• Journal of Power Electronics
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• v.15 no.4
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• pp.910-919
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• 2015

The use of a PV grid-connected inverter with non-isolated topology and without a transformer is good for improving conversion efficiency; however, this inverter has become increasingly complicated for eliminating leakage current. To simplify the complicated architecture of traditional three-level dual buck inverters, a new dual Buck three-level PV grid-connected inverter topology is proposed. In the proposed topology, the voltage on the grounding stray capacitor is clamped by large input capacitors and is equal to half of the bus voltage; thus, leakage current can be eliminated. Unlike in the traditional topology, the current in the proposed topology passes through few elements and does not flow through the body diodes of MOSFET switches, resulting in increased efficiency. Additionally, a multi-loop control method that includes voltage-balancing control is proposed and analyzed. Both simulation and experimental results are demonstrated to verify the proposed structure and control method.

• Journal of Power Electronics
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• v.15 no.4
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• pp.899-909
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• 2015

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.67-73
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• 2011

Ceramic metal halide lamps have been widely used due to long lifetime, high luminous efficiency and good colour rendering. In this paper, we developed dimming control system of electronic ballast for 70W ceramic metal halide lamp by using 1-10V interface. The proposed electronic ballast is consists of EMI filter, Full-wave rectifier, Active PFC, DBI(Dual Buck Inverter), Igniter and control circuit.It enables to supply both low-frequency rectangular wave voltage and current to the lamp by using DBI(Dual Bcuk Inverter) structure. By using 1-10V interface, the system that able to dimming the lamp is demonstrated by P-spice simulation and experimental results.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.1-7
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• 2010

Ceramic metal halide lamps have been widely used due to long lifetime, high luminous efficiency and good colour rendering. 35[W] ceramic metal halide lamps has very different characteristics between ignition state and steady state. The developed electronic ballast is satisfied to both ignition state and steady state characteristics by using a micro-controller. The proposed electronic ballast is consists of EMI filter, Full-wave rectifier, Active PFC, DBI(Dual Buck Inverter), Igniter and control circuit. It enables to supply both low-frequency rectangular wave voltage and current to the lamp by using DBI(Dual Bcuk Inverter) structure.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.154-155
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• 2010

본 논문은 최소의 스위칭 소자를 이용한 절연형 Full-Bridge (FB) buck-boost DC-DC 컨버터를 제안한다. 기존의 dual-bridge 방식을 이용한 buck-boost 컨버터와는 달리 본 논문에서 제안한 방식은 변압기 1차측에만 스위칭 소자를 사용하고 2차측에는 다이오드 정류기를 사용한다. 필요한 buck-boost 기능을 구현하기 위하여 입력단에 2개의 인덕터를 추가하여 2 phase interleaved 방식으로 동작을 한다. 500 W 의 prototype을 제작하여 본 논문에서 제안한 방식의 타당성을 실험적으로 검증 한다.

• Journal of IKEEE
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• v.15 no.4
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• pp.319-323
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• 2011

In this paper presents a new model of dual-mode synchronous buck converter with dynamic control for mobile applications was proposed. The proposed circuit can operate at 2.5MHz with supply voltage 2.5V to 5V for low ripple and minimum inductor and capacitor size, which is suitable for single-cell lithium-ion battery supply mobile applications. For high efficiency, the proposed circuit adopts synchronous type and dynamic control. The proposed circuit is designed by using the device parameter of TSMC 0.18um BCD process and the performance is evaluated by Cadence spectre. Experimental board level results show the maximum conversion efficiency is 96% at 100mA load current.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.11
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• pp.635-644
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• 2002

Many generating units can be in parallel connection to one battery and inverter. However, one of the biggest problems we encountered is that wind speed is fluctuated sharply in accordance with the unstable weather conditions. To solve this problem, we need energy storage equipment such as storage lead-acid battery. We design a system and analyze its modeling so that it supplies a stable power to the load through DC-AC inverter part. In this paper, we applied dual step-up/down buck-boost converter and dual high-frequency half-bridge converter to the proposed system. These converters are used to store energy in the battery regardless of the change of the wind speed. The operation process of two proposed types of converters for high-power battery charging is discussed along with simulation and experimental result. We design a charging circuit which is applicable in the actual wind power generation system for 30kw and confirm the circuit's validity.

• Journal of Power Electronics
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• v.19 no.2
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• pp.431-442
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• 2019

This paper proposes a unified high-frequency bipolar buck-boost (UHFBB) control strategy for a dual-active-bridge (DAB), which is derived from the classical buck and boost DC/DC converter. It can achieve optimized current stress of the switches and soft switching in wider range. The UHFBB control strategy includes multi-control-variables, which can be achieved according to an algorithm derived from an accurate mathematical model. The design method for the parameters, such as the transformer turns ratio and the inductance, are shown. The current stress of the switches is analyzed for selecting an optimal inductor. The analysis is verified by the experimental results within a 500W prototype.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.940_941
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• 2009

Dual Buck Inverter구조를 가지는 70W CDM 램프용 전자식 안정기의 제어기를 설계하였다. 전자식 안정기는 EMI filter, Active PFC, Dual Buck Inverter, Igniter, SMPS로 구성 된다. 제어기는 크게 2개로 구분 할 수 있다. MC33262를 이용하여 Inverter의 전압, 전류를 센싱 받아 70kHz의 Zero Voltage Switching을 위한 제어기와 시간의 경과에 따라 PFC의 출력 전압 제어, Ignition Pulse 제어 및 무부하 보호를 위한 제어기로 구성되어 있다. 본 논문은 ATmega8을 이용하여 제어기를 설계하였고 실험으로 시간의 경광 따른 안정기의 제어가 안정적인 동작을 하고 있음을 증명하였다.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.286-287
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• 2018

Recently, the development of renewable energy using solar energy is drawing attention. One of these PV systems, the Dual buck Inverter, is one of the topologies used in conjunction with the system, characterized by high efficiency and shoot-through reduction. However, current distortion appears severely in grid connection. So, in this paper, the method of compensation through PR controller was verified through simulation as an analysis of current distortion components and a control method to improve them.