• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.1
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• pp.35-43
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• 2002

In the last decade, considerable efforts have been made to make a new class of solid state high power, high speed electronic device, namely, the Photo-Conductive Power Switch(PCPS), and to characterize the high-field performance of PCPS under high power, high voltage conditions. But the problem of surface flashover phenomena persist, preventing the realization of reliable and efficient high-speed, high voltage switching devices. It is essential to have a clear understanding on the physical processes behind the surface flashover problem to develop new technologies and device architectures so as to fabricate PCPS that are capable of high-field high-voltage. Also, it is imperative to identify new materials that could satisfy the requirements for high-field, high-power devices. Since surface flashover, surface breakdown phenomena is observed for all the devices that foiled at the applied field much lower than semiconductor bulk breakdown field, surface passivation is considered one of the important practical methods to improve the high field performance of the devices. Therefore, this paper was studied the main properties and mechanism of the semiconductor surface flashover before and after passivation under high electric-field.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.110-119
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• 2013

As the technologies such as middle-range resonant WPT (wireless power transfer) advance that utilizes medium and low-frequency magnetic field, the importance of safety of such magnetic field is growing. The research on the effect of electromagnetic field on the human body has been mainly done on the GHz range of mobile phones, or 50~60Hz range of electric power systems. However, there has been relatively few works on the 100kHz~10MHz range used in the resonant wireless power transfer. Since there is a difference in the limiting value of magnetic field between widely used ICNIRP EMF guideline and IEEE C95.1 standard, there can be possible confusion when establishing EMF (Electromagnetic Field) standard on the wireless power transfer device in the future. In this paper, the induced current in the human body, which is the basic restriction of the EMF guideline, is calculated using Quasi-static FDTD method when 3D high-resolution human model is exposed to the 100kHz~10MHz magnetic field. Using this result, the feasibility of the magnetic field reference level in the ICNIRP guideline is analyzed.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.78.1-78.1
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• 2010

Recently, as much supplied with new-renewable energy, as much invested in PV system. PV system consists of PV module, PCS and Monitering system, and also could be classified into the type and the capacity by installation method and cost etc. When various systems are installed in the field, it is needed to research for applying in the field and establish infrastructure in order to ensure stable efficiency and reliability. In this study, as the basic design of the demonstration test facility, it is designed the basic PV systems for each capacity to test each PCS. In addition, It is drew the climatic conditions such as insolation, temperature and the design parameters such as installation angle, shades for the local demonstration project and expected the generation of each PV system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.1
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• pp.20-26
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• 2000

In order to propose the design and installation information of vegetation belt, field investigation were carried out in the noise pollution control facilities of highway and the streets of a city for two years(1998~1999), and field tests were performed to analyze the noise attenuation effect of them. The noise pollution control facilities were generally classified into three types (noise barrier and vegetation belt type, mounding and vegetation belt type, vegetation belt type only). Most soundproof facilities were proved the noise reduction effects. But according to width, height, structure, auditory distance and planting forms of them, difference of noise reduction effects were investigated. The soundproof facility was suitable the mounding and vegetation belt type in the consideration of road environment, and the installation standard of vegetation was estimated that the width of vegetation was at least 20m and the length of that was 2 times in the distance from noise source.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.147-150
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• 2002

Domestic electrical construction inspection system was introduced into building site in 1963 by registered architects' law, meanwhile, inspector appointed by ministry of owners lake charge of Government managing building site. Afterwards several systems has been adopted to heal some problems each of them has revealed. These times Government granted authority for inspection on surveillancer, furthermore, formulate a supervising system which articulate the responsibilities of supervision and put it in effect as of 1st, January, 1994. This supervision system gets rid of factors causing faulty work to a considerable extent. However, as it is still in early stage, the system has various problems to overcome, For example, actual state of handling modifications of design in accordance with supervision system in field shows a difference between process provided by law and field process. Thus this study inquire and analyze actual condition of supervision system, at the same time, problems occuring in modifications of design under supervision, and then propose a way to improve it

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.97-100
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• 2004

This paper introduced an artificial fault generator which was operated in the Go-Chang field-test center and explained the result of single line-to-ground fault by AFG. The AFG can basically experiment line-to-line and line-to-ground faults. This facility directly connected distribution transmission lines, so the test results are very useful for power system analysis and protection. Using the function of the AFG, we briefly said the test methods ud results for the 22.9[kV-v] and $6.6[kV-{\Delta}]$ system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.111-116
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• 2011

This paper deals with the electromagnetic clutch which stop the generator at emergency by using the engine power of generator. The electromagnetic field was analyzed using Flux-2d program with different conditions : voltage, air gap, coil locations. As a result, the maximum magnetic flux density of electromagnetic clutch occurred between the coil and wheel : 0.27[T], 0.41[T] at 12[V], 24[V]. The maximum flux density was at the center location of the coil.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.3
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• pp.96-101
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• 2015

Induction machine requires a rotating magnetic field for energy conversion. The current to generate a rotating magnetic field is the magnetization current. This magnetization current corresponds to the reactive power. Reactive power is higher than active power at start-up of induction motor. As the rotation speed is increased, their magnitudes are reversed each other. The active power is higher than the reactive power at near the synchronous speed. This paper is dealing with the analysis result for the changes of the magnetizing current and reactive power when the induction machine is operating as a motor or generator near synchronous speed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1090-1095
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• 2007

A study was carried out to investigate the fluid-structure interaction phenomena of buried hydrophone system that exposed complex loads due to handling, transportation and installation. The buried hydrophone system has necessarily neighborhood structures for installation. Because of the neighborhood structure, acoustic field is deformed. We analyze the piezoelectric-structural-acoustic coupled problem and the results to use a finite element analysis software, ANSYS, which has an coupled field analysis capability. The effect of the component of hydrophone system is revealed altogether in pressure distribution. So, we classify and analyze the problem by four different compositions for decomposition.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.561-565
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• 2006

The paper presents a method of assessing the adequate tapaclty of photovoltaic generation systems for public buildings based on analysis of load variation patterns of customers. When PV systems are installed for supplying power for the customer load, reverse power relay is required by the guideline to be installed at the point of common coupling with the power network. The suggested method analyzes daily, weekly and monthly load demand of the customer that Irishes PV system installation, and determines the appropriate rating of the PV system for preventing PV generation from exceeding the customer demand. This work is expected to support renewable energy dissemination projects of public organizations.