• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1212-1220
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• 2013

In general, for a large power system like DC distribution system for buildings, several power converters are modularized for parallel operation. However, in parallel operation, inconsistency of parameters in each module causes circulating current in the whole system. Circulating current is directly related to loss, and, therefore, it is most important for the safety of the power system to supply the suitable current to each module. This paper proposes a control method to reduce circulating current caused during parallel operation. Accordingly, the validity of parallel operation system including response characteristics and normal state was verified by simulation and experiment result.

• Journal of Power Electronics
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• 제19권6호
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• pp.1366-1379
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• 2019

High-gain DC/DC converters have become one of the key technologies for the grid-connected operation of new energy power generation, and its research provides a significant impetus for the rapid development of new energy power generation. Inspired by the transformer effect and the ripple-suppressed ability of a coupled inductor, a double-coupled inductor high gain DC/DC converter with a ripple absorption circuit is proposed in this paper. By integrating the diode-capacitor voltage multiplying unit into the quadratic Boost converter and assembling the independent inductor into the magnetic core of structure coupled inductors, the adjustable range of the voltage gain can be effectively extended and the limit on duty ratio can be avoided. In addition, the volume of the magnetic element can be reduced. Very small ripples of input current can be obtained by the ripple absorption circuit, which is composed of an auxiliary inductor and a capacitor. The leakage inductance loss can be recovered to the load in a switching period, and the switching-off voltage spikes caused by leakage inductance can be suppressed by absorption in the diode-capacitor voltage multiplying unit. On the basis of the theoretical analysis, the feasibility of the proposed converter is verified by test results obtained by simulations and an experimental prototype.

• Journal of Power Electronics
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• 제11권4호
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• pp.479-489
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• 2011

The bidirectional dc-dc converter, being the interface between Energy Storage Element (ESE) and DC bus, is an essential component of the power management system for vehicle applications including electric vehicle (EV), hybrid electric vehicle (HEV), and fuel cell vehicle (FCV). In this paper, a novel multiphase bidirectional dc-dc converter interfacing with battery to supply and absorb the electric energy in the FCV system was studied with the help of real time digital simulator (RTDS). The mathematical models of fuel cell, battery and dc-dc converter were derived. A power management strategy was developed and first simulated in RTDS. A Power Hardware-In-the-Loop (PHIL) simulation using RTDS is then presented. The main challenge of this PHIL is the requirement for a highly dynamic bidirectional Simulation-Stimulation (Sim-Stim) interface. This paper describes three different interface algorithms. The closed-loop stability of the resulting PHIL system is analyzed in terms of time delay and sampling rate. A prototype bidirectional Sim-Stim interface is designed to implement the PHIL simulation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.696-703
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• 2000

This paper describes the capacity calculation of power supply system for light Rail Transit Three factors are considered for the design i.e. substation arrangements, line configuration and substation power capacity. In this study, we considered all of them for capacity calculation of power supply system for LRT. At first DC-fed-traction system is introduced on an outline, a characteristics of train and fed network, and design method of substation arrangements. Optimal design procedures are described, and program for capacity calculation of the system is presented. In addition, the computer simulated results are computed with the conventional simple calculation method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.104-107
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• 2007

Among the alternative energy sources, the solar energy is recognized as an important energy source and its application is increasing. Especially in future, the hybrid solar energy generation system with battery will be widely used as an independent distributed power generation system. In this paper, a solar power hybrid home generation system using a contact-less power supply (CPS) that can transfer an electric power without any mechanical contact by using magnetic coupling instead of the power transfer by directly supplying the DC power to the home electric system is proposed. The proposed system consists of a ZVS boost converter, a half bridge LLC resonant converter and contact-less transformer.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2002년도 전력전자학술대회 논문집
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• pp.378-381
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• 2002

This paper describes a novel multilevel ad/dc power converter suitable for the protection of frequent output short-circuit. The output dc power of the proposed converter can be disconnected from the load within several hundred microseconds at the instant of short-circuit fault. The rising time of the dc load voltage is as small as several hundred microseconds, and there is no overshoot of the do voltage because the dc output capacitors keep undischarged state. Analysis and simulations are carried out to investigate the operation and usefulness of the proposed scheme.

• Journal of Power Electronics
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• 제15권4호
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• pp.886-898
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• 2015

The design feasibility of a micro unidirectional DC transmission system based on an input-parallel output-parallel (IPOP) converter is analyzed in this paper. The system consists of two subsystems: an input-parallel output-series (IPOS) subsystem to step up the DC link voltage, and an input-series output-parallel (ISOP) subsystem to step down the output voltage. The two systems are connected through a transmission line. The challenge of the delay caused by the communication in the control system is addressed by introducing a ring communication structure, and its influence on the control system is analyzed to ensure the feasibility and required performance of the converter system under practical circumstances. Simulation and experiment results are presented to verify the effectiveness of the proposed design.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.394-400
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• 2007

This thesis aims the development of power supply for the BTS of Mobile Telecommunication system. Specially, it receives AC power and it can be possible both supply the uninterrupted and stabile DC Power to BTS and simultaneously maintain full charging the back-up battery that is used in case failing AC power supply. In addition, easy maintenance is also the main purpose of it regardless of front and left side except rear side. In these days, it needs more small size power supply system in order to comply with the user needs regarding more easy maintenance and more less space as become smaller main telecommunication systems. This system can be installed close to wall and support more easy maintenance and it was considered easy expansion in case when it needs.

• 전력전자학회논문지
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• 제7권4호
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• pp.339-345
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• 2002

본 논문에서는 입력 전압 DC 24 [V]로 출력 전압 AC 220 [V] 정현파 출력을 낼 수 있는 인버터 기능과 충전 전압 및 충전 전류를 조정할 수 있는 DC 24 [V]용 자동 충전기 기능을 동시에 가지는 전원 장치의 시작품을 제작하고 실험을 통해서 타당성을 검증하였다. 본 논문에서 제안하는 전원장치는 두 기능을 동시에 가지면서도 전력 수수의 라인을 하나의 라인으로 회로 구성을 실현하여 스위치 소자 및 고주파 트랜스를 인버터 동작이나 충전기 동작 시에 겸용으로 사용함으로서 인버터나 충전기 각각의 제품을 구성하는데 사용된 제품 구성품에 비하여 매우 경제적이며, 저가의 마이크로 프로세스 (PIC16C74)를 사용하여 스위칭 동작 및 시？스 회로의 동작을 제어함으로서 전 체적인 제품의 구성을 간략화 하였다.

• 한국전자통신학회논문지
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• 제11권7호
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• pp.653-658
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• 2016

본 논문은 릴레이 장치 및 구동 제어 방법에 관한 것으로서, DC 고전압 배터리의 전력을 전기자동차의 인버터를 구동하기 위해 전력을 접속하거나 차단하는 릴레이에 관한 것이다. 본 논문을 통해 DC 고전압 배터리에서 릴레이가 접속되는 순간 릴레이의 접점에서 강한 스파크가 발생하는 것을 방지하고 접점의 열화 및 노후로 인해 증가하는 릴레이 내부 저항값을 보상하기 위한 서브릴레이가 제안되었다. 제작된 릴레이의 정격 전력은 10KW 정도이며 전기적 순단시험 등을 통해 릴레이의 전기적 특성을 검증하였다.