• Journal of Energy Engineering
• /
• v.23 no.3
• /
• pp.132-145
• /
• 2014

There is a general agreement that performance of hydrogen fuel cell vehicle(FCV) with respect to cold start, packaging, acceleration, refueling time and range has progressed to the point where vehicles that could be brought to market in 2015_2020 will satisfy customer expectations. However cost, durability and the lack of refueling infrastructure remain significant barriers. Cost have been dramatically reduced and durability has been enhanced over the past decade, yet are still about twice what appears to be needed sustainable market success. Advanced Technologies for the commercialization of hydrogen FCV were reviewed.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.590-595
• /
• 2016

The US is pursuing a plan to raise the subsidies for electric vehicles by more than 30%. The number of electric vehicles in Europe is expected to be one million by 2020 and 2030 and there are plans to expand in the center of Germany to supply six million electric vehicles on the dissemination and development policies. The development of the electric vehicle is not simply a technical trend but there is the potential to improve the access to this technology and the possibility of changing the entire social system and long-term energy security. Domestic competition is also increasing the supply of electric vehicles, as new blue ocean markets are emerging. The current domestic On-board Charger (Home Charger) plans to be suspended from the 2015 government-sponsored installation, This paper on the IEC 61851-1 and IEC 61851-22 specifications analyzes the development of a midnight electricity charger as a low-cost algorithm, the decrease in price and the improved convenience of the On-board Charger for Bluetooth module with the ATmega128 existing charger system, and the UI configuration via the LCD Panel to a Smartphone app are proposed.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.4
• /
• pp.455-478
• /
• 2019

In this paper, we conducted experimental investigation on the field applicability through the verification of reinforcement effect of the steel pipe reinforcement grouting using high strength steel pipe. SGT275 (formerly known as STK400) steel pipe is generally applied to the traditional steel pipe reinforcement grouting method. However, the analysis of tunnel collapse cases applying the steel pipe reinforcement grouting shows that there are cases where the excessive bending and breakage of steel pipe occur. One of the reasons causing these collapses is the lack of steel pipe stiffness responding to the loosening load of tunnels caused by excavation. The strength of steel pipe has increased due to the recent development of high strength steel pipe (SGT550). However, since research on the reinforcement method considering strength increase is insufficient, there is a need for research on this. Therefore, in this study, we conducted experiments on the tensile and bending strength based on various conditions between high strength steel pipe, and carried out basic research on effective field application depending on the strength difference of steel pipe through the conventional design method. In particular, we verified the reinforcement effect of high strength steel pipe through the measurement results of deformed shape and stress of steel pipe arising from excavation after constructing high strength steel pipe and general steel pipe at actual sites. The research results show that high strength steel pipe has excellent bending strength and the reinforcement effect of reinforced grouting. Further, it is expected that high strength steel pipe will have an arching effect thanks to strength increase.

• Journal of Energy Engineering
• /
• v.28 no.3
• /
• pp.10-17
• /
• 2019

According to South Korea's policy of supplying eco-friendly hydrogen vehicles, related industries are actively conducting research on the development of hydrogen cars and hydrogen charging station infrastructure. On the other hand, there is a lack of empirical research and assessment of the risk of non-metallic materials (such as liners, seals, gaskets) for classified materials that directly affect the durability and reliability of hydrogen vehicles and hydrogen charging stations. In this study, the risk factors for liners and seals of non-metallic parts used in high-pressure hydrogen installations were derived using FMEA, and the RPN values were calculated by converting the severity, frequency of occurrence and degree of detection into scores. The maximum value of the RPN 600, minimum value 63, average value 278.5 was calculated and periodic control of the liner and seal was identified as important. In addition, through hydrogen soakage and oxygen aging tests for non-metallic rubber products, physical test values that can be used as basic data were presented.

• Journal of the Korea Society for Simulation
• /
• v.25 no.4
• /
• pp.93-108
• /
• 2016

Electric vehicle car sharing (EV-sharing) system is noted as an eco-friendly system of transportation in global warming crisis and has been practically implemented in some cities around the world. However, methodologies to find the efficient operation conditions of EV-sharing systems reflecting a typical characteristic 'charging' have not been fully investigated yet. In the paper a generalized model has been developed to identify optimal level of infrastructure for EV-sharing system which provides the optimum operation efficiency under service level constraints. From the simulation analysis based on the developed model the relationships between the operational variables to describe EV-sharing system have been identified and optimal capacity to maximize the operational efficiency have been found. From the analysis of simulation results it has been found that increases in the number of vehicles and chargers improve the service level until certain value beyond which increasing rate and the efficiency have been reduced. From the cost-revenue analysis the optimal numbers of vehicles and chargers have been identified which maximizes the annual operational profit.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.4
• /
• pp.617-624
• /
• 2022

