• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.303-305
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• 2000

Many standards have published for calculating the ampacity of bare overhead conductors. Although these standards use the same basic heat balance concept, they use different approaches to calculate ampacity ratings. This paper looks at the different approaches used to calculate individual heat balance terms, at the overall impact of these terms on the ampacity rating. And this paper is proposed to the selection of proper standard and atmospheric conditions for calculating the ampacity of bare overhead conductors.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1136-1149
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• 2018

With the increasing of urban electricity demand, making the most use of the power cable carrying capacity has become an important task in power grid system. Contrary to the rated ampacity obtained under extremely conservative conditions, this paper presents the various steady value of cable ampacity by using the changing surrounding parameters under operation, which is based on cable ampacity calculation equation under the IEC-60287 standard. To some degree, the cable ampacity analysis of actual surroundings improves the transmission capacity of cables. This paper reveals the factors that influence cable ampacity such as insulating layer thickness, allowable long-term conductor temperature, the ambient temperature, soil thermal resistance coefficient, and so on, then gives the class of the influence of these parameters on the ampacity, which plays a great role in accurately calculating the real-time ampacity and improving the utilization rate of cable in the complex external environment condition. Furthermore, the transient thermal rating of the cable is analyzed in this paper, and temperature variation of the conductor under different overload conditions is discussed, which provides effective information for the operation and control of the system.

• Journal of Information Processing Systems
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• 제13권5호
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• pp.1358-1371
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• 2017

Dynamic thermal rating (DTR) system is an effective method to improve the capacity of existing overhead line. According to the methodology based on CIGRE (International Council on Large Electric systems) standard, ampacity values under steady-state heating balance can be calculated from ambient environmental conditions. In this study, simulation analysis of relations between parameters and ampacity is described as functional dependence, which can provide an effective basis for the design and research of overhead transmission lines. The simulation of ampacity variation in different rating scales is described in this paper, which are determined from real-time meteorological data and conductor state parameters. To test the performance of DTR in different rating scales, capacity improvement and risk level are presented. And the experimental results show that the capacity of transmission line by using DTR has significant improvement, with low probability of risk. The information of this study has an important reference value to the operation management of power grid.

• Journal of Electrical Engineering and Technology
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• 제7권3호
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• pp.384-388
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• 2012

Finite Volume Method (FVM) is chosen to calculate the heat transfer field and the heat generation with in the cable and heat dissipation in the surrounding soil of a three phase 145kV underground cable brunch that make it possible to analyze the ampacity of the cable. FLUENT as the proper software in this field is used to generate and solve the problem. Non-homogenous environment is considered for cable ampacity calculation and results are compare with homogenous environment condition.

• 조명전기설비학회논문지
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• 제30권2호
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• pp.57-64
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• 2016

Power demand has continuously increased with technological and economical development. The load density is also growing in the center of downtown area. In particular, underground facilities have been increased on the purpose of the prevention of urban disasters and pedestrian environment improvement. Based on this situation, the underground space in urban surroundings has gradually decreased because of the limited space. The ampacity of buried cables is affected by various factors such as cable size, soil thermal resistance, burial depth and filling material. The thermal capacity of the facilities is determined by the absorb heat surrounding the cable and the soil. The maximum operating temperature of cable is the highest temperature when the insulator of cable is not damaged in the case of high enough temperature. In this paper, the most effective cabling configuration is suggested using the duct array adjustment. It was also considered to increase the number of cable line. This underground distribution system was simulated by using ETAP(Electrical Transient Analysis Program).

• 대한전기학회논문지:전력기술부문A
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• 제52권7호
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• pp.414-420
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• 2003

The domestic needs for larger capability of power sources are increasing to cope with the expanding power load which results from the industrial developments & the progressed life style. In summer, the peak load is mainly due to the non-industrial reasons such as air-conditioners and other cooling equipments. To cover the concentrated peak load in stable, the power transmission lines should be more constructed and efficiently operated. The ampacity design of the underground cable system is generally following international standards such as IEC287, IEC60853 and JCS168 which regards the shape of 100% daily full power loads. It is not so efficient to neglect the real shapes of load curves generally below 60~70% of full load. The dynamic (real time) rating system tends to be used with the measured thermal parameters which make it possible to calculate the maximum ampacity within required periods. In this paper, the CTM(Conductor Temperature Monitoring) which is the base of dynamic rating systems for tunnel environment is proposed by a design of lumped thermal network ($\pi$-type thermal model) and distribution temperature sensor attached configuration, including the estimation results of its performances by load cycle test on 345kV single phase XLPE cable.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.349-354
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• 2002

A size of low-voltage conductor cables is determined by the voltage drop of a system, the cable impedance and the cable ampacity based on temperature correction factor in accordance with the condition of cable installation. Therefore, the proper temperature correction factor according to the condition of cable installation should be applied to determining the cable ampacity and also the skin effect and proximity effect, along with the kind and size of conductor and the condition of cable installation, should be properly considered to analyze the proper value of resistance and the reactance of the conductors. This paper addresses the systematic design flow for determining the size of low voltage level conductor cables in calculating the temperature character where error should be minimized in comparison with the general formula and which can be applied in design work for determining the size of conductor cables.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.274-275
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• 2006

The IEEE std 738 and Cigre Electra documents are well known as the standard of calculating the ampacity of overhead conductors. Although these two standards use the same basic heat balance concept, they use different applicable methods to calculate ampacity ratings. This paper examines the concept of basic heat balance equation and the differences of each term of basic heat balance equation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.272-273
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• 2006

Recently KS standards being kept in step with IEC standard in electrical safety. This paper examines thermal parameters of KS C IEC 60364-5-523(2002) to calculating the ampacity of insulated cable at 1kV below.

• KEPCO Journal on Electric Power and Energy
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• 제2권3호
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• pp.383-389
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• 2016

국내 154 kV 복도체 가공송전선로를 대상으로 전자력에 의한 소도체간 접촉현상을 실증적으로 재현하고 대처 방안을 제시하였다. 도체에 흐르는 전류의 크기가 클수록, 스페이서의 간격이 클수록 소도체간에 작용하는 전자력은 크게 측정되었다. 스페이서 간격이 68 m일 경우 전류 크기가 2,000 A 일 때부터 소도체는 불안정한 상태가 되어 소도체간 간격이 변화하는 횡방향 진동이 시작되었다. 스페이서 간격이 136 m일 경우 전류 크기가 증가할수록 소도체간 간격은 좁아지다가 2,250 A 일 때 두 소도체는 완전히 접촉하였다. 스페이서 간격에 따른 전자력의 크기를 도식화하고 안전한 스페이서 간격을 제시하였다. 시험선로와 실선로 간에는 접촉현상이 발생하는 조건이 상이한 것으로 나타났으며, 이는 송전선로 가선 과정에서 도체에 가해진 여러 형태의 잔류 응력, 바람 조건 등의 차이 때문으로 판단되었다.