• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.3
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• pp.193-198
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• 2017

This paper discusses the design and control of a switched reluctance motor (SRM) drive system for a built-in car vacuum cleaner. The growing popularity of outdoor activities and recreation has led the automobile industry to expand technologies that increase the convenience of vehicles, and thus, a built-in car vacuum cleaner was introduced. However, the existing DC motor of a vacuum cleaning system has several disadvantages, such as maintenance cost and lifespan issues of its commutator-brush structure. An SRM can be a good alternative to the existing DC motor because of its high-speed capability, long lifespan, low maintenance cost, and high efficiency, among other advantages. A prototype SRM drive is designed and manufactured to verify its feasibility for use in a built-in car vacuum cleaning system. Dynamic simulation is conducted to determine the optimal switching angle for maximum efficiency and minimum torque ripple. Load test, noise measurement, and suction-power tests are also carried out.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.169-172
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• 2003

A design power supply for car audio installation which uses SCR phase control method is able to get output DC 15[V]-100[A] in US wall outlet restricted to input AC 120[V]-15[A]. As the power supply for car audio is tested, output is DC 15[V]-100[A] in ripple voltage 110[mV].

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.319-329
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• 2016

Globally, many researchers have been trying to improve the fuel economy of a vehicle for satisfying future $CO_2$ regulation and minimizing air pollution problem. For the same background, diesel engine and vehicle system optimization using simulation models have been key technologies for the improvement of vehicle system efficiency. Therefore, in this study, calibration method for the air breathing system of a WGT diesel engine using mean value model has been composed for efficient engine and vehicle optimization simulation researches. And virtual WGT performances have been calculated for a 2 cylinder downsized diesel engine system. From these researches, the calibration method for the boost pressure and EGR rate of a virtual diesel engine related with WGT performances could be composed and some of technical issue related with downsized diesel engine could be investigated.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.208-214
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• 2000

Reduction of structure-borne noise of the compartment in a car is an important task in automotive engineering. Transfer path analysis using vibroacoustic reciprocity technique or multiple path decomposition method has generally been used for structure-borne noise path analysis. These methods are useful in solving particular problem but do not quantify the effectiveness of vibration isolation of each isolator of a vehicle. To quantify the effectiveness of vibration isolation, the vibrational power flow has been used for a simple isolation system or a laboratory based isolation system. It is often difficult to apply the vibrational power flow technique to the complex isolation system like a car. In this paper, a simple equation is derived for calculation of the vibrational power flow of an isolation system with multiple isolators such as a car. It is successfully applied to not only quantifying the relative contributions of eighteen isolators but also reducing structure-borne noise of a passenger car. According to the results, the main contributor of eighteen isolators is the rear roll mount of an engine. The reduced structure-borne noise level is about 5dBA.

• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.1-12
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• 2021

As increasing the international community's awareness of greenhouse gas reduction, the demand for eco-friendly ship fuel has accelerated recently. The fundamental aim of this study is to develop a new type of fully electrified ferry for passengers and cars considering Korean domestic coastal environmental conditions. Several technical difficulties are encountered in applying a fully electric propulsion system based on removable battery systems into a ship due to limitations imposed by the batteries' size and capacity. This paper reviews and analyzes marine environment regulations strengthened recently, technology trends related to fully electric propulsion vessels in each country, and Korean domestic coastal environments. We propose a new fully electrified car ferry design with a displacement of 400 t applied in Korea. It is powered by removable battery systems pre-charged in a safe inland charging station. The mobile battery system is developed to enable roll-on and roll-off using wheels. The characteristics of the ship motion are analyzed based on the weight and location of the battery systems. We expect our battery systems to be applicable to larger ships in the future.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.816-823
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• 2007

Electric car tract plays the role of supply high electric power to the electric car from the substation by using Pantograph of the electric car. It is always exposed to the external atmosphere, which results in quite substantial fluctuations in current and voltage during operation of electric car. This generates possibility of occurrence of accident at all times. Since range of wiring metallic globe installed on the catenary cannot achieve complete electrical contact, accidents are occurring due to circulating current caused by arc caused by incomplete contact due to occurrence of hairline fracture of Pantograph due to pressure or vibration of wiring. Furthermore, rapid increase in the operational current due to increase in the operational frequency of the electric car is causing erosion and short circuit of the metallic globe at the contact points. This study on arc is generated as current transmitted out of the substation courses through power line or wiring metallic globe other than the main circuit as the current is being collected at the electric car through feeder and feeder divergence device. Accordingly, since heat generated by the arc becomes the cause for generation of circulating current due to melting of metal or softening of metal due to increase in temperature accompanying increase in contact resistance, this research shall describe causes and measures against occurrence of circulation current.

• Journal of Korea Multimedia Society
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• v.14 no.6
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• pp.752-758
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• 2011

In this paper, we perform a research on a message delivery link based on visible light communication using illumination light-emitting diodes (LEDs) for car-to-car communications and the link transmission success probability is analyzed for the link. The message delivery system is modeled and the signal-to-noise ratio is calculated from the received optical power. Then, the link transmission probability is estimated from the calculated bit error rates (BERs). The message delivery system has optical links from an LED transmitter near the rear lamp of a car ahead to a receiver near the headlamp of a car behind, whose positions are assumed to follow the normal Gaussian distribution. The link transmission success probability is calculated considering the physical characteristics of the optical link. The car positions are generated according to the normal distribution and the bit error rates are calculated for all links. The link transmission success probability is defined. For the unoptimized optical car-to-car message delivery links, it is shown that the link transmission success probability is larger than 0.9 with the transmitted optical power of 400 mW and the semi-angle at half power of 30 degree.

• Journal of Power System Engineering
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• v.19 no.2
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• pp.70-77
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• 2015

Nowadays, car manufacturers applied many high strength steels such AHSS or UHSS to car bodies for weight lightening. Therefore, a variety of applied steel sheet to car bodies increased and the needs of simulation to evaluate weldability also increased in order to reduce the cost and time. In this study, resistance spot welding simulations for DP 780 Steel with 1.0 and 1.4 mm thickness were conducted with respect to lobe curve. 2 regression models to estimate tensile shear strength were suggested and they were second order polynomial regression model and optimized second order regression model. The performance of these models was evaluated in terms of the coefficient of determinant and average error rate.

• Tribology and Lubricants
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• v.22 no.4
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• pp.196-202
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• 2006

This paper presents a case study on the tribological failure analysis of a clutch system for a manual transmission car. The clutch systems are composed of clutch disk, clutch pressure plate, flywheel rubbing surface, coil and diaphragm springs, release bearing and lever, clutch spline and shaft. The purpose of a clutch system is to transmit and disconnect the driving power of engines by frictional farce from a rubbing surface of a flywheel to a clutch disk and clutch pressure plate with a minimum power loss. In this study, many tribological failure cases based on the wear phenomena and thermal distortions have been presented, which are collected from the car repair shop and maintenance center. The triboiogicai failures are mostly come from the driving conditions, overloading of a car, and especially driving style and personal habit of a car driver.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1232-1240
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• 2001

In this study. a computer simulation of the Korean High Speed Prototype Test Train was performed to investigate the dynamic behavior(running stability. safety and comfort) in detail design process. The simulation model which was prepared by ADAMS/Rail V10.l consists of power car and middle car assembly (2 motorized cars ＋ 3 trailer cars). The nonlinear analysis takes into account the full vehicle model including wheel/rail contact and the influence of disturbed track. Throughout the dynamic calculation of KHST on the straight and the curved track. accelerations in car body. ride comforts and wheel rail forces were investigated.