• 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.

• Journal of Power Electronics
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• v.13 no.1
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• pp.1-8
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• 2013

This paper presents a resonant non-inverting buck-boost converter in which all switches operate under ZCS conditions. In a symmetric configuration, a CLL resonant tank along with an inverter arm and a rectifying diode are employed. The diode is turned off at ZCS and hence the problem of its reverse recovery is obviated also. As a result switching losses and EMI are reduced and switching frequency can be increased. The converter can work at DCM and CCM depend on the switching frequency and the load-current. Experimental results from a 200W/200KHz laboratory prototype verify operation of the proposed converter and the presented theoretical analysis.

• Journal of Power Electronics
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• v.3 no.2
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• pp.90-98
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• 2003

This paper presents a performance analysis in steady-state of a novel type Auxiliary Resonant Commutation Snubber-linked 3-level 3-phase voltage source soft switching inverter suitable and acceptable for high-power applications in comparison with other three types of 3-level 3-phase voltage source soft switching inverters. This soft switching inverter operation which can operate under a condition of Zero Voltage Switching (ZVS). The practical steady -state performances of this inverter are illustrated and evaluated on the basis of the experimental results.

• Journal of Power Electronics
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• v.13 no.4
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• pp.626-635
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• 2013

An analysis of the junction capacitance in resonant rectifiers which has a significant impact on the operating point of resonance circuits is studied in this paper, where the junction capacitance of the rectifier diode is to decrease the resonant current and output voltage in the circuit when compared with that in an ideal rectifier diode. This can be represented by a simplified series resonant equivalent circuit and a voltage transfer function versus the normalized operating frequency at varied values of the resonant capacitor. A low voltage to high voltage push-pull DC/DC resonant converter was used as a design example. The design procedure is based on the principle of the half bridge class-DE resonant rectifier, which ensures more accurate results. The proposed scheme provides a more systematic and feasible solution than the conventional resonant push-pull DC/DC converter analysis methodology. To increase circuit efficiency, the main switches and the rectifier diodes can be operated under the zero-voltage and zero-current switching conditions, respectively. In order to achieve this objective, the parameters of the DC/DC converter need to be designed properly. The details of the analysis and design of this DC/DC converter's components are described. A prototype was constructed with a 62-88 kHz variable switching frequency, a 12 $V_{DC}$ input voltage, a 380 $V_{DC}$ output voltage, and a rated output power of 150 W. The validity of this approach was confirmed by simulation and experimental results.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.59-64
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• 2008

Recently, DC-DC choppers must be increased switching frequency in order to achieve a small size, a light weight and a low noise. However, the switches of chopper are subjected to high switching power losses and switching stresses. As a result of these, the chopper system bring on a low power efficiency. To improved these, this paper is studied on a new DC-DC chopper of high efficiency operated with soft switching(that is, zero current switching and zero voltage switching, ZVCS), of semiconductor switches using in chopper. The soft switching operation is applied to a partial resonant method that the switches operate at zero current of inductor and zero voltage of capacitor in resonant circuit. And the partial resonant circuit makes use of a inductor using step-up and a snubber capacitor, the circuit topology of chopper is simple. Some simulative results on computer and experimental results confirm the validity of analytical results of the DC-DC chopper.

• Journal of Power Electronics
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• v.4 no.4
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• pp.237-245
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• 2004

In this paper, a two-switch high frequency flyback transformer linked zero voltage soft switching PWM DC-DC power converter implemented for distributed DC- feeding power conditioning supplies is proposed and discussed. This switch mode power converter circuit is mainly based on two main active power semiconductor switches and a main flyback high frequency transformer linked DC-DC converter in which, two passive lossless quasi-resonant snubbers with pulse current regeneration loops for energy recovery to the DC supply voltages composed of a three winding auxiliary high frequency pulse transformer, auxiliary capacitors and auxiliary diodes for inductive energy recovery discharge blocking due to snubber capacitors are introduced to achieve zero voltage soft switching from light to full load conditions. It is clarified that the passive resonant snubber-assisted soft switching PWM DC-DC power converter has some advantages such as simple circuit configuration, low cost, simple control scheme, high efficiency and lowered noises due to the soft switching commutation. Its operating principle is also described using each mode equivalent circuit. To determine the optimum resonant snubber circuit parameters, some practical design considerations are discussed and evaluated in this paper. Moreover, through experimentation the practical effectiveness of the proposed soft switching PWM DC-DC power converter using IGBTs is evaluated and compared with a hard switching PWM DC-DC power converter.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.3
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• pp.146-152
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• 2015

In this paper, we propose a boost DC-DC converter using a modification of the passive auxiliary resonant snubber circuit with a DC-DC converter in a typical active auxiliary resonant snubber-bridge inverter. The proposed boost DC-DC converter is small compared to the DC-DC converter according to the soft-switching scheme that requires a general auxiliary switch by realizing the soft switching operation as a DC-DC converter which does not require an auxiliary switch. It is light-weight, switch the turn-on and turn-off switching loss at the time of the superposition of the voltage and current is extremely small, so small. And the reduction of the surge voltage and current of the switch. In addition, the proposed boost DC-DC converter has a high efficiency over a wide load characteristics change area than conventional hard switching PWM boost converter using an RC snubber loss.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1951-1953
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• 2004

In this study, we propose a small high voltage power supply which use a half-bridge ZCS resonant and Cockroft-Walton on circuit, for ESP (Electrostatic Precipitator). This power supply transfers energy from ZCS resonant inverter to step-up transformer and the transformer secondary is applied to the Cockroft-Walton circuit for generating high voltage as discharging source of electrodes. It is highly efficient because its amount of switching losses are reduced by virtue of the current resonant half-bridge inverter, and also due to the small size, low parasitic capacitance in the transformer stage owing to the low number of winding turns of the step up transformer secondary combined with the Cockroft-Walton circuit. From these results, the best operational condition is obtained at the switching frequency of 9 kHz and the duty ratio of 50 % in this ESP.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1038-1040
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• 2001

A half-bridge type resonant current injection type high frequency resonant inverter using ZVS(Zero-Voltage-Switching) used as power source of induction heating at high frequency is presented in this paper. This proposed inverter can reduce distribution of the switching current because of using the current of serial resonant circuit to the input current of the parallel one. The analysis of the proposed circuit is generally described by using the normalized parameters, the principle of basic operating and the its characteristics are estimated by the parameters such as switching frequency and load resistance. According to the calculated characteristics value, this paper proves the validity of theoretical analysis through the Pspice.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.169-172
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• 2000

This paper describes a Push-Pull type high frequency resonant inverter composed of consolidation of boost converter circuit and resonant inverter circuit. By using a boost converter circuit, the proposed inverter can obtain a twice input voltage of resonant circuit and reduce a secondary turn ratios. also, by using both switching device of boost-converter and resonant circuit, the number of switching device can be reduced by half, the analysis of the proposed circuit was generally described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future, this proposed inverter shows that is can be practically used as a power source system for the lighting equipment of discharge lamp, induction heating applications.