Design and development of a fuel cell-powered small unmanned aircraft

Kim, Taegyu,Kwon, Sejin Elsevier 2012 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.37 No.1

<P><B>Abstract</B></P><P>The design, construction, and flight test of a fuel cell-powered small unmanned aircraft are described. A fuel cell system featuring a polymer electrolyte membrane fuel cell combined with a hydrogen generator, which serves as a new power source alternative to the existing batteries, is proposed. The hydrogen generator uses a catalytic hydrolysis reaction to extract hydrogen from an alkaline solution of sodium borohydride, and constructed with a reactor, pump, separator, and fuel cartridge. Considering the performance characteristics of the fuel cell, the hybrid power management of a fuel cell and a battery was contrived. The fuel cell stack, hydrogen generator, and power management system were evaluated at the various load conditions. A high efficiency unmanned aircraft was designed and fabricated to validate the possibility of the proposed fuel cell system, and a small flight control system was developed for a high endurance test flight. Wind-tunnel tests were conducted before the flight tests under actual flight conditions. The possibility for the utilization of a fuel cell in a small aircraft was validated through the fuel cell powered flight test. The fuel cell aircraft flew for 2 h without incidents in the fuel cell system.</P> <P><B>Graphical abstract</B></P><P><ce:figure id='dfig1'></ce:figure></P><P><B>Highlights</B></P><P>► Small aircraft using PEMFC combined with NaBH<SUB>4</SUB> hydrogen generator was developed. ► Hybrid power management of a fuel cell and a battery was evaluated. ► High efficiency aircraft was designed and wind-tunnel tests were conducted. ► The fuel cell aircraft flew for 2 hours without incidents in the fuel cell system.</P>

연료전지 하이브리드 자동차의 부하추종 방식 운전전략에 관한 연구

정재화(Jaehwa Jeong),이동율(Dong-ryul Lee),배중면(Joongmyeon Bae) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Fuel cell hybrid vehicle with auxiliary energy storage devices has several advantages such as fuel cell stack down sizing, down cost, use regenerative braking, and flexible operating strategy. Fuel cell hybrid vehicle is divided into non plug-in type and plug-in type. Driving range of plug-in type fuel cell hybrid vehicle is limited by hydrogen consumption and battery state of charge(SOC). Therefore, plug-in type hybrid fuel cell vehicle needs the operating strategies to effective use of hydrogen and battery SOC. In this research, load follow type operating strategies of fuel cell and lead-acid battery plug-in type hybrid vehicle were proposed in terms of power distributed ratio of fuel cell and battery, change control current, battery SOC, battery discharge limit, and stable operation of fuel cell. A vehicle loaded fuel cell and lead-acid battery hybrid system was operated in field and simulated by MATLAB/Simulink™. Established load follow type operating strategies are as follows : ⅰ) fuel cell is operated by load following mode ⅱ) On/Off time of Battery discharge for power distributed ratio change of fuel cell and battery is changed by control current ⅲ) Fuel cell and battery share load after battery discharge start ⅳ) Driving range is changed by hydrogen consumption and battery SOC according to power distributed ratio change. Selection of control current is maximum value as much as possible at ideal state if fuel cell stack operation is stable.

KS C 8569 기반의 연료전지시스템 성능평가 및 그 운영에 관한 고찰

차정은(Jung-Eun Cha),이남진(Nam Jin Lee),최영우(Young-Woo Choi),윤영기(Young Ki Yoon),김원배(Won Bae Kim) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.4

