• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.824-827
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• 1987

The miniturization of a DC-DC converter circuit in connection with the stability is investigated in this paper. As both the capacitance of the smoothing capacitor and the inductance of the reactor are reduced by raising the switching frequency, it is known that the stability of the buck converter declines with the switching frequency but the buck-boost converter has a nearly uniform stability. Furthermore, that in the frequency region above a certain switching frequency the buck-boost converter is suitable for the miniturization of circuit is cleared.

• Journal of Power Electronics
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• 제16권3호
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• pp.1046-1055
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• 2016

A controller to mitigate the destabilizing effect of constant power load (CPL) is proposed for a DC/DC buck-boost converter. The load profile has been considered to be predominantly of CPL type. The negative incremental resistance of the CPL tends to destabilize the feeder system, which may be an input filter or another DC/DC converter. The proposed sliding mode controller aims to ensure system stability under the dominance of CPL. The effectiveness of the controller has been validated through real-time simulation studies and experiments under various operating conditions. The controller has been demonstrated to be robust with respect to variations in supply voltage and load and capable of mitigating instabilities induced by CPL. Furthermore, the controller has been validated using all possible load profiles, which may arise in modern-day DC-distributed power systems.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.223-226
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• 2003

This paper presents a high-frequency ZVS-PWM boost chopper-fed DC-DC converter with a single active auxiliary edge-resonant snubber which is used for power conditioner such as solar photovoltaic generation and fuel cell generation. The experimental results of boost chopper fed ZVS-PWM DC-DC converter are evaluated. In audition to its switching voltage and current waveforms, and the switching v-i trajectory of the power devices are discussed and compared with the conventional hard switching DC-DC converter treated here. The temperature performance of IGBT module,, efficiency, and EMI noise characteristics of this ZVS-PWM DC-DC converter using IGBTs are measured and evaluated from an experimental point of view.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.571-575
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• 2002

Generation of electrical energy faces many problems today. Solar power converters were used to convert the electrical energy from the solar arrays to a stable and reliable power source. The object of this paper is to analyze and design DC-DC converters in a solar energy system to investigate the performance of the converters. A DC-DC converter can be commonly used to control the power flow from solar cell to load and to achieve maximum power point tracking(MPPT), DC-AC converter can also be used to modulate the DC power to AC power being applied on common utility load. A DC-DC converter is used to boost the solar cell voltage to constant 360(V) DC link and to ensure operation at the maximum power point tracking, If a wide input voltage range has to be covered a boost converter is required. In this paper, author described that simulation and experimental results of PV system contain solar modules, a DC-DC converter(boost type chopper), a DC-AC converter (3-phase inverter) and resistive loads.

• 전기전자학회논문지
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• 제23권1호
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• pp.273-279
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• 2019

A high boost dc-dc converter based on the switched-inductor cell (SL-cell) is suggested in this paper. The suggested converter can provide a high voltage gain that is more than 6. Moreover, the voltage gain can be easily increased by extending a SL cell or a modular voltage boost stage. This paper shows the key waveforms, the operating principles at the continuous conduction mode (CCM), and a comparison between the suggested converter and the other non-isolated converters. In addition, the extension of the suggested converter is presented. The simulation results were shown to reconfirm the theoretical analysis.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.412-415
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• 2015

본 논문에서는 진동에너지 수확을 위한 MPPT(Maximum Power Point Tracking) 제어 CMOS 인터페이스 회로를 설계하였다. 제안된 회로는 AC-DC 변환기, MPPT 제어회로, DC-DC 부스트 변환기, 그리고 PMU(Power Management Unit)로 구성된다. AC-DC 변환기는 진동소자(PZT)에서 출력되는 AC 신호를 DC 신호로 변환해주는 역할을 하며, MPPT 제어회로는 진동소자로부터 최대전력을 수확하여 효율을 높이는 역할을 한다. DC-DC 부스트 변환기는 AC-DC 변환기에서 공급된 에너지를 원하는 값으로 승압 및 안정화 시키는 역할을 하며 PMU를 통해 부하로 에너지를 전달한다. AC-DC 변환기는 효율 특성이 좋은 능동 다이오드를 이용한 전파정류기를 사용하였으며, DC-DC 부스트 변환기는 제어 회로가 간단한 쇼트키 다이오드를 사용한 구조를 사용하였다. 제안된 회로는 0.35um CMOS 공정으로 설계되었으며, 설계된 칩의 면적은 $950um{\times}920um$이다.

