• 전기전자학회논문지
• /
• 제23권3호
• /
• pp.994-1002
• /
• 2019

본 논문은 농업용 전기차량의 전기식 동력인출장치용 전력변환시스템에 대해 제안한다. 대부분의 전기식 동력인출장치(Electric Power Take-Off : e-PTO)는 상용전원 $220V_{AC}$를 사용한다. 농업용 전기차량의 낮은 배터리 전압을 사용하여 높은 출력 전압을 공급하기 위한 DC-DC 컨버터와 DC-AC 인버터로 구성된 2단 구조를 갖는 양방향 전력변환시스템이 적합하다. 제안하는 전력변환시스템은 1단의 Dual Active Bridge(DAB)컨버터와 2단의 양방향 풀 브릿지 인버터로 구성된다. 또한, 초기 구동시 DC 버스단 커패시터 충전에 의해 발생되는 돌입 전류 저감을 위해 소프트 스타트 알고리즘을 제안한다. 3kW급 전력변환시스템 시제품 및 알고리즘을 구현하고 실험을 통해서 실용성을 입증하였다.

• 한국기계가공학회지
• /
• 제9권2호
• /
• pp.66-72
• /
• 2010

Recently a large number of electronic control devices are abruptly increasing in vehicles as the electronic industry advances. Also the number of wiring harnesses and complexity of wiring is proportionally increased to the devices. A newly developed connector named bridge connector is introduced in this study for the purpose of the wiring structure changes. A wiring structure among distributed control systems by using serial communication is proposed with the bridge connector in this paper. The bridge connector contains a auto-recovery fuse made by PTC thermistor material for the protection of the over-currents on local control devices. The auto-recovery function of the fuse is needed for the maintenance free system in the distributed controls. The PTC fuse characteristics organized in this study is tested and the results are showed in detail for the real application.

• 전력전자학회논문지
• /
• 제25권6호
• /
• pp.425-432
• /
• 2020

The phase-shifted, full-bridge (PSFB) DC-DC converter is widely used in electric vehicles (EVs) to charge a low-voltage (12 V) battery from a high-voltage battery. A Photovoltaic (PV) module-integrated PSFB converter is proposed for the EV power conversion system. The converter is useful because solar energy can be utilized to extend the driving range. The buck converter circuit is simply realized by adding one switch to the conventional PSFB converter's secondary side. For the inductor and diode, the existing components in the PSFB converter are shared. The proposed converter can charge a low-voltage battery from the PV module with maximum power point tracking. In addition, the two power sources can be used simultaneously, and efficiency is increased by reducing the circulating current, which is a problem for the conventional PSFB converter.

• Smart Structures and Systems
• /
• 제21권4호
• /
• pp.449-467
• /
• 2018

In this paper, a theoretical and numerical study on bridge simultaneous damage detection procedure for identifying both the system parameters and input excitation mass, are presented. This method is called 'Adjoint Variable Method' which is an iterative gradient-based model updating method based on the dynamic response sensitivity. The main advantage of proposed method is inclusion of an analytical method to augment the accuracy and speed of the solution. Moving mass is a model which takes into account the inertia effects of the vehicle. This interaction model is a time varying system and proposed method is capable of detecting damage in this variable system. Robustness of proposed method is illustrated by correctly detection of the location and extension of predetermined single, multiple and random damages in all ranges of speed and mass ratio of moving vehicle. A comparison study of common sensitivity and proposed method confirms its efficiency and performance improvement in sensitivity-based damage detection methods. Various sources of errors including the effects of measurement noise and initial assumption error in stability of method are also discussed.

• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
• /
• pp.792-795
• /
• 2008

경량전철은 기존 지하철의 지선과 중소도시의 간선, 그리고 대도시 및 위성도시를 연결하는 교통수요 처리에 적합하다. 또한 기존 도로변이나 도로위에 지상이나 고가로 건설할 수 있고, 차량 회전반경, 등판능력, 가감속 및 차량운행 간격 등에서 성능이 뛰어나다. 게다가 접근성 향상, 소음 및 대기오염 감소, 무인운전등도 가능하여 건설운영 및 수송효율, 환경보전 측면에서 효율적인 교통수단이다. 따라서 이러한 지하철 위주의 도시철도 건설로 인한 문제점을 해결하기 위하여 당해지역의 교통수요 및 재정여건에 걸맞게 다양한 시스템의 선정 및 운영이 가능한 경량전철을 건설하도록 추진되고 있다. 본 연구에서는 교량응답 최대가속도와 변위, 변형률을 차량속도와 비교하여 분석하였다. 이를 위하여 PSC교량에서 안내레일에 발생할 수 있는 단차를 인위적으로 설정하여 차량주행실험을 수행하였다. PSC 교량은 지간길이 30m로서 두 개의 주형과 콘크리트 슬래브로 구성되었으며, 실험에 사용된 차량은 AGT 고무차륜이며 20km/h ~ 60km/h사이를 속도 20km/h 씩 증가시키면서 차량속도와 안내레일의 단차 유무에 따른 교량의 동적응답인 교량응답신호와 충격계수를 비교 분석하였다. 일반적으로 차량주행에 의한 교량의 동적응답 신호인 가속도, 변위, 변형률은 장기적으로 크게 발생하면 피로 손상과 더불어 사용성과 내구성에 악영향을 미친다. 가속도와 변위, 변형률에 대한 동적응답 제한 범위는 현재 경량전철 설계기준에 도입되어 있지 않으므로 본 연구에서 발생된 결과를 바탕으로 안내레일 유무에 따른 동적응답 차이를 확인하고 경량전철 주행시 교량에 발생하는 동적응답의 제한을 제시하고자 하였다.