The small electric vehicles equipped with V2X(vehicle to everything) systems may provide more information and function to the existing navigation system of the vehicle. The key components of V2X technology include V2V (vehicle to vehicle), V2N(vehicle to network) and V2I (vehicle to infrastructure). This study is to design and implementation of VI type E-PTO which is interfaced with external equipments, the work designs the components of E-PTO such as DC/DC converter, DC/AC converter, battery bidirectional charging system etc. Also, it implements the devices and control systems for driving. The test results of VI type E-PTO components showed allowable 10% requirements of transient voltage variation rate and recovery time within 100ms for start/stop and normal operation.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.22 no.1
• /
• pp.181-186
• /
• 2022

The world's electric automobile sector has shifted beyond technological environmental changes to a stage that has an impact on the market environment. And automakers are shifting from the existing strategy of "technological advantage → brand enhancement → sales expansion of existing internal combustion engine vehicles" to the expansion of the electric automobile market itself, which is to enhance market competitiveness. In addition, competition in the electric automotive parts market is expected to intensify due to the expansion of the business areas of existing parts makers and the entry of new companies, and development cooperation is expected to actively proceed to improve the efficiency of major eco-friendly parts. Along with this prospect, electric vehicles are expected to change the overall structure of the automobile industry, the overall growth of the electric vehicle value chain such as batteries, power trains (motors, power management and control systems), electric vehicle production, and charging infrastructure Is expected. Therefore, in this thesis, in order to cultivate a variety of high-quality human resources that companies want to keep pace with the changing automobile industry, we study a professional manpower training program that leads the growth engine of the electric automobile industry.

• Journal of the Korean Institute of Gas
• /
• v.26 no.4
• /
• pp.58-63
• /
• 2022

With the emergence of environmental problems caused by fine dust worldwide, LNG, which is cheaper and less pollution than diesel, is attracting attention as the next generation energy of automobiles and is expanding its supply. However, it is difficult to operate smoothly due to the lack of infrastructure for LNG charging stations in Korea and the limited size of containers that can be installed according to regulations. In Korea, research and development on the contents of containers for the smooth operation of natural gas vehicles are underway, but there is a problem that the container directly receives the impact of the vehicle collision and explodes, causing a major disaster. Therefore, in this study, the safety of the container was verified by deriving the strain and stress values through ANSYS Explicit Dynamics analysis. As a result, a maximum stress of 565.37MPa occurred in the container, and it is expected that plastic deformation will occur as it exceeds the yield stress of STS304 used as a material for the container, which is beyond 505MPa. When an impact caused by a collision between a vehicle and a container is applied, it is considered necessary to design a support or reinforcement because the container may be damaged or defective.

• Journal of Appropriate Technology
• /
• v.7 no.2
• /
• pp.127-135
• /
• 2021

To respond to the threat of global warming, countries around the world are promoting the spread of renewable energy and reduction of carbon emissions. In accordance with the United Nation's Sustainable Development Goal to combat climate change and its impacts, global automakers are pushing for a full transition to electric vehicles within the next 10 years. Electric vehicles can be a useful means for reducing carbon emissions, but in order to reduce carbon generated in the stage of producing electricity for charging, a power generation system using eco-friendly renewable energy is required. In this study, we propose a smart electric mobility operating system integrated with off-grid solar power plants established in Tanzania, Africa. By applying smart monitoring and communication functions based on Arduino-based computing devices, information such as remaining battery capacity, battery status, location, speed, altitude, and road conditions of an electric vehicle or electric motorcycle is monitored. In addition, we present a scenario that communicates with the surrounding independent solar power plant infrastructure to predict the drivable distance and optimize the charging schedule and route to the destination. The feasibility of the proposed system was verified through test runs of electric motorcycles. In considering local environmental characteristics in Tanzania for the operation of the electric mobility system, factors such as eco-friendliness, economic feasibility, ease of operation, and compatibility should be weighed. The smart electric mobility operating system proposed in this study can be an important basis for implementing the SDGs' climate change response.

• Journal of Energy Engineering
• /
• v.25 no.4
• /
• pp.93-102
• /
• 2016

Vehicle-to-Grid (V2G) system, bi-direction power trading technology, enables drivers possessing electric vehicle to sell the spare electricity charged in the vehicle to power distribution company. The drivers gain profit by charging electricity in the day time of high electricity rate. In this regard, the government is preparing the policies of building and supporting V2G infrastructure and demanding the potential consumers' preference for the V2G system. This paper attempts to analyze the consumers' preference using the data from obtained a survey of randomly selected 1,000 individuals. To this end, choice experiment, an economic technique, is employed here. The attributes considered in the study are residual amount of electricity, electricity trading hours, required plug-in time, and price measured as an amount additional to current gasoline vehicle price. The multinomial logit model, which requires the assumption of 'independence of irrelevant alternatives', is applied but the assumption could not be satisfied in our data. Thus, we finally utilized nested logit model which does not require the assumption. All the parameter estimates in the utility function are statistically significant at the 10% level. The estimation results show that the marginal willingness to pay (MWTP) for one hour increase in electricity trading hours is estimated to be KRW 1,601,057. On the other hand, a one percent reduction in residual amount of electricity and one hour reduction in required plug-in time in V2G system are computed to be KRW -91,911 and -470,619, respectively. The findings can provide policy makers with useful information for decision-making about introducing and managing V2G system.