• Proceedings of the KIEE Conference
• /
• 2004.05b
• /
• pp.180-182
• /
• 2004

We have investigated characteristics of varnish and oil impregnant. When transformers are manufactured with some moisture and varnish impregnant not entirely dried, those should be caused by factors that deteriorate the electrical or mechanical property after installation. Therefore, in this study we experienced moisture content of the new insulating paper and the varnish impregnant paper in the ratio of time for confirming factors that deteriorate the paper characteristics. Besides, we investigated a property study that was experienced the value of dielectric strength and tensile strength as no serviced insulating samples of transformer.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.9
• /
• pp.1146-1151
• /
• 2018

Recently, researches on the intelligence of electric power facilities have been trying to apply artificial intelligence techniques as computer platforms have improved. In particular, faults occurring in substation should be able to quickly identify possible faults and minimize power fault recovery time. This paper presents fault location technique for 154kV substation using neural network. We constructed a training matrix based on the operating conditions of the circuit breaker and IED to identify the fault location of each component of the target 154kV substation, such as line, bus, and transformer. After performing the training to identify the fault location by the neural network using Weka software, the performance of fault location discrimination of the designed neural network was confirmed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2003.11a
• /
• pp.269-272
• /
• 2003

The importance of the improving quality of electric power is being strongly raised, owing to an increasing use of sensitive and small-sized electronic devices and system. The transient overvoltage on low-voltage AC power distribution system are induced by direct or indirect lightning return strokes, and those can cause damage and/or malfunction of the utility system for borne automation, office automation and factory automation as well as medical equipments. The behavior of lightning surge transferred to the primary side from the primary side in distribution transformers were experimentally investigated the protection effect of low voltage SPD installed at the secondary side of distribution transformers was analyzed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.5
• /
• pp.61-66
• /
• 2011

An accidental disconnection of power supply for operating theatres may result in fatal accidents. Thus, it is necessary to import the electric safety system in medical locations. This paper shows an analysis of simulation for the safety in medical IT system based on KS C IEC 60364-7-710(Electrical Installations of Buildings - Requirements for special installations or locations - Medical locations). The analysis was progressed by measuring leakage currents according to variation of volts, circuits and loads. And it was made database for calculation the reasonable length of branch circuit.

• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.237-238
• /
• 2014

A studies about HID resonanse ignition circuit. it need more than 2kV of the output voltage. then the breakdown voltage of the output capacitor must be higher, size of the capacitor must be larger, and price are higher. so were studied possible ways by resonating by distributing the secondary number of turns of the transformer, it would reduce the breakdown voltage of the output capacitor. we also studied the method can be lit at long distance, to control the resonance frequency in dependence on its parasitic capacitor that vary according to the length of the wire.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.252-253
• /
• 2012

본 연구에서는 단상 1.9 kV/220 V, 2 kVA 용량의 양방향 지능형 반도체 변압기의 새로운 회로구성을 제안하고 그 동작과 성능을 분석한 내용에 대해 기술하고 있다. 제안하는 반도체 변압기는 고압 고주파 AC-DC 정류기와 저압 양방향 DC-AC 컨버터로 구성되어 있으며, 회로적인 특성을 다양하게 분석하기 위하여 먼저 PSIM 소프트웨어를 이용한 시뮬레이션을 실시하였고 이를 기반으로 반도체변압기를 제작하여 실험을 통해 그 동작과 성능을 검증하였다. 제안하는 반도체변압기는 최근 많은 관심이 고조되고 있는 Smart-Grid에 효율적으로 적용 가능할 것으로 보인다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.631-635
• /
• 2000

Recently, the epoxy molded type PT for indoor and applied 25.8kV was often distroyed by degradation of insulation that effected many electric stress and defect of manufactured goods. therefore In this work, We can present a method of solution in the process of produce the PT through analysis of experiments. In order to reduce the PD (Partial Discharge) which was occurred at the insulation material of epoxy resin, we has many tried to remove faults In the process of the products,

• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.183-186
• /
• 2002

It is well known that a discharge in oil is the source of various physical and chemical phenomena. One of them is ultra-sonic wave, and its detection is a useful method to the diagnosis of the transformer insulation condition. Conventionally, ultra-sonic waves are detected by Piezo-electric trans-ducer(PZT), and we use optical method that has many advantages. In this paper, we constructed a Mach-Zehnder interferometer with optical fiber and investigated the principle of operation. Test of the ultrasonic-detecting ability was performed for both of PZT and fiber-optic sensor. Discharge test arrangement is based on the needle-plane electrode system in oil and applied AC high voltage. Ultrasonic waves were detected and showed time-delay characteristics. We analyzed the data with frequency domain and wavelet transform.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.240-241
• /
• 2006

변류기의 제조공법에는 conventional 방식이 있다. Conventional 방식은 부분적으로 불규칙한 경화에 의한 굴곡형태, 단기간에 금형의 손상이 많이 가고, 제한된 생산량으로 금형이 많아야하고 또한 금형의 예열이 필요한 단점을 가지고 있다. 이를 개선한 APG(Automatic Pressure Gelation) 주형방식은 제품의 외관을 매끄럽게 하고, 자동화에 따른 금형수명을 연장하고, 1일 생산량이 conventional 방식보다 8배나 많고 제품의 후경화 설비만 필요한 장점이 있다. 생산성 향상 및 제조원가 절감을 위하여 새로운 제조공법인 APG 방식의 제조공법에 맞는 원재료 및 작업조건을 표준화하고 한국전기연구원이 보유하고 있는 고가장비인 내후성시험기, 성분분석시험기, 충격시험기, 단락시험설비 등을 이용하여 시제품에 대한 평가 시험을 하여 제품의 품질을 향상하고 안정성을 확보함으로써 국내 기업의 기술 경쟁력을 향상하고자 하였다.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1521-1523
• /
• 2005

High voltage plasma power supply was adopted to control polluted gases and an ozone generation. Bidirectional pulse power supply consisted of power semiconductor switch devices, a high voltage transformer, and a control board adapted switching method. Plasma power supply with sinusoidal bidirectional pulse, which has output voltage range of 0-20kV and output frequency range of 1kHz-20kHz, is realized. Using proposed system, pulsed high voltage/high frequency discharges were tested in a DBD(dielectric barrier discharge) reactor, and the spatial distribution of a glow discharge was observed. The system showed stable operational characteristics, even though the voltage and the frequency increased. Above features were verified by experiments.