• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.598-599
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• 2010

Low Voltage DC/DC Converter(LDC) is the power conversion unit for suppling the power to the auxiliary battery and the electric loads on vehicle. LDC has the capabilities of stability and efficient control method so that the electric loads are fully functional. This paper proposes a control method based on one PI-controller and verifies the stable performance from simulation.

• Journal of Power Electronics
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• v.16 no.6
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• pp.2005-2015
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• 2016

A high-step-up DC/DC converter for renewable energy systems is proposed. The proposed structure provides high voltage gain by using a coupled inductor without the need for high duty cycles and high turn ratios. The voltage gain is increased through capacitor-charging techniques. In the proposed converter, the energy of the leakage inductors of the coupled inductor is reused. This feature reduces the stress on the switch. Therefore, a switch with low ON-state resistance can be used in the proposed converter to reduce losses and increase efficiency. The main switch is placed in series with the source. Therefore, the converter can control the energy flow from the source to the load. The operating principle is discussed in detail, and a steady state analysis of the proposed converter is conducted. The performance of the proposed converter is verified by experimental results.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.2
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• pp.219-226
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• 2019

This paper describes the development of a 500W DC/DC converter for use with a thermoelectric module(TEM). A thermoelectric device is a structure in which a P-type semiconductor and an N-type semiconductor are electrically connected in series and thermally connected in parallel. There is a feature that an electromotive force is generated by making a temperature difference between both surfaces of a thermoelectric element. This feature can be used as a renewable power source without the need for fossil energy. The proposed converter boosts the low generation voltage of the thermoelectric element to secure the voltage for the grid connection. This converter is a combination of a resonant converter for boosting and a boost-converter for output voltage control. This structure has an advantage that a voltage can be stepped up at a high efficiency and precise output voltage control is possible. We carry out simulations and experiments to verify the validity.

• Journal of IKEEE
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• v.23 no.3
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• pp.1054-1060
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• 2019

A extension of the high boost voltage-lift DC-DC converter with large conversion ratio has been proposed in this paper. The proposed extension is combined the switched-inductor cell (SL-cell) and modular voltage cell (MV-cell). The proposed structure can achieve the large voltage conversion without high duty-cycle and the low voltage of the components. Moreover, the PID controller for novel SL-MV voltage-lift DC-DC converter also introduces. This technique a good-performance output voltage can kept constant with an good transient performance when the output load is suddenly changed. In order to prove the theoretical analysis, the experimental setup has been built for the DC load of $150[{\Omega}]$ and $300[{\Omega}]$. In addition, the transient of output voltage has been tested to determine the controller. Experimental results validate the effectiveness of the theoretical analysis proving the satisfactory converter performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.6
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• pp.9-17
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• 2011

The high-power LED (Light Emitting Diode) which is recently gaining popularity as a digital light source has such advantages as low power consumption, long life, fast switching speed, and high efficiency. Thus, many efforts are being made to use the high-power LEDs for general lighting. This paper proposes LED driving circuit uses a DC/DC converter that can recover energy to compensate for the current variations caused by changes in LED equivalent resistance following a temperature change instead of serial resistance. The maximum input voltage of this DC/DC converter has low voltage variations by temperature change when the rated current is formed. In order to return current to the input side, we need a high boosting at low power. Thus, to improve the low efficiency of power converter, the power converter can be configured in such a way to gather the powers of low-capacity DC/DC converters and return the total power. Experiments showed that the proposed system improved efficiency compared to the conventional LED drive using the existing DC/DC converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.6
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• pp.557-563
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• 2014

This study deals with a resonant converter of an anti-start air conditioner compressor for commercial vehicles. The anti-start air conditioner compressor must generally have a high current, high efficiency, a low volume, and a low weight. To reduce the switching losses and voltage and current stresses of the device, the anti-start air conditioner compressor applies the full-bridge L-C resonant converter topology. Hardware parameters are designed to have a wide voltage range, and the switching frequency range of the L-C resonant converter is determined. Simulation is implemented using PSIM and an experiment is performed to verify the proposed converter.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.67-76
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• 2012

Due to the increasing amount of applications of power electronic ac-dc converters, it is necessary to design a single-stage converter that can reliably perform both buck and boost operations. Traditionally, this can be achieved by double-stage conversion (ac/dc-dc/dc) which ultimately leads to less efficiency and a more complex control system. This paper discusses two types of modern ac-dc converters. First, the novel impedance-source ac-dc converter, abbreviated as custom Z-source rectifier, is analyzed; and then, switched inductor (SL) Z-source ac-dc converter is proposed. This paper describes the Z-source rectifiers' operating principles, the concepts behind them, and their superiorities. Analysis and simulation results show that the proposed custom Z-source rectifier can step up and step down voltage; and the main advantage of the SL Z-source ac-dc converter is its high step-up capability. Low ripple of the output dc voltage is the other advantage of the proposed converters. Finally, the SL Z-source ac-dc converter is compared with the custom Z-source ac-dc converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.56-64
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• 2007

Recently, the high frequency link boost DC/DC converter has been used widely for PCS (Power Conditioning System) because of the requirements of small size and low cost. However, the high frequency link boost DC/DC converters applied the conventional voltage-fed converter and current-fed converter have some problems like high conduction losses and high surge voltage due to high circulating current and leakage inductance, respectively. To improve these problems, a novel secondary LLC (called SLLC) series resonant converter is proposed in this paper and its theoretical analysis, its operating waveforms, simulation and experimental results for a boost DC/DC converter using SLLC series resonant topology verifies the proposed topology. 800W experimental prototype is tested.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1085-1088
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• 2007

A new DC-DC converter was designed for gate driver circuit using low temperature poly-Si TFT technology. To achieve high efficiency and small area, we proposed a cross-coupled type DC-DC converter which converts 5V of input voltage to 9V of output voltage and supplies 120$\mu$A of current to load. Its efficiency is 92.9% and the area is reduced as much as 19% compared to the previously reported latch type DC-DC converter.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.2
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• pp.95-103
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• 2007

Dynamic voltage scaling (DVS) is a well-known and effective power management technique. While there has been research on slack distribution, voltage allocation and other aspects of DVS, its effects on non-voltage-scalable devices has hardly been considered. A DC-DC converter plays an important role in voltage generation and regulation in most embedded systems, and is an essential component in DVS-enabled systems that scale supply voltage dynamically. We introduce a power consumption model of DC-DC converters and analyze the energy consumption of the system including the DC-DC converter. We propose an energy-optimal off-line DVS scheduling algorithm for systems with DC-DC converters, and show experimentally that our algorithm outperforms existing DVS algorithms in terms of energy consumption.