http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Kai Ou (검색결과 11 건)
- 무료
- 기관 내 무료
- 유료
-
-
Ou, Kai,Yuan, Wei-Wei,Choi, Mihwa,Yang, Seugran,Jung, Seunghun,Kim, Young-Bae Elsevier 2018 International journal of hydrogen energy Vol.43 No.32
<P><B>Abstract</B></P> <P>This research develops an efficient and robust polymer electrolyte membrane (PEM) fuel cell/battery hybrid operating system. The entire system possesses its own rapid dynamic response benefited from hybrid connection and power split characteristics due to DC/DC buck-boost converter. An indispensable energy management system (EMS) plays a significant role in achieving optimal fuel economy and in a promising running stability. EMS as an indispensable part plays a significant role in achieving optimal fuel economy and promising operation stability. This study aims to develop an adaptive supervisory EMS that comprises computer-aided engineering tools to monitor, control, and optimize the performance of the hybrid power system. A stationary fuel cell/battery hybrid operating system is optimized using adaptive-Pontryagin's minimum principle (A-PMP). The proposed algorithm depends on the adaptation of the control parameter (i.e., fuel cell output power) from the state of charge (SOC) and load power feedback. The integrated model simulated in a Matlab/Simulink environment includes the fuel cell, battery, DC/DC converter, and power requirements models by analyzing the three different load profiles. Real-time experiments are performed to verify the effectiveness of EMS after analyzing the simulated operating principle and control scheme.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An adaptive power management strategy is developed for fuel cell/battery. </LI> <LI> Power split between two sources is done through DC/DC converter control. </LI> <LI> Minimization of fuel and constant charge level of battery are proved experimentally. </LI> </UL> </P>
-
-
-
Performance increase for an open-cathode PEM fuel cell with humidity and temperature control
Ou, Kai,Yuan, Wei-Wei,Choi, Mihwa,Yang, Seugran,Kim, Young-Bae Pergamon Press 2017 International journal of hydrogen energy Vol.42 No.50
<P><B>Abstract</B></P> <P>Water and thermal management of an open-cathode proton electrolyte membrane (PEM) fuel cell is developed in this study. A bubble humidifier, which is one of the balance of plant (BOP) systems, is newly installed to control the humidity of the fuel cell. A multiple-input-multiple-output (MIMO) fuzzy controller is developed, and proven to be superior in controlling a strong non-linear dynamical fuel cell system in real-time. According to the fuzzy control stratagem, the two main control objectives are the axial fan speed control for regulating temperature and the solenoid valve on/off control of the bubble humidifier for humidity variation. First, the axial fan speed is controlled to keep the fuel cell temperature within the desired point. Second, the bubble humidifier is utilized to humidify the inlet hydrogen to manage the water content of a membrane. After simulating the electrochemical and thermal fuel cell models, the optimal operating conditions are determined. A fuzzy logic controller with five inputs and two outputs is constructed and utilized to regulate the temperature and relative humidity of an open cathode fuel cell in real time. Results show that the proposed fuzzy controller effectively increased the output power of PEM fuel cell.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An advanced control is developed for controlling fuel cell temperature and humidity. </LI> <LI> An open-type fuel cell model is developed to find optimal operating points. </LI> <LI> About 10% of power increase is achieved using our method. </LI> </UL> </P>
-
Zhang, Tieqing,Ou, Kai,Jung, Seunghun,Choi, Byungchul,Kim, Young-Bae Elsevier 2018 International journal of hydrogen energy Vol.43 No.29
<P><B>Abstract</B></P> <P>Low-temperature polymer electrolyte membrane fuel cell (PEMFC) acts as a promising energy source due to the non-pollution and high-energy density. However, as hydrogen supply is a major constraint limiting the wide spread of fuel cell vehicles, a dimethyl ether (DME)-steam on-board reformer (SR) based on catalytic reforming via a catalytic membrane reactor with a channel structure is a possible solution to a direct hydrogen supply. The DME-SR reaction scheme and kinetics in the presence of a catalyst of CuO/ZnO/Al<SUB>2</SUB>O<SUB>3</SUB>+ZSM-5 are functions of the temperature and hydrocarbon ratio in the hydrogen-reforming reaction. An electric heater is provided to keep the temperature at a demanded value to produce hydrogen. As there is no available analysis tool for the fuel cell battery hybrid vehicle with on-board DME reformer, it is necessary to develop the tool to study the dynamic characteristics of the whole system. Matlab/Simulink is utilized as a dynamic simulation tool for obtaining the hydrogen production and the power distribution to the fuel cell. The model includes the effects of the fuel flow rate, the catalyst porosity, and the thermal conductivity of different subsystems. A fuel cell model with a battery as a secondary energy storage is built to validate the possible utilization of on-board reformer/fuel cell hybrid vehicle. In consideration of time-delay characteristic of the chemical reactions, the time constant obtained from the experiment is utilized for obtaining dynamic characteristics. The hydrogen supplied by the reformer and the hydrogen consumed in the PEMFC prove that DME reformer can supply the adequate hydrogen to the fuel cell hybrid vehicle to cope with the required power demands.