연료전지는 수소와 산소로부터 전기화학 반응을 통해 직접 전기를 생산하는 발전장치로, 연료전지 시스템은 연료전지 스택, 연료변환기, 주변기기(MBOP: Mechanical Balance of Plant, EBOP: Electrical Balance of Plant) 및 제어기술을 포함한다. 연료전지 보급이 확대되면서, 안전과 성능 검증을 위한 표준이 요구되었으며, 이에 따라 표준서 KS C 8569는 2015 년 고분자연료전지(PEMFC) 시스템에 대하여 KS 제정을 시작으로 2019 년에는 직접 메탄올 연료전지(DMFC)시스템을, 2020 년에는 고체고분자연료전지(SOFC)시스템을 포함함으로써 현재의 표준서가 완성되었다. KS C 8569는 발전효율, 열효율, 기동/정지 특성, 부하변동 등을 포함하는 성능평가와 온도상승, 절연, 계통 보호, 내전기환경시험 등의 안정성 평가, 그리고 배출가스, 소음측정 등 환경성 평가로 구분되며, 총 49 개 상세항목으로 구성되어 있다. 초반 4 개 기업의 정지형, 즉 건물용 PEMFC 연료전지시스템의 KS 인증을 시작으로 현재 SOFC까지 포함하여 13 여개 기업으로 확장되었다. 또한, 초반에 1 kW 급 이하의 시스템이 대부분이었으나 2017 년 이후부터는 5 kW이상, 최근에는 10 kW 시스템이 주력을 이루고 있다. 하지만, 지금의 표준서는 기존의 정지형에서 이동형을 결합한 것으로 평가내용이 혼재되고, 이동형의 기본성능 (직류), 내열, 충격, 진동, 냉온 등의 안전성 검사 기준이 미흡하다. 또한, 정지형의 경우 10kW 급 이하로 규정되어 있어서 100 kW 이하의 과도기적인 시장 제품에 적합하지 못하다. 따라서, KS C 8569를 재정비하고, 국제표준과의 부합화를 통하여 국내 연료전지 산업 육성과 더불어 수출전략 고도화 가능성을 모색해야한다. The fuel cell is one of the power generating systems converting the chemical energy of hydrogen and oxygen into electricity through a pair of redox reactions, which mainly consists of a fuel reformer, cell stack, and an inverter. With the expansion of the supply of fuel cell systems, test standards and certifications have been required to verify the safety and performance of fuel cells. Starting with KS certification for polymer electrolyte membrane fuel cell (PEMFC) systems in 2015, KS C 8569 has been completed by including direct methanol fuel cell (DMFC) systems in 2019 and solid oxide fuel cell (SOFC) systems in 2020. This certification is divided into the performance assessment including power generation efficiency, thermal efficiency, start-up/shut-down characteristics, stability evaluation for the increase in temperature, electric resistance test, and the environmental assessment such as emissions and noise measurements. Initially, four fuel cell system manufacturers obtained KS certification for the stationary system, and now it has been expanded to a total of 13 companies including SOFC and DMFC system manufacturing companies. Besides, most of the systems were 1 kW or lower in the beginning, however since 2017, the capacity has increased to 5 kW or higher, and 10 kW systems have recently become the main focus. However, this standard has been revised to add the mobile fuel cell system standard to the existing stationary fuel cell standard, which lacks basic performance (direct current), heat resistance, shock, vibration, cold and hot tests that conform to the mobile fuel cell system standard. In addition, stationary fuel cell systems are not suitable for transition market products under 100 kW because they are defined as less than 10 kW. Accordingly, KS C 8569 should be reviewed to suit international standards and transitional market products to promote the domestic fuel cell industry and seek the possibility of upgrading its export strategy.

주택용 연료전지 효율 향상Power Distribution Optimization of Multi-stack Fuel Cell Systems for Improving the Efficiency of Residential Fuel Cell을 위한 다중 스택 연료전지 시스템의 전력 분배 최적화

강태성,함성현,오환영,최윤영,김민진 한국수소및신에너지학회 2023 한국수소 및 신에너지학회논문집 Vol.34 No.4

The fuel cell market is expected to grow rapidly. Therefore, it is necessary to scale up fuel cells for buildings, power generation, and ships. A multi- stack system can be an effective way to expand the capacity of a fuel cell. Multi-stack fuel cell systems are better than single-stack systems in terms of efficiency, reliability, durability and maintenance. In this research, we developed a residential fuel cell stack and system model that generates electricity using the fuel cell-photovoltaic hybrid system. The efficiency and hydrogen consumption of the fuel cell system were calculated according to the three proposed power distribution methods (equivalent, Daisy-chain, and optimal method). As a result, the optimal power distribution method increases the efficiency of the fuel cell system and reduces hydrogen consumption. The more frequently the multi-stack fuel cell system is exposed to lower power levels, the greater the effectiveness of the optimal power distribution method.

