• Proceedings of the KSR Conference
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• 2003.05a
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• pp.409-414
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• 2003

In this study we examined the method to select the size of the conductor rail for light rail system. Study results shows that using the conductor rail with lower resistivity requires fewer power substation, which results in lower construction cost. It also produces less copper loss. Therefore first choose the conductor rail with lowest resistivity and select the substation location, Next conduct computer simulation study to confirm it meets voltage requirement. if the minimum voltage is well above the required minimum voltage, substation number can probably be further reduced.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.194-199
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• 2003

The traction drive system for the urban transit Rubber-tire system is described in this paper. To control the magnitude and frequency of the output voltage of induction motor transiently, the vector control strategy is generally used. But in case of the traction drive system for the railway vehicle, it is difficult to use the vector control caused by the one-pulse mode in the high speed region. Therefore, this paper proposes the control strategy combined the vector control in the low speed region and the slip frequency control in the high speed region. And also, the overmodulation PWM method is discussed to make the change to the one-pulse mode softly. The performance of the Proposed traction drive system is verified by the MATLAB simulation results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.104-109
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• 2004

Recently, when electric traction system used DC 1500[Vdc] runs on decline of rail road track and slows down, dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. Therefore this paper proposes that the extra power is regenerated through regeneration inverter to AC utility in result this system obstruct to go beyond regular voltage and improve the efficiency. In addition, electric traction system products harmonic current and voltage distortion and reactive power because power converter is used so regeneration inverter normally runs such as active power filter(APF) for improving power quality.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.7
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• pp.357-363
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• 2002

The target reliability values are defined for the train, signaling, rail track and electric power supply system of the LRT under development. The allocation of the reliability value is based on the failure rate and the failure type in the Korean subways. The reliability allocation in the train system is the made ore detail than others. The purpose of the allocation is to verify the reliability value of the results from each of the development stage, which could be the designing, manufacturing and purchasing work. The reliability of braking system, traction system, door system and other control system could be verified by establishing reliability models of these system. It could also enable us to estimate and analyse the reliability value and redo the work if necessary to achieve the shooting reliability value. A guide to the LRT reliability criteria is to be prepared after running test on the test track.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1694-1700
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• 2007

In the electrified section, both of return current and signal current are flowing in the same rail in common. But signal current shall be allowed to flow in the specific track circuit and not in the other circuit while the traction return current shall come back to power sub-station. This paper presents measuring system that use both sensor and antenna. The aim of the system is to achieve the difference in current between the two rails and the presence of trimming capacitors. In order to improve the transmission level, trimming capacitors are connected between the two rails at constant spacing. To maintain the balance of traction return current, rails of both sides may be jointed by the so-called SVPMM. The traction return current is sometimes unbalanced owing to the ill-contact of SVPMM. In this paper, we propose a diagnosis method based on a short-circuited current(Icc), trimming capacitors and traction return current measured by Korail inspection vehicles. Whether Icc is good or bad depends not only on the presence of trimming capacitors but also on the unbalance of the traction return current.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.804-808
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• 2007

when electric traction system used DC 1500V runs on decline of rail road track and slows down, Dc voltage goes beyond regular voltage. In this case extra power is forcibly wasted by resister because rectifier of substation and electric train including power converter and so on are out of order. This paper described a DC electric railway system, which can generate the excessive DC power form DC bus line to AC source in substation for traction system. The proposed regeneration inverter system for DC traction can be used as both an inverter and an active power filter(APF). As a regeneration inverter mode, it can recycle regenerative energy caused by decelerating tractions and as an active power filter mode, it can compensate for harmonic distortion produced by the rectifier substation. In addition, electric traction system products harmonic current and voltage distortion and reactive power because power converter is used so regeneration inverter normally runs such as active power filter(APF) for improving power quality. From the viewpoint of both power capacity and switching losses, the system is designed on the basis of three phase PWM inverters and composed of parallel inverters, output transformers, and an LCL filter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.331-337
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• 2015

The power flow analysis of electrified railway is required complicated calculation, because of variable load. Train runs trough rail supplied by electric power therefore, the load value in electrified railway system fluctuates along time. The power flow algorithm in electrified railway system is different from general power system, and the power flow simulation is peformed by the particular simulation software. Powerail is simulation software for analysis of traction power supply system developed by KRRI, in 2008. This consists of load forecasting module, including TPS and time scheduling, and power flow module. This software was verified by measured current under normal feeding condition, however, has not been verified by voltage on the condition of extended feeding. This paper presents the verification of PowerRail based on voltage drop under extended feeding condition. This is performed by comparing simulation result with field test. Field test and simulation is done in commercial railway line.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.118-121
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• 1999

In this pager, we studies IGBT VVVF inverter for 1C4M propulsion system of railway traction. This inverter is consisted in inverter stack, DB unit, and control unit. To prove performance of inverter carry out combine test. This test verifies that performance of inverter is excellent.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.646-658
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• 2006

In this paper, the details of electric traction voltages which are widely used for metro and mainline trains are presented. The problems encountered in catenaries, pressure of the pantograph pan, catenary contact cross sectional area, materials etc are well covered. Catenary height from the rail for main line, bridges, sheds etc is discussed. The catenary running details and switching of one catenary to another are explained. The dead zones in 3 phase grid as well as in DC are presented here. The pantograph structure, blades, shoes etc. for AC/DC EMUs are dealt. The schematic diagram for electrification systems used for railways are given and explained with typical electrical parameters of Indian Railways.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1160-1165
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• 2008

The development of a new railway vehicle is under progress through the Next Generation High-Speed Rail Development Project in Korea. Its aim is to develope fundamental technology of the vehicle that can run over 400km/h. The new distributed traction bogie system, 'HEMU'(High-speed Electric Multiple Unit), will be used and is different from previously developed high speed railway vehicles. Previous vehicles adopted push-pull type system, which means one traction-car drives rest of the vehicle. Due to the difference, investigation on dynamic behavior and its safety evaluation are necessary, as a part of verification of the design specification. In this paper, current progresses of researches are presented. And the High-Speed Railway vehicle system is evaluated for a dynamic characteristic simulation. Proper models including air-suspension system, wheel-rail, bogie and car-body will be developed according to the vehicle simulation scenario. International safety standard will be applied for final verification of the system. This research can propose a better solution when test running shows a problem in the parts and elements. Finally, the vehicle that has excellent performance will be developed, promoting academic achievement and technical development.