• Journal of the Korean Society for Precision Engineering
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• v.19 no.3
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• pp.46-51
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• 2002

Recently, High capacity alternator are used fur some special equipments in industry. But, several serious problem are occured, especially, broken coil of rotor, caused by crash with stator on rotating the rotor. Although added coil cover thor protect coil of rotor, coil cover is broken. In this study purpose 2 step for corrected that problems. First, three dimensional finite element method far investigate what is most important point. For that purpose, performed stress analysis of coil and coil cover that modeling and finite analysis by ANSYS software. Second, Apply prestress when winding the coil on stator to modify direction of net force. Vector analysis is used for determine corrected prestress. Result of the analysis and prestress are reviewed.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.402-403
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• 2011

EMI 필터 설계 시 주로 사용되는 공통모드 초크의 경우 자화 인덕턴스로부터 공통모드 노이즈 감쇠를, 누설 인덕턴스로부터 차동모드 노이즈 감쇠를 기대할 수 있다. 이때, 누설인덕턴스가 너무 클 경우 차동모드 노이즈 감쇠에는 우수하지만, 전기/전자제품이 슬림화됨에 따라 공통모드 초크의 누설 자속과 전원공급기를 덮고 있는 금속덮개 사이에 자계 간섭에 의한 진동/소음문제가 발생될 수 있다. 본 논문에서는 누설자속을 조절할 수 있는 공통모드 초크의 코어형상 및 권선기법을 제안한다. 제안된 방법은 진동 및 소음을 제어할 수 있는 장점을 지니고 있다.

• Fire Science and Engineering
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• v.28 no.5
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• pp.8-13
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• 2014

The purpose of this study is to analyze the damage pattern when overcurrent is applied to a thermal magnetic type molded case circuit breaker (MCCB) using a Primary Current Injection Test System (PCITS). When an overcurrent of 150 A was applied to the PCITS for 5 seconds with the trip bar of an MCCB being damaged, it was found that the surface of the temperature control device (bimetallic strip) positioned at the right was significantly carbonized. When an overcurrent of 300 A was applied to the PCITS for 5 s under the same conditions, the entire temperature control device was deteriorated, becoming flattened and in close contact with the MCCB. When an overcurrent of 450 A was applied to the PCITS for 5 s, the coil of the temperature control device was melted and disconnected. In addition, it was observed that the contacts, the enclosure and upper cover were deformed and there was a trace of carbonization on them. When approximately 3 s had elapsed after an overcurrent of 600 A was applied, white smoke occurred inside the MCCB and a flame was radiated out, after which the overcurrent supply stopped with "phutt" (whomp) sound. It was observed that when the same type of MCCB is damaged by a general flame, the surfaces of its handle, terminal, arc divider (extinguisher) and temperature control device were carbonized uniformly. In addition, it was found that the trip bar of the operating mechanism was melted down and the metal operation pin was moved while being tripped.