• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.200-205
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• 2017

In this paper, we propose a technique to determine the normal and arc of an alternating current using a mixed filter composed of an average filter and a band-pass filter and a frequency analysis. The proposed method uses the moving average filter of the FIR filter structure for noise removal and the band-pass filter of the IIR filter structure for detecting only specific frequency components after normalizing the measured current signal based on the maximum value. After performing Fast Fourier Transform (FFT) using the band-pass filtered signal, the total energy is calculated using the magnitude component of the frequency, and the arc is detected using the magnitude of the calculated energy. In order to show the validity of the proposed method, we experimented with various data and found that arc and steady state can be easily discriminated by calculating spectral energy. Therefore, it is considered that the proposed method can be applied to arc diagnosis of low voltage electric wire.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.250-252
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• 2006

In this paper, we studied for the measurement system for on-line testing and evaluation of tilting train express(TTX). The measurement system is installed in each train for the performance measurement during the test run. It is composed of software part, hardware part and can measure various signals such as velocity, voltage, temperature. The software controls the hardware of the measurement system, performs the analysis and calculation of measurement data and acts as interface between users and the system hardware. The hardware is consisted of 7 DAMs(Data Acquisition Modules) and 6 monitoring modules.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1391-1397
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• 2015

Recently, various researches are conducted in the application of regenerative energy produced during the operation of an electric locomotive. Regenerative energy is produced by a generator in the brake procedure. The generator is operated by kinetic energy of an electric railroad using an electric motor. The process of producing regenerative energy varies with the current type of a railroad and its running condition. The quality of electric power can be improved and electric energy can be utilized effectively, especially in the use of an energy storage system (ESS). Thus, it is necessary to apply ESS into AC section and high speed railway. This study analyses the composition of the regenerative ESS equipment installed in Yong-Jeong sectioning post, operational principle, charge and discharge algorithm and energy efficiency. The analysis shows that CO2 emissions can be reduced about 0.5 ton per a day. In addition, ESS helps saving the energy and the compensation of the voltage drop caused by the operation of high speed train when it is installed at the end of the feeder section. The number of high speed train will be increased continuously related to the electrification rate. Therefore, applying the ESS to high speed railway is expected to solve the instability of the feeder voltage and the equipment capacity problem caused by the high speed trains.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.128-131
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• 2000

The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for DC power system of railroad vehicles. The rated voltage is 1500V direct current. The main research works are focused on structure design by finite element method, rating voltage, temporary over voltage and studies of characteristics of polymeric surge arrester.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1919-1924
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• 2016

In general, Diode rectifier has been applied to DC traction power supply system. Diode has some characteristics which is voltage drop in inverse proportion of load because of non-controlled switch, and cannot flow a current in reverse bias. So, voltage drop occurs frequently, and regenerated power cannot use in substation. The PWM rectifier is able to control output voltage constantly to reduce voltage drop and to use regeneration power without additional inverter. This paper proposes analysis algorithm for DC traction power supply system with PWM rectifier.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1381-1383
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• 2000

A multi-train operation simulation software is under development, in this G7 Project for a High Speed Train System, to simulate the running performance, power consumption, signalling and operation. In the first stage, a Train Performance Simulation (TPS) software is introduced in this paper. This is a core module of whole system and gives some parameters of a train, e.g., its position, speed traction and braking power and electric power system state, etc. In this paper, calculation technique was used for voltage drop at the train's positions and major posts along the catenary line. The final program will be used as an evaluation tool for system performance in constructing a new line or introducing a new train system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1169-1170
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• 2007

The primary objective of this paper is to examine the capacity of electrical transmission in electric railway according to the type of feeding system. Although supply capacity of railway substation are sufficient and there is no accident, due to the electrical transmission limit of feeding line the voltage breakdown may occur when large capacity of electric load at feeding line exist. So, using multi-port analysis model, we draw P-V curve due to feeding method, load, location and power factor of electric locomotive.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.108-115
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• 2000

This paper presents the new simulation algorithms using network methods to analysis the steady-state train voltage distribution characteristics in ac auto-transformer fed railroads. In general, the supply system of railroads is composed of non-symmetrical and unbalance transmission line. Therefore, the general method using simplified old algorithms have the self-contradictory errors because the supply line of train railroads is completely unbalanced. In this paper, the simulation results of new developed algorithms is compared with those of EMTP to confirm the effectiveness.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2215-2216
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• 2011

In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to electrical railway vehicle is investigated from an electrical response point of view. To analysis voltage and current waveforms by induced contact loss phenomenon on driving electrical railway vehicle, a hardware Simulator which considered contact loss between contact wire and the pantograph as well as contact wire deviation is developed. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system. Throughout prototype simulator and contact wire and catenary wire experiments, it is confirmed that current waveforms is distorted by contact loss phenomenon and in case of driving electrical railway vehicle.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.1130-1136
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• 2015

Most equipments which are used to measure the switching power of the turnout depend on imports. As the data is limited to the measurements of the switching power, it is said that the equipment is insufficient to check the errors of the turnout and the electrical point machine, and set up the data for operating and maintenance. We studied not only measurements of the switching power of all turnout being used in domestic but also the development of the turnout performance total analysis equipment which can measure switching time, voltage, and current etc. at the same time. Considering that switching power of the turnout is the most basic element to check the irregularities of the turnout, in this paper, we analyzed the irregularities of the turnout through correlation between switching power of the turnout, voltage, and current of the electrical point machine. Also we performed test in commercial railway line where the turnout of MJ81 type and NS type was installed. And it is said that the test results can be used as basic technologies for ICT based real-time diagnosis and monitoring of the turnout.