• Journal of Power Electronics
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• 제18권3호
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• pp.651-661
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• 2018

This paper suggests a new non-isolated high voltage gain DC-DC converter with two switches. The proposed two-switch converter has the following characteristics: a high voltage gain, a continuous input current with a small ripple, a reduction in the size of the inductor, and a simple circuit with only a few elements. A theoretical analysis, guidelines for parameter selection, and a comparison with conventional non-isolated high step-up converters are presented. A prototype of 250 W is set up to demonstrate the correctness of the proposed converter. Results obtained from simulations and experiments are presented.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.11-13
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• 2019

This paper proposes a novel high step-up non-isolated DC-DC converter, suitable for regulating dc bus in various inherent low voltage micro sources especially for photovoltaic (PV) and fuel cell sources. This novel high voltage Non-isolated Boost DC-DC converter topology is best replacement, where high voltage conversion ratio is required without the transformer and also need continuous input current. Since the proposed topology utilizes the stack-based structure, the voltage gain, and the efficiency are higher than other conventional non-isolated converters. Switches in this topology is easier to control since its control signal is grounding reference. Also, there is no need of extra gate driver and extra power supply for driver circuit, which reduces the cost and size of system. In order to show the feasibility and practicality of the proposed topology principle operation, steady state analysis and simulation result is presented and analyzed in detail. To verify the performance of proposed converter and theoretical analysis 360W laboratory prototype is implemented.

• 전기학회논문지P
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• 제54권4호
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• pp.171-178
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• 2005

The proposed dual-output DC-DC converter that bases on flyback converter can obtain two output voltage with non-isolated main-output and isolated sub-output at the same time using single-winding high frequency transformer. It can solve problems in multi-winding converter that use one main-switch, and also control quality of isolated sub-output voltage can be improved by additional sub-switch to the second. For analysis and design of the proposed converter system, converters are classified as operation mode from switching state and are become modeling by applying state space averaging method. Steady-state characteristics and dynamic characteristics are analyzed by DC component and perturbation component from state space averaging model. From experiment converter, validity of analysis and design for the propose converter system is confirm.

• Journal of Power Electronics
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• 제19권5호
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• pp.1278-1288
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• 2019

A DC-DC Non-Isolated Three-Port Cuk-Cuk (NI-TPCC) converter for interfacing renewable energy sources (RESs) such as Fuel Cell (FC) and Photovoltaic (PV) energy with a DC load is presented in this paper. It features single-stage power conversion from both of the input ports to the load port. The proposed NI-TPCC converter is designed based on the classical Cuk converter. The operational modes and power flow are analyzed in the continuous conduction mode (CCM), and the relationships among the port voltages are derived. Continuous currents in all three ports with less ripple enhance the performance of a fuel cell and its operating life. Furthermore, the output inductor is shared with both of the input ports, which reduces the number of active and passive components. The effectiveness of the designed NI-TPCC converter has been validated through simulation and experimental results.

• Journal of Power Electronics
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• 제19권2호
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• pp.394-402
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• 2019

This paper proposes a single-phase non-isolated onboard battery charger (OBC) for electric vehicles (EVs) that only uses small film capacitors at the DC-link of the AC-DC converter. In the proposed charger, an isolated DC-DC converter for low-voltage batteries is used as an active power decoupling (APD) circuit to absorb the ripple power when a high-voltage (HV) battery is charged. As a result, the DC-link capacitance in the AC-DC converter of the HV charging circuit can be significantly reduced without requiring any additional devices. In addition, some of the components of the proposed circuit are shared in common for the different operating modes among the AC-DC converter, LV charging circuit and active power filter. Therefore, the cost and volume of the onboard battery charger can be reduced. The effectiveness of the proposed topology has been verified by the simulation and experimental results.

• Journal of Power Electronics
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• 제19권5호
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• pp.1069-1073
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• 2019

In this paper, an alternative non-isolated DC-DC converter with a high voltage boosting capability is proposed. Two inductors are used and one of them has its flux linkage increases during its charging period to achieve a high step-up voltage gain. Among the three integrated capacitors, one portrays the partial characteristic of the switched-capacitor technique, while the other two are connected in series across the load. With the two switches controlled using the same duty cycle, the proposed topology demonstrates the merits of a higher and wider range of step-up voltage gain when compared with recent topologies. In addition, a reduction in loss is induced and a higher efficiency is ensured with all the voltage stresses constrained within the output voltage. Operation of the proposed converter is analyzed and validated through experimental results obtained with a prototype.

• Journal of Electrical Engineering and Technology
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• 제1권3호
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• pp.343-350
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• 2006

This paper introduces a new high efficient bi-directional, non-isolated DC/DC converter. Through variations of the topology of the conventional Cuk converter, an optimum bi-directional DC/DC converter is proposed. Voltage and current in the proposed DC/DC converter are continuous. Furthermore, the efficiency in both step-up and step-down mode is improved over that of the conventional bi-directional converter. To prove the validation for the proposed converter, simulations and experiments are executed with a 300W bi-directional converter.

• 전력전자학회논문지
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• 제17권2호
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• pp.142-149
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• 2012

The independently regulated dual-output LLC resonant converter using only one power stage and one control IC is proposed in this paper. The conventional dual-output LLC resonant converter requires the extra non-isolated DC/DC converter to obtain the tightly regulated slave output voltage, which results in the low power conversion efficiency and high production costs. On the other hand, since the proposed converter controls the master and slave output voltages by pulse width modulation(PWM) and pulse frequency modulation(PFM), it can achieve tightly regulated dual output voltages without the additional non-isolated DC/DC converter. Therefore, it features a high efficiency and low cost. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a 40W LED driver prototype are presented.

• 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.

• 한국정보전자통신기술학회논문지
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• 제12권1호
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• pp.99-105
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• 2019

전기 자동차의 배터리 충전용 OBC는 주로 PFC회로와 절연형 DC-DC 컨버터 회로를 포함한 2단으로 구성된다. 일반적으로 PFC 회로로는 구조가 간단한 비절연형 부스트 컨버터가 사용되고, 절연형 DC-DC 컨버터로는 ZVS(Zero Voltage Switching)가 가능한 공진형 컨버터가 이용되고 있다. 전기자동차의 주행거리 증가에 따른 넓은 배터리 출력에 대응하기 위해서는 OBC의 넓은 출력범위가 필요하지만, 이러한 시스템 회로 구성에서는 ZVS를 위한 회로설계의 한계와 제어기 구성이 복잡해지기 때문에 배터리 충전에 요구되는 넓은 범위의 출력에 효과적으로 대응하기에는 어려움이 있다. 본 논문에서는 절연형 전류원 방식의 PFC 회로와 벅 DC-DC 컨버터로 구성된 OBC를 제안하였다. 제안된 OBC는 회로 및 제어기 구성이 용이하고, 넓은 출력범위에 대한 대응이 가능하다. 제안된 회로의 유효성을 검증하기 위해 3.3㎾급 시작품을 제작 하였으며, 동작결과 출력전압 150V~400V에서 동작안정성 및 정격 부하 조건에서 최대 효율 94.4%, 최대 역률 99.2%를 확인하였다.