• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.308-310
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• 1996

Recently, as a result of the progress in power electronics and microelectronics, the inverter technology is quickly developing. Also, by using the fast microprocessor and small-sized switching devices, such as IPM, the Inverter becomes more compact and cheap. This paper proposes an inexpensive and small-sized vector controller for induction motors using 87C196MC and IPM. The proposed inverter contributes further space-saving, and high performance features to motor drives system.

• International Journal of Automotive Technology
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• v.8 no.5
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• pp.533-542
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• 2007

The two stroke spark ignition engine is the greatest contributor of the total vehicular pollution in a country like India. It is therefore an item that requires great attention in order to reduce fuel consumption and its concomitant pollution. The use of strong magnetic charge in the fuel line gives a complete and clean burn so that power is increased while operating expenses are reduced. The magnetic flux on the fuel line dramatically reduces harmful exhaust emissions while increasing mileage, thereby saving money and improving engine performance. It increases combustion efficiency and provides higher-octane performance. The experimental results show that the magnetic flux on fuel reduces the carbon monoxide emission up to 13% in a base engine, 23% in a copper-coated engine and 29% in a zirconia-coated engine.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.159-162
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• 2001

This paper is proposed an efficiency optimization operation algorithm for synchronous reluctance motor (SynRM) using current phase angle control technique. The SynRM has to controlled with the optimal current phase angles with load and operation speed variation, to obtain high efficiency over the wide speed ranges. An efficiency optimization condition in SynRM which minimizes the copper and iron losses is derived based on the equivalent circuit model of the machine. The objective of the efficiency optimization control algorithm compensating the optimum current angle, is to seek a combination of d and q-axis current components which provides minimum losses at a certain operating point in steady state. The usefulness of the proposed efficiency optimization control is verified through vector-controlled inverter system with the SynRM.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.2 no.4
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• pp.75-81
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• 1988

TRIAC 위상제어 방식은 교류전류의 제어에 편리한 방법으로 많이 응용되고 있다. 유도전동기는 부하변화에 따라 역율과 효율이 변화하며 특히 무부하와 경부하에서는 큰 전력손실을 유발한다. 본 연구에서는 TRIAC 위상제어 방식을 이용하여 유도전동기의 기계적부하에 따른 최적의 전압을 공급함으로써 효율과 역율을 개선시켜 전력손실을 줄이는 것을 기본동작원리로 하며 종래의 구조의 복잡성과 경제성 및 실용성을 크게 개선 하는데 설계의 주된 목표를 두었다. 제안된 절전회로는 실험결과 부하의 변화가 빈번한 곳에 운용되는 소형유도전동기에서 상당한 절전효과가 나타났다.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.61-63
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• 2008

An inverter with large capacity has been demanded at a factory automation and diffusion of the energy saving work. As the capacity of inverter is larger, the stary inductance has much influence on both the di/dt of IGBT current, and voltage stress across IGBT. Also, the life of the snubber capacitor may be shortened due to overheating of the snubber capacitor. In this paper, a planar busbar which consists of two layers is applied to N700-series inverter in order to minimize stray inductance. The voltage stress across IGBT is changed by both the DC busbar structure and the capacity of snubber capacitor.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.871-874
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• 2003

The T-5 Lamps developed in 1996 is the high efficiency fluorescent lamps, the lamps voltage is high, and the lamps current small because the lamps are slender tube of 16mm diameter. And so, the electrical characteristics of the Ballast for the lamps are different from of the Ballast for T-10 or T-8 lamps. Therefore, the know-how of the exclusive Ballast for the T-5 fluorescent lamps should be as soon as possible. We described the electrical and optical characteristics of the Electronic Ballast for T-5 Circular Fluorescent lamps. The developed Electronic dimming Ballast for T-5 Circular Fluorescent lamps has the 45% energy saving effects than the T-10 lamps. And it has the promotion of the THD less than 10%, CF less than 1.5%, Flickering less than 5% and 99% power factor. And it is available for two T-5 Circular fluorescent Lamps dimming, 22W and 40W.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.3
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• pp.271-281
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• 2010

Brazing fitting which is one of the aircraft hydraulic power system components is widely used for saving weight and achieving higher reliability. Any inherent defects or damage of fitting can cause system failure and/or physical damage of human body due to highly pressurized fluid. Radiographic testing(RT) technique and additional micro-structure investigation on cut-away surfaces have been accomplished to find out some defect-like-inhomogeneity in the fittings. The radiography results showed that some defect-like-inhomogeneity existed inside body. Additional micro-structure investigation on cut-away surface reveals that the inhomogeneity is due to internal voids. In this study, it can be is said that RT technique can be a useful tool for field acceptance test of hydraulic brazing fitting in short time.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.512-518
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• 1999

This paper proposed the optimal operational scheduling of cogeneration system for paper mill connected with several auxiliary devices Auxiliary devices that include auxiliary boilers, waste heat boilers and sludge uncinerators operate with multi-cogeneration systems. Especially environment element was considered in objective function to solve environment problem. Electricity can be purchased through power system from utility. The proposed operational strategy on cogeneration system for paper mill to increase energy efficiency can be applied to the similar cogeneration system is industrial field.

• Journal of the Korea Safety Management & Science
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• v.5 no.4
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• pp.257-266
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• 2003

3D Modeling Solution can reduce projecting error and also make possible to design visually, so that it can minimize human resources. On the other hand, it has defects of operating difficulties caused by too much complex function, thus it consequently prevent user from prompt handling. According to this paper, the developed party S/W will help that user can construct the parts easily, can let everybody use 3D modeling solution readily, and make fast development of new product. This software will carry out prompt development of new product and derive satisfaction of customers from high quality. Also, saving time and expense naturally raise competitive power in consequence.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1294-1302
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• 2008

Talk-Back systems comprised of master-equipment at the control room and slave-equipment at turnouts refer to the intercommunication facilities that optimize mutual communication between maintenance staff on trackside and the control room to facilitate quickness and accuracy of train operation control and its maintenance within depot and on mainlines with turnouts for direction switching of the trains in operation. The weakness lies in additional maintenance costs of cables since the Talk-Back system installed on line 1 along with line 2-4 has a profound effect on the voice quality leading to the attenuation and crosstalk of the system due to the deterioration of cables and environmental factors. This paper discusses the Talk-Back system in a radio communication environment with the application of RF(Radio Frequency) communication system from the wire communication system by cables to ameliorate these problems, and deals with the energy saving environmentally friendly facilities in consideration of replacing power section at salve-equipment with solar batteries benefitting the system in light of energy consumption.