• 전기학회논문지P
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• 제59권3호
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• pp.288-292
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• 2010

Recently, in energy storage system, the EDLC is paid attention as a new environmentally friendly energy storage element. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. But the EDLC must have a each charge-discharge controller to effectively control, an energy design method circuit to use effectively energy, and several compensation techniques to control a optimal operating. In this respect, this study suggests major parameters to effectively represent the characteristics of EDLC, the measurement methods of those parameters have been investigated with experiments, and the interpretation about the buck/boost DC/DC converter for the operation of EDLC.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 전력전자학술대회
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• pp.401-402
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• 2017

넓은 범위의 토크-속도 특성을 가지는 직류기는 소형에서부터 대형까지 다양한 산업분야에서 폭넓게 사용되고 있다. 이러한 직류기 중 영구자석으로 자기장을 형성하는 영구자석 직류기 (Permanent magnet dc motor, PMDC motor)의 제어방식에 대해 비교 분석했다. 가장 대중적으로 사용되고 있는 진폭 변조 방식 (PWM, Pulse Width Modulation)과 벅-부스트 컨버터 (Buck-Boost converter)를 이용한 직류기 제어 방식에 대해 비교했다. PWM 방식은 인버터를 이용하여 펄스폭을 변조하였고, 벅-부스트 컨버터를 이용하는 방식은 스위치의 듀티비를 제어하여 직류 전압의 크기를 조절하였다. 시뮬레이션 결과 벅-부스트 컨버터를 이용한 방식이 PWM 방식보다 5 rad/s 까지 정착 시간은 54.4 % 단축되었지만, 전력 소모는 194 % 증가하는 결과를 얻었다.

• 조명전기설비학회논문지
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• 제29권2호
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• pp.27-32
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• 2015

A maximum power point tracking (MPPT) algorithm using fuzzy controller was considered. MPPT method was implemented based on the voltage and reference PV voltage value was obtained from Artificial Neural Network (ANN)-model of PV modules. Therefore, measuring only the PV module voltage is adequate for MPPT operation. Fuzzy controller is used to directly control dc-dc buck converter. The simulation results have been used to verify the effectiveness of the algorithm. The proposed method is compared with conventional PO(perturbation & observation), IC(Incremental Conductance) method. The nonlinearity and adaptiveness of fuzzy controller provided good performance under parameter variations such as solar irradiation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 전력전자학술대회 논문집
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• pp.439-440
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• 2014

본 논문에서는 발생전압이 충전전압보다 높은 경우는 Buck 컨버터로 동작하고 발생전압이 충전전압보다 낮은 경우 Boost 컨버터로 동작하는 모드 자체를 독립적으로 구현할 수 있는 새로운 형태의 DC-DC 컨버터를 제안함으로서 시비율 변화를 줄여 인덕터의 전류 리플을 줄임으로서 효율을 개선하고자 한다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.205-210
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• 2001

A new single stage power factor corrected AC/DC converter has been proposed, that is unified with buck topology and suitable for universal input. The design example of the proposed converter lot 5V 12A application has been presented. The design considerations and simulation results for the proposed converter have been shown. The simulation results show that the line input current harmonics can meet IEC 1000-3-2 Class D requirements for the line input voltage from 90 to 260V.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1049_1050
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• 2009

This paper deals with development of a low cost VI(Voltage-Currrent)-tracer for PV(Photovoltaic) system using LabVIEW and DSP(Digital Signal Processor). Although the conventional VI-tracer is a high cost equipment, it can‘t abstract the detailed parameters of solar cell. To overcome above mentioned disadvantages, in this paper, a converter type VI-tracer is developed. The DSP, which controls the buck-boost DC-DC converter, is used to implement the proposed VI-tracer algorithm. The proposed VI-tracer can abstract more detailed parameters of solar cell; A(temperature constant), Rs(series resistance), and Rsh(parallel resistance). The authors emphasize that the proposed VI-tracer can satisfy the users who need to get various parameters. A comparison between the proposed VI-tracer and the conventional VI-tracer is presented to show the effectiveness of the proposed system.

