http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
내장 순시 트립장치를 이용한 MOV의 열폭주 보호와 SPD의 안전성 개선
김주철(Ju-Chul Kim),전주술(Joo-Sool Jeon),기채옥(Che-Ouk Ki),최경래(Gyung-Ray Choi),이상중(Sang-Joong Lee) 한국조명·전기설비학회 2011 조명·전기설비학회논문지 Vol.25 No.2
SPDs are increasingly being used against lightning and switching surge according to the applicable revised standard and equipotential grounding system. SPDs are equipped usually with a MOV voltage regulating element. The MOV, however, always is exposed to the danger of thermal runaway resulting from inrushing temporary overvoltage and deterioration. In this paper, the authors made two prototype SPDs built-in Instantaneous trip device and analyzed their limiting voltage through test of the MOV breakdown. As the result of the analysis, the SPDs built-in Instantaneous trip device was proven to be effective for protecting MOV against thermal runaway and Instantaneous trip device react for limiting voltage is considered that is applicable to SPD.
30AF 차단기 순시 Trip 동작 특성분석을 통한 저압차단기의 안전성 개선방안
김주철(Ju-Chul Kim),임정균(Jeong-Kyun Lim),이상중(Sang-Joong Lee) 한국조명·전기설비학회 2010 조명·전기설비학회논문지 Vol.24 No.12
The domestic 30AFs that are currently being produced show many problems due to different instantaneous trip characteristics in case of short-circuit. The troubles may cause explosion by excessive short-circuit capacities and arc emission, which results in a wide range of blackout. The function and safety of the low voltage circuit breakers installed before the end load are very important. This paper presents an idea on the safety improvement of the low voltage circuit-breakers through the analysis of instantaneous trip characteristics of domestic 30AF circuit-breakers.
인청동 스위칭 모듈을 이용한 전력계통 및 전자기기 내부회로의 MOV 열폭주 방지와 안전성 개선
김주철(Ju-Chul Kim),최경래(Gyung-Ray Choi),이상중(Sang-Joong Lee) 한국조명·전기설비학회 2011 조명·전기설비학회논문지 Vol.25 No.9
The MOV(Metal Oxide Varistor), a voltage limiting element, has been installed in the SPD(Surge Protective Device) or inside the internal circuit of an electronic appliance for protection of the electric power system and electronic device against electrical surge. Such an MOV is exposed, however, to the risk of the thermal runaway resulting from excessive voltage and deterioration. In this paper, a reciprocal action has been tested and analyzed using a phosphorus bronze switching module and the low-temperature solder. And a short current break characteristic test linked with the circuit breaker has been performed to limit the inrush current when the MOV breaks down. It has been proven that the phosphorus bronze switching module installed inside the internal circuit can improve the safety of the power line system and the electronic device.
ΔABC 삼각형과 Fermat tree의 관계에 대한 연구
김주철(Ju-Chul Kim),이상중(Sang-Joong Lee) 대한전기학회 2019 전기학회논문지 Vol.68 No.10
The Fermat point minimally connects three points of ΔABC and resultant tree(=Fermat tree) is shorter than the path lengths connected via the excenter, circumcenter, centroid, orthocenter, and incenter, respectively. Fermat point and Fermat tree have a useful meaning in physical and engineering point of view. Finding Fermat point and Fermat tree can contribute to cost reduction for electric circuits, power transmission/distribution lines, and etc, especially for high cost conductors, e.g., the superconducting power cable. This paper shows a brief review of a recently published article on Fermat point and presents detailed derivation procedure and application example of the formula by which the length of the Fermat tree can be directly calculated.
MOV 열폭주 방지용 스위칭 모듈의 과전류 차단특성 시험 및 분석
김주철(Ju-Chul Kim),전주술(Joo-Sool Jeon),김태진(Tai-Jin Kim),홍진무(Jin-Moo Hong),이상중(Sang-Joong Lee) 한국조명·전기설비학회 2011 한국조명·전기설비학회 학술대회논문집 Vol.2011 No.5월
The MOV(Metal Oxide Varistor), a voltage limiting element, has been installed inside the SPD(Surge Protective Device) or inside the internal electronic circuit for protection against the electrical surge. It is exposed, however, to the risk of the thermal runaway resulting from excessive voltage and the deterioration. In this paper, the blocking effect of the inrushing current when the MOV breaks down is tested and analyzed using a phosphorus bronze switching module and the low-temperature solder. It has been proven that, as the result, the switching module is effective for blocking the excessive current along the increase of test current.
Ju-Chul Kim(김주철),SangJoong Lee(이상중) 대한전기학회 2020 전기학회논문지 Vol.69 No.6
The angle reference, the reference for the angles of all bus voltages in a power system, has been specified conventionally on the slack bus in power flow computation(e.g., θ₁=0), however, it can be specified on any bus in the system without affecting the power flow solution. In this paper, loss sensitivities, ∂Ploss/∂PG, ∂Ploss/∂QG, Qloss/∂PG and ∂Qloss/∂QG, of all generators including the slack bus are derived by specifying the angle reference on a load bus that has no generation using the nature of the Jacobian matrix which is re-constructed by transposition of the angle reference bus. With these loss sensitivities, this paper shows the following four example applications to power system computation: New calculation of penalty factors for classical ELD computation Optimal P-Q generation for cost minimization Optimal P generation for system loss minimization Optimal P-Q generation for system loss minimization Derived loss sensitivities and application algorithms are tested and verified on a sample system.
누전차단기의 트립 동작시간 분석을 통한 전류ㆍ시간적(積) 개선
김주철(Ju-Chul Kim),이상중(Sang-Joong Lee) 한국조명·전기설비학회 2012 조명·전기설비학회논문지 Vol.26 No.12
The earth leakage circuit-breakers installed to protect the human body against electrical shock have conventionally had a sensitivity current of 30 mA and an operating time of 30 ms or less. No reviews are found, however, on the operating time of the current conducting through the human body due to the electrical shock or ground fault. This paper measures the trip-operating time against the earth leakage under the condition of increased current as well as under the condition of rated sensitivity current of the earth leakage circuit-breakers. Further measurement with a prototype model showed an improved operating time of 16 ms or less under the condition of rated sensitivity current. It is expected that development of circuit-breakers with higher safety is possible if the performance of the electronic circuit can be improved.