고분자 전해질 연료전지의 공급기체 압력에 따른 저항변화

신동규(Dong Kyu Shin),김성일(Sung Il Kim),김동규(Dong Kyu Kim),김민수(Min Soo Kim) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

In this study, difference of resistance of fuel cell is measured with inlet pressure change. In the other studies, HFR(High Frequency Resistance) of fuel cell is increased with channel depth narrowed. This experiment is performed to determine the reason of HFR increasing. The result of experiment indicate that the inlet pressure of fuel cell affect resistance of fuel cell. First of all, the resistance of fuel cell is measured with using oxygen as fuel cell inlet gas. The resistance of fuel cell is increased with inlet gas increasing. Second, HFR of fuel cell is measured when fuel cell operate. Then, the results indicate that ohmic resistance of fuel cell is increasing with inlet gas pressure increasing. This experiment demonstrates that the reason of fuel cell resistance increasing is related with inlet gas of fuel cell.

A Power Control Scheme of a Fuel Cell Hybrid Power Source

Yujin Song(송유진),S. B. Han(한수빈),S. I. Park(박석인),H. G. Jeong(정학근),B. M. Jung(정봉만),G. D. Kim(김규덕),S. W. Yu(유승원) 한국조명·전기설비학회 2008 한국조명·전기설비학회 학술대회논문집 Vol.2008 No.10월

This paper describes a power control scheme to improve the performance of a fuel cell-battery hybrid power source for residential application. The proposed power control scheme includes a power control strategy to control the power flow of the fuel cell hybrid power system and a digital control technique for a front-end dc-dc converter of the fuel cell. The power control strategy enables the fuel cell to operate within the high efficiency region defined by the polarization curve and efficiency curve of the fuel cell. A dual boost converter with digital control is applied as a front-end ed-ed converter to control the fuel cell output power. The digital control technique of the converter employs a moving-average digital filter into its voltage feedback loop to cancel the low frequency harmonic current drawn from the fuel cell and then limits the fuel cell output current to a current limit using a predictive current limiter to keep the fuel cell operation within the high efficiency region as well as to minimize the fuel cell oxygen starvation.

수소 재순환 특성을 고려한 연료전지 시뮬레이터

엄태호(Tae-Ho Eom),김준모(Jun-Mo Kim),이정(Jeong Lee),정성문(Sung-Mun Jeong),신민호(Min-Ho Shin),이정효(Jung-Hyo Lee),원충연(Chung-Yuen Won) 한국조명·전기설비학회 2018 조명·전기설비학회논문지 Vol.32 No.7

In order to compensate a loss from the dynamic, a hydrogen fuel cell supplies the hydrogen more than 10% to its rated capacity. It brings the issue that a utilization rate of fuel cell degrades to 10%, therefore, the method is applied which recirculating the emitted hydrogen after their reaction. When their hydrogen recirculating, it results in emitting not the pure hydrogen but impurity, as a result it enables the electric energy to unstable. When a load requires certain power, a membrane of fuel cell has damaged due to voltage drop. In order to develop the charger which charging the energy into battery in fuel cell and battery hybrid system, it requires protection operation according to fuel cell output characteristic results from hydrogen recirculation. In fuel cell charger, selecting the level of protection operation voltage and current through experiment brings significant problem that damage of costly fuel cell. In this paper, we explain the design and control method of the fuel cell simulator which has output characteristic according to current density, temperature of fuel cell including hydrogen recirculation function and verify the validity through simulation and experiment.