• 전력전자학회논문지
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• 제25권1호
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• pp.21-28
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• 2020

Integrated bidirectional OBC/LDC was developed to reduce the volume for elements, avoid space restriction, and increase efficiency in EV vehicles. In this study, a DC-DC converter in integrated OBC/LDC circuits was composed of an SRC circuit with a stable output voltage relative to an LLC circuit using a theoretical method and simulation. The resonant network of the selected circuit was optimized to minimize the power loss and element volume under constraints for the buck converter and the battery charging range. Moreover, the validity of the optimal model was verified through an analysis using a theoretical method and a numerical analysis based on power loss at the optimized resonant frequency.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 Proceedings ICPE 01 2001 International Conference on Power Electronics
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• pp.189-192
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• 2001

This paper proposed that an AC-DC converter system using multiple buck-chopper operates with four choppers connecting to a number of parallel circuits. To improve these, a large number of soft switching topologies included a resonant circuit have been proposed. And, some simulative results on computer are included to confirm the validity of the analytical results. The partial resonant circuit makes use of an inductor using step-down and a condenser of loss-less snubber. The result is that the switching loss is very low and the efficiency of system is high. And the snubber condenser used in a partial resonant circuit makes charging energy regenerated at input power source for resonant operation. The proposed conversion system is deemed the most suitable for high power applications where the power switching devices are used.

• 전기전자학회논문지
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• 제26권4호
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• pp.584-589
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• 2022

고전압 태양광 패널에서 단상 계통으로의 직류-교류 전력 변환을 위해 벅부스트 컨버터에 풀브리지 인버터를 종속적으로 연결하는 두 단계의 무변압기 인버터가 주로 사용된다. 태양광 패널의 큰 기생 커패시턴스에 기인하는 과도한 누설 전류를 피하기 위해 풀브리지 인버터는 단극성 PWM에 비해 훨씬 더 많은 전력 손실을 초래하는 양극성 PWM으로만 스위칭할 수 있다. 그런 낮은 효율을 개선하기 위해 본 논문은 벅부스트 컨버터에 회로 절연을 위한 IGBT와 다이오드를 하나씩 추가한 새로운 토폴로지를 제안한다. 제안된 회로 절연 방식은 누설 전류를 증가시키지 않으면서 풀브리지 인버터에서 단극성 PWM을 가능케 함으로써 전체 효율을 개선한다. 제안된 방법의 타당성은 컴퓨터 시뮬레이션과 전력 손실 계산을 통해 검증한다.

• 전기학회논문지
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• 제66권2호
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• pp.328-338
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• 2017

In this paper, a zero torque control scheme adopting current sharing function (CSF) used in integrated Switched Reluctance Motor (SRM) drive with DC battery charger is proposed. The proposed control scheme is able to achieve the keeping position (KP), zero torque (ZT) and power factor correction (PFC) at the same time with a simple novel current sharing function algorithm. The proposed CSF makes the proper reference for each phase windings of SRM to satisfy the total charging current of the battery with zero torque output to hold still position with power factor correction, and the copper loss minimization during of battery charging is also achieved during this process. Based on these, CSFs can be used without any recalculation of the optimal current at every sampling time. In this proposed integrated battery charger system, the cost effective, volume and weight reduction and power enlargement is realized by function multiplexing of the motor winding and asymmetric SR converter. By using the phase winding as large inductors for charging process, and taking the asymmetric SR converter as an interleaved converter with boost mode operation, the EV can be charged effectively and successfully with minimum integral system. In this integral system, there is a position sliding mode controller used to overcome any uncertainty such as mutual inductance or DC offset current sensor. Power factor correction and voltage adaption are obtained with three-phase buck type converter (or current source rectifier) that is cascaded with conventional SRM, one for wide input and output voltage range. The practicability is validated by the simulation and experimental results by using a laboratory 3-hp SRM setup based on TI TMS320F28335 platform.