• Proceedings of the KIEE Conference
• /
• 2001.04a
• /
• pp.429-432
• /
• 2001

This study presents an approach to model and to analyse traction power feeding system focused on the amplification of harmonic current. Through the research, 8-port network model which can be effectively applied to harmonic analysis is derived.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.7
• /
• pp.1013-1018
• /
• 2014

This paper described the development of equalizing spacer for minimization of voltage drop according to DC feeder extension. Power consumption is increased as shorter interval of train driving time and transportation capacity increase in urban subway. Therefore we investigated voltage drop of catenary at a point in case of traction driving of a train in parallel to the DC power supply system. Based on it's result, equalizing spacer is designed and fabrication to minimize the voltage drop in accordance with the power supply line arranged in three rows, and then its performance was confirmed that the stress distribution of main body and the distributed load are satisfied through the body structure modeling.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.3
• /
• pp.233-240
• /
• 2005

In this paper, AC electric vehicle propulsion system(Converter/Inverter) using high power semiconductor, IPM is proposed. 2-Parallel operation of two PWM converter is adopted for increasing capacity of system and the harmonic content is eliminated by the phase shaft between two PWM converters switching phase. VVVF inverter control is used a mixed control algorithm, where the vector control strategy at low speed region and slip-frequency control strategy at high speed region. The proposed propulsion system is verified by experimental results with a 1,350kW converter and 1,100kVA inverter with four 210kW traction motors.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.3
• /
• pp.299-306
• /
• 2001

It is one of the most effective methods for performance improvement of electric railway vehicle to make better the wheel-rail adhesion character. In order to research adhesion character, adhesion system is developed. The experiment system makes it possible to change various adhesion parameters. This paper studied to restrain vibration of slip speed using torque control gy means of slip speed.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.206-209
• /
• 2004

The switched reluctance motor(SRM) drive system provides a good adjustable speed and torque characteristics. SRM has the possibility of maintaining full power over a wide speed range. So, many attempts are being done from home appliances to industrial machinery and tools. Especially, a traction drive of an SRM is one of a good application for it's DC-series characteristic. However, because of the switching mechanism it has some disadvantage of noise and vibration. It is difficult to adopt to an appliance demanding silency. A noise simulation and design of 6/4 and 12/8 SRM was done in order to compare each other.

• Proceedings of the KIPE Conference
• /
• 2003.11a
• /
• pp.109-112
• /
• 2003

SRM(switched reluctance motor) provides a excellent adjustable speed and torque characteristics. SRM has the possibility of maintaining full power over a wide speed range. So, many attempts are being done from home appliances to industrial applications. Especially, a traction drive of an SRM is one of a good application for it's DC-series characteristic. However, because of the switching mechanism and reluctance torque, it has some disadvantage Of noise and Vibration. It is difficult to adopt to an appliance demanding silency. A performance and noise tests with 6/4 and 12/8 SRM were done to compare the characteristics.

• Journal of Power System Engineering
• /
• v.3 no.3
• /
• pp.76-82
• /
• 1999

This study presents a methodology to predict the hardenability of quenched carbon steels. The equation of transient heat conduction is analyzed to formulate a cooling curve by a finite element method which incorperates coupled effects of temperature on physical properties, the metallic structures and also the latent heat by phase transformation. The volume traction of martensite and pearlite are the structural analysis for hardenability analysis. In order to demonstrate the feasibility of adopting a full quench model respectively. This procedure could be used as the database for optimal condition of heat treatment processes.

• Journal of Power System Engineering
• /
• v.14 no.3
• /
• pp.52-57
• /
• 2010

Interlaminar stresses near the free edges of composite laminates have been analyzed considering wall effects. Interface modeling of bonding layer was introduced to explain the wall effect. Using Lekhnitskii stress functions and the principle of complementary virtual work, the interlaminar stresses were obtained, which satisfied the traction free boundary conditions not only at the free edges, but also at the top and bottom surfaces of laminates. The interface modeling provides not singular stresses but concentrated finite interlaminar stresses. The significant amount of reductions of stresses at the free edge are observed compared to the results without interface modeling. The real stress state can be predicted accurately and the results demonstrate the usefulness of the proposed interface modeling for the strength design of composite laminates.

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

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.1
• /
• pp.74-80
• /
• 2002

A propulsion system apparatus for railroad vehicle is estimated it's performance because of safety and confidence. In general, flywheel type testing method is widely used in the equipment. However, mechanical inertia generated by the flywheel can not be varied (or controlled) and can not be represent actual running resistance. In this study, we have focused on the development of variable vehicle load generation. Therefore, we have proposed the method which uses variable vehicle load controlled by vector motor to get the characteristics of the real vehicle load and confirmed the results with those of computer simulations.