• 전기전자학회논문지
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• 제24권2호
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• pp.610-618
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• 2020

본 논문에서는 규칙기반 알고리즘을 이용한 수소연료전지/배터리 하이브리드 철도차량 모델링을 제시한다. 모터의 운전영역에 따른 토크 곡선을 계산하여 견인 시스템의 구동 전력을 결정하고 철도차량의 각 운전 모드에 적용하여 전기 시스템을 모델링 한다. 전기 시스템의 전력은 규칙기반 알고리즘을 이용한 에너지 관리시스템(Energy Management System, EMS)으로 결정한다. 배터리의 충전상태(State Of Charge, SOC)에 따라 운전 영역을 세분화하여 수소 소비량을 효율적으로 관리한다. 제안하는 철도차량 모델링의 타당성은 MATLAB/Simulink 시뮬레이션을 통해 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.218-220
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• 2008

Urban air quality, including carbon-dioxide emissions, and national energy security are related issues affecting the rail industry and transportation sector as a whole. They are related by the fact that (in the United States) 97-98% of the energy for the transport sector is based on oil, and more than 60% is imported. A fuelcell locomotive combines the environmental advantages of a catenary-electric locomotive with the higher overall energy efficiency and lower infrastructure costs of a diesel-electric. Catenaryelectric locomotives, when viewed as only one component of a distributed machine that includes an electricity-generating plant and transmission lines, are the least energy-efficient locomotive type. The natural fuel for a fuelcell is hydrogen, which can be produced from many renewable energies and nuclear energy, and thus a hydrogen-fuelcell locomotive will not depend on imported oil for its energy supply. This paper proposes a base models of Hybrid fuel cell/IPT railway vehicle power system, the necessary of this research.

• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.212-225
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• 2023

This study presents a modularized process of a hybrid renewable energy system that combines photovoltaic power and wind power to supply stable power in a unit area (1 km²). The water electrolysis process and fuel cells process also contributes to the supply of the stable power. The entire system can constantly supply power of 4.39 MW/km². Actual meteorological data is used for simulation.

• 전력전자학회논문지
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• 제8권6호
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• pp.551-560
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• 2003

본 논문은 5KW급의 SOFC와 저전압 배터리를 복합전원으로 하는 10KW급 독립형 연료전지발전시스템의 전력변환장치의 개발에 관한 것이다. 이를 위한 전격변환장치는 연료전지로부터의 저전압을 상승시키기 위한 고주파 DC-DC 컨버터 및 이를 안정된 교류전원으로 변환하기 위한 DC-AC 인버터 그리고 저전압 배터리를 충$.$방전하기 위한 양방향 DC-DC 컨버터로 구성된다. 미국 에너지부 및 IEEE가 주최한 "2003 International Future Energy Challenge Competition"에서 제시한 90%이상의 효율과 $40/KW 이하의 양산가등의 사양을 목표로 개발된 본 전력변환장치에 대한 토폴로지, 주요 부품의 설계 및 제어방식에 관하여 기술하고 실험결과를 제시한다.험결과를 제시한다.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• 제34권8호
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• pp.1040-1049
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• 2010

GHG 및 대기오염물질 배출 규제는 고효율 및 친환경에 적합한 새로운 선박용 동력장치의 필요성을 제기하고 있다. 최근 이와 같은 문제들을 근본적으로 해결하기 위한 지속가능한 방법으로서 연료전지를 선박의 동력발생장치로 도입하고자 하는 검토가 진행되고 있다. 본 논문은 액체연료인 메탄올을 기반으로 한 고체산화물형 연료전지/가스터빈 하이브리드시스템의 성능을 평가한 것으로 스택의 작동온도, 전류밀도, 가스터빈 압력비, 공기예열기 온도효율, TIT(turbine inlet temperature)의 영향을 시뮬레이션으로 검토하고 그 결과를 기체연료인 메탄의 경우와 비교하고 있다.

• 드라이브 ㆍ 컨트롤
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• 제9권4호
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• pp.8-13
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• 2012

Recently, researches about the eco-friendly vehicles such as hybrid electric vehicle, fuel cell vehicle and electric vehicle have been actively carried out. The regenerative braking system is a key technology to improve the vehicle energy utilization efficiency because it transforms the kinetic energy to the electric energy through the electric motor. This new braking system requires cooperative control between electric controlled brake and regenerative brake. Therefore, it is necessary to establish fault-diagnosis and fail-safe evaluation criteria to secure reliability of the regenerative braking system. In this paper, the failure types and causes in regenerative braking system were analyzed. The transient behavior characteristics were examined based on fault-diagnosis and fail-safe upon failure of regenerative braking system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2070-2075
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• 2004

Performance of a solid oxide fuel cell (SOFC) can be enhanced by converting thermal energy of its high temperature exhaust gas to mechanical power using a micro gas turbine (MGT). A MGT plays also an important role to pressurize and warm up inlet gas streams of the SOFC. In this study, the influence of performance characteristics of the tubular SOFC on the hybrid power system is discussed. For this purpose, detailed heat and mass transfer with reforming and electrochemical reactions in the SOFC are mathematically modeled, and their results are reflected to the performance analysis. The analysis target is 220kWe SOFC/MGT hybrid system based on the tubular SOFC developed by Siemens-Westinghouse. Special attention is paid to the ohmic losses in the tubular SOFC counting not only current flow in radial direction, but also current flow in circumferential direction through the anode and cathode.

• 한국기계가공학회지
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• 제20권4호
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• pp.57-65
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• 2021

This paper explains a DMFC-Lithium Battery hybrid system applied to a forklift. A conventional Lead Acid battery forklift has several problems: long charging times, short operation times, and frequent battery replacements. As a result, hydrogen-powered forklifts are replacing Lead acid battery-powered forklifts due to their shorter refueling time and longer operation times. However, in doing so, we are confronted with the problem of a high hydrogen refueling infrastructure. A Direct Methanol Fuel Cell (DMFC), on the other hand, is an eco-friendly generator that directly converts the chemical energy of methanol into electricity. In general, DMFC is regarded as a small power generator under kW power. In this paper, a DMFC-Battery hybrid system is applied to a 1.5 ton forklift by increasing the power output of the DMFC stack and utilizing the high charge-discharge characteristics of a lithium battery.

• 전력전자학회논문지
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• 제18권1호
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• pp.45-53
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• 2013

Fuel cell power system is one of the most promising energy source for the alternative energy because it has unique advantages such as high energy density, no power drop during operation, and feasible to make compact size. However, due to very low response time, fuel cell is difficult to correspond to drastic load changes and start-up operation. For solving these problem, fuel cell power system must include energy storage device such as Li-Poly battery or super capacitor. Therefore, bi-directional DC-DC converter must be required for this storage device and fuel cell-PCS control. This paper presents a design and modeling of the bi-directional DC/DC converter. Firstly, we present modeling the boost and buck mode of the bi-directional converter through both PWM switch model and state space averaging technique. Secondly, in order to minimize output ripple and transient response overshoot, we have two identical DC-DC converters interleaved and adopt two-loop voltage-current controller. The proposed bi-directional DC-DC converter's modeling method and control design have been verified with computer simulation and experimentation.