• 전력전자학회논문지
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• 제19권2호
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• pp.116-123
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• 2014

In this paper, a soft-switching scheme for the PWM interleaved buck converter(IBC) is newly proposed to obtain the advantages of both the conventional PWM interleaved buck and resonant converters such as ease of control, reduced switching losses and stresses, and low EMI. To obtain the soft-switching action, the proposed scheme employs an auxiliary circuit, which is added to the conventional interleaved buck converter and used to achieve soft-switching for both the main switches and the output diodes while not incurring any additional losses due to the auxiliary circuit itself. In this paper, the basic operations are discussed and design guidelines are presented. And through the experimental results, the usefulness of the proposed converter is verified.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.43-48
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• 2006

This paper presents a scheme on the characteristics of induction motor under the combination of linear & non-linear loads at the three phase 4-wire power distribution system. Under the combination operation of single & three phase load, voltage unbalance will be generated and current unbalance will be more severe by the dropped voltage quality. All power electronic converters used in different types of electronic systems can increase harmonic disturbances by injecting harmonic currents directly into the feeder grid of three phase 4-wire. Harmonic current may cause torque to decrease. Moors may also overheat or become noisy and torque oscillation in the rotor can lead to mechanical resonance and vibration.

• 전력전자학회논문지
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• 제23권6호
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• pp.397-402
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• 2018

In this study, a high-efficiency flyback converter that uses a soft-switching auxiliary circuit is proposed. The structure of the proposed converter adds an inductor, switch, diode, and capacitor to the conventional flyback converter. The switch in the auxiliary circuit and the main switch are turned on and off under soft-switching conditions. Therefore, the switching losses of the proposed flyback converter are considerably smaller than those of conventional flyback converters. The performance of the proposed flyback converter is validated by experiments on a 100 W single-output flyback converter prototype, and design guidelines are presented.

• 전력전자학회논문지
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• 제24권5호
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• pp.372-378
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• 2019

This study proposes a new zero-current-zero-voltage-transition (ZCZVT) boost-flyback converter using a soft switching auxiliary circuit. The proposed converter integrates the boost and flyback converters to increase the voltage with a low duty ratio. The main and auxiliary switches turn the ZCZVT conditions on and off. Thus, the proposed converter has high efficiency. The voltage gain at the steady state is derived, and the inductor volt-second balance and the design guidelines are presented. Finally, the performance of the proposed converter is validated by experimental results from a 200 W, 30 V DC input, 400 V DC output, and 200 kHz boost-flyback converter prototype.

• 센서학회지
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• 제33권3호
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• pp.134-138
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• 2024

In this study, we propose a ternary D flip-flop using tristate ternary inverters for an energy-efficient ternary circuit design of sequential logic. The tristate ternary inverter is designed by adding the functionality of the transmission gate to a standard ternary inverter without an additional transistor. The proposed flip-flop uses 18.18% fewer transistors than conventional flip-flops do. To verify the advancement of the proposed circuit, we conducted an HSPICE simulation with CMOS 28 nm technology and 0.9 V supply voltage. The simulation results demonstrate that the proposed flip-flop is better than the conventional flip-flop in terms of energy efficiency. The power consumption and worst delay are improved by 11.34% and 28.22%, respectively. The power-delay product improved by 36.35%. The above simulation results show that the proposed design can expand the Pareto frontier of a ternary flip-flop in terms of energy consumption. We expect that the proposed ternary flip-flop will contribute to the development of energy-efficient sensor systems, such as ternary successive approximation register analog-to-digital converters.

• 한국전기전자재료학회논문지
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• 제25권12호
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• pp.1021-1027
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• 2012

In this paper, multi-string power balancing system for streetlight was developed. Accordingly, the components of the system was developed, unit converters, MPPT control unit, a bank of Li-ion battery and controls the charging and discharging. Loss by improving the efficiency of the system through the parallel operation of the unit converter output will be reduced. And by improving the efficiency of the system through the unit converter parallel operation, output losses will be reduced. Charging and discharging efficiency of the device used in a typical solar streetlight is calculated based on the maximum power input. Because of the variation of the input power has a weakness. In this paper, flexible to changes in the input, and a system was developed to minimize the cost per watt. Measure the performance of the unit module from the system, the result was more than 91%. And the charging capacity 12 V/105 Ah, module power 180 W, respectively. Should expect to be able to improve performance through continuous monitoring in the future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.269-272
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• 1988

This paper introduces a method to reduce the reactive power required by electronic converters. The instantaeous reactive power is calculated and compensated by the current controlled PWH voltage source converter connected parallel between the power lines and the converter. A high performance current control technique which is based on the current deviation vector is used for the PWM converter as compensator of reactive power. Accurate compensation of the reactive power and t control system ensuring fast response to the sudden change of loaf are attained. The converter structure and control scheme are discussed. Simulation of the system is performed.

• 전기학회논문지P
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• 제61권4호
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• pp.161-167
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• 2012

Energy conversion systems such as power inverters and converters are basically significant in establishing photovoltaic power systems to enhance power effectiveness. This paper proposes a new converter control method by using the Lyapunov redesign approach. We construct the proposed control mechanism linearly composed of nominal control and auxiliary control laws. The former is generally designed through a well-known power electronic technology and the latter is implemented to compensate real-time control error due to uncertain natures of converter systems in practice. For realizing adaptive control capability in the proposed control mechanism, a control parameter vector is estimated by utilizing a steepest descent based optimization method. We carry out numerical simulation with Matlab(c) software to demonstrate reliability of the proposed converter control system and conduct a comparative study to prove its superiority by comparing with a generic converter control methodology.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.189-197
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• 2017

This paper elaborates two novel proposed topologies (type-I and type-II) of the high step-up DC-DC converter using switched inductor and voltage multiplier cell. The advantages of these proposed topologies are the less voltage stress on semiconductor devices, low device count, high power conversion efficiency, high switch utilization factor and high diode utilization factor. We analyze the Type-II topologies operating principle and mathematical analysis in detail in continuous conduction mode. High-intensity discharge lamp for the automotive application can use the derived topologies. The proposed converters give better performance when compared to the existing types. Also, it is found that the proposed type-II converter has relatively higher voltage gain compared to the type-I converter. A 40 W, 12 V input voltage and 72 V output voltage has developed for the type-II converter and the performances are validated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.31-33
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• 2008

A novel lossless current sensing technique for a synchronous buck converter is presented. The inductor DCR method is generally used as a low cost and lossless current sensing technique of DC/DC converters. It is however difficult to obtain the accurate current value for the conventional DCR method because the inductor resistance varies depending on the operating frequency. In order to overcome this problem, an improved current sensing technique is proposed, which has the separated DC and AC sensing circuits. The concept and operation of the proposed method are explained and the experimental results are provided to show its effectiveness.