• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.699-701
• /
• 2001

The expert system monitoring and diagnosing 765kV power apparatus was described in this paper. To develop this expert system, we studied the knowledge bases and data bases for 765kV transformer and GIS. In order to make the reliable inference of knowledge base and the good MMI(Man Machine Interface), the data bases were consisted of the tables of power apparatus information, limit level value, measured input data, inference result and diagnosis result. The knowledge base had various rules to infer the conditions of transformer and GIS. We applied both the forward chaining and backward chaining methods to these rules of system for good inferences. This paper describes the applied methods for expert system. Also, this developed system was tested with dissolved gas analyzing result and the result was shown.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.53 no.2
• /
• pp.83-90
• /
• 2004

This paper describes investigations of the UHF(Ultra High Frequency) PD(Partial Discharge) measuring technology designed for monitoring of PD in high power apparatus. Based on the spiral antenna theory, the hole type sensor for GIS with metal flange spacer and injection type sensor for oil filled transformer are developed. The experimental results show measurement characteristics of the PD sensor for several artificial defects in gas-insulated system(GIS) and oil transformer. Moreover, we proposed the new $\phi$-f-q method for the purpose of condition assessment of high power apparatus.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.617-618
• /
• 2012

Recently as the inactive response characteristics of the existing RCD(Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is proposed a prevention apparatus using neutral line voltage and semiconductor switching devices for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The proposed prevention apparatus confirms the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker(RCD) through various operation performance analysis.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2326-2328
• /
• 1999

Developments of effective and economic diagnostic apparatus for industrial plastic insulated high voltage power cables are in discontented condition still. Some report told that DC high voltage was damaged plastic insulation of a partially aged power cable to lead breakdown easily. But now, we have no alternative tools of DC diagnostic apparatus, and we try to reduce a possibility of hazard DC diagnosis. DC diagnostic apparatus still have many advantages to field cable engineer like low price, portability easy applications and sufficient data. Main hazard of DC diagnosis is excessive hight of applied voltage Recent developments for DC diagnosis use considerably low voltage. But new test methods need special measuring device and manipulator, like high input impedance voltmeter, low leakage current high voltage switches, etc. So that reason, new DC diagnostic devices are normally very expensive and have low efficiency, economically. We try to design a composite test device for 3$\sim$4 newly developed method, have economical benefit th industrial engineer.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.17 no.5
• /
• pp.107-115
• /
• 2008

In this research, it has been developed the tongs mechanism by a friction force for curbstone working. This tongs apparatus was farmed to grip and rotate the rectangular curbstone. Specification of this tongs apparatus has been determined by considering a loading weight and reversal load preventing reversal of 1.5 ton excavator. And, specification of the linear actuator has been determined with considering mechanical structure and the operation power demanded by the grip pad friction of tongs apparatus. The safety of the part has been examined from the 3D numerical simulation of the tongs apparatus. The operation system has been arranged to grip and rotate curbstone by on-off switching. The prototype has been established to carry out experiment after installing 1.5 ton excavator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.496-496
• /
• 2007

Low level laser therapy has various therapy effects. This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The apparatus has been fabricated using the laser diode and microprocessor unit. The apparatus used a 7850m Laser diode for blood stream improvement and was designed for a pulse width modulation type to increase stimulation effects. In result, we could get the light power of 785nm wavelength.

• Journal of Biosystems Engineering
• /
• v.40 no.3
• /
• pp.284-288
• /
• 2015

Training power tiller operators in safe farming is necessary to avoid farming accidents. With the continuing progress in computational technology, driving simulators have become increasingly popular for conducting such training. Purpose: The objective of this study is to develop mock control devices and data acquisition apparatus for a tiller simulator. Methods: Except for the stand and tail wheel adjusting levers, the mock control devices were developed using a tiller handle assay. The data acquisition apparatus was realized using an embedded data-logging device and LabVIEW, the system design software. Results: The control devices of a real handle assay were successfully mimicked by the mock operator control devices, which used sensors for the relevant measurements. The data from the mock devices were acquired and transmitted to the main computer at intervals of 10 ms via Wi-Fi. Conclusions: The developed mock control devices operate similar to real power tillers and can be utilized in power tiller training simulators.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.458-461
• /
• 2009

In 3-phase 4 wire system, appearance of the $3^{rd}$ harmonic current by increasing non-liner load is the one of causes overheating neutral wire of power line, and apparatus. So it is necessary to protect power-factor decreasing by the $3^{rd}$ harmonic, and electric power apparatus, and line safely, in this study, power system accidents caused by the $3^{rd}$ harmonic were investigated, then harmonic components analysis and unbalanced load analysis got accomplished. As result, we proposed the method to protect the power line and apparatus from over-current of neutral line by using the most economic 4-pole low voltage circuit breaker.

• Proceedings of the KIEE Conference
• /
• 2002.07a
• /
• pp.348-350
• /
• 2002

In the high-power tests to be performed on electrical apparatus as switchgears, transformers, insulators, cable and so on the results of tests on these apparatus are extremely important to evaluate the performance of test object. The reliability of the results depends on the reliability of measuring systems used in the laboratories where tests are performed. This paper introduces factors of uncertainty and describes estimation of uncertainty in high-voltage measuring system used in high-power testing LAB. 1 in KERI.

• Journal of Power Electronics
• /
• v.2 no.1
• /
• pp.11-18
• /
• 2002

The development of the solar and the wind energy is necessary since the future alternative energies that have no pollution and no limitation are restricted. Currently MW Class power generation system has been developed, but it still has a few faults with the weather condition. In order to solve these existing problems, combined generation system of photovoltaic and wind power was suggested. It combines wind power energy and solar energy to have the supporting effect from each other. However, since even combined generation system cannot always generate stable output with everchanging weather condition, power storage apparatus that uses elastic energy of spiral spring to combined generation system was also added for the present study.