• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.747-750
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• 1995

As railway trains run faster high performance braking system are necessary because more energy needs to be dissipated due to increased kinetic energy. In this work a portable computer based prediction system for emergency braking distance has been developed. The algorithm for the system is based on braking theory and empirical results of actual braking test. The computer is connected to the sensors to measure the velocity and the braking pressure in real train. It is expected that this system will be utilized to predict emergency braking distance during actual operation of the train

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.653-661
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• 2016

This paper proposes a capacitance estimation method of the dc-link capacitor for brushless DC motor (BLDCM) drive systems. In order to estimate the dc-link capacitance, the BLDCM is operated in quadrant-II or -IV among four-quadrant operation. Quadrant-II and -IV are called reverse braking and forward braking, respectively. During the braking operation of the BLDCM, the capacitor is charged by the phase current and then the voltage is increased during the braking operation time. The capacitor current and voltage can be obtained by using the phase current sensor of BLDCM and the dc-link voltage sensor. The capacitance and be easily obtained by the voltage equation of the capacitor. The proposed method guarantees the reliable and simple calculation of the dc-link capacitance without additional hardware system except several the sensors already installed for the motor control system. The effectiveness of the proposed method is verified through both the simulation and experimental results.

• International Journal of Railway
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• v.2 no.4
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• pp.139-146
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• 2009

Vehicle braking in non-electrified rail systems wastes energy. Advanced flywheel technology presents a way to capture and reuse this braking energy to improve vehicle efficiency and so reduce the operating costs and environmental impact of diesel trains. This paper highlights the suitability of flywheels for rail vehicle applications, and proposes a novel mechanical transmission system to apply regenerative braking using a flywheel energy storage device. A computational model is used to illustrate the operation and potential benefits of the energy storage system.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.616-620
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• 2003

Brake action is important in train operation. In case of diesel motor cas, coachs and wagon, the brake system is only act on the stop of train, but it is emphasis on safety and convenience in urban transit system such as EMU, subwar, AGT, etc. Brake of EMU has two types. one is called service brake that is used at normal operation. The other is called emergency brake. it is used at emergency operation. Service brake bring a EMU to a halt through a blending brake that form electronic brake and frictional brake. Generally EMU compose motor car and trailer car. Blending brake bring a EMU to a halt through a blending brake that form electronic brake of motor car and frictional brake of trailer car. Blending braking technology have different characteristics each nations or manufacturing companies. but deceleration command that is parameter decide blending brake. According to deceleration command, electronic brake and frictional brake are applied differently So braking power is different. electronic brake and frictional brake must be used appropriately as deceleration command. Also braking facilities must be stopped EMU more economically and safely through revision of algorism about blending brake according to output diagram. Thus The purpose of paper is to propose blending braking control way as consideration of braking output diagram used deceleration command that influence blending brake of EMU.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1049-1058
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• 2011

This paper suggests blending time adjusting method of braking command characteristics management and Set value test for optimizing of braking deceleration to enhance the precise position stopping. This method minimizes pneumatic-braking degree deviation by characteristics management, and secures braking stability at braking. By Set value test method, braking blending characteristics are analyzed accurately. And by optimal timing tuning at braking blending, It enhanced the precise position stopping with stabilization of deceleration To demonstrate the usefulness of these suggestion, I modeled for Deajeon Line #1. And through comparison with case of related companies, the proposed method which this paper suggested is proved to be superior to others.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.299-300
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• 2007

In this paper, slip wear phenomenon of train was studied by traction force of acceleration and braking force of deceleration. First, the slip wear phenomenon on train operation mode was analyzed when powering, coasting and braking each and then rail wear was analyzed from the slip wear data. Especially, the data proved correlation between slip wear and deceleration rather than acceleration. Second, If velocity of a train is constant, even though the velocity is high, ATO logging data and measurement data proved that the rail wear is not serious. It will help for efficient braking force operation providing fundamental data to braking step control.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1866-1870
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• 2008

In this paper, electric braking performances of linear induction motor(LIM) designed for propelling the MAGLEV are presented. Regenerative braking is carried out from 110km/h to 20km/h, and plugging which converts the direction of travelling magnetic field is carried out in the low speed region below 20km/h. It is important to reduce attractive force which can affect the magnetic levitation load during regenerative braking or plugging operation mode. So in this paper the braking performances are analyzed by finite element method. As a result, braking force, attractive force, phase current, voltage to frequency patterns and its magnetic fields of braking LIM are presented.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.11B no.3
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• pp.64-69
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• 2001

Energy recovery in the regenerative region is very important when SRM is used in traction drive, This is to reduce en-ergy loss during mechanical braking and/or to have a high efficiency drive during braking To control excitation voltage in motor operation and regenerative voltage in the generator operation in the SRM multi-level voltage control is effective The paper sug-gests multi-level inverter which is useful for motoring and regenerative operation in SRM

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.294-296
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• 2000

Energy recovery in the regenerative region is very important when SRM(Switched Reluctance Motor) is used in traction drive. This is because that to reduce energy loss during mechanical braking and/or to have a high efficiency drive during braking. To control excitation voltage in motor operation and regenerative voltage in the generator operation in the SRM, multi-level voltage control is effective. This paper suggests multi-level inverter which is useful for motoring and regenerative operation in SRM.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.91-98
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• 2020

In order to prevent a collision accident during sudden braking, we have proposed an hazard lamps automatic operation system that can be easily installed in existing vehicles that do not have hazard lamps automatic operation. There are several ways to recognize sudden braking. Using GPS, the system does not work in a tunnel, and it is difficult to install the system additionally on an existing vehicle using a vehicle speed sensor. Therefore, the proposed system eliminates these problems by using the acceleration sensor and makes it possible to recognize even the sudden turning and bounce of the vehicle.