• New & Renewable Energy
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• v.4 no.3
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• pp.51-57
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• 2008

The objective of this study is to develop and validate a compressed hydrogen storage system for fuel cell vehicles. The type3 composite cylinder consists of full wrapped composites on a seamless aluminum liner. The key technologies, including design, analysis, and optimized fabrication process for 350bar composite cylinder, were established and verified, and the facilities for fabrication and validation testing have been constructed. Prototype cylinders were fabricated and validated through burst test and ambient cycling test in accordance with international standard.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.31-39
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• 2013

A virtual chassis platform for Fuel Cell Hybrid Electric Vehicles(FCHEV) has been developed, and a virtual platform similar to the actual system has been composed. In addition, major components such as a motor, fuel cell and battery for the virtual platform have been constructed by using a mathematical formulation. The FCHEV virtual platform using a detailed model based on the mathematical formula is capable of simulating various conditions according to changes of the control logic and component modules to evaluate performance, considering the vehicle dynamic characteristics. Usability of the mathematical model has been verified by comparative simulations according to the motor current control variation. In addition, reliability of the developed virtual chassis platform has been verified by simulating its fuel consumption with the UDDS(Urban Dynamometer Driving Schedule) FTP-72 velocity profile.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.4
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• pp.228-235
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• 2021

Polymer electrolyte membrane fuel cells (PEMFC) are currently being used in various transport applications such as drones, unmanned aerial vehicles, and automobiles. The power required is different according to the type of use, purpose, and the conditions adjusted using a cell stack. The fuel cell stack is compressed to reduce the size and prevent fuel leakage. The unit cells that make up the cell stack are subjected to compression by clamping force, which makes geometrical changes in the porous media and it impacts on cell performance. In this study, finite elements method (FEM) and computational fluid dynamics (CFD) analysis for the deformed unit cell considering the effects of clamping force is performed. First, structural analysis using the FEM technique over the deformed gas diffusion layer (GDL) considering compression is carried out, and the resulting porosity changed in the GDL is calculated. The PEMFC model is then verified by a three-dimensional, two-phase fuel cell simulation applying the physical properties and geometry obtained before and after compression. The detailed simulation results showed different concentration distributions of fuel between the original and deformed geometry, resulting in the difference in the distribution of current density is represented at compressed GDL region with low oxygen concentration.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.531-539
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• 2019

The development of cost-effective electrocatalysts with high durability is one of the most important challenges for the commercialization of polymer electrolyte fuel cells (PEFCs). The durability of the electrocatalyst has been studied in terms of structural change in the active metal and the support. In particular, in fuel cell vehicles, degradation of the carbon-based support is known to have a significant effect on the electrocatalyst deterioration since the start-up/shut-down cycle is frequently repeated. The requirements for the support of the electrocatalyst include high surface area, electrical conductivity, chemical stability, and so on. In this study, we propose the evaluation methods for choosing better support materials and present the physicochemical properties that promising carbon supports should have. Three kinds of carbon materials with different crystallinity are compared. From in-depth study using X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and accelerated stress test, it is clearly confirmed that the durability of carbon-supported electrocatalysts is closely related to the physicochemical properties of the carbon supports.

• Journal of the Korean Electrochemical Society
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• v.9 no.3
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• pp.118-123
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• 2006

Degradation of polymer electrolyte membrane fuel cell (PEMFC) that is facilitated by on/off cycles is one of the most important issues for commercialization of fuel cell vehicles. When a PEMFC stack is shut down, residual hydrogen and induce high voltage equivalent to open circuit voltage to the cathode side that might cause sintering of Pt catalyst and facilitate formation of hydrogen peroxide at the anode side that might decompose $Nafionc\'{A}$ membrane. In this study, degradation of PEMFC exposed to repetitive on/off cycles was investigated by measuring i-V characteristics, ac impedance, cyclic voltammograms, gas leak, cross-sectional SEM images, and TEM images. To prevent degradation of PEMFC caused by the residual gases, hydrogen was removed from anode gas channel by gas-purging and by using a dummy resistance, that were found to be a very effective method.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.37-44
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• 2022

