• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.67-75
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• 2011

The development of electric vehicle power electronics system control, composed of DC-AC inverters and DC-DC converters, attract much research interest in the modern industry. A DC-AC inverter supplies the high-power motor torques of the propulsion system and utility loads of electric vehicles, whereas a DC-DC converter supplies the conventional low-power and low-voltage loads. However, the need for high-power bidirectional DC-DC converters in future electric vehicles has led to the development of many new topologies of DC-DC converters. The nonlinear control of power converters is an active research area in the field of power electronics. This paper focuses on the use of the fuzzy sliding mode strategy as a control strategy for buck-boost DC-DC converter power supplies in electric vehicles. The proposed fuzzy controller specifies changes in control signals based on the surface and knowledge on surface changes to satisfy the sliding mode stability and attraction conditions. The performance of the proposed fuzzy sliding controller is compared to that of the classical sliding mode controller. The satisfactory simulation results show the efficiency of the proposed control law, which reduces the chattering phenomenon. Moreover, the obtained results prove the robustness of the proposed control law against variations in load resistance and input voltage in the studied converter.

• KIEAE Journal
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• v.13 no.6
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• pp.39-44
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• 2013

As the use of electric vehicles perspectively increases, infrastructures for charging car batteries need to be properly planned for satisfying new requirements. This study aimed at theoretically investigating the relative laws, size of existing parking lots, and diverse car sizes for suggesting parking places for electric vehicles. In addition, potential problems for changing existing parking lots to new parking lots for electric vehicles were thoroughly considered. Based on the problem recognition, the feasibility, in particular, of the change of existing parking place to new place equipped with electricity charging systems was investigated. The comprehensive reviews and surveys revealed that additional systems for charging electricity need to be developed to be suspended on the ceiling for existing parking lots in order to prevent changing current layout of the space. This system will alleviate the perspective problems when the charging systems are located on the floor such as contamination, electric shock, and damage by cars. Further study will be followed for testing performance of the suggested systems in the actual parking lots.

• Tribology and Lubricants
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• v.36 no.2
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• pp.96-104
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• 2020

The electric vehicle industry is rapidly developing because of enforced environmental regulations, and several studies have been conducted on the multispeed transmission to improve the fuel efficiency of electric vehicles. Among these studies, research on the power density improvement of electric vehicle transmission is critical. Thus, the optimal design of the gear train is necessary to enhance transmission efficiency. In this study, an optimal design methodology for the lightweight two-speed transmission of electric vehicles is proposed. Because a multispeed transmission has many operating conditions and equality and inequality constraints, a new gear design method that combines analytical and iterative methods is applied without using complex optimization algorithms. Sets of possible design variables are generated considering the operating conditions and various design variables. The modules and face width ratios of each stage gear that satisfy the corresponding operating conditions are analytically calculated. The volume of the gear train is calculated, evaluated, and arranged using these values to determine the optimal solution for minimizing the volume, and the proposed methodology is applied to the actual model to verify its effectiveness. The design of a two-speed transmission with multiple operating conditions and constraints without complicated optimization algorithms can be optimized.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.5
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• pp.597-602
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• 2012

In this paper, a manual and automatic steering system for electric vehicles capable of manned and unmanned driving is proposed. The automatic steering systems, EPS, MDPS, used in conventional engine based car includes the problem of handle lock phenomenon while driving of overloading, therefore it has a drawback to apply to manned and unmanned electric vehicles. By using electronic clutch and pulleys, the proposed manual and automatic steering mechanism was designed so that it is possible to convert from manual to automatic steering mode. To experiment the performance of the proposed steering system, we made an experimental setup of an electric vehicle. We confirmed that the proposed manual and automatic steering system was useful for manned and unmanned electric vehicles.

