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一、交联聚乙烯绝缘电力电缆简介
A brief introduction to XLPE insulated power cable
交联电缆是用化学方法(过氧化物交联或硅烷交联) 或物理方法 (辐照交联) 使绝缘中的聚乙烯分子由线型分子结构转变为空间的网状结构，即把热塑性的聚乙烯变为热固性的交联聚乙烯，从而大幅度地提高了电缆的机械性能、耐热老化、化学腐蚀和耐环境应力能力的特性。交联电缆具有结构简单、外径小、重量轻、使用方便、不受敷设落差的限制和运行维护简便等优点，加之其优良的电气性能，使其成为最有发展前途的电力电缆。
In manufacturing XLPE cables, either the chemical process (peroxide of silane cross-linking) or physical process (irradiation cross-linking) may be employed to transform the molecular structure of PE from linear chain into three-dimensional network，i.e. to change the thermoplastic PE into thermosetting XLPE．After cross-linking，the gear, ageing，corrosion and environment resisting character as well as the mechanical physical properties of cable are thus greatly improved．XLPE cables possess the advantages of simple structure, small overall diameter, light weight and easy employment. They can be installed without limitation of level difference．With excellent electrical properties, XLPE cables have become the power cables that have the greatest potentiality for future development．
二、交联电缆的型号及主要用途 (见表1-1)
XLPE Cable's Type and Main Application (Table 1-1)
三、交联电缆额定电压等级、芯数、截面范围表 (见表 2-2)
Rated voltages，number of cores and cross-section of XLPE Cables (Table 2-2)
额定电压属第二类的电缆，适用于接地故障时间一般不超过2小时，最长不超过8小时的场合。 |
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The cables of the 1st class are suitable for earth fault time not exceeding 1 minute. The cables of the 2nd class are suitable for earth fault time not exceeding 2 hours generally, maximum 8 hours．
四、电缆主要技术指标
Main technical characteristics
A．直流电阻：成品电缆导电线芯的电阻在20℃时每公里的数值不大于下表规定。(见表3-3)
D．C．Resistance：Conductor resistance of finished cable at 20℃ per kilometer is not more than the following values (Table 3-3)
B和C. 电压试验及局部放电试验 (见表4-4)
B and C. Voltage Test and Partial Discharge Test (Table 4-4)
五、电缆运行状态及参数
Service conditions and parameters of cable
导线最高工作温度90℃
Max conductor operating temperature：90℃
短路温度250V持续时间最长不超过2秒
Short circuit temperature：250℃, lasting for max 2 sec．
敷设环境温度
Ambient temperature of for cable installation：
空气中25℃
25℃ in air
土壤中15℃
15℃ under ground45%
直埋敷设深度500-700mm
Depth of direct burial：500-700mm
土壤热阻系数350℃.cm/W
Coefficient of thermal resistivity of soil：350℃.cm/w
聚氯乙烯热阻系数700℃.cm/W
Coefficient of thermal resistivity of PVC：700℃.cm/W |
