• Structural Engineering and Mechanics
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• 제76권2호
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• pp.163-173
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• 2020

As a vehicle moves on multiple equal-span beams at constant speed, the running vehicle would be subjected to repetitive excitations from the beam vibrations under it. Once the exciting frequency caused by the vibrating beams coincides with any of the vehicle's frequencies, resonance would take place on the vehicle. A similar resonance phenomenon occurs on a beam subject to sequential moving loads with identical axle-intervals. To reduce both resonant phenomena of a vehicle moving on guideway girders, this study proposed an additional feedback controller based the condensed virtual dynamic absorber (C-VDA) scheme. This condensation scheme has the following advantages: (1) the feedback tuning gains required to adapt the control currents or voltages are directly obtained from the tuning forces of the VDA; (2) the condensed VDA scheme does not need additional DoFs of the absorber to control the vibration of the maglev-vehicle/guideway system. By decomposing the maglev vehicle-guideway coupling system into two sub-systems (the moving vehicle and the supporting girders), an incremental-iterative procedure associated with the Newmark method is presented to solve the two sets of sub-system equations. From the present studies, the proposed C-VDA scheme is a feasible approach to suppress the interaction response for a maglev vehicle in resonance moving on a series of guideway girders.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권2호
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• pp.102-109
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• 2000

The magnetically levitated system technology is highly expected to contribute the new transportation system of the 21st century with its high velocity operation, better riding comforts, friendliness to environment and saving of maintenance labour. Its development has been completed in low speed and in high speed application. In 2005, the Transrapid with 430 km/h speed will go into operation between Berlin and Hamburg[1]. In the year 2000, the realization of JR-Maglev will be basically evaluated for commercial operation[2]. In korea, maglev test vehicle with magnet for levitation and single sided linear induction motor for propulsion is under test at 1 [km] test track in KIMM.[3,4] Here, a transverse flux linear motor in combination with the levitation and the guidance leads to a considerable high power density and high efficiency simultaneously. The designed and measured performance of transverse flux linear motor for maglev system revealed a great potential of system mass reduction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 특별세미나 특별세션
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• pp.189-197
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• 2006

Maglev using EMS becomes unstable by unexpected big air-gap disturbance. The main causes of the unexpected air-gap disturbance are step-wise rail joint and large distance between rail splices. For the stable operation of the Maglev, the conventional system uses the threshold method, which selects one gap sensor among two gap sensors installed on the magnet to read the gap between magnet and guide rail. But the threshold method with a wide bandwidth makes the discontinuous air-gap signal at the rail joints because of the offset in air gap sensors and/or the step-wise rail joins. Further more, in the case of the one with a narrow bend-width, it makes Maglev system unstable because of frequent alternation. In this paper, a new method using fuzzy rule to reduce air-gap disturbances proposed to improve the stability of Maglev system. It treats the air-gap signal from dual gap sensors effectively to make continuous signal without air gap disturbance. Simulation and experiment results proved that the proposed scheme was effective to reduce air-gap disturbance from dual gap sensors in rail joints.

• 연구논문집
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• 통권26호
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• pp.5-14
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• 1996

Test results of electromagnetic suspension (EMS) type urban transit maglev system are reported. Electromagnetic levitation system is a transportation system taking advantage of the attraction of normal conducting electromagnets to support and guide the train in combination with the linear induction traction motors. Urban Transit Maglev (UTM) Which is being developed by the maglev team in KIMM and the Hyundai Precision Company since 1995 consists of three bogies. In the first year, two types of Bogies are developed. Bogie I uses an analog controller for levitation and guidance control and is driven by two linear induction motors (LIM) mounted on the right and left side of module. Bogie II uses a digital controller and is driven by one LIM mounted along the center line of the bogie. Test results reported in this paper are those obtained with Bogie II with a digital controller. Also included in this paper is a brief explanation of the electromagnetic suspension levitation system which is being developed by the maglev team in KIMM.

