• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.51-53
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• 2005

At the railway feeding system, a role of dead section is very important. Because, dead section is essential installation that AC feeding system meets DC feeding system or phase is changed between AC feeding systems. But, in dead section it is possible that an electric train meets interruption. In Korea, a study on the dead section isn't yet accomplished in depth. Accordingly. In this paper, when electric train is in dead-section power quality problem on electric train was dealt. Modeling and simulation using PSCAD/EMTDC was accomplished to analyze.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.73-77
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• 2002

The requirements for higher productivity call for high speed of the machine tool axes. Iron core type linear DC motor is growly accepted far a viable candidate of the high speed machine tool feed unit. LDM, however, has inherent disturbance force components: cogging and force ripple. These disturbance force directly affects tracking accuracy of the carrage and must be eliminated or reduced. Reducing motor ripple, this paper adapted the feed forward compensation method and neural network control. Experiments carried 7ut on the linear motor test setup show that this control methods is usable in order to reduce the motor ripple.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.71-73
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• 2001

The requirements for higher productivity call for high speed of the machine tool axes. Iron core type linear DC motor is growly accepted for a viable candidate of the high speed machine tool feed unit. LDM, however, has inherent disturbance force components: cogging and force ripple. These disturbance force directly affects the carrage tracking accuracy and must be eliminated or reduced. Reducing motor ripple, this paper adapted the feed forward compensation method. Experiments carried out on the linear motor test setup show that this compensation method is usable in order to reduce the motor ripple.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 춘계학술대회 논문집
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• pp.1088-1095
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• 2006

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.2200-2201
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• 2011

DC railway systems have been adopted in the urban rail train. When EMU decelerates using electric breaking, regenerative power occurs. extra power is forcibly wasted by resisterIf DC transit system has inverter for reusing regenerative power, energy efficiency in DC transit system will be increased. in this paper present developed regenerative power inverter and its field test result.

• 한국생산제조학회지
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• 제7권4호
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• pp.96-103
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• 1998

With the advance of processing technology , so as to spare fuel, piston heads used in automobile reciprocating engine have complex 3-dimension, with respect to shape such as ovality, profile, eccentricity, offset, recess. Therefore, coming out of the existing process work used master cam. the process work is performed using a CNC lathe. For a precision processing, the processing work is need to make study of high speed feed gear synchronized with the rotative speed of main spindle. And then the high speed feeding system must maintain high dynamic stiffness, high speed and high positioning accuracy . In this paper, in order to achieve high speed cutting tool feeding. The linear brushless DC motor is used for satisfying this process work. The ball bush and turicite is used as the guidance of the feed gear system. Also linear encoders, digital servo amplifiers and controller are used for controlling driving motor. This paper presents the design and simulation of the new tool feed system for noncircular machining.

• 한국철도학회논문집
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• 제7권4호
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• pp.412-417
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• 2004

In urban rail transit systems, ground faults in the DC traction power supply system are currently detected by the potential relay, 64P. Though it detects the fault it cannot identify the faulted region and therefore the faulted region could not be isolated properly. Therefore it could cause a power loss of the trains running on the healthy regions and the safety of the passengers in the trains could be affected adversely. Two new ground fault protective relay schemes that can identify the faulted region are presented in this paper. A current limiting device, called Device X, is newly introduced in both system, which enables large amount of ground fault current flow upon the positive line to ground fault. One type of the relaying schemes is called directional and differential ground fault protective relay which uses the current differential scheme in detecting the fault and uses the permissive signal from neighboring substation to identify the faulted region correctly. The other is called ground over current protective relay. It is similar to the ordinary over current relay but it measures the ground current at the device X not at the power feeding line, and it compares the current variation value to the ground current in Device X to identify the correct faulted line. Though both type of the relays have pros and cons and can identify the faulted region correctly, the ground over current protective relaying scheme has more advantages than the other.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.250-252
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• 2008

DC traction system generates leakage current because running rails are used in return circuit. And it is very important to estimate the leakage current to the train operation situation. Therefore this paper presents dynamic simulation technique that is very similar to the real operation situation using TPS and PSCAD/EMTDC. For this we model DC traction system included in DC substation, variable feeding circuit model and variable train model. And we extract train location and power using TPS program and use these data for dynamic simulation. Finally we can estimate leakage current to the various operation condition using dynamic simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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• pp.524-527
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• 2004

When the electric tractions are stopped or driven through the falling slope way, it occured to surplus energy in the DC power line. At present, these energy are exhausted by breaking-system. The converter is not only capable of feeding energy back into the AC source during excessive regeneration. It is issued for this surplus energy regenerating system. These systems are faced with high voltage and high power for railway DC power regeneration. This paper proposed a parallel PWM converter how to solve these problem.

• 조명전기설비학회논문지
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• 제19권4호
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• pp.98-107
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• 2005

브러시리스 DC 전동기(BLDCM)는 일반적으로 $120[^{\circ}]$ 구형파 전압을 인가하여 구동하며 속도 제어를 위하여 2상 PWM 형태의 펄스로 이를 인가한다. 본 논문은 네 가지 PWM 방법을 이용한 BLDCM 제어 시스템을 소개하고, 2차원 시간차분 유한요소법을 이용하여 각 PWM 방식에 따른 전동기 성능 특성을 해석하고 비교한다. 또한 제안한 해석 기법의 타당성을 입증하기 위하여 BLDCM 시작기를 제작, 실험을 통하여 해석치와 실험치를 비교한다.