• 연구논문집
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• 통권27호
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• pp.35-45
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• 1997

The dynamic design process for the articulated bogie of light rail vehicle(LRV) was studied to design a primary and secondary suspension elements. Suspension stiffness and damping is selected on the basis of the ride quality and suspension stroke trade-off. LRV was modeled as a 2 d.o.f linear system for the design of vertical suspension characteristics and a 4 d.o.f linear system for the design of lateral suspension characteristics. FRA's class-4-track irregularity was used for the exciting disturbance on track. The optimum value of primary and secondary suspension characteristics was determined using this design process.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.251-257
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• 2007

This paper describes the variation of the critical speed of an urban railway vehicle according to the change of suspension characteristics. Suspensions of a railway vehicle are composed of primary and secondary suspensions. Generally, main focus of the stability analysis has been the primary suspension. However, secondary suspension has large effects on the stability as well as the ride quality of a vehicle. In this paper, stability of an urban railway vehicle is discussed in relation to the variation of characteristics of both primary and secondary suspension. For this, modal analysis is carried out using a linear dynamic model of a half vehicle and a polynomial fit for Kalker's creep coefficients. Stability along with change of the effective conicity of a wheel is also investigated.

• Journal of Power Electronics
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• 제16권1호
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• pp.111-120
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• 2016

Generally, a single phase H-bridge converter feeding a single primary track is employed in conventional inductive power transfer systems. However, these systems may not be suitable for some high power applications due to the constraints of the semiconductor switches and the cost. To resolve this problem, a novel dual coupled primary tracks IPT system consisting of two high frequency resonant inverters feeding the tracks is presented in this paper. The primary tracks are wound around an E-shape ferrite core in parallel which enhances the magnetic flux around the tracks. The mutual inductance of the coupled tracks is utilized to achieve adjustable power sharing between the inverters by configuring the additional resonant capacitors. The total transfer power can be continuously regulated by altering the pulse width of the inverters' output voltage with the phase shift control approach. In addition, the system's efficiency and the control strategy are provided to analyze the characteristic of the proposed IPT system. An experimental setup with total power of 1.4kW is employed to verify the proposed system under power ratios of 1:1 and 1:2 with a transfer efficiency up to 88.7%. The results verify the performance of the proposed system.

• 한국철도학회논문집
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• 제9권6호
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• pp.798-803
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• 2006

The suspension elements like primary coil spring, yaw damper, body to body damper are core parts of high speed railway bogie and the faults relating to these elements are reported recently. Thus, this study is started to analyze the displacements characteristics of suspension elements of high speed railway rolling-stock for the purpose of preventing the faults and developing the maintenance technology for suspension elements like spring and dampers. For this purpose, we made a plan to measure the displacements of the primary coil spring, yaw damper and body to body damper in actual running condition. We developed the measurement device to measure the longitudinal displacement and angular displacement of suspension elements and installed this device to test suspension elements. Test to measure displacements of suspension elements is conducted in service line of high speed railway. The displacement data which is acquired from the test with actual vehicles was analyzed for its maximum displacement depending on the track sections. As a result of analysis, we obtained the displacement trends occurring with the sections and valuable results like maximum values and the displacement distribution.

• 한국정밀공학회지
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• 제32권7호
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• pp.597-602
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• 2015

In this paper, we studied the steering performance of wheelset with primary suspension characteristics of railway vehicle. We carry out dynamic analysis and experimental study for the vehicle models which are different primary suspension characteristics. The steering angle of a vehicle model (Case 1) operating in domestic subway lines is insufficient compared with an objective steering angle for curved track. And the steering angle of a vehicle model (Case 2) with improved self-steering performance of wheelset is a little improved compare to previous vehicle model. But also Case 2 model is still insufficient compared with an objective steering angle and has its limit in steering performance. So to overcome this limit of steering performance of passive type railway vehicle, an active steering technology is being developed. In case of vehicle model with active steering system, the steering performance is improved remarkably compared to passive type vehicle model.

