CAJ | 학술논문

在人口稠密的大城市,电力通常通过直埋电力电缆集群来传输.电缆载流量是电缆设计和运行中的一个重要参数.IEC 60287标准给出了单一媒质即均匀土壤中电缆群稳态载流量的计算方法,并给出了有回填土的非单一媒质中电缆群的载流量修正计算方法.为给电缆工程的设计与运行提供科学依据,采用基于场路结合的有限差分法,提出了非单一媒质中电缆群的载流量数值计算方法,深入研究了不均匀土壤中的电缆载流量及其影响因素.计算结果表明,IEC外部热阻修正计算方法的计算精度与回填土热阻系数有关.回填土热阻系数较大时,IEC计算载流量显著偏低.
재인구주밀적대성시,전력통상통과직매전력전람집군래전수.전람재류량시전람설계화운행중적일개중요삼수.IEC 60287표준급출료단일매질즉균균토양중전람군은태재류량적계산방법,병급출료유회전토적비단일매질중전람군적재류량수정계산방법.위급전람공정적설계여운행제공과학의거,채용기우장로결합적유한차분법,제출료비단일매질중전람군적재류량수치계산방법,심입연구료불균균토양중적전람재류량급기영향인소.계산결과표명,IEC외부열조수정계산방법적계산정도여회전토열조계수유관.회전토열조계수교대시,IEC계산재류량현저편저.
International Electrotechnical Commission (IEC) methods for calculating cable ampacity assume that bur-ied cables are surrounded by a single, homogeneous material.These ampacity methods have limited application when a thermal backfill is used.IEC correction methods are presented to calculate cables' ampacity of non-homogeneous soil.Based on the finite difference method of field-circuit coupling theory, a new numerical calculation method of ca-ble ampacity of non-homogeneous soil is presented.The numerical calculation method which is accomplished through the calculation of cable temperature field distribution can deal with any combination of backfill materials that are placed adjacent to the cable.The calculated results show that IEC thermal resistance correction methods can be ef-fectively used to calculate amapcity when the thermal resistivity of the backfill soil is lower.When the thermal resis-tivity of the backfill soil is higher, IEC calculating ampacities of correction methods are obviously lower.