• Journal of the Korean Applied Science and Technology
• /
• v.22 no.3
• /
• pp.234-240
• /
• 2005

In this study, we have prepared three kinds of enteric tablet coating formulations for prevention the crack incidence and enhanced process improvement of enteric tablet using aqueous system. we determined the mechanical strength of three formulatons on the enteric film-coating process. The compared experiment of one-layer and two-layer (A), (B) coating treated having placebo tablets without breakline and logo. In result, the breaking force time of two-layer (B) film strength was found to increase 0.8min than two-layer (A). We confirmed the half reduction of working hour and the simplification in the one-layer coating process, and the coating troubles was solved as setting up a dehumidifier in inlet of coater. In result, we recovered that optimum running capacity(g/kg) of dehumidifier is 10g/kg and below.

• Proceedings of the KIEE Conference
• /
• 2008.11a
• /
• pp.153-154
• /
• 2008

우리나라 전력수요의 지속적인 증가는 발전설비 및 송전망의 동반 성장으로 전력계통 규모가 꾸준히 확장되어 왔다. 그러나 이로 인해 전력계통 고장전류가 증가하는 문제가 발생하여, 그에 대한 대책으로 차단기 교체 등을 시행하고 있다. 이와 관련하여 고객서비스차원에서 한국전력은 전원 측 계통확장으로 인한 차단용량 부족 154kV 이상 수전고객에 대해서 차단기를 교체하도록 차단기 교체을 지원하기로 하였다. 이에 본 논문에서는 한국전력에서 시행하고자 하는 대용량고객 차단기 교체 지원내용에 대하여 알아보고자 한다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.2
• /
• pp.321-326
• /
• 2012

The mechanism unit, arc chamber and trip unit are imperative components of MCCB which will decide the level of performance of MCCB. Among them, Arc chamber unit is used for extinguishing arc rapidly of fault current and induce the arc inside of grid. At that time inducing arc will split into parts and cooled rapidly so the arc would disappear. This paper suggests new arc chamber unit to improve arc extinguishing performance with optimum design and are applied to actual products based on the results.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.569-571
• /
• 2005

In case of dead-tank circuit breaker with the earthed enclosure, the dielectric performance for phase to ground should be verified under the hot-gas condition produced by the current interruption. This test condition is required in breaking test duties with the rated short-circuit current and rated voltage. And, KERI has completed the reinforcement of the synthetic testing facilities and these facilities have the testing capacity which enables the full-pole testing for 800kV circuit breaker by adopting the series voltage injection method. So, this paper introduced the test circuit and procedures about the full-pole and the multi-part testing method which was devised to estimate the full -insulation of phase-to-ground for the multi-pole and dead-tank circuit breaker.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.50 no.6
• /
• pp.287-292
• /
• 2001

This paper deals with the configuration, operating principles, systematic calculation method of parameter and optimization method of test circuit for parallel current injection method, series voltage injection method and hybrid synthetic test method as the method for performance test of circuit breaker with extra high interrupting capacity. The test method depicted above is applied to short-circuit making and breaking test (operating sequence :Os CdOs, Od-CdOs) and out-of-phase tests(operating sequence :Os, CdOs) for performance test of the newly-developed 420kV, 50kA and 800kV 50kV puffer-type gas circuit-breaker according to IEC 60056 and IEC 60427. The testing results, evaluation of equivalence for test and analyzed results are also presented in this paper.

• Proceedings of the KIEE Conference
• /
• 2002.07a
• /
• pp.159-162
• /
• 2002

A software, called touch-one, is developed about the determination of short-circuit values and protective co-ordination in power system. The used solution algorithm reviewed intensively, and the protective co-ordination determination technique presented by using the circuit-breaker's current-limitation characteristic. The protective coordination concerns the behaviour of two devices placed in series in an electrical network, with a short-circuit downstream circuit-breaker. It has two basic principles: First, discrimination which is an increasing requirement of low voltage electrical distribution systems. Second, which is less well known: cascading, which consists of installing a device, whose breaking capacity is less than the three-phase short-circuit current at its terminals and helped by main circuit-breaker. With this software, we can construct a electric-power system which is reliable and economic according to user's purpose.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.11 s.176
• /
• pp.104-110
• /
• 2005

GIS(Gas Insulated Switchgear) is used in electric power system, to insure non conductivity, breaking capacity and operating reliability. The commercial dynamic analysis code COSMOS MOTION and 3-D modeling program SOLID WORKS were used to simulate dynamic analysis of the closing resistors of the GIS in this paper. To reduce chatter vibration of closing resistors, the motion of moving and fixed parts of closing resistors were simulated by varying the spring constant, the damping coefficient and the mass of moving and fixed parts. The simulated results were compared with experimental results. As a result, chatter vibration of closing resistors of the GIS could be reduced by using the results. These data can be used to determine the spring constant, the damping coefficient and mass of a moving part to reduce chatter vibration when the next model is developed.

• The Research Journal of the Costume Culture
• /
• v.11 no.4
• /
• pp.551-561
• /
• 2003

The regulations for costume were set to improve people's moral fiber and cultural standards. In the 17th and 18th century, the main aim of this regulation was to prohibit luxury. But being the turning point to a modem state, with breaking social status and development of commerce, industry, and the mind of imitation, regulation for luxury wasn't enforced, but rather it brought many revolutionary changes in costume. Restraining human impulse to express beauty was no longer subject to regulation. Therefore, people started to recognize the human figure with shorter Jegory(저고리) and strengthened ceremonial capacity by broadening po's(포) sleeves. The silk fabrics were the most popular fabric during this era, special patterns were added for decoration and also for blessings. Complementary colors were used for contrast on the collar (깃), cuffs (끝동), Gyotrnagi (곁마기), and sash (고름). This color composition gave a younger and more active look. And with red stripes on the sleeves, it emphasized the beauty of the color arrangements as well as providing protection from the devil.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1751-1753
• /
• 2002

Arc phenomena occur in the air, must be more diverse than vacuum and SF6. An air arc interruption method has been used in low rated voltage circuit breakers such as ACB, MCCB and MCB. Most of them have the arc chamber composed of arc chutes and lateral walls that made of many kinds of materials. Therefore, the criterion of material selection is necessary for breaking capacity improvement. So, we selected some contact and lateral wall materials, and carried out short circuit tests. Especially, some parameters of arc plasma properties were very different each polymeric wall material.

• Proceedings of the KIEE Conference
• /
• 1999.11d
• /
• pp.900-902
• /
• 1999

This paper deals with the interrupting characteristics of fuses element in different media of arc extinguisher. Aluminum hydro-oxide, boron nitride, silica and there size have been investigated here for their prospects as filling media in heavy current, high breaking capacity fuses. The result of these study are compared with those on silica sand at high current. This study demonstrates that silica sand is far superior filler in fuses for heavy current interrupting then the compound tested.