• 한국정밀공학회지
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• 제19권3호
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• pp.123-130
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• 2002

Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force measured and analyzed. To improve the thermal characteristics of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1425-1431
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• 2006

In this study, An analysis of correlation between the vibration transmissions and the dynamic characteristics for floor impact sound insulation materials through model test was carried out. As the results, the correlation coefficients between the vibration transmissions and the dynamic characteristics for floor impact sound insulation materials were over 0.8 at the heavy and light floor impact source and less dynamic stiffness was more effective in reducing the vibration transmission.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.226-227
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• 2007

Nanostructured materials are attracting increased interest and application. Exciting perspectives may be offered by electrical insulation. Epoxy/Organoclay nanocomposites may find new and upgraded applications in the electrical industry, replacing conventional insulation to provide improved performances in electric power apparatus, e.g, high voltage motor/generator stator winding insulation, dry mold transformer, etc. This paper shows that electrical and thermal properties of epoxy/organoclay nanocomposites insulating materials for dsc, dielectric constant, I-V characteristics, breakdown volatge, can improve significantly with respect to the basic, virgin materials.

• 한국초전도ㆍ저온공학회논문지
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• 제11권1호
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• pp.45-48
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• 2009

Research on the mechanical properties of the dielectric paper and mini-model cable are important for optimum electrical insulation design of HTS cable, because the HTS cable experience of mechanical stress, such as tensile and bending stress. Also, it is operated at cryogenic temperature. Therefore, this paper discusses the experiment results on the AC and lighting impulse breakdown characteristics, partial discharge inception and extinction characteristics, and external shape change of the insulation layer according to bending strain of the mini-model cable.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1773-1779
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• 2015

Insulation coordination is a key problem in UHVDC systems in terms of safety and cost. Although high-voltage ±1100kV UHVDC projects are being planned in China, the characteristics and key points of high-voltage systems have not yet been analyzed. This study aims to improve the safe, effective operation of these high-voltage power transmission systems. First, we analyzed two typical insulation coordination schemes used in ±800kV UHVDC systems in China. Next, we used the two typical ±800kV insulation coordination schemes as a reference to analyze the ±1100kV UHVDC system. Finally, we compared these schemes and proposed an effective insulation coordination solution, as well as developing principles for ±1100kV UHVDC systems. Our findings indicate that the points enduring the highest voltage in the system should be protected separately by special arresters. Our analysis of the insulation coordination of ±800kV and ±1100kV UHVDC systems concluded that, in ±1100kV UHVDC systems, the main goal of insulation coordination is to lower the insulation level of points enduring the highest voltage. However, in a ±800kV UHVDC system, the main goal is to reduce the cost of manufacture for arresters, as well as the space occupation in the valve hall, with an acceptable insulation level.

• 전기학회논문지
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• 제57권10호
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• pp.1731-1737
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• 2008

This paper present the fundamental insulation characteristics of Dry Air gas and insulation coating in high voltage power apparatus. It is known that the dielectric strength. of Dry Air is approximately one-third that of SF6 gas. we attempt that the insulation coating and dry air gas have replaced the SF6 gas as insulation of the switchgear. We proposed the dry air insulated switchgear(DAIS) for High Voltage apparatus. To acquire technology of insulation characteristic improvement made standards for complex insulation structure and conducted simulations and experiments

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.194-197
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• 2001

Traction motors driven by high speed switching inverters is demanded higher operating temperature, severe duty cycles, higher starting current, frequent voltage transients and finally severe environmental exposure. For applications to inverter duty, traction motors needs a special insulation system, which has characteristics of increased bond strength, lower operating temperature and higher turn-to-turn insulation. In this paper, design considerations and manufacturing procedure of 200 Class insulation system with polyimde(Kapton) main insulation and silicone resin VPI process on the traction motor for EMU will be reviewed. And performance test and long life evaluation test which prove stability and long life evaluation test which prove stability and reliability of insulation system for traction motor will be introduced.

• 한국철도학회논문집
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• 제6권1호
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• pp.10-14
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• 2003

Since most of main noise sources of the railroad vehicle are transmitted to the passenger's ear through the vibration of the panel, the sound insulation performance of the panels should be high enough to protect the passenger's ear from the noisy environment. Specifically, the composite materials which are generally used for reducing the weight of the vehicle compartment have the low insulation performance, thus noise control actions should be taken appropriately by considering the insulation performance of the panels. In this study, the insulation performances of the inner/outer panels of the compartment are evaluated. In addition, the contribution of the insulation performance of aluminum door is estimated and compared to those of composite panels. The results can furnish an in-depth understanding of the insulation characteristics of the panel of railroad vehicle.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.163-166
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• 1998

In this paper, breakdown strength and dielectric characteristics were experimented in the structures of insulation/insulation/insulation and insulation/semiconductor/insulation by using of insulation material of polyethylene terephthalate film. The breakdown strength and the permitivity of each specimen were measured as a function of temperature and frequency respectively. The breakdown strength of PET/PET/PET did not changed greatly but that of PET/SEMl/PEr increased as a function of temperature. As the frequency inclosed, the permitivity of PET/PET/PET and PET/SEMI/PET decreased. The tan $\delta$ of PET/PET/PET showed lower than that of PET/SEMl/PET in low frequency but higher in high frequency .

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.335-339
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• 2001

The recent advancements in power electronic switching devices have enabled high frequency switching operation and have improved the performance of pulse-width modulated (PWM) inverters for driving induction motors. But, the insulation failures of stator winding have attracted much concern due to high dv/dt of IGBT PWM inverter. In this paper, the test results for evaluation on the stator winding insulation of low-voltage induction motors for IGBT PWM inverter applications are presented. The insulation characteristics are analyzed with partial discharge and dissipation factor tests. Also, insulation breakdown tests by switching pulse voltage are performed. An effective insulation technique to enhance the insulation strength is suggested from the test results.