• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.1
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• pp.16-28
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• 2014

This paper presents a novel high-power-factor circuit topology of AC to AC current-fed type high frequency resonant inverter which includes the function of power factor correction(PFC) in the proposed inverter to operate the AC input block with high power factor. The proposed circuit topology of AC to AC current fed type high resonant inverter removes DC link electrolytic capacitor and has also the one of power factor correction(PFC) in the inverter circuit without an additional PFC circuit since the input current by constituting it in parallel as an unit inverter, which assumes the class-E high frequency resonant inverter of conventional current-fed type, flows in the form of the resultant current flowing through each constant current reactor($L_{d1}$, $L_{d2}$). The circuit analysis of proposed inverter is generally described by adopting the normalized parameters and the evaluation of its operating characteristics are conducted by using the parameters such as the ratio of switching and resonant frequency(${\mu}$), coupling coefficient(k) and so on. An example of procedure for circuit design based on the characteristic values obtained from the theoretical analysis is presented. To confirm the validity of the theoretical analysis, the experimental results are also presented. In the future, the proposed inverter shows it can be practically used as power supply system for induction heating application, DC-DC converter etc.

• Journal of Power Electronics
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• v.18 no.4
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• pp.955-964
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• 2018

In this paper, an active capacitor-diode-switch (CDS) snubber is proposed for L-type current-fed isolated DC-DC converters. The proposed CDS-clamped converter has a number of advantages. It can achieve wide range zero-voltage switching (ZVS) on two switches, a continuous input current with a low ripple, a reduction of one active switch and high efficiency. The operating principles, analysis and parameter design guideline are presented. A 300 W prototype is built to test the proposed converter. Simulation and experimental results are shown at 30 V input voltage and 400 V output voltage.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.266-269
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• 1999

Several power factor correction(PFC) circuits are presented to achieve high PF electronic ballast for both voltage-fed and current-fed electronic ballast. The proposed PFC circuits use valley-fill(VF) type DC-link stages modified from the conventional VF circuit to adopt the charge pumping method for PFC operations during the valley intervals. In voltage-fed ballast, charge pump capacitors are connected with the resonant capacitors. In current-fed type, the charge pump capacitors are connected with the additional secondary-side of the power transformer. The measured PF and THD are higher than 0.99 and 15% for all proposed PFC circuits. The lamp current CF is also acceptable in the proposed circuits. The proposed circuit is suitable for implementing cost-effective electronic ballast.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2795-2797
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• 1999

Several power factor correction(PFC) circuits are presented to achieve high PF electronic ballast for both voltage-fed and current-fed electronic ballast. The proposed PFC circuits use valley-fill(VF) type DC-link stages modified from the conventional VF circuit to adopt the charge pumping method for PFC operations during the valley intervals. In voltage-fed ballast, charge pump capacitors are connected with the resonant capacitors. In current-fed type, the charge pump capacitors are connected with the additional secondary-side of the power transformer. The measured PF and THD are higher than 0.99 and 15% for all proposed PFC circuits. The lamp current CF is also acceptable in the proposed circuits. The proposed circuit is suitable for implementing cost-effective electronic ballast.

• Journal of IKEEE
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• v.25 no.4
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• pp.741-749
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• 2021

This paper presents the current-fed type LLC AC to DC high frequency resonant converter capable of ZVZCS(Zero-Voltage and Zero-Current Switching). The current-fed type LLC AC to DC high frequency resonant converter proposed in this paper could operate not only in ZVS(Zero-Voltage Switching) operation by connecting the resonant capacitors(C₁, C₂) in parallel across the switching devices but also in ZCS(Zero-Current Switching) operation of the secondary diode. The ZVS and ZCS operations can reduce the turn-on loss of the switching devices and the turn-off loss of the secondary diodes, respectively. The circuit analysis of current-fed type LLC AC to DC high frequency resonant converter proposed in this paper is addressed generally by adopting the normalized parameters. The operating characteristics of proposed LLC AC to DC high frequency resonant converter were also evaluated by using the normalized control parameters such as the normalized control frequency(μ), the normalized load resistor(λ) and so on. Based on the characteristic values through the characteristics of evaluation, an example of the design method of proposed LLC AC to DC high frequency resonant converter is suggested, and the validity of the theoretical analysis is confirmed using the experimental results and PSIM simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.6
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• pp.515-522
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• 1999

Several power factor correction(PFC) circuits are presented to achieve high PF electronic ballast for both v voltage-fed and current-f,어 ek'Ctronic ballast. The proposed PFC circuits use valley-fil[(VF) type DClink s stages modified from the conventional VF circuit to adopt the charge pumping method for PFC operations d during the valley intervals. In voltage-fed ballast, charge pump capacitors are connected with the resonant c capaCltor In current-fed type, the charge pump capacitors are connc'Ctc'Cl with the additional second따y-side of t the power transformer. The measured PF is higher than 0.99 and THD is about 10% for all proposed PFC c circuits. The lamp current CF is also acceptable in the proposed circuits. The proposed circuit is suitable for i implementing cost longrightarroweffective electronic ballast.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.587-590
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• 1991

It is general to make the circuit analysis of current-fed type inverter driven by current source with rippleless input under the assumption of infinite induction Ld in direct current reactor(DCL). This paper focusing on the fact that Ld has bounded value in real circuit, examines operating characteristics by analysis of static state characteristics of current type inverter driven by voltage source and compares it with the operating characteristics of the circuit driven by current source.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.189-194
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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. The theoretical results are in good agreement with the experimental ones. In the future the proposed circuit is considered to be useful for induction heating applications.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.225-230
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• 2000

This paper describes a double-ended current fed push-pull type high frequency resonant inverter used as the power supply for wax-sealing. The proposed inverter can realize ZVS operation by using resonant capacitor to ZVS capacitor and has some merits not only reduction of switch current distribution but also extension of load range compare to the conventional single-ended current fed push-pull type high frequency resonant inverter. This analysis of proposed circuit uses normalized parameter ad characteristic estimation which is needed in each step before design is generally described according to normalized frequency($\mu$), normalized resistance(λ) and parameters. It is also presented as an example of method of the circuit design based on estimation analysis values from theoretical analysis. The theoretical analysis is proved through experiment and this circuit shows that it can be used practically as the power supply system for wax-sealing and DC-DC converter.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1324-1326
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• 2000

This paper proposes a Current-Fed Push Pull type DC-DC converter using LCCC Resonant circuit and Zero Voltage Switching function to reduce turn on and off loss at the switching instants. This paper have the advantage which is able to operating safely in load short, because of DC reactor is connected with resonance reactor in order to supply a fixed current with low ripple from DC Power supply. The capacitor ($C_1$, $C_2$) connected in switch are common using as resonance capacitor and ZVS capacitor. The analysis of the proposed Current-Fed Push Pull type DC-DC converter is generally described by using normalized parameter, and we have evaluated characteristic values which is needed to design a circuit. We confirm a rightfulness theoretical analysis by comparing a theoretical values and experimental values obtained from experiment using MOSFET as switching devices.