• International Journal of Railway
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• 제4권4호
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• pp.97-102
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• 2011

In an EMS (Electromagnetic suspension)-type Maglev (Magnetically-levitated) vehicle, the flexibility of the bogie frame may affect the acceleration of the electromagnet that is input into the control system, which could lead to instability in some cases. For this reason, it is desirable to consider bogie frame flexibility in air gap simulations, for the optimization of bogie structure. The objective of this paper is to develop a flexible multibody dynamic model of 1/2 of an EMS-type Maglev vehicle that is under testing, and to compare the air gap responses obtained from the rigid and the flexible body model. The feedback control system and electromagnet models that are unique to the EMS-type maglev vehicle must be included in the model. With this model, dynamics simulations are carried out to predict the air gap responses from the two models, of the rigid and flexible model, and the air gaps are compared. Such a comparative study could be useful in the prediction of the air gap in the design stage, and in designing an air gap control system.

• 한국철도학회논문집
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• 제14권2호
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• pp.116-120
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• 2011

현재 초고속 자기부상열차시스템에 적용하고 있는 위치검지기술은 불연속적으로 열차위치를 파악하는 절대위치검지기술과 연속적으로 열차의 위치를 파악하는 상대위치검지기술로 구분된다. 본 논문에서는 대표적인 초고속자기부상열차인 독일 Transrapid에 적용된 절대위치검지장치의 구조와 수치모델을 분석하고, Transrapid에 적용된 절대위치검지장치와 유사한 구조를 가지는 절대위치검지장치의 인식구조별 모델을 설계하고 시뮬레이션을 통해 설계한 모델의 적합성을 검증하고 최적의 절대위치검지장치 구조를 제안한다.

• 전력전자학회논문지
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• 제12권3호
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• pp.258-266
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• 2007

자기부상열차는 초기부상에서 정상상태에 이르는 짧은 시간동안 전류변화가 매우 큰 단점이 있다. 본 연구에서는 이를 안정적으로 제어하기 위해서 다중루프제어를 적용하였다. 제어기가 포함된 전체시스템에 상태방정식의 특성방정식을 구하여 원하는 특성의 제어이득을 쉽게 구할 수 있도록, Bessel function 원형모델을 도입하여 극점을 설정하였다. 설정된 극점을 바탕으로 제어기를 구성하고, 시스템의 특성방정식을 구하여 계수비교 함으로써, 시스템의 안정된 제어 특성을 확인하였다.

• 한국전산구조공학회논문집
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• 제33권6호
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• pp.367-374
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• 2020

승객에게 편안한 승차감을 제공할 수 있도록 자기부상열차 차체 연직가속도의 진동크기에 대한 기준을 제시하고 이를 만족하는 가이드웨이 구조물의 처짐한계를 제안한다. 차량-구조물 상호작용을 고려한 해석기법을 사용하여 자기부상열차 시스템의 매개변수 해석을 수행하고, 차체 연직가속도에 대한 기준을 만족할 수 있는 가이드웨이 구조물의 처짐한계를 L/300로 제안한다. 이를 실제 자기부상열차 시스템의 동적 해석에 적용하여 제안한 처짐한계의 적절성을 검토한다. 기존의 자기부상철도 가이드웨이 구조물의 설계 기준과 비교하였을 때, 이 연구에서 제안한 처짐한계를 적용하면 경제적인 가이드웨이 구조물의 설계와 시공이 가능할 것으로 기대된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2400-2404
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• 2011

Power spectral density (PSD) model of irregularities for the maglev test track is presented. Track irregularities (gauge, cant, twist and vertical) were calculated from the survey data of sleepers on the test track. PSD model was constructed from the estimated PSDs of each track irregularities. Versine (gauge, cant, twist, vertical and lateral) of the track is obtained and their PSDs were estimated, too. Presented PSD model can be used for the analysis of levitation stability and ride quality of the maglev system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1303-1307
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• 2004

MAGLEV is the vehicle which can run in levitated condition by the electro-magnets, and the vehicle can run without any contact condition. In MAGLEV system achieving a high magnetic field for minimum weight is a noteworthy goal. Unfortunately the two aspects of this goal high field and low weight are contradictory. Suitable designs must be sought using optimization techniques. In this paper, magnet attraction force is calculated and conformed by experimental data for designing a electro-magnet.