• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2783-2785
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• 1999

A fast switching gate driver suitable for high performance self resonant electronic ballasts is presented. The proposed gate driver has negligible switching loss and driving loss owing to pnpn structure and zero voltage switching( ZVS ); moreover, the gate driver has frequency control capability. Therefore, a self resonant inverter using proposed gate driver can operate as external exciting resonant inverters. The experiments confirm that the proposed gate driver perform the desired operations over full power control range for 40W fluorescent lamp electronic ballast.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.348-351
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• 2001

In this paper, voltage-fed high frequency resonant inverter of instantaneous current phaser control method used to DC voltage source separated is proposed. In the output control method, a novel circuit type of phase shift driving signal method with CVCF illustrated, also the operation principle of the proposed circuit is described in detail and its characteristics are presented as to normalized parameters. According to the each mode, in order to the circuit analysis and characteristic evaluation of the state equation are derives and present used to normalized parameter. In the future, this proposed inverter show that it can be practically used as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.223-225
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• 2005

This paper presents a novel prototype of a current source resonant inverter using insulated gate bipolar transistors for driving a streamer reactor, streamer generation technology has been recognized as one of the best methods for water treatment, disinfection, industrial wastes utilization, and so on. However, some technological difficulties related to efficient streamer production have been significant problems restricting streamer usage in the industrial plants. Introduced in this paper is a pulse density modulated high frequency inverter for a plasma generate, which is developed with the aim to improve power conversion and control characteristics of the streamer reactor by using advances in power electronic technology. The developed system implements the feedforward control-based pulse density modulation control scheme with pulse width modulation feedback control strategy to compensate temperature and other environmental influences on streamer discharge.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.263-266
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• 2002

In this paper, It is indicating that an issues of the conventional boost converter for high frequency induction heating. To improve those issues, it is proposed, simulated and analyzed that the current resonant circuit, simulated. As the result, we knew that the proposed circuit has a good point to improve the waveform of input current and to make high efficiency. On the other side, in the inverter for the high current power supply, it is proposed that the high frequency inverter of the half bridge topology, be done the circuit analysis to extract the optimal circuit parameter. It is making sure of the soft switching operating by the inductor to reverse parallel connected on the inverter main switch, decreasing the surge voltage when the switch is turn-off by compulsion, and repressing the switch current and bringing the high current amplitude operation by the multi resonance.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.328-332
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• 1996

Current controlled inverter is the device which gives fast and accurate current output response for current command Existing current controlled inverters have no way but to take a narrow bandwidth due to resonance of output filter. In this paper, High performance current controlled inverter with multiloop structure is designed and modeling is executed in that basis. This paper realizes the high performance current controlled inverter with the bandwidth above resonant frequency, controls proposed inverter by analog controller, analyzes the performances through simulation and tests 2kW prototype system.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.66-72
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• 1999

This paper deals with the output characteristics of resonant PWM inverter type X-ray generators connected to different DC power units i.e. a single phase full bridge rectifier, a three phase full bridge rectifier and a power storage unit(PSU). The quality of X-ray beam depends on the pulsating waveforms of DC voltage supplied to the X-ray tube. In a X-ray generator, the waveform of DC output voltage can be affected from affected from harmonic distortion of DC input power. When a tube voltage waveform is distorted, the property of X-ray beam such as reproducibility, linearity and dose can be reduced. Therefore, we compared DC output waveforms and dose with three type of DC power units and show the experimental results in this paper.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.1
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• pp.72-81
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• 2009

This paper presents quasi-resonant type high power factor ac power supply for atmospheric pressure plasma cleaning system adopting three phase PFC boost converter and it's control method. The presented ac power supply consists of single phase H-bridge inverter, step-up transformer for generating high voltage and three phase PFC boost converter for high power factor on source utility. Unlikely to the traditional LC resonant converter, the propose one has an inductor inside only. A single resonant takes place through the inside inductor and the capacitor from the plasma load modeled into two series capacitor and one resistance. The quasi-resonant can be achieved by cutting the switching signal when the load current decrease to zero. To obtain power control ability, the propose converter controlled by two control schemes. One is the changing output pulse period scheme in the manner of PFM(Pulse Frequency Modulation) control. On the other, to provide more higher power to load, the DC rail voltage is directly controlled by the 3-phase PFC boost converter. The significant merits of the proposed converter are the uniform power providing capability for high quality plasma generation and low reactive power in AC and DC side. The proposed work is verified through digital simulation and experimental implementation.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.584-588
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• 2001

A conventional power supply to drive a microwave oven has ferro-resonant transformer and high voltage Capacitor(HVC). Though it is simple, transformer is bulky, heavy and has low-efficiency. To improve this defect a high frequency inverter type power supply has been investigated and developed in recent years. But, because of additional control circuit and switching device, inverter-type power supply is more expensive than conventional one. In this study, A new pulse power supply for Microwave Oven using novel HVC embedded high frequency transformer is proposed for down-sizing, cost reduction, and efficiency emprovement of Inverter type power supply. Also, equivalent circuit model is derived by impedance measurements. And the operation of proposed pulse power supply is verified by simulations and experimental results.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2638-2640
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• 1999

This paper proposes a current-fed type high frequency inverter using a soft switching technology Zero-Voltage-Switching to reduce turn on and off loss at the switching. The analysis of the proposed circuit was described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future, the proposed circuit is considered to be useful for induction heating applications.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.233-235
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• 2005

Non-contact power supply (NCPS), as a clean and safe energy supply concept has been applying wildly. Comparing with the conventional transformer the non-contact transformer has a large air gap between the long primary winding and the secondary winding. Due to it, the non-contact transformer has increased leakage inductance and reduced magnetizing inductance. So the high frequency series resonant converter has been widly used on the non-contact power supply system for transferring the primary power to the secondary one, from what a high influence voltage can be gained on the secondry coil even though the large air gap exists. However, it still has the disadvantages of the load sensitive voltage gain characteristics when load is changing. In this paper, we propose a fuzzy logic controller to adjust the frequency of the inverter to track the resonat which is changing when the load is change.