Plug-in Hybrid electric vehicles (PHEV) show great potential to reduce gas emission, improve fuel efficiency and offer more driving range flexibility. Moreover, PHEV help to preserve the eco-system, climate changes and reduce the high demand for fossil fuels. To address this; some basic components and energy resources have been used, such as batteries and proton exchange membrane (PEM) fuel cells (FCs). However, the FC remains unsatisfactory in terms of power density and response. In light of the above, an electric storage system (ESS) seems to be a promising solution to resolve this issue, especially when it comes to the transient phase. In addition to the FC, a storage system made-up of an ultra-battery UB is proposed within this paper. The association of the FC and the UB lead to the so-called Fuel Cell Battery Electric Vehicle (FCBEV). The energy consumption model of a FCBEV has been built considering the power losses of the fuel cell, electric motor, the state of charge (SOC) of the battery, and brakes. To do so, the implementing a reinforcement-learning energy management strategy (EMS) has been carried out and the fuel cell efficiency has been optimized while minimizing the hydrogen fuel consummation per 100km. Within this paper the adopted approach over numerous driving cycles of the FCBEV has shown promising results.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.72-77
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• 2014

In the ongoing debates over the need to identify new sources of energy and to reduce the emissions of greenhouse gases. Hydrogen has emerged as one of the most promising alternatives due to its emissions from the vehicle being virtually zero. The governments have identified the development of regulations and standards as one of the key requirements for commercialization of hydrogen-fueled vehicles. Regulations and standards will helpful in overcoming technological barriers to commercialization. Developments of a technique for safety assessment of Hydrogen Fuel Cell Vehicle(HFCV) includes four tasks, research for regulation system and policy, hydrogen safety, vehicle operation safety and protection against high-voltage. The objective is to establish a technique for safety assessment and amend safety standards for HFCV and consequently reflect research results to vehicle management policy. We devised safety standards and evaluation techniques with regard to high-pressure gas and high voltage of hydrogen fuel cell vehicle. Korean Motor Vehicle Safety Standards(KMVSS) for HFCV was amended to June 10, 2014. including the results of the safety assessment technology for high-voltage and hydrogen characteristics.

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.4
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• pp.369-380
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• 2023

There is no clear standard for estimating the power distribution of fuel cells and batteries to meet the required power in hydrogen electric vehicles. In this study, a hydrogen electric vehicle simulation model equipped with a vehicle electric component model including a fuel cell system was built, and a power distribution strategy between fuel cells and batteries was established. The power distribution model was operated through two control strategies using step control and fuzzy control, and each control strategy was evaluated through data derived from the simulation. As a result of evaluation through the behavior data of state of charge, fuel cell current and balance of plant, fuzzy control was evaluated as a proper strategy in terms of control stability and durability.

• Journal of Electrochemical Science and Technology
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• v.7 no.1
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• pp.41-51
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• 2016

In the stratosphere, the air is stable and a photovoltaic (PV) system can produce more solar energy compared to in the atmosphere. If unmanned aerial vehicles (UAVs) fly in the stratosphere, the flight stability and efficiency of the mission are improved. On the other hand, the weakened lift force of the UAV due to the rarefied atmosphere can require more power for lift according to the weight and/or wing area of the UAV. To solve this problem, it is necessary to minimize the weight of the aircraft and improve the performance of the power system. A regenerative fuel cell (RFC) consisting of a fuel cell (FC) and water electrolysis (WE) combined PV power system has been investigated as a good alterative because of its higher specific energy. The WE system produces hydrogen and oxygen, providing extra energy beyond the energy generated by the PV system in the daytime, and then saves the gases in tanks. The FC system supplies the required power to the UAV at night, so the additional fuel supply to the UAV is not needed anymore. The specific energy of RFC systems is higher than that of Li-ion battery systems, so they have less weight than batteries that supply the same energy to the UAV. In this paper, for a stratospheric long-endurance hybrid UAV based on an RFC system, three major design factors (UAV weight, wing area and performance of WE) affecting the ability of long-term flight were determined and a simulation-based feasibility study was performed. The effects of the three design factors were analyzed as the flight time increased, and acceptable values of the factors for long endurance were found. As a result, the long-endurance of the target UAV was possible when the values were under 350 kg, above 150 m² and under 80 kWh/kg H₂.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.911-915
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• 2007

This paper deal with the design concept of traction motor for Bimodal low floor vehicles that are CNG(Compressed Natural Gas) hybrid bus and Fuel-cell bus. The design concept of the traction motor is studied in terms of electrical characteristics and mechanical construction. Finally, this paper introduces the characteristic of the traction motor for low floor vehicles which are applied in the world, and mentioned the detail design concept of traction motor.