• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.447-448
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• 2012

With wireless power transfer the of ECR device the designed with a high-frequency and high frequency AC power to the device that may enter the high-frequency switching inverter to be possible. In this paper, is designed to 2MHz switching frequency by using ECR device capable of 2MHz Class ${\Phi}_2$ inverter was designed as a wireless power transmission.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.892-897
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• 2007

This paper presents the output filter design and the output characteristic analysis by cut-off frequency set up of the LCR filter on NPC multi-level inverter with trap-filter. The single-phase NPC three-level inverter operates at low switching frequency. The proposed LC trap filter is comprised of a conventional LCR output filter, by using LC trap filter the need for high damping resistor and low LC cut-off frequency is eliminated. Also. low damping resistor is increased the output filter system. The multilevel inverter system used NPC type inverter in proper system for high power application and controller is used DSP(TMS320C31). The effectiveness of proposed system confirmed the validity through SPICE simulation and experimental results.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.371-376
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• 2009

The Power Conditioning System is Power Transfer System which make array DC current to the Grid sinusoidal current. These are Low Frequency Transformer Inverter Type, High Frequency Transformer Inverter Type and Transformer-less Type. Low Frequency Transformer Type has a Excellent Isolation property, but doesn't have competitiveness in Size and Cost. Also High Frequency Transformer Type has a good Isolation property but there are many steps in Power transfer Switching. Nowadays, Transformer-less Type inverter change a transformer to DC/DC Converter which is small and cost effective. In this paper shown the DC/DC Converter Transformer-less Type multi-string inverter design and simulation. The Control Algorithm will be introduced and Simulation was accomplished.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.927-935
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• 1994

Detailed analysis of the commutation circuit of the proposed wide-frequency current source inverter is given. In this inverter a spike-limit circuit and a precommutation circuit are used. The spike-limit circuit is intended to limit spike voltage which is arising during commutation time in a current source inverter, and the precommutation circuit to reuse the energy which flows from main inverter to spike-limit circuit during commutation time to aid commutation. Thus voltage stress of main thyristor is minimized. Since this inverter can be made up of thyristors for phase control, it has some advantage in high voltage and high power application.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.5
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• pp.481-487
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• 2005

Proposed induction-heated system is innovative system which applied special high-frequency power circuit technique for thermal converse technique and IH(Induction-Heating) magnetic induction heating generated from induction-heated metallic package that is for distillation unit. In this occurs not burning, so that the working environment can be improved. This electromagnetic induction heating technique is used high frequency inverter, By using high frequency inverter high frequency alternative current in the range of [kHz] can be made with conventional alternative current. In this contribution IGBT module is used for high frequency inverter. This paper proposes new fluid heating method. Which is operated as follows. Working coil, which is wrapped outside of pipeline, makes the eddy current. Inside of heating vessel in isolated pipeline the specially designed stainless metallic package is inserted, which can be heated by eddy current losses. And then In this paper are discussed action analysis and characteristics analysis of 5[kW] class full-bridge resonant inverter system and resonant metallic package. In addition, by using this system, how high-efficiency heater is developed and application of system are also discussed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.1
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• pp.34-39
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• 2002

Most X-ray generator had been used do rectifier type transformer high tension generator which is supplied in a clinical diagnosis. But it is difficult to miniaturize and become light weight. Also, because the ripple rate of tube voltage is high, X-ray generating efficiency is very low. Therefore, it is supplied gradually from abroad being developed high tension generator for inverter type X-ray generator which use semi-conductor switching element for electric power that have high speed switching ability to solved these problem. But, semi-conductor element of big capacity are used by X-ray tube's big consumption power and diffusion is difficult in the small size hospital because production cost is ascending by doing digital control through DSP and product price becomes expensive. Therefore, in this paper, design and manufactured CR type voltage divider for feedback control of tube voltage of high frequency resonance type inverter and high tension transformer for high frequency to apply economical diffusion type X-ray generator which have wide output voltage and load extent. It is Proved do X-ray generator and stability of X-ray tube's output characteristics through an experiment.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.1
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• pp.3-8
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• 1987

The conventional autosequentially commutated current-fed inverter (ASCI) is widely employed with the induction motor drives for speed control. Howener, this inverter has a limit of high power and high frequency indution motor drives. One of the limitations is to be found in the commutation capacitors in the main circuit of this inverter. A new current-fed gate turn-off thyristor (GTO) inverter is developed. This inverter is composed of the main GTO bridge configuration and the improved energy rebound circuit (ERC)without the commutation capacitor. This inverter works stable at high frequency from light load to heavy one. The improved ERC is used not only to rebound the load reactive power to the dc link, but also to return the power in the load to the ac source. The new GTO inverter circuit and the characteristics of the inverter induction motor drives are explained and analyzed.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.368-371
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• 2000

The PLL(Phase-Locked Loop) techniques re employed to make the switching frequency of a resonant inverter follow the resonant frequency which may vary due to the load variations during operation. The conventional design guide of PLL is not suitable in these case since the inverter characteristics are not considered. In this paper the phase characteristics of a resonant inverter is analysed and added to the closed loop. And the design of PLL with digital phase detector is illustrated for the output frequency to track the resonant frequency of the inverter.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.19-27
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• 2007

This paper presents a novel soft-switching PWM utility frequency AC to high frequency AC power conversion circuit incorporating boost H-bridge inverter topology, which is more suitable and acceptable for cost effective consumer induction heating applications. The operating principle and the operation modes are presented using the switch mode equivalent circuits and the operating voltage and current waveforms. The performances of this high-frequency inverter using the latest IGBTs are illustrated, which includes high frequency power regulation and actual efficiency characteristics based on zero voltage soft-switching(ZVS) operation ranges, and the power dissipation as compared with those of the conventional type high frequency inverter. In addition, a dual mode control scheme of this high frequency inverter based on asymmetrical pulse width modulation(PWM) and pulse density modulation(PDM) control scheme is discussed in this paper in order to extend the soft switching operation ranges and to improve the power conversion efficiency at the low power settings. The power converter practical effectiveness is substantially proved based on experimental results from practical design example.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.7
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• pp.272-277
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• 1986

The system that follows to the resonance frequency of high frequency MOSFET inverter and varies according to the changes of load characteristics is proposed. Also we suggested a method how to select the resonant load type between series and parallel circuit for a given inverter type. It leads to the conclusion that in the case of high impedance loads, parallel resonant circuits are preferable, on the other hand, for low impedance loads, series resonant circuits are more preferable. For frequency tracking, a PLL circuit is used as main control element to detect the phase difference of current and voltage of load. The realized apparatus composed of control circuit and voltage type full-bridged MOSFET elements as main parts of inverter. A stable frequency follow-up characteristics are obtained for 1.2MHz, 1.5KW high frequency output and power is always supplied to the load with unity power factor.