Young-Jae Han

Analysis on the half bridge resonant DC to DC converter for electrical multiple units train set

The half bridge series resonant converter used for low output voltage power supply applications. This system has soft switching implementation without additional device, high efficiency and compact control. These advantages make this converter promising for high power applications such as auxiliary power supply in the EMU train set. The system consists of hard switched boost chopper, soft switched high frequency inverter based on split capacitors in DC link, high frequency transformer and rectifier. This paper describes several aspects relating to the design of resonant DC/DC converter operating at high frequency and converter topologies are discussed. Simulation and Experiment are performed. These results show that the power electronics converter using resonance DC-DC converter is feasible to the power supply system for EMU train set.

A Study on Mechanical Characteristics for Induction Motor of Rolling Stock

High-speed railway vehicle has many electric devices such as main transformer, motor block and traction motor. As the on-board electric devices determine the performances of vehicles, production of reliable devices is important. To keep the reliability of devices constant, management of temperature characteristics of the on-board devices is crucial. Because temperature has a serious effect on failures of the components of the devices, its measurement is the first step for good management. In the previous testing methods for measuring the temperature characteristics of electric devices, measurement was conducted only once and continuous measuring was impossible. So, to make clear the effect of temperature on the electric devices was very difficult. In this research, using the measurement system, the temperature characteristics considering speed of electric traction motor, operating time and month was measured and investigated

Development of Train Communication Network Simulator for Tilting Train

An international standardization of data communication is necessary at both the train and vehicle levels. Trains with varying composition during daily service-such as metros, or suburban and international trains, need a standard form of data communication for train control, diagnostics, and passenger information. Such communication should configure itself when vehicles are coupled on the track. At the vehicle level, a standard attachment of equipment would serve manufacturers, suppliers, and operators. Manufacturers could assemble pretested units, such as doors manufactured by subcontractors, which include their own computers. This paper presents a train communication network simulator (TCNS) that can be used to evaluate the performance of TCN. TCN was accepted as the standard of the protocol for the communication network in trains. We carry out some simulation tests using the TCNS to show practical uses of the simulator. Results of some simulation tests are also reported

Development of the linear synchronous motor propulsion testbed for super speed maglev

For the development of a super speed maglev train with 500km/h level, the high power and efficient linear synchronous motor(LSM) as a propulsion device is necessary. To control the LSM, the precise position information of maglev must be detected and transmitted to the inverter controller which provides the synchronized power to the LSM stator attached on the guideway. To minimize the power input to the stator, the whole guideway is devided into several sections and the power is supplied to the only one section which the train is running on. In this case, precise section change control is needed to mitigate the vibration and noise. In this study, to evaluate and test the control technologies for super speed maglev, the infinite loop type LSM testbed is developed.

Investigation on stray magnetic field of high speed maglev

Magnetic fields (MF) generated both on board the vehicle and along the guideway provide levitation and propulsion forces. High speed maglev trains adopt electromagnet or superconducting magnet to realize levitation and propulsion functions. However, stray fields existing in passenger compartment and regions surrounding the vehicle and guideway have effect on passengers and environment. To investigate stray magnetic field effect, model of Transrapid and MLX are studied.

Study on the effectiveness of high-speed railway communication and signaling system based on 4G LTE technology

Due to speed acceleration, higher requirements have been put forward to high speed railway communication and signaling system. The railway applications, including intra-train, train to ground and trackside networks, demand larger bandwidth, higher reliability and shorter response time from railway communication networks to ensure security operation and passenger communication. However, the current railway communication and signaling system has lagged behind the railway development, so advanced communication technologies are needed to improve the current situation. This paper presents high speed railway communication and signaling system based on 4G LTE technology, introduces its network architecture, key technology and analyzes its technical advantages compared with GSM-R system. According to analysis, LTE based high-speed railway communication network is more effective and reliable.

A Study on Trend of Technology Development for Super-Speed Maglev

In this study, to understand the technology development trend of super-speed maglev, the patents applied by major countries are analyzed. And based on the analyzed results, the domestic technology development direction are suggested. For patent analysis, the major technologies for super-speed maglev are classified into 14 parts. Then, through the quantitative analysis method such as number, increase rate and share rate, the overview of technology development and focused parts by each country are investigated. Also through the qualitative analysis method such as concentration degree, citation index and market share index, the technology level and market securing ability of each country are anticipated. Considering the analyzed results and technology development trend, the domestic technology development direction such as priority development fields and methods are proposed.

Thrust Performance Improvement through Position Signal Compensation and Estimation in Super Speed Maglev

In position detection for super speed maglev propulsion control, the influence of position signal delay and transmit cycle on propulsion power degradation is investigated analytically and validated by test bed experiments. As a solution to the problem caused by signal transmit, position signal compensation and estimation method is proposed and applied to the test bed. Through experiments, it is confirmed that by adapting the proposed method, the propulsion power is increased remarkably, which results in acceleration and velocity performance improvement. This method could be effectively applied to position detection system of Korean super speed maglev which is under development.

Propulsion system characteristics of TTX (Tilting Train eXpress)

Speeding up of the conventional railways adopted in Japan and Europe requires less investment than laying a new infrastructure dedicated to fast railway systems. In this way, tilting trains that can negotiate curves at high speed will be introduced along with partial improvement of the related infrastructure. Tilting trains are currently in operation in 13 countries around the world. With the advances in tilting technology, verification of economic efficiency, and changes in economic situations, the introduction of tilting trains will rapidly spread across the globe. The Korean tilting train developed in this project is designed for a design speed of 200 km/h and a maximum operating speed of 180 km/h for bidirectional operation on the conventional lines in a power-distributed EMU type.

Development of Measurement System for Traction and Braking

In this paper, we introduce the software and hardware of the measuring system for on-line test and performances evaluation of traction and braking in KTX(Korea Train Express). The measuring system focuses on the verification of the performance and acquisition of test data. The hardware is connected many kinds of sensors, such as speed sensor, thermocouple. The software controls the hardware of the measuring system, performs the analysis and calculation of measurement data and acts as interface between users and the hardware. For this purpose, three programs, such as a measuring program, a back-up program and a analysis program, have developed.