• Computers and Concrete
• /
• 제23권6호
• /
• pp.445-457
• /
• 2019

Cracks are an important distress of concrete bridges, and may reduce the life and safety of bridges. However, the traditional manual crack detection means highly depend on the experience of inspectors. Furthermore, it is time-consuming, expensive, and often unsafe when inaccessible position of bridge is to be assessed, such as viaduct pier. To solve this question, the real-time automatic crack detecting system with unmanned aerial vehicle (UAV) become a choice. This paper designs a new automatic detection system based on real-time comprehensive image processing for bridge crack. It has small size, light weight, low power consumption and can be carried on a small UAV for real-time data acquisition and processing. The real-time comprehensive image processing algorithm used in this detection system combines the advantage of connected domain area, shape extremum, morphology and support vector data description (SVDD). The performance and validity of the proposed algorithm and system are verified. Compared with other detection method, the proposed system can effectively detect cracks with high detection accuracy and high speed. The designed system in this paper is suitable for practical engineering applications.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.484-486
• /
• 2004

In this paper, the power electronics requirement and the controls of an induction motor for fuel cell electric vehicle system are presented. The power topology is selected based on performance, cost, size, volume, manufacturability, component count and simplicity. Another highlight of the topology is the reduction of battery bank and its control strategy. The proposed approach consists a full-bridge DC/DC converter to boost the fuel cell voltage. The induction motor operated with vector control is driven by a three-phase PWM inverter supplied by the DC-link voltage. The investigation of the electric vehicle performed due to parameter variation of the induction motor has been presented.

• 전기학회논문지
• /
• 제64권10호
• /
• pp.1517-1522
• /
• 2015

Since electric railroad vehicle pass through repeatedly on the railroad bridge, the dynamic load that causes the change of tension of contact wire affect it constantly. In this paper, we measured the dynamic displacement of the railroad bridges to analyze the effect of tension in the catenary. A result of dynamic measurement of the longitudinal displacement, it's maximum value was 39.9mm which was lower than the primary management criteria 378mm. Also on the based of a maximum temperature, it shows a feature that the longitudinal displacement value increased as temperature rise from April to October. In terms of behavior characteristics of a tensioning device, it was confirmed to be the value of 50mm stroke movement when the temperature changes ±5℃.

• Structural Engineering and Mechanics
• /
• 제29권2호
• /
• pp.155-169
• /
• 2008

A MOM-based algorithm (MOMA) has been developed for moving force identification from dynamic responses of bridge in the companion paper. This paper further evaluates and investigates the properties of the developed MOMA by experiment in laboratory. A simply supported bridge model and a few vehicle models were designed and constructed in laboratory. A series of experiments have then been conducted for moving force identification. The bending moment and acceleration responses at several measurement stations of the bridge model are simultaneously measured when the model vehicle moves across the bridge deck at different speeds. In order to compare with the existing time domain method (TDM), the best method for moving force identification to date, a carefully comparative study scheme was planned and conducted, which includes considering the effect of a few main parameters, such as basis function terms, mode number involved in the identification calculation, measurement stations, executive CPU time, Nyquist fraction of digital filter, and two different solutions to the ill-posed system equation of moving force identification. It was observed that the MOMA has many good properties same as the TDM, but its CPU execution time is just less than one tenth of the TDM, which indicates an achievement in which the MOMA can be used directly for real-time analysis of moving force identification in field.

• 조명전기설비학회논문지
• /
• 제29권6호
• /
• pp.96-108
• /
• 2015

his study deals with a power conversion unit of an anti-start air conditioner compressor system for the commercial vehicle. In case of converter, to reduce the switching losses and current stresses of the device, applies LLC resonant topology. Transformer leakage inductance in the full-bridge converter is used for making the resonance with the capacitor of the voltage-doubler. Through this method we can increase power and decrease volume of system. Both circuit analysis and design guideline are described. So in this paper, power conversion unit is designed. 2.5kW anti-start air conditioner compressor system was implemented, and system operation and stability was verified through experiment.