• Journal of Environmental Health Sciences
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• v.32 no.6
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• pp.533-538
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• 2006

The nano-particles are known to influence the environmental protection and human health. The relationships between transient vehicle operation and nano-particle emissions are not well-known, especially for diesel passenger vehicles with DPF(Diesel Particulate Filter). In this study, two diesel passenger vehicles were measured on a chassis dynamometer test bench. The particulate matter (PM) emission of these vehicles was investigated by number and mass measurement. The mass of the total PM was evaluated using the standard gravimetric measurement method, and the total number concentrations were measured on a ECE15+EUDC driving cycle using Condensation Particle Counter (CPC). According to the investigation results, total number concentration was $1.14{\times}10^{11}$M and mass concentration was 0.71mg/km. About 99% of total number concentration was emitted during the $0{\sim}400s$ because of engine cold condition. In high temperature and high speed duration, the particulate matter was increased but particle concentration was emitted not yet except initial engine cold condition According to DPF performance deterioration, the particulate matter was emitted 2 times and particle concentration was emitted 32 times. Thus DPF performance deterioration affects particle concentration more than PM.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.3
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• pp.165-172
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• 1998

The electromechanical energy conversion conditioning and processing implementation in USM direct motion control system is generally divided into two power stages: the two-phase high-frequency ac power inversion stage for driving piezoelectric ceramic PZT transducer array off the USM stator and the mechanical thrust power conversion stage based on the frictional force between the piezo electric stator array and the rotary slider of the USM. However, the dynamic and steady-state mathematical modeling of the USM is extremely default from a theoretical point of view because it contains many complicated an nonlinear characteristics dependant on operation temperature. In +2$0^{\circ}C$~3$0^{\circ}C$, the operating characteristics of the USM has represented normal condition. But the other temperature, it has abnormal condition so that driving frequency, current and motor speed will be down. The recent USM has controller without temperature compensation. This study represents the fuzzy controller for speed compensation according to operating temperature by driving frequency.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1398-1402
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• 2007

In a high speed train, OBCS(On-Board Computer System) is a up-to-date computer control system that provide controlling, monitoring, maintaining and reparing of the important device, supporting a driver, status of a train, service maintenance, managing the remote control mode, driving order & control, control of a electrical or pneumatic circuit and a passenger service. In general, OBCS is located in each car but in a power car, both main and auxiliary computers are used. These avoid a network collision and maintain the independence of condition and failure records with the information of line number, train number and car number. This paper is intended to provide the information about the identification coding method of domestic and foreign OBCS, for the new high speed train (KTX-II).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.881-885
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• 2013

In this paper, we present a deterioration judgment model of urban rail power equipment using driving history, the frequency and number of failures. In addition, we have developed a deterioration judgment program based on the derived failure rate. A deterioration judgment model of power equipments on metro system was designed to establish how much environmental factors, such as thermal cycling, humidity, overvoltage and partial discharge. The deterioration rate of the transformers followed the Arrhenius log life versus reciprocal Kelvin temperature (hotspot temperature) relation. The deterioration judgment program is linked to the online condition monitoring system of urban railway system. The deterioration judgment program is based on the user interface it is possible to apply immediately to the urban rail power equipment.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.207-213
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• 2019

The fuel-cut coast-down driving mode is activated when the acceleration pedal is released with transmission gear engaged, and it's a default function for electronic-controlled engine of vehicles. The fuel economy becomes better because fuel injection stops during fuel-cut driving mode. A fuel-cut detection method is suggested in the study and it's based on the speed, acceleration and road gradient data from GPS sensor. It detects fuel-cut driving mode by comparing calculated acceleration and realtime acceleration value. The one is estimated with driving resistance in the condition of fuel-cut driving and the other is from GPS sensor. The detection accuracy is about 80% when the method is verified with road driving data. The result is estimated with 9,600 data set of vehicle speed, acceleration, fuel consumption and road gradient from test driving on the road of 12km during 16 minutes, and the road slope is rather high. It's easy to detect fuel-cut without injector signal obtained by connecting wire. The detection error is from the fact that the variation range of speed, acceleration and road gradient data, used for road resistance force, is larger than the value of fuel consumption data.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.335-341
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• 2009