인산형 연료전지 스택에 대한 3차원 모사

안현식,김효 서울시립대학교 산업기술연구소 1999 산업기술연구소논문집 Vol.7 No.-

A fuel cell is an electrochemical device that can continuously convert the chemical energy of a fuel and an oxidant to electrical energy by processes involving essentially invariant electrode-electrolyte system. Phosphoric acid fuel cell employs concentrated phosphoric acid as an electrolyte. The cell stack in the fuel cell, which is a core component of the fuel cell system, is made up of anode, where oxidation of the fuel occurs; electrolyte, to separate the anode and cathode and to conduct the ions between them; and cathode where reduction of the oxidant occurs. Fuel cell performance is associated with many parameters; operating and design parameters associated with the system configuration. Hence, we have modeled the fuel cell stack and computed the temperature distribution and the concentration of reactants and products in the cell stack of a phosphoric acid fuel cell using the computational fluid dynamics technique. Computational results are capable of predicting fuel-cel3 stack performance and easy understanding the heat and mass diffusion in the fuel cell stack.

NEW APPROACH FOR PERFORMING FAILURE ANALYSIS OF FUEL CELL-POWERED VEHICLES

V. MOTEVALLI1,M.-S. MOHD 한국자동차공학회 2009 International journal of automotive technology Vol.10 No.6

Safety of hybrid-electric and fuel cell vehicles is a critical aspect of these new technologies, since any accident exposing occupants of such vehicles to unconventional hazards may result in significant setbacks to successful market penetration. Fuel cell and hybrid-electric drive systems are complex, and it is essential to perform a thorough analysis to determine critical failure conditions. There are several safety concerns for routine operation of such systems, particularly for hydrogen-fueled vehicles. A modified Failure Modes and Effect Analysis (FMEA) has been developed, along with a Criticality Analysis (CrA), to identify potentially hazardous conditions for crash and non-crash situations. A mathematical model of fuel cell operation has been developed and used here in conjunction with the FMEA. Component failures during the event modes are simulated using vehicle models developed with Matlab Simulink tools. Six simulation models were created using the software. In addition, a preliminary finite element model of a fuel cell vehicle, using a Ford Taurus (91’) model year sedan, has been developed and implemented. This finite element model is used as a demonstration of the crash simulation of the vehicle. Safety of hybrid-electric and fuel cell vehicles is a critical aspect of these new technologies, since any accident exposing occupants of such vehicles to unconventional hazards may result in significant setbacks to successful market penetration. Fuel cell and hybrid-electric drive systems are complex, and it is essential to perform a thorough analysis to determine critical failure conditions. There are several safety concerns for routine operation of such systems, particularly for hydrogen-fueled vehicles. A modified Failure Modes and Effect Analysis (FMEA) has been developed, along with a Criticality Analysis (CrA), to identify potentially hazardous conditions for crash and non-crash situations. A mathematical model of fuel cell operation has been developed and used here in conjunction with the FMEA. Component failures during the event modes are simulated using vehicle models developed with Matlab Simulink tools. Six simulation models were created using the software. In addition, a preliminary finite element model of a fuel cell vehicle, using a Ford Taurus (91’) model year sedan, has been developed and implemented. This finite element model is used as a demonstration of the crash simulation of the vehicle.

연료전지 발전 시스템의 특성을 고려한 모델링

박봉희(Park, Bong-Hee),김승민(Kim, Seung-Min),최주엽(Choi, Ju-Yeop),최익(Choy, Ick),이상철(Lee, Sang-Chul),이동하(Lee, Dong-Ha) 한국태양에너지학회 2012 한국태양에너지학회 학술대회논문집 Vol.2012 No.11

This paper proposes a modeling of fuel cell which replaces dc source during simulation. Fuel cells are electrochemical devices that convert chemical energy in fuels into electrical energy. This system has high efficiency and heat, no environmental chemical pollutions and noise. These fuel cells are consisted of many different materials such as solid oxide fuel cell(SOFC) and proton exchange membrane fuel cell(PEMFC). But these fuel cells have similar electrical characteristics such as a low voltage and high current compared with solar cells. However, there are different behaviors in the V-I curve in the high temperature. Therefore, the modeling of fuel cell should consider wide voltage range and slow current response and the resulting electrical model is applied to power converter system(PCS) with fuel cell as an input source.