• International Journal of Railway
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• 제7권2호
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• pp.57-63
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• 2014

This paper presents the optimization of suspension characteristics under the condition of curved track railway vehicles. Reducing lateral acceleration on curved track is an issue for high-speed railway vehicles. In terms of curved track running environments, reducing the lateral vibration of railway vehicles is critical to safety and curving performance. The properties of lateral damping and stiffness of both primary and secondary suspension show effect on wheel-set, bogie and car-body. Analysis for reducing the lateral vibration of rail vehicles with respect to the characteristics of both primary and secondary suspension has been developed using ADAMS/Rail. Response Surface Method has been chosen for the purpose of verifying correlation effects among design parameters. Also, this paper suggests the method for designing optimal suspension of railway vehicles on curved track. The optimization result indicates decrement of lateral acceleration on wheel-set by 3% and bogie by 1% on curved track. Finally, this paper comes to the conclusion that suspension system of railway vehicle (KTX I) is properly designed when regarding lateral vibration of railway vehicle on diverse curved track condition.

• 한국철도학회논문집
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• 제12권6호
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• pp.909-914
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• 2009

철도차량의 주행안전성과 승차감을 결정하는데 있어서 현가장치는 중요한 요소이며, 현가장치 강성은 차량 설계 단계의 중요한 설계변수이다. 고속에서의 주행안전성을 위해 1차 현가장치에 강한 강성을 부여하는데 이는 곡선 주행성능을 감소시키는 단점이 있어 주행안전성과 곡선주행성능을 절충하면서 현가장치의 강성을 조절하고 있다. 본 연구에서는 철도차량의 현가장치 강성을 변화시켜 가면서 주행안전성 향상을 위한 현가장치를 최적화하는데 목적을 두고 있다. 현가장치 최적화를 위해 1, 2차 현가장치의 위치 및 길이, 폭, 강성, 감쇠력 등을 설계 변수로 하여 해석을 진행하였다. 현가장치 최적화 해석결과, 1, 2축 내 외측 차륜의 탈선계수 값이 초기 모델과 비교하여 감소한 결과를 확인할 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1578-1583
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• 2007

The suspension system of railway rolling-stock is composed of the primary and secondary suspension elements. Recently, a conical rubber spring is widely used as the primary suspension element due to the merits of the three directional stiffness characteristics. So, understanding the properties and characteristics of the conical rubber spring is very important from the viewpoint of vehicle stability and efficient maintenance. Thus, this study is started to acquire the basic data for maintaining spring elements efficiently. For this, we tested the conical rubber spring samples including a new and old specimen with aging. As a test result, we have obtained the property characteristics of the aged spring comparing with the new product and we describe the results.

• 한국정밀공학회지
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• 제20권7호
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• pp.201-207
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• 2003

Sensitivity analysis of suspension elements of an articulated bogie for light railway vehicles is presented. The ride, stability and safety are used as dynamic performance indices. Suspension elements of 10 and a conicity of wheel are used as design variables. To analyze sensitivity of design variables. the railway vehicle dynamics analysis program AGEM is used. The results show that the secondary suspension elements have a strong effect on ride and the primary suspension elements have a moderate effect on ride. Conicity of wheel has a strong effect on the stability. The safety is not effected by all the design variables.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.540-547
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• 1998

light rail vehicle is modeled as a 2 d. o. f linear system for the design of vertical suspension characteristics and a 4 d. o. f. linear system for the design of lateral suspension characteristics. FRA's class-5-track irregularity is used for the exciting disturbance on track. Suspension stiffness and damping is selected on the basis of the ride quality and suspension stroke trade-off for the bogie of light rail vehicle. The optimum value of primary and secondary suspension characteristics is determined. And the stability of full vehicle model for the LRV is analyzed using the VAMPIRE program and critical speed is determined.