To predict efficiency of interior permanent magnet synchronous motor (IPMSM) for traction motor and to cope with the risk of demagnetization in the permanent magnets, accurate iron loss analysis and understanding of the characteristic of the iron loss are very important at motor design stage. In this paper, we present the method to estimate the iron loss for the IPMSM considering the driving conditions such as both field weakening control and maximum torque per ampere control.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1178-1187
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• 2008

According to the operation data between $2007{\sim}2008$(January$\sim$June) for essential safety equipment including ATC, there were nothing special but stable and steady. And also emergency stop number of count are decreasing. But the frequency are still above the resonable count and it means driving condition should be improved through interface between ground and locomotive same as come to an understanding with driver. The number of count of emergency stop for VACMA(vigilance system) are also decreasing but also the frequency are above resonable count. This phenomenon caused by careless driving for the driver or the system malfunction. So the continuous monitoring for the data is necessary.

• Journal of Magnetics
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• v.18 no.3
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• pp.268-275
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• 2013

This paper shows the characteristics of performance for interior permanent magnet machine (IPM) considering driving conditions such as maximum torque per ampere (MTPA) and flux-weakening control especially in terms of harmonic loss. In particular, based on finite element analysis (FEA), permanent magnet (PM) eddycurrent loss and the harmonic iron loss have been computed where the models have been intentionally designed to identify the effects of pole-slot combinations on the loss while maintaining the required power for electric vehicle. From the analysis results, it was shown that the rotor iron loss and PM eddy-current loss of machine employing fractional slot winding are extremely large at load condition. Furthermore, it was revealed that the harmonic iron loss at high-speed operation is mainly distributed over stator teeth and rotor surface, which may aggravate cooling system of the rotor structure in the vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.21-29
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• 2003

Boosting of engine power by using Turbo- or Super-charger is a solution to comply with $CO_2$-regulation in Europe. Turbo-charger is now playing a major role in the field of charging system thank to its technical advantages such as no demand of operation power from engine. A mechanically driven Super-charger, however, is now popular due to quick speed response to change of the driving mode-high engine torque even at low engine speed. Since Super-charger needs operation power from engine, it is difficult to improve its relatively higher fuel consumption than that of Turbo-charger. This negative point is still an obstacle to the wide use of Super-charger. This study aims to develop power control concept to achieve the minimization of operation power when it is not necessary to charge at idling or part load driving condition. A screw type Super-charger was modified in design partially and adapted an internal bypass valve and a bypass tube to control charging pressure at part load. The various control concepts show a possibility to reduce operation power of Super-charger and result in improvement of fuel consumption.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.148-156
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• 2014

The objective of this study is to compare NOx emissions from light duty diesel vehicles measured from on-road tests that conducted under various driving routes and seasonal conditions. We measured real-driving NOx emissions using PEMS, portable emissions measurement system, under the urban, rural and motorway road traffic conditions. On-road tests were repeated at summer, fall and winter season. The accumulated driving distance is more than 1,200 km per each vehicle. Route average NOx emission factors were compared among nine route-season combinations. The emission characteristics of each combinations were investigated using time series mass emission rates and vehicle operation-based emission rates and activities, which is based on U.S. EPA's MOVES model. Most concerned route-season combination is "urban road condition at summer", which shows two to eleven times higher NOx emissions than other combinations. The emission rates and activities under low speed operating conditions should be managed in order to reduce urban-summer NOx. From a NOx control strategy perspective, the exhaust gas recirculation, EGR, is observed to be properly operated under wide range of vehicle driving conditions in Euro-5 vehicles, even if the air conditioner turns on. In high power demanding conditions, the effect of overspeeding could be more critical than that of air conditioner activation.