5X00622G01 导线的截面选择

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5X00622G01 导线的截面选择

确定线路设计的气象条件。对于在大气中运行的架空线路机械计算来说，气温、风速和履冰厚度三种气象因素为重要。因此，应根据当地的有关气象资料和当地已有线路的运行经验进行综合考虑。根据广东省梅州市气象资料：（1）大风速不大于25m/s，温度为-5℃；（2）履冰厚度不大于5mm，温度为-5℃；（3）高温度不+40℃（4）低温度不低于-40℃。上述资料可以确定：10kV配电线路选用LGJ型钢芯铝绞线，0.4kV配电线路采用架空绝缘电线，即铝芯塑料线（BLV）型。   4.2导线的截面选择。一般是按允许电压损耗确定，同时满足发热条件和机械强度的要求。还应根据负荷情况留有发展的裕度。但为了确保线路运行质量和安全，要求10kV线路及0.4kV主干线路截面不小于35mm2，三相四线的零线截面积不宜小于相线截面的50％，其余0.4kV分支线、接户线均按实际用电设备容量具体确定。 [b]5 导线弧垂及排列方式的选择 [/b]  5.1 导线弧垂的确定。导线的弧垂与导线的截面、气象条件和电杆的档距有关。根据气象条件和运行经验，可通过查计算出不同档距、不同温度时的导线弧垂表。

5X00622G01 导线的截面选择

Determine meteorological conditions for route design. For the mechanical calculation of overhead lines operating in the atmosphere, three meteorological factors, temperature, wind speed and ice thickness, are important. Therefore, comprehensive consideration should be made according to the relevant local meteorological data and the operation experience of the existing local lines. According to the meteorological data of Meizhou City, Guangdong Province: (1) the wind speed is not more than 25m/s, and the temperature is -5℃; (2) The ice thickness is not more than 5mm, and the temperature is -5℃; (3) The high temperature is not +40℃ (4) the low temperature is not less than -40℃. The above information can be determined: 10kV distribution line uses LGJ steel core aluminum stranded wire, 0.4kV distribution line uses overhead insulated wire, that is, aluminum core plastic wire (BLV) type. 4.2 Selection of cross section of wire. It is generally determined according to the allowable voltage loss, while meeting the requirements of heating conditions and mechanical strength. There should also be a margin for development according to the load situation. However, in order to ensure the quality and safety of the line operation, the cross-section of the 10kV line and 0.4kV trunk line is required to be not less than 35mm2, the neutral line cross-sectional area of the three-phase four-wire should not be less than 50% of the phase line cross-section, and the remaining 0.4kV branch line and access line are determined according to the actual capacity of electrical equipment. [b]5 Choice of wire sag and arrangement [/b] 5.1 Determination of wire sag. The sag of the wire is related to the cross section of the wire, weather conditions and the spacing of the pole. According to the weather conditions and operating experience, the traverse sag table can be calculated at different intervals and temperatures.