.534-538
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    • 2010
  • X-ray systems for medical treatment use noninvasive procedures. Being capable of locally inspecting the inside of the body, X-ray systems are routinely used for basic diagnosis. X-ray systems to be used for medical purposes were originally made with a gas filled tube inside an induction coil in the initial stages of development but with this approach it becomes difficult to take a satisfactory picture through thick body sections, non invasively. However continued development made it possible to take non-invasive pictures of breasts, blood vessels and other body parts through thick body sections. Recently, high-voltage X-ray generators of more compact size, increased generation efficiency, and sophisticated output control have become possible. All of these features are made possible by the use of a high-frequency output from an inverter and a fast switching semiconductor device. In this paper, we describe a new X-ray generator operating with a resonant inverter in order to reduce switching loss and high frequency noise. In addition, in order to identify the differences amongst types of rectification, we have compared output and the quality of X-ray pictures obtained with full-wave rectification and dual-voltage rectification methods.

A Study on High Efficiency Electronic Ballast for Metal Halide Discharge Lamps (메탈핼라이드 램프용 고효율 전자식 안정기에 관한 연구)

  • Kim, Hae-Jun;Won, Jae-Sun;Park, Jae-Wook;Seo, Cheol-Sik;Lee, Seung-Hee;Sim, Kwang-Yeal;Kim, Jong-Hae;Kim, Dong-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.12
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    • pp.2157-2165
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    • 2007
  • A novel design technology for a high frequency electronic ballast for metal-halide discharge lamps is proposed. A PFC technique is adopted to get unit power factor and output frequency alteration technique is adopted to avoid acoustic resonance. For characteristics evaluation, the designed electronic ballast is presented using normalized parameter. To reduce losses of the ballast. ZVS control technique is adopted and the maximum flux density of magnetic core for inductor should be kept lower. The electronic ballast for 250[W] metal-halide discharge lamp is implemented and 96[%] efficiency and low conducted EMI level are accomplished.

High Power Factor Converter for Electric Vehicle Chargers (전기자동차 충전기용 고역율 콘버어터 회로)

  • 김영민;이수원;모창호;유철로
    • The Transactions of the Korean Institute of Power Electronics
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    • v.2 no.1
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    • pp.33-38
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    • 1997
  • Generally, various semiconductor switching devices for power systems are used in battery chargers for electric vehicle. When these used, it takes the problems of transient-current or distortion of waveforms in power systems near by battery chargers because of harmonics and large peak-current, low power factor, etc., caused by the non-linearity of these devices. Recently, power factor control, line current peak-cut, harmonics reduction which was ignored in past is more and more important. In this paper, to solve those problems we will improve the characteristics of voltage rising and propose the high power factor converter circuit for battery chargers. Our proposed system convert commutated voltage to AC resonant wave in high frequency inverter and rectify the link voltages passed high-frequency transformer and transfer the DC voltages. Especially, the effect using these converter system can be improved very large by power factor control and we have to verify the possibilities of improvement through the experiment of Pb-Acid battery application.

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The power regulation of a High-Frequency Induction Heating System with time variance load using a neural fuzzy controller (뉴로퍼지 제어기를 이용한 고주파 유도 가열기의 시변부하에 대한 정전력 제어)

  • 장종승;김승철;임영도
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.2
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    • pp.223-230
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    • 1998
  • This paper describes a phase-shift pulse-width modulation and pulse-frequency modulation series resonant high-frequency inverter using IGBT(Insulated-Gated Bipolar Transistor) for the power control of high-frequency induction heating using neuro-fuzzy, which is practically applied for 20KHz~500KHz induction-heating and melting power supply in industrial fields. The adaptive frequency tracking based phase-shifting PWM(Pulse-Width Modulation) regulation scheme is presented in order to minimize switching losses. The trially-produced breadboards using IGBT are successfully demonstrated and discussed.

