• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.42-43
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• 2015

본 논문은 출력 전류 리플이 없는 소프트 스위칭 승압 컨버터를 제안한다. 제안하는 컨버터는 결합 인덕터와 보조 커패시터와 보조 인덕터를 사용하여 스위치의 영전압 스위칭이 가능하도록 하여 스위칭 손실을 줄이고 출력 전류 리플을 제거하였다. 제안하는 회로의 동작원리를 설명하고, 시뮬레이션으로 확인한 후 60[W]급 하드웨어 시작품을 이용하여 검증하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.154-162
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• 2000

A technique to suppress the low frequency ripple voltage of the DC output ${\gamma}$oltage in three-phase buck d diode rectifiers is presented in this paper. The proposed pulse frequency modulation method is employed to r regulate the output voltage of the buck diode rectifiers and guarantee zero-current switching of the switch over the Vvide load range. The pulse frequency control method used in tIns paper shows generally good p performance such as low THD of the input line current and unity power factor. In addition, the pulse f freιluency method can be effectively used to suppress the low frequency voltage ripple appeared in the dc output voltage. The proposed technique illustrates its validity and effectiveness through the respective s simulations and experiments.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.2
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• pp.7-14
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• 2005

This paper presents a method to reduce torque ripple of brushless DC motor by compensating phase delay due to winding inductance. For considering torque ripple comes from the phase winding inductance, torque equation of one phase is derived as Fourier series that is function of the delay. From the equation, also the resultant equation that the current delay is compensated is derived. It is validated that the compensated torque has a form of Fourier series for rectangular wave that is ideal torque, and torque ripple is reduced, consequently. Experimental method for the compensation is realized by replacing switching pattern of inverter by pattern of compensated rotor position. The effectiveness of the proposed method to reduce torque ripple has been demonstrated by the simulation and experimental results using 3 phase 4 pole brushless DC moor.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.341-344
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• 1991

Current controlled pulse width modulation(PWM) for voltage source inverter(VSI) is one of the control method which controls the current directly so that we can perform vector control because it reduces the orders of differential equations of the induction machine. This paper propose a Fuzzy current controlled PWM which properly minimize a current ripple using Fuzzy theory in a constant switching frequency. This technique is applied to an electrical drive system with an induction machine(IM) by simulation. By comparison with the known classical method such as ramp comparison, hysteresis band method, our contribution shows the better performances.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2020-2022
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• 1997

An active clamp forward converter is proper for minimization and basically makes high efficiency of the system because of soft switching type. Especially, when applied to forward converter, it widens the control range of duty ratio and is suitable for high input voltage. In other hand, the current doubler has high utility efficiency of transformer and reduces output current ripple because it always transfers the power through the transformer and has two inductor with opposite slope. So, this paper explained the conduction mode of an active clamp forward converter with the current doubler rectifier.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.447-454
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• 1998

This paper describes a modeling and current control techniques of Distribution static condenser (D-STATCON) for power factor compensation. The current control is based on the predictive and the space vector PWM scheme. The predictive current controlled PWM D-STATCON can maintain its performance with power factor compensation and fixed switching frequency. By using the space vector control low ripple and offset in the current and the voltage as well as fast dynamic responses are achieved with a small DC link capacitance employed.

• Journal of Power Electronics
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• v.13 no.1
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• pp.9-19
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• 2013

In this paper, a ripple input current embedded switched-inductor Z-source inverter (rESL-ZSI) and a continuous input current embedded switched-inductor Z-source inverter (cESL-ZSI) are proposed by inserting two dc sources into the switched-inductor cells. The proposed inverters provide a high boost voltage inversion ability, a lower voltage stress across the active switching devices, a continuous input current and a reduced voltage stress on the capacitors. In addition, they can suppress the startup inrush current, which otherwise might destroy the devices. This paper presents the operating principles, analysis, and simulation results, and compares them to the conventional switched-inductor Z-source inverter. In order to verify the performance of the proposed converters, a laboratory prototype was constructed with 60 $V_{dc}$ input to test both configurations.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.81-88
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• 2007

This paper proposes a coupled inductor-based rectifier of a Three-Level (TL) DC/DC converter and compares the rectification methods of a TL converter. The CICDR- TL (Coupled Inductor Current Doubler Rectifier Three-Level) converter achieves ZVS (Zero Voltage Switching) for the switches in a wide load range. CDR (Current Doubler Rectifier) and CICDR Three-Level converter have low voltage and current ripple. Advantages and disadvantages of topology compared to the rectifier of bridge, center-tap, CDR, and CICDR are discussed. Experimental estimation results are obtained on a 27V, 60A DC/DC TL converter prototype for the 1.8kW, 40kHz IGBT based experimental circuit.

• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.159-161
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• 2007

$CO_2$ laser sees that is most suitable to get this effect through minimum formation damage and advantage that is root enemy of effect that happen in minimum cellular tissue depth of 0.1mm is stable living body organization or internal organs institution. Formation damage by ten can be related in formation's kind or energy density, length of evaporation time. If shorten evaporation time, surroundings cellular thermal damage 200 - because happen within 400ums laser beam in rain focus sacred ground surroundings cellular tissue without vitiation me by evaporation Poe of very small floor as is clean steam can. Application is possible to vulva cuticle cousins by a paternal aunt quantity, uterine cancer, cuticle tumor by laser system that $CO_2$ laser gets into standard in obstetrics and gynecology application. Because effect that super pulse output is ten enemies of laser if uniformity one pulse durations are short almost is decreased, most of all pulse module special quality of pulse style $CO_2$ laser for obstetrics and gynecology mode stabilization by weight very, in this research to get into short pulse duration and higher frequency density, do switching by high frequency in DC-DC Converter output DC's ripple high frequency to be changed, high frequency done current ripple amount of condenser for output filter greatly reduce can. Ripple of output approximately to Zero realization applying possible inductor realization through a special quality experiment do.

• Journal of Power Electronics
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• v.11 no.4
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• pp.499-506
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• 2011

This paper presents an interleaved active-clamping zero-voltage-switching (ZVS) forward-flyback converter without an output choke. The presented topology has two active-clamping circuits with two separated transformers. Because of the interleaved operation of the converter, the output current ripple will be reduced. The proposed converter can approximately share the total load current between the two secondaries. Therefore, the transformer copper loss and the rectifier diodes conduction loss can be decreased. The output capacitor is made of two series capacitors which reduces the peak reverse voltage of the rectifier diodes. The circuit has no output inductor and few semiconductor elements, such that the adopted circuit has a simpler structure, a lower cost and is suitable for high power density applications. A detailed analysis and the design of this new converter are described. A prototype converter has been implemented and experimental results have been recorded with an ac input voltage of 85-135Vrms, an output voltage of 12V and an output current of 16A.