• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.1257-1259
• /
• 2001

In this paper, the diagnosis method for AC traction motor is to reduce their maintenance loads. We tried to apply this method to maintenance of traction motor in railway vehicle. Sample coils for stator of traction motor were tested by accelerative thermal degradation which composed of heat, vibration, moisture, and overvoltage applying. Reliability and expected life were evaluated on the insulation system for 200 class traction motor.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2000년도 추계학술대회 논문집
• /
• pp.674-679
• /
• 2000

Designing of the squirrel cage AC Traction Motor has many difficulties which has to be small size in order to be suitable into bogie frame, high efficiency and light weight. It means that induction motor for tractive purpose has to be different magnetic and electric loading ratio from industrial induction motor. This paper is devoted to an examination of how this ratio affects overall design concept and hence the main design points for traction motor. Also studied is tile changed coefficients of the magnetic and electric loading ratio squirrel cage induction motor for the traction purpose which has been already identified from tile reference book for industrial purpose induction motor.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 춘계학술대회 논문집
• /
• pp.782-787
• /
• 2005

Magnitude of generated harmonic currents along with the operation of AC traction has nonlinear characteristics, and generated harmonic currents for high speed traction are more and more in high speed railroad(HSR) systems, especially. This paper presents probabilistic approximation method for the harmonic currents analysis about the operating speed of AC traction. To use probabilistic method for HSR system, probability density function(PDF) for collected operating speed based measure data is calculated. Mean and variance of harmonic currents of single traction are obtained based on the operating speed PDF and electrical traction model. The results of Monte Carlo Simulation(MCS) are in well accordance with the experimental and analytic methods. The harmonics of different number of trainloads are systematically investigated. It is assessed by the total demand distortion(TDD) for the HSR system.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1999년도 춘계학술대회 논문집
• /
• pp.328-335
• /
• 1999

Three phase full bridge rectifier has been used to obtain dc voltage from three phase ac voltage source. The rectifier system has drawbacks that power factor is low and power flow is unidirectional. Therefore, when dc voltage increases due to regeneration of power the dynamic resister for dissipation of regeneration power must be installed. But three phase PWM converter can be controlled to operate with unity power factor and bidirectional power flow. Therefore when the PWM converter is used as do supply system, the dissipating resistor is not necessary. On this thesis, in order to design a controller having good performance, the hee phase PWM converter is completely modeled by using circuit DQ-transformation and thus a general and simple instructive equivalent circuit is obtained; the inductor set becomes a second order gyrator-coupled system and three phase inverter becomes a transformer as well. Under given phase angle(${\alpha}$) and modulation index(MI) of the three phase inverter, the dc and ac characteristics are obtained by analysis of the transformed equivalent circuit The validity of the equivalent circuit is confirmed through PSPICE simulation. And based on the dc and ac characteristics a controller with unity power factor is proposed.

• 전기학회논문지
• /
• 제59권12호
• /
• pp.2125-2130
• /
• 2010

The neutral section on electric railway system is significant sector in order to prevent short circuit of two electric powers. However, while electric trains pass the neutral section, those speed is decreased and the accident of AC electric traction system and the electric train would be occurred. So the countermeasures are urgently needed. The automatic power switching technology system that is current being research and development is system to improve these problems. Because main object of this system is power change using static switch in the neutral section, it's expected to cause a variety of transients. Especially, onboard transformer inrush current for electric railway train can be occurred more than rated current according to switching time. Therefore, the analysis and improvement are needed to ensure the stability of this system. In this paper, we analyze the operating characteristics of the automatic power switching technology system. Especially, it reviews inrush current according to the closing phase angle. And we propose control plan of inrush current considering the case that voltage is maintained due to counter electromotive force and regenerative braking operation of electric railway train. Finally, the proposed control scheme was reviewed using the transient analysis program.

• 한국전자파학회논문지
• /
• 제20권9호
• /
• pp.983-988
• /
• 2009

본 논문에서는 고속전철 운행에 따라 인접 통신 선로에서 발생하는 유도전압을 국내 고시에 제시된 측정 회로에 따라 측정하고 유도전압의 특징을 분석하였다. 고속전철 선로와 2 km 병행하는 2개 루트의 시험용 통신선로를 구성하여 이격 거리, 병행 거리에 따른 유도전압을 측정 및 분석하고, 측정 회선 단말 접지 위치의 레일과의 거리에 따라 측정값에 대한 영향 여부를 검토하였다. 또한 1일간 시간에 따른 변화, 요일별 변화 등을 분석하였으며, 유도전압에 포함되어 있는 고조파 성분을 확인하였다. 이론과 같이 이격 거리에 따른 유도전압의 차이를 보였으며, 단말의 접지 위치는 측정값에 큰 영향을 주지 않음을 확인하였다. 또한 특정 시간대 및 특정 날짜에 상대적으로 큰 유도전압이 나타남을 확인하였다.

• 전기학회논문지P
• /
• 제58권4호
• /
• pp.432-436
• /
• 2009

This paper is described that advanced study on network design of remote diagnosis system for power facilities of electric railway. In the field, it is very difficult for worker to diagnosis power facilities including catenary because workers should be maintenance on AC power supply. Therefore, to properly design on remote diagnosis system, we have searched the inside and outside of the country-related technology trends. Also we confirmed that required technologies to design interface technology required for the development of sensor devices and the USN network was designed in accordance with required skills. Throughout variety of requirements, we have development iRFS based ZA sensors and iRFM to receive data of sensor. Also CC2420 is applied as single-chip which used 2.4GHz IEEE802.15.4 compliant RF tranciver designed for low-power and low-voltage wireless applications for ZigBee communication.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.299-302
• /
• 1997

Recently, many people are interested in the electromagnetic fields(EMF), so we measured the strength of electromagnetic fields in the carriages of national railways and subways. We also measured on the platforms of national railways and subways. The strength of EMFs on the platforms of national railways was stronger than that of subway's platforms. EMF measured on the platform during railway carriage's arriving and leaving was stronger than that without carriages. The strength of the magnetic fields in the carriages of national railways was measured stronger than that of subway's carriage while national railway is run by AC while subway is run by DC. Also The strength of the subway line 8 were measured stronger two to three times than others.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.1236-1238
• /
• 2001

The electrified railway has various power supply schemes. Although the identical trains are operated in same condition and the impedance of track are equal, the genealogy impedance of track is changed according to composition method of feeding scheme. So, the collection voltage of train and supplying power from railway substation are greatly unlike. For simulation of collection voltage and power supply according to feeding scheme, using 6-port network analysis proposed previously simulate collection voltage and supply power according to feeding scheme(Parallel Post feeding system, normal feeding system and tie feeding system) and compare and investigate each characteristics.

• 전기학회논문지
• /
• 제64권2호
• /
• pp.342-348
• /
• 2015

In this paper, fuel cell power generation system that is being studied in recent railway field was applied to compensate for the voltage drop due to the load as driving electric vehicle. PSIM simulation program is to be used to implement the modeling of the electric railway for AC AT feeder system. For it, It was applied to the product-type single-phase PLL algorithm, step-down converter is controlled as power so as to have the fuelcell generation system. Based on it's result, a reactive power due to the catenary impedance in accordance with the current flowing is compensated as linked with fuelcell generation system which supplied the current to the power supply grid. and then its performance was confirmed that voltage compensation effect obtained at SubStation (SS), SubSectioning Post (SSP), Sectioning Post (SP).