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Characteristic Analysis and Design of High Frequency Resonant Inverter(SEPP Type) using ZVS (ZVS를 이용한 고주파 공진 인버터(SEPP형)의 특성해석과 설계)

  • 민병재;노채균;김동희;김종해;문창수
    • The Transactions of the Korean Institute of Power Electronics
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    • v.2 no.4
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    • pp.19-27
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    • 1997
  • This paper has described about principle and form of proposed circuit made use of soft switching technology ZVS(Zero Voltage Switching) to reduce turn on and off loss at switching. Also, the analysis of the proposed circuit has described generally by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. Based on the characteristics value, a method of the circuit design is proposed. In addition, this paper proves the propriety of theoretical analysis in terms of the experimental waveforms. In the future, this proposed inverter shows that it can be practically used as power source system for induction cooker etc.

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Modal Analysis of Resonance and Stable Domain Calculation of Active Damping in Multi-inverter Grid-connected Systems

  • Wu, Jian;Chen, Tao;Han, Wanqin;Zhao, Jiaqi;Li, Binbin;Xu, Dianguo
    • Journal of Power Electronics
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    • v.18 no.1
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    • pp.185-194
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    • 2018
  • Interaction among multiple grid-connected inverters has a negative impact on the stable operations and power quality of a power grid. The interrelated influences of inverter inductor-capacitor-inductor filters constitute a high-order power network, and consequently, excite complex resonances at various frequencies. This study first establishes a micro-grid admittance matrix, in which inverters use deadbeat control. Multiple resonances can then be evaluated via modal analysis. For the active damping method applied to deadbeat control, the sampling frequency and the stable domain of the virtual damping ratio are also presented by analyzing system stability in the discrete domain. Simulation and experimental results confirm the efficiency of modal analysis and stable domain calculation in multi-inverter grid-connected systems.

Comparison of PI and PR Controller Based Current Control Schemes for Single-Phase Grid-Connected PV Inverter (단상 계통 연계형 태양광 인버터에 사용되는 PI 와 PR 전류제어기의 비교 분석)

  • Vu, Trung-Kien;Seong, Se-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.8
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    • pp.2968-2974
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    • 2010
  • Nowadays, the PV systems have been focused on the grid connection between the power source and the grid. The PV inverter can be considered as the core of the whole system because of an important role in the grid-interfacing operation. An important issue in the inverter control is the load current regulation. In the literature, Proportional Integral (PI) controller, which is normally used in the current-controlled Voltage Source Inverter (VSI), cannot be a satisfactory controller for an AC system because of the steady-sate error and the poor disturbance rejection, especially in high-frequency range. Compared with conventional PI controller, Proportional Resonant (PR) controller can introduce an infinite gain at the fundamental frequency of the AC source; hence it can achieve the zero steady-state error without requiring the complex transformation and the de-coupling technique. Theoretical analyses of both PI and PR controller are presented and verified by simulation and experiment. Both controller are implemented in a 32-bit fixed-point TMS320F2812 DSP processor and evaluated on a 3kW experimental prototype PV Power Conditioning System (PCS). Simulation and experimental results are shown to verify the controller performances.

A Modeling and Driving Performance for CCFL Applied to the Display Unit (표시장치에 적용되는 CCFL의 모델과 인버터 구동)

  • Kim, Cherl-Jin;Yoo, Byeong-Kyu;Yoon, Shin-Yong
    • Proceedings of the KIEE Conference
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    • 2005.04a
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    • pp.197-199
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    • 2005
  • The Cold cathode fluorescent lamp (CCFL) are widely used to illuminate the liquid crystal display(LCD). Ballasts are required for CCFL because the lamp need high starting voltage and behave negative dynamic resistant characteristics in the desired region of operation. Dimming methods of CCFL are used to pulse frequency modulation(PFM) or pulse width modulation(PWM). In this paper, CCFL driving and control circuit is designed by half-bridge type series and parallel resonant inverter that variable frequency modulation method to control the output voltage current. The validity of this study is confirmed from the simulation and experimental results.

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