• Journal of Digital Convergence
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• v.15 no.2
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• pp.165-172
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• 2017

In this paper, we analyze the research / technology trends of electric vehicles from 2001 to 2014, through keyword analysis using paper data published in SCIE or SSCI Journal on electric vehicles, time series analysis using patent data by IPC, and network analysis using nodeXL. also we predicted promising technologies of electric vehicles using one of the prediction methods, weighted moving average method. As a result of this study, battery technology among the electric vehicle component technologies appeared as a promising technology.

• The Journal of Information Systems
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• v.31 no.4
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• pp.47-73
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• 2022

Purpose The purpose of this study is to select the electronic architecture concept of the powertrain domain of the electronic platform to be applied to electric vehicles after 2025. Previously, the automotive electrical and electronic architecture was determined only by trend analysis, but the purpose was to determine the scenario based on the data and select it with clear evaluation indicators. Design/methodology/approach This study identified the function to be applied to the powertrain domain of next-generation electric vehicle, estimated the controller, defined the function feature list, organized the scenario candidates with the controller list and function feature list, and selected the final architecture scenario. Findings According to the research results, the powertrain domain of electric vehicles was selected as the architectural concept to apply the DCU (Domain Control Unit) and VCU (Vehicle Control Unit) integrated architecture to next-generation electric vehicles. Although it is disadvantageous or equivalent in terms of cost, it was found to be excellent in most indicators such as stability, security, and hardware demand.

• Tribology and Lubricants
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• v.38 no.2
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• pp.70-72
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• 2022

In this study, we report on a power system developed as a decelerator for a driving module in an electric vehicle. The system is to be mounted in a limited space. The research focus was on development of miniaturization, light weight, and high power density. In particular, we aimed to minimize the layout of existing external components as integrated or built-in, and to maximize the power density by applying optimal cooling technology to increased requirements for developing modular power systems applicable to various OEM models. South Korean automakers ranked fourth in global electric-vehicle sales in 2020, but domestic sales are relatively slow. Despite government's expansion in subsidies for eco-friendly cars, consumers are delaying purchases after 2021 considering the cost-effectiveness of electric vehicles. In major European markets, the demand for electric vehicles exceeded the demand for diesel cars, and sales of hybrid cars, which used to represent eco-friendly cars, are slowing down as Toyota, started selling electric vehicles. In this study, the internal lubrication characteristics of a decelerator installed in an electric vehicle were analyzed in terms of the deceleration time while driving. By selecting the proper oil and oil viscosity, it was confirmed that there is no problem in lubricating the bearings and gears of the decelerator.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.81-91
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• 2012

The world has been replacing fast fossil fuels vehicles with electric vehicles(EVs) to cope with climate change. The government set a goal which EVs will be substitute at least 10% of the domestic small vehicles with EVs until 2020, and will try to build electric charging infrastructures in apartments with the revision the law of 'the housing construction standards'. In apartments the EVs charging infrastructure and parking space is, essential to accomplish the goal. But the studies on EVs demand are few. In this study, we predicted that the demand for EVs using time-series analysis of statistical data, survey results for apartments residents in the metropolitan area. As a result, the ratio of the EVs appeared to be 6~21% for the total vehicles in a rental apartments for the years 2020, 21~39% in apartments for sales. For the EVs, the maximum power required for 1,000 households in rental apartment is predicted to be about 4200 kwh on a daily basis, while the maximum power in the apartment for sales is predicted to be 7800kwh.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.4
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• pp.80-86
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• 1993

This paper presents an advanced AC drive system used in electric vehicles. The system consists of a drive motor, a PWM transistorized inverter, a PCL-812PG data card, and a controller. This paper describes a design method for RSPWMSS and PID controller. This controller system is implemented on computer and applied to drive motor(induction motor), yielding satisfactory result.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.1
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• pp.10-15
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• 2001

Urgent increasing of the vehicles influence air pollution and the damage of the plants and animals. Particularly, exhaust-ing particulate of diesel vehicles give serious effect to human life. Therefore, this study aim to reduce amount of particulate and to contribute developing after-treatment in diesel engine. Through the experimental and theoretical study about charac-teristics of the electric heat regeneration, various results are obtained.