• Proceedings of the KSR Conference
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• 2011.10a
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• pp.3117-3123
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• 2011

An Electric railway system has the characteristics. The train powered by substations generates regenerative power when it runs on railway of various slope. A regenerative braking is an ideal system on account of reducing mechanical braking as well as recycling the energy. In this study, Seoul Metropolitan Rapid Transit (substation) Precision analysis of the power of the electric car was carried out. Through this use of power substations, power supplies and trains through the regenerative power of the data analysis was performed utilizing research-based work.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.470-474
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• 2010

Up until now, power centralized trains have been produced due to the maintenance convenience and comfortableness, but there are some problems, such as limitation of viscosity and maintenance difficulty of railroad due to recently increasing axle mass. In order to improve the problems, power decentralized trains have been developed to improve traction power. In the case of using electrical braking system, it is possible to improve braking friction power. Induction motors have been developed for power decentralized high speed train because of less structural defection, and low maintenance and production cost. However, induction motors have limitations, such as assuring enough power capacity and efficiency with reduced size. PMSM (Permanent magnet synchronous motor) have been newly developed to improve shortcomings of induction motors. The PMSM can be produced small and light weighted. Also if the PMSM and induction motors have the same size and power capacity, the PMSM have better power efficiency. In this pater, the prototype and modified type of PMSM for "High-speed Electric Multiple Unit-400km/h eXperimmen" will be introduced.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.228-230
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• 2006

While trains perform a complete precision stopping control at stop point, it is essential to keep better commuters comfort in prompt. Because a train's brake force tends to increase a brake effort in a low speed and a low brake effort, a brake force in motor cars must be increased to keep better passenger comfort, to control the special braking qua1ities and to prevent the impact of the automatic coupler rather than trailer's, Rail cars must have a special braking process for the train stopping control. In the train stop mode, the train stopping control is designed to start at 20km/h. It starts by Dynamic brake blending, and then finally stops by only the friction. If these process are not exactly activated, the train may fail a complete precision stop. In this report, it studied the electric and friction brake processing during the precious stopping control. To achieve exact test results, the speed reference has to be reduced the calculated difference. In the precision stopping control. the ways of the keeping brake force in motor car was analyzed and some solutions of controling air pressure was brought up by means of direct test in main line, This study was based on line 5 in Seoul Metropolitan subway.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.298-302
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• 2016

Currently, logistics are in small quantities and in diverse forms, and the amounts are continuously increasing. Railway logistics however are losing their market share every year mainly due to low operation speed and loading time, which means the trucks are covering the most of the freights. In order to solve these situations, this paper proposed the high speed freight train as working multi-modality with other modes to make effective transshipment. The high speed freight train has maximum operation speed of 300km/h and electric power to run centralized power supply. There are large dual door system, bogie system covering fluctuating load of 15[ton], automatic loading device, ULD(unit load device) bed and ULD locking system in this freight rolling stock. We calculated the performance of powering and braking capacity for this train and proposed how many vehicles are composed of train set. The results in this paper can help to make a decision to define the technical specification of High-speed freight train for the efficiency of rail freight service.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.519-528
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• 2019

Current brake system changes the kinetic energy into heat energy by friction-type of brake that the braking action is diverging into the air. The system has a device called a retarder that generates braking force. High-tech research on the high-speed response characteristics of retarders utilizing part of the braking energy of the retarder to save electrical energy consumption is already underway in advanced countries. In this paper, we propose DC-DC converter which converts 3-phase voltage generated from retarder to 24V DC voltage for battery charging and verify its validity through experiments.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.836-845
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• 2007

In DC 1500V electric traction substations, diode rectifiers are commonly used to supply stable DC power with electric train sets. However, it operates in the first quadrant of the voltage-current plane and thus needs regenerative inverters which transfer the surplus regenerative power caused by regenerative braking of electric train sets into the grid. In order to select the proper capacity and installation position of regenerative inverter, it needs to investigate the consumed and regenerative energy of the electric traction substations in advance. This paper presents an analysis of regenerative energy in two substations operating in Seoul line 2 and Kwangju line 1. DC line voltage and feeder currents are measured for a day to calculate consumed and regenerative power for four feeders. We calculated an amount of regenerative energy consumed in other feeders and estimated the cost reduction in energy consumption due to the reuse of regenerative energy.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.40-48
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• 2013

Recently, many types of electric vehicles including a heavy duty vehicle have been developed and released because of the better fuel economy and less gas products. In this study, research about an electric bus which utilizes the wheel motor drive system was conducted. The wheel motor is a motor connected to the wheel directly only with a simple gear so that the developer can utilize the space efficiently and the whole system efficiency will be better because of simple structure. However, because it is different from former types of vehicles which use the differential gear, the development of the integrated control logic is required in order to meet the vehicle stability and driving performance. The developed control logic is composed with direct yaw moment control, regenerative braking control and slip control logics. It is compared to the control logics which does not consist of direct yaw moment control and slip control when the vehicle is exposed in tough situations. For the unification of the control logic, a few maps were developed and applied to determine the output torque of each motor according to the driving status. As a result, it is shown that the developed control logic is more safe and well follow the target speed than the other control logic applied simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.1
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• pp.46-53
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• 2002

The brake system of a high speed train has a crucial role for the safety of the train. To develop a safe brake system of the high speed train, it is necessary to understand the braking principle and phenomena of the total brake system and its subsystems. In this paper, we have suggested a mathematical model which includes car dynamics, interactions between cars, adhesive forces, brake blending algorithm, and the dynamics of each brake devices. Also, we have proposed a ready-time compensation algorithm of eddy-current brake system and a brake control logic on electric-pneumatic blending. A simulation study has shown the proposed models and algorithms are effective on the braking of the train.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.855-857
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• 2000

Brake system using eddy current is adequate to obtain safe braking force in high speed transportation system and electric vehicle etc. In this paper, we propose the new type eddy current braker using Halbach array. which compared with the conventional permanent magnet array. The airgap flux density of Halbach array is higher 25% then conventional array, therefor we can predict that braking force is much large 1.56 times then conventional array.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1039-1044
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• 2005

The Objective of advanced EMU Project is development of new technologies, that can resolve the system problems of conventional EMU, for reducing vehicle maintenance, improving passenger's service using IT and providing environmental friendly. As a concept of advanced EMU, We will develop the DDM with individual driving wheel for reducing of maintenance cost and full-electric braking system without pneumatic braking, and a new bogie for loadable DDM, and pre-diagnosis system which informs possible system error, and decentralization of vehicle control. To improve transport reliability, and energy storage system for saving energy, and fallen passenger detection system for improving passenger's safety at the platform.