基于BP网络预测