• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.65-72
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• 2004

This paper proposes the novel boost input type resonant AC/DC converter. Since the proposed converter is single stage topology, it controls both of the input power factor and the output voltage at the same time, and resultingly obtains the high power factor of 99% with average current mode pulse width modulation. Especially, to accomplish the zero voltage switching, the resonance between the leakage inductance and external capacitor is used. For the theoretical consideration of the proposed converter, the six operation modes divided by means of current path are discussed, and the resonance characteristics in steady state are analyzed. To verify the validity of the proposed converter, a 200[W]($120[V_AC],\; 출력\; 48[V_DC],\; 4[A]$prototype converter was built and its experimental results were presented in this paper.

• Journal of IKEEE
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• v.20 no.1
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• pp.45-53
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• 2016

This paper presents a CMOS interface circuit for vibration energy harvesting with MPPT (Maximum Power Point Tracking). In the proposed system a PMU (Power Management Unit) is employed at the output of a DC-DC boost converter to provide a regulated output with low-cost and simple architecture. In addition an MPPT controller using FOC (Fractional Open Circuit) technique is designed to harvest maximum power from vibration devices and increase efficiency of overall system. The AC signal from vibration devices is converted into a DC signal by an AC-DC converter, and then boosted through the DC-DC boost converter. The boosted signal is converted into a duty-cycled and regulated signal and delivered to loads by the PMU. A full-wave rectifier using active diodes is used as the AC-DC converter for high efficiency, and a DC-DC boost converter architecture using a schottky diode is employed for a simple control circuitry. The proposed circuit has been designed in a 0.35um CMOS process, and the designed chip occupies $915{\mu}m{\times}895{\mu}m$. Simulation results shows that the maximum power efficiency of the entire system is 83.4%.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.6
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• pp.16-28
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• 2012

This paper proposes a quasi Z-source converter(QZSC) with a diode-capacitor output filter to improve the output DC voltage boost ability. The proposed converter has the same quasi Z-source network topology compared with the conventional converter. But the proposed method is adopted a diode-capacitor filter as its output filter, since the conventional method is used an inductor-capacitor as its output filter. Under the condition of the same input-output DC voltage, the proposed method has more lower shoot-through duty ratio than the conventional method. Also, because the proposed converter has same voltage boost factor under lower shoot-through duty ratio compared with the conventional converter, the proposed converter can be operated with the lower capacitor voltage of Z-source network and the lower input current. To confirm the validity of the proposed method, PSIM simulation and a DSP based experiment were performed to acquire the output DC voltage 120[V] under the input DC voltage 80[V]. And the capacitor voltage and inductor current in Z-source network, the output voltage of each converter were compared and discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.301-310
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• 2007

Bidirectional DC-DC converters allow transfer of power between two dc sources, in either direction. Due to their ability to reverse the direction of flow of power, Dey are being increasingly used in many applications such as battery charge/dischargers, do uninterruptible power supplies, electrical vehicle motor drives, aerospace power systems, telecom power supplies, etc. This Paper Proposes a new bidirectional Sepic/Zeta converter. It has low switching loss and low conduction loss due to auxiliary communicated circuit and synchronous rectifier operation, respectively Because of positive and buck/boost-like DC voltage transfer function(M=D/1-D), the proposed converter is very desirable for use in distributed power system. The proposed converter also has both transformer-less version and transformer one.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.160-163
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• 2004

A passive lossless turn-on/turn-off snubber network is proposed for the boost PWM converter. Previous AC/DC PFC Boost Converter perceives feed forward signal of output for average current-mode control. Previous Boost Convertor, the Quantity of input current will be decreased by the decrease of output current in light load, and also Power factor comes to be decreased. Also the efficiency of converter will be decreased by the decrease of power factor. The proposed converter presents the good PFC, low line current harmonic distortions and tight output voltage regulations using energy recovery circuit. All of the semiconductor devices in the converter are turned on under exact or near zero voltage switching(ZVS). No additional voltage and current stresses on the main switch and main diode occur. To show the superiority of this converter is verified through the experiment with a 640W, 100kHz prototype converter.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.815-818
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• 2004

The emerging applications such as reliable back-up power system and renewable energy call for high boost U-n converter. The conventional topologies to get high output voltage are using flyback circuit, cascade converters, and coupled inductor DC-DC converter. They have the stress and loss related to the leakage energy which results in low efficiency Tn this paper, novel high boost converter is presented. It has a structure of cascade boost converter but only one switch. Therefore, drive circuit is simple and extreme duty ratio is eliminated. To verify the proposed circuit, theoretical analysis and experimental results has been done using a prototype power supply.

• Journal of Power Electronics
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• v.14 no.5
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• pp.899-907
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• 2014

This paper proposes a single-phase bidirectional AC/DC converter topology applied in V2G systems, which consists of an inverter and a bidirectional non-inverting buck-boost converter. This topology can operate in four modes: buck charging, boost charging, buck discharging and boost discharging with high input current quality and unity input power factor. The inverter switches at line frequency, which is different from conventional voltage source inverters. A bidirectional buck-boost converter is utilized to adapt to a wider charging voltage range. The modulation and control strategy is introduced in detail, and the switching patterns are optimized to reduce the current ripple. In addition, the semiconductor losses are analyzed. Simulation and experimental results demonstrate the validity and effectiveness of the proposed topology.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.135-140
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• 1997

A highly efficient single-phase/three-phase compatible ac-to-dc converter is proposed and analyzed, which includes three identical single-phase both soft-switched dc-to-dc converter with boost converter as a pre-regulator for input power factor correction (PFC). The proposed converter structure provides a cost reduction and easy implementation of compatibility between single-phase 220V and three-phase 220V/380V with their inputs in delta or wye connections.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.320-321
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• 2018

A non-isolated high voltage gain bidirectional DC-DC converter for battery storage system has been presented in this paper. The topology is composed of boost converter and traditional SEPIC converter. The proposed converter can achieve higher voltage conversion ratio with reduced voltage and current stresses in the switches. In additional, a reduced number of components are included in this topology. The PSIM simulation is carried to validate the analysis and operation of the converter.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.414-416
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• 2005

In this paper, a new scheme of current programmed control for three phase PWM AC-AC converter is presented. By considering only the magnitude components, a similar scheme in the DC-DC converter can be extended to the three phase PWM AC-AC converter. The proposed current programmed control will be well adopted into various converter topologies though three phase PWM AC-AC boost converter is treated as an example. The converter analysis is carried out by applying the vector DQ transformation to obtain physical insight into the converter operation. Finally, the experiment result shows the validity of the proposed scheme.