• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.4
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• pp.146-154
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• 2003

This paper describes various characteristics of the new compounds for cable jackets and model cables advanced in waterproof performance in order to essentially solve the problems of underground (URD) distribution class power cable failures. Several compounds were manufactured by the inclusion of additives to base resins available in Korea and tested for basic property, mechanical and electrical characteristics. Two model cables were created by using the compounds determined in the test as being the most appropriate for new structured model cable jacket material. The waterproof performance and mechanical strength of the new cable jackets were verified by applicable tests. As a result, MDPE and LLDPE compounds were superior as cable jackets in both mechanical and electrical characteristic aspects when compared with conventional PVC. In addition, the model cables composed of the new compounds based on MDPE showed good quality results in the water permeability test.

• Nuclear Engineering and Technology
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• v.36 no.5
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• pp.475-484
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• 2004

Extending the lifetime of a nuclear power plant [(hereafter referred to simply as NPP)] is one of the most important concerns in the global nuclear industry. Cables are one of the long-life items that have not been considered for replacement during the design life of a NPP. To extend the cable life beyond the design life, it is first necessary to prove that the design life is too conservative compared with actual aging. Condition monitoring is useful means of evaluating the aging condition of cable. In order to simulate natural aging in a nuclear power plant. a study on accelerated aging must first be conducted. In this paper, evaluations of mechanical aging degradation for a neoprene cable jacket were performed after accelerated aging under tcontinuous and intermittent heating conditions. Contrary to general expectations, intermittent heating to the neoprene cable jacket showed low aging degradation, 50% break-elongation, and 60% indenter modulus, compared with continuous heating. With a plant maintenance period of 1 month after every 12 or 18 months operation, we can easily deduce that the life time of the cable jacket of neoprene can be extended much longer than extimated through the general EQ test. which adopts continuous accelerated aging for determining cable life. Therefore, a systematic approach that considers the actual environment conditions of the nuclear power plant is required for determining cable life.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.969-980
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• 2017

Purpose: The purpose of this study was to estimate the lifetime, and verify the target lifetime at steady state temperature, of communication cable jackets used in nuclear power plants. Method: This study was completed according to test and analysis methods required by international standards. After measuring the residual elongation(%) of specimens at specific points in time with the accelerated degradation test, average failure time of each temperature was computed. Thus, the activation energy could be derived by applying the temperature-Arrhenius law to estimate cable jacket lifetime at steady state temperature. Results: The cable jacket lifetime was estimated as 363.8 years assuming a normal nuclear power plant operating temperature of $90^{\circ}C$. Conclusion: To ascertain stable operating conditions for a nuclear power plant, accelerated degradation tests were performed according to the Arrhenius law for components of the nuclear power plants. The lifetime was estimated from the degradation data collected during the accelerated degradation test.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.596-602
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• 2020

Blending process of adhesive production has a cooling process to cool down the temperature of the solution which was heated up to 76 ℃ with a mineral insulated (MI) cable by 30 ℃ at room temperature. Using a MI cable in the adhesive production process makes the production inefficient because it takes about 10 h for the cooling process. If a jacketed vessel is used instead of the MI cable, it would shorten the cooling downtime without any additional cooling system by using cold water. However, there are various types of jacketed vessels, and thus the most suitable type should be found before set up. In this study, we designed the optimized jacketed vessel for the adhesive production process by calculating the cooling downtime, which impacts production efficiency, as a function of the jacket types using computational fluid dynamics. As a result, the cooling performance of the plain jacket was 32.7% superior to that of the half-pipe coil jacket with the same height. In addition, the plain jacket with 60% spiral baffle reduced the cooling downtime and operating time by 80.4% and 25.1%, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.3-6
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• 2004

In this paper, we studied on permissible current of unperfected earthing for cross-bond system. The factors of unperfected earth were jacket damage, cross-bonding mistake, arrestor damage, effect of other circuit but we only studied permissible current of arrestor or jacket damage. In the result, we earned that permissible current of normal 154[[kV]] CV $1C{\times}400SQMM$ cable is 760[A] but current of unperfected earthing cable is 76[A], unperfected earthing confirmed that accident of underground cable could occur. So, we could confirmed that Earthing resistance of unperfected earthing need to limit.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.12
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• pp.1115-1121
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• 2012

In this paper, the design of UTP LAN cable with enhanced alien crosstalk characteristic is proposed. Proposed LAN cable is made with jacket of the irregularly corrugation type. If necessary, it is possible to use the special cross-filler. The alien crosstalk characteristic is enhanced by using proposed cable with inner jacket of the irregularly corrugation type in wide frequency band. The design of the cable was based on parameters of the standard EIA/TIA 568-B.2-10.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.513-515
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• 1999

In this study, we evaluated the relation of the test and theory of low impedance cable As the result We could obtained the result in accordance the test with theory in 85 ~ 95% tolerance . Test method measured the relation of the current and temperature of cable jacket in using CT to put in 3 phase AC current simultationiously. The current and temperature of it was calculated in according to JCS- l68D

• Journal of the Korean Society of Safety
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• v.20 no.1 s.69
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• pp.1-6
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• 2005

Stick type ignition coil is new development that connect directly with ECU(Electronic control unit), without needing a spark plug cable and distributor. Glass-fiber reinforced ploymeric composites provide the desirable properties of high stiffness and strength as well as low specific weight. Stick type ignition coil jacket is using PBT CF30 resin. PBT CF30 resin is a kind of electric insulation which is a superior engineering plastic that is used to prevent the leakage of the electrical current. If PET receive a mistake of design or excessive force when HV terminal oppress on jacket, it can happen to crack. Local stress concentrations occurring on the contact surface, the contact phenomenon becomes a direct cause to the wear and failure of mechanical structures. When it is cracked, it can allow a leakage of the electrical current. So, in this study, we analyze the contact stress to PBT jacket using ANSYS program, when HV terminal oppress on jacket. We suppose PBT to be Jacket and we analyzed contact stress that happens in PET like PBT analysis method. We compared the use of PBT and PET.

• Journal of Ocean Engineering and Technology
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• v.38 no.2
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• pp.74-85
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• 2024

Offshore wind turbines are supported by various foundations, each with its considerations in design and construction. Gravity, monopile, and suction bucket foundations encounter geotechnical issues, while jacket and tripod foundations face fatigue problems. Considering this, a gravity foundation based on a steel skirt was developed, and a monopile foundation was analyzed for Pile-Soil Interaction using the p-y curve and 3D finite element method (3D FEM). In addition, for suction bucket foundations, the effects of lateral and vertical loads were analyzed using 3D FEM and centrifuge tests. Fatigue analysis for jacket and tripod foundations was conducted using a hotspot stress approach. Some hybrid foundations and shape optimization techniques that change the shape to complement the problems of each foundation described above were assessed. Hybrid foundations could increase lateral resistance compared to existing foundations because of the combined appendages, and optimization techniques could reduce costs by maximizing the efficiency of the structure or by reducing costs and weight. This paper presents the characteristics and research directions of the foundation through various studies on the foundation. In addition, the optimal design method is presented by explaining the problems of the foundation and suggesting ways to supplement them.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.251-254
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• 2001

Internal and external forces may be applied on the power cable in the both process of transportation and installation. Even though the EHV power cables have the structure of metal sheath and plastic jacket etc. to minimize these negative influences, the unusual forces result in the unexpected deformation of the cable. Compressing moulded XLPE model cable sheets were prepared and locally dented with round-edge and square-edge tools. All data were analyzed employing Weibull distribution. The breakdown strength of dented molded specimens showed lower values than the normal ones by 10-60%.