• ETRI Journal
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• v.44 no.4
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• pp.695-707
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• 2022

As for the insufficient nature of the fossil fuel resources, the renewable energies as alternative fuels are imperative and highly heeded. To deliver the required electric power to the industrial and domestic consumers from DC renewable energy sources like fuel cell (FC), the power converter operates as an adjustable interface device. This paper suggests a new boost structure to provide the required voltage with wide range gain for FC power source. The proposed structure based on the boost converter and the quazi network, the so-called SBQN, can effectively enhance the FC functionality against its high operational sensitivity to experience low current ripple and also propagate voltage and current with low stress across its semiconductors. Furthermore, the switching power losses have been decreased to make this structure more durable. A full operational analysis of the proposed SBQN and its advantages over the conventional and famous structures has been compared and explained. Furthermore, a prototype of the single-phase converter has been constructed and tested in the laboratory.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.84-86
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• 2009

Isolated boost converter is desirable in the dc/dc converter applications where isolation is required and a large step up is needed. In this paper, it is proposed and analyzed the isolated boost converter which can step up low input voltage to high output voltage using transformer. Instead of using a conventional scheme, the proposed converter has the reset winding for volt-sec balance of transformer. Finally, the validity of the proposed isolated boost converter is verified by simulation.

• 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.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1484-1494
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• 2017

We present a two-stage inverter with high step-up conversion ratio engaging modified finite-set Model Predictive Control (MPC) for utility-integrated photovoltaic (PV) applications. The anticipated arrangement is fit for low power PV uses, the calculated efficiency at 150 W input power and 19 times boosting ratio was around 94%. The suggested high-gain dc-dc converter based on Cockcroft-Walton multiplier constitutes the first-stage of the offered structure, due to its high step-up ability. It can boost the input voltage up to 20 times. The 3S current-source inverter constitutes the second-stage. The 3S current-source inverter hires three semiconductor switches, in which one is functioning at high-frequency and the others are operating at fundamental-frequency. The high-switching pulses are varied in the procedure of unidirectional sine-wave to engender a current coordinated with the utility-voltage. The unidirectional current is shaped into alternating current by the synchronized push-pull configuration. The MPC process are intended to control the scheme and achieve the subsequent tasks, take out the Maximum Power (MP) from the PV, step-up the PV voltage, and introduces low current with low Total Harmonic Distortion (THD) and with unity power factor with the grid voltage.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.2
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• pp.79-87
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• 2008

Boost Converters have been used to step up and regulate the low and widely varing voltage from the fuel cell. A transformer-less boost converter which does not have lossy, bulky, and costly high frequency transformers has an advantage in applications where galvanic isolation is not required. In this paper a new transformer-less boost converter is proposed. The proposed boost converter has practically usuable 6 to 8 times of step up ratio and is suitable for fuel cell applications due to very low input and output current ripples. The proposed converter is verified through the theorical analysis, simulation and experimental waveform.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.91-93
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• 2020

In recently days using distributed power generation systems constructed with boost type dc-dc converters is being extremely popularized because of the rising need of environment friendly energy generation power systems. In this paper a new constructed An efficient Step-Up DC-DC Converter for DC Grid Applications s proposed to boost a low level DC voltage(36-80V) to high DC bus (380V) level. When comparing to other step-up converters, the proposed topology has a reduced number of switching devices, can make high quality power with lower input current ripple and has wider input DC voltage range. Finally, the performance of the proposed topology is presented by simulation results with 350W hardware prototype.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.189-192
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• 2001

A new phase-shifted parallel-input/series-output dual converter for high-power step-up applications has been proposed. It features a high efficiency due to the low switch turn-off voltage, low device stresses, low ripple contents, and a fast control-to-output dynamics compared to its PWM counterpart. To confirm the validity of the proposed converter, experimental results from an 800W, 350Vdc prototype are presented.

• Journal of Electrical Engineering and Technology
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• v.11 no.4
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• pp.860-868
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• 2016

A bidirectional DC-DC converter (BDC) is an indispensable electrical unit for the electric vehicles (EVs). High efficiency, high power density, isolation, light weight and reliability are all essential requirements for BDC. In this paper, a 3 kW BDC for the battery charger of EVs is proposed. The proposed converter consists of a half-bridge structure on the primary side and an isolation transformer and a synchronous rectifier structure on the secondary side. With this topology, minimum number of switching devices are required for bidirectional power flow between the two dc buses of EVs. The easy implementation of the synchronous rectification gives advantages in terms of efficiency, cost and flexibility. The proposed BDC achieves high efficiency when operating in both modes (step-up and step-down). A 3 kW prototype is implemented to verify theoretical analysis and the performance of the proposed converter.

• Proceedings of the KIEE Conference
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• 2008.11b
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• pp.77-78
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• 2008

Recently, a fuel cell is remarkable for new generation system. The fuel cell generation system converts the chemical energy of a fuel directly into electrical energy. The fuel cell generation is characterized by low voltage and high current. For connecting to utility, it needs both a step up converter and an inverter. The step up converter makes DC link and the inverter changes DC to AC. In this paper, full bridge converter and the single phase inverter are designed and installed for fuel cell. Simulation and experiment verify that fuel cell generation system could be applied for the distributed generation. In this paper, the 1.5kW active clamp current-fed full bridge converter employing MOSFETs is operated to discharge the battery whereas a voltage-fed half bridge converter employing IGBTs is operated to charge the battery.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.2
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• pp.142-148
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• 2006

In this paper, authors propose a novel step-up AC-DC converter operated with power factor correction (PFC) and with high efficiency. The proposed converter behaves with discontinuous current control (DCC) of input current. The input current waveform in the proposed converter is got to be a discontinuous sinusoid form in proportion to magnitude of at input voltage under the constant duty cycle switching. Therefore, the input power factor is nearly unity and the control method is simple. In the general DCC converters, the switching devices are turned-on with the zero current switching (ZCS). But turn-off of the switching devices is done at the maximum current. To achieve a soft switching at turn-off, the proposed converter uses a new partial resonant circuit, which results in the very low switching loss and the high efficiency of converter.