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Optimized operating conditions are obtained for DME hydrogen reformer. </LI> <LI> Dynamic model of DME reformer is obtained via experiment. </LI> <LI> Hybrid vehicle dynamic characteristics with PEMFC, battery, and reformer is analyzed. </LI> </UL> </P>
-
-
Wang, Ya-Xiong,Ou, Kai,Kim, Young-Bae Pergamon 2017 RENEWABLE ENERGY Vol.111 No.-
<P><B>Abstract</B></P> <P>Polymer electrolyte membrane fuel cell hybridized with lithium-ion battery possesses significant advantages, including the combination of large energy carrier feature with high power density to provide a power source for large fluctuated areas such as a vehicle or a construction equipment. A hybrid system obviously requires a suitable power management means to distribute each power source optimally and ensure safe and efficient power system operation. This study investigates hybrid system power distribution and the protection of power sources, namely, PEMFC and/or LIB, to extend their lifetimes under the condition of external load variations. Power distribution with the purpose of power source protection is developed to balance the power and stabilize the DC-link voltage with the developed hybrid model. In particular, two new power splitting methods are proposed: coordinated current–voltage control and dual-voltage control. Moreover, these two control schemes are selected depending on the threshold load current. The threshold load current is decided by fuzzy logic rules to prevent power shortage in PEMFC by current control for higher load and to regulate LIB's state-of-charge for lower load. To validate the proposed power management approach, experimental tests are conducted on a hybrid PEMFC/LIB power system prototype.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hybrid models including PEMFC, LIB, and dc converters are developed. </LI> <LI> Power source protection is designed and proved through simulation and experiment. </LI> <LI> Fuel cell protection from sudden power requirement is achieved using current-voltage control scheme. </LI> <LI> Battery protection from overcharge is prohibited using dual voltage control scheme. </LI> <LI> Current-voltage control method and dual voltage control method is selected through fuzzy logic rules. </LI> </UL> </P>
-
Ya-Xiong Wang,Fei-Fei Qin,Kai Ou,Young-Bae Kim 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6
DC/DC converters with hybrid proton exchange membrane (PEM) fuel cell and battery power sources are designed and implemented using sliding mode control (SMC). The converters are typically comprised by unidirectional boost converter and bidirectional converter which are used for regulating the bus voltage and managing power distribution. SMC is selected to control the converters since it can cope with the high non-linear characteristic of the coupled system as well as ensure the stability. The hybrid power control system is constructed in MATLAB/Simulink platform. A comparative approach based on conventional proportional-integral (PI) control is developed to compare the control performance with SMC. The experimental validation is carried out with National Instruments (NI) LabVIEW-based hybrid PEMFC/battery supplied DC/DC converters system prototype.
-
Temperature Control for a Polymer Electrolyte Membrane Fuel Cell by Using Fuzzy Rule
Ya-Xiong Wang,Fei-Fei Qin,Kai Ou,Young-Bae Kim IEEE 2016 IEEE transactions on energy conversion Vol.31 No.2
<P>Temperature control for a polymer electrolyte membrane fuel cell (PEMFC) is important in improving power efficiency and increasing fuel cell lifetime. If the temperature of the cell is too low, then the electrochemical reaction response becomes slow, thereby preventing evaporations of liquid water in the membrane. As a result, cell performance is decreased. However, too high temperature leads to waste in catalyst and heat because of excessive chemical reactions and to liquid water evaporation, which decreases proton conductivity. This study develops an electrochemical dynamical model and a thermal model of a PEMFC using MATLAB/Simulink for simulation. Fuzzy control rules are also built to regulate the temperature of a PEMFC. The fuzzy inputs include temperature error, its derivative, and external load current. The cooling fan speed is chosen as an output variable to regulate the temperature of a fuzzy control because the fuel cell utilizes the air cooling method. After confirming that the designed fuzzy rules are effective for controlling cell temperature, a real experimental device is built using an H-100 fuel cell and a cooling fan to verify the effectiveness of the proposed method.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
