• Proceedings of the KSR Conference
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• 2005.11a
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• pp.665-670
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• 2005

This paper introduces the propulsion system(Motor Block) stabilization test result for Korean High Speed Railway(HSR). The developed propulsion system using high power semiconductor, IGCT(Integrated Gate Commutated Thyristor) consists of two PWM converter and VVVF inverter. In this paper, overall configuration of propulsion system is briefly described and stabilization tests are made to verify the developed propulsion system. The presented test results shows beatless control method of inverter output current at the 200km/h and performance test of BCH.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.202-203
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• 2007

Induction Motor is important at tilting train. Tiling train induction motor should be operated to commercial servicespeed 180km/h at Korea Conventional Line upgrade railroad. As the induction motors are without commutators, maintenance is easy and it is far lighter than the conventional motors with the same capacity. The induction motor, however, posed problems in use as its motor torque is not large enough compared with DC motors. With the recent advances in power semiconductors, it is possible to apply the induction motors to trains by applying VVVF inverter control method to the traction motor. In this study, we realize the stable measurement AC motor temperature characteristic of TTX train.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.5
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• pp.71-85
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• 1993

The Cycloconverter that the author is going to treat in this paper, has strong advantages over the D.C. Link Inverter in points of chattering torque problem and natural commutation. Thus, the Cycloconverter is expected to be well applied to large and low-speed machines which require better speed control at low frequency. But the control circuit of Cycloconverter has two weak points described as follows. 1) Because of its rather complicated control circuit, it is likely to be illoperating due to unexpected noise signals, thus the higher the accuracy and reliability of the circuit is required to be, the more the circuit may cost. 2) Because the load current is not purely sinusoidal, the Cycloconverter may possibly be destroyed in case of inaccurate convert switching resulted from the difficulties in detecting the load current-zero and the current direction at the moment. In this paper, the author first of all intends to design and build a modified VVVF-type Noncirculating Current Cycloconverter to which recently proposed control methods are applied for improving the circuit simplicity, the control performance, and the system reliability. And then, experiments for observing the output waveforms of the Cycloconverter which is controlled by Singled-Board Computer using 8086 16-bit microprocesser are carried out. Finally the author concludes the result of this study as follows. 1) By replacing the conventional analog control circuits such as Reference Wave Generator, Cosine Timing Wave Generator, and Comparator with softwares, a great circuit simplicity is achieved. 2) The output of the designed Cycloconverter changes its frequency very fast without showing discontinuity of its waveform, and this waveform characteristics enables the smooth speed control of Induction Motor. 3) The design control circuit of Cycloconverter can be applied to the systems of 12 or 24 pulses because of its short processing period.

• Journal of the Korean Society of Safety
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• v.28 no.3
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• pp.23-28
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• 2013

This study focuses on finding ways to derive train's optimal ECO driving pattern, which can improve the ride quality and reduce driving energy consumption with keeping the time interval between the stations. As research method, we compared difference of currently operating train's ATO and MCS driving patterns, and concentrated upon the things need to consider in simulation in order to improve the existing pattern of ATO driving pattern's issues with securing the train operation safety. Determining driving pattern minimizing energy consumption by controlling powering within speed limit and controlling switching to coasting at appropriate point considering the track conditions for each section, and determining braking control starting time considering ride comfort and precise stopping is considered to be most important.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.186-192
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• 1998

This paper presents a high performance low switching PWM technique or the propulsion system of railway such as subway and high speed train. In order to achieve the continuous voltage control to six-step and s low harmonics with low switching frequency under 500Hz, the synchronous technique is combined with a space vector overmodulation and implemented by using DSP. Improved performance and a validation of proposed method are showed by the digital simulation and the experimental results using a 1.65MVA IGBT VVVF inverter and inertia load equivalent to 160 tons railway cars.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.5
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• pp.8-17
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• 2016

While greenhouses have been utilized as a sustainable alternative to traditional soil farming, they are often powered by diesel boilers that necessitate vast amounts of non-renewable energy and emit toxic fumes. Thus, geothermal heat pumps have been proposed as a more energy-efficient substitution for diesel boilers. Currently, most horticultural facilities in the United States use shallow geothermal systems, and are often equipped with horizontal underground heat exchangers as well as heat pump equipment. These shallow geothermal systems require a large drilling site and heat pump to function, which results in high maintenance costs. The heat pump itself consumes a large amount of power, which degrades system performance. Conversely, high temperatures can be attained within a single borehole in deep geothermal vertical closing systems without using a heat pump. This setup can dramatically reduce the power consumption and improve system performance. In this study, we have modeled a circulation simulator after the circulation systems in deep geothermal facilities to analyze a 2000-meter borehole in Naju-Sanpo-myeon. The simulator is operated by manipulating various putative parameters affecting system performance to analyze the system's coefficient of performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.109-117
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• 2000

A full bridge type double resonant high frequency resonant inverter to give VVVF function in the inverter used as power source of induction heating at high frequency is presented in this paper. This proposed inverter can reduce distribution of the switching current because of using the current of serial resonant circuit to the input current of the parallel one and this paper also realize the output control of independence irrespective of the switching frequency using Phase-shift. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, the principle of basic operating and the its characteristics are estimated by the parameters, such as switching frequency, the variation of phase angle ($\phi$) of Phase-shift.