• 조명전기설비학회논문지
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• 제29권8호
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• pp.70-75
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• 2015

High Step-up DC-DC Converters have been demanded for renewable energy applications. Transformer or coupled inductor is generally used to boost output voltage of converters. This methods can relatively obtain high voltage than others, whereas have heavy weight and high cost. To complement these disadvantages, we studied transformerless high step-up DC-DC converter. In various transformerless topologies, Boost converters combined with Cockcroft-Walton have studied. In this paper, we proposed a symmetrical Cockcroft-Walton circuit for transformerless high step-up DC-DC converter. Finally, we simulated proposed converter to compare with existing converter. As a result, proposed converter has higher duty ratio or lower cost than existing transformerless converters which are discussed in this paper.

• 조명전기설비학회논문지
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• 제26권3호
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• pp.31-39
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• 2012

This paper presents a high efficiency coupled inductor boost DC-DC converter that uses a simple clamp circuit and the coupled inductor and thus overcomes output voltage limit of the conventional boost converter. The proposed converter solves problems of voltage stress of the power semiconductor switch and reverse recovery of the output diode using a simple clamp circuit composed of a diode and a capacitor, and thus the converter improves its total efficiency. In this paper, the operational principle of the proposed converter is explained by each mode and then a design example for the prototype converter based on the explanation is shown. And good performance of the proposed converter is verified through experimental results of the prototype converter that is implemented with the designed circuit parameters.

• Journal of Power Electronics
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• 제14권2호
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• pp.203-216
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• 2014

In the conventional dc-dc converter, a pair of additional diode and the adjacent passive component capacitor/inductor can be added to the circuit with an X-shape connection, which generates a family of new topologies. The novel circuits, also called diode-assisted dc-dc converter, enhance the voltage boost/buck capability and have a great potential for high step-up/step-down power conversions. This paper mainly investigates and compares conventional dc-dc converter and diode-assisted dc-dc converter in wide range power conversion from the aspects of silicon devices, passive components requirements, electro-magnetic interference (EMI) and efficiency. Then, a comprehensive comparison example of a high step-up power conversion system was carried out. The two kinds of boost dc-dc converters operate under the same operation conditions. Mathematical analysis and experiment results verify that diode-assisted dc-dc converters are very promising for simultaneous high efficiency and high step-up/step-down power conversion in distributed power supply systems.

• Journal of Power Electronics
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• 제13권5호
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• pp.766-778
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• 2013

The depletion of natural resources and renewable energy sources, such as photovoltaic (PV) energy, has been highlighted for global energy solution. The PV power control unit in the PV power-generation technology requires a high step-up DC-DC converter. The conventional step-up DC-DC converter has low efficiency and limited step-up ratio. To overcome these problems, a novel high step-up DC-DC converter using an isolated switched capacitor cell is proposed. The step-up converter uses the proposed transformer and employs the switched-capacitor cell to enable integration with the boost inductor. The output of the boost converter and isolated switched-capacitor cell are connected in series to obtain high step-up with low turn-on ratio. A hardware prototype with 30 V to 40 V input voltage and 340 V output voltage is implemented to verify the performance of the proposed converter. As an extended version, another novel high step-up isolated switched-capacitor single-ended DC-DC converter integrated with a tapped-inductor (TI) boost converter is proposed. The TI boost converter and isolated-switched-capacitor outputs are connected in series to achieve high step-up. All magnetic components are integrated in a single magnetic core to lower costs. A prototype hardware with 20 V to 40 V input voltage, 340 V output voltage, and 100 W output power is implemented to verify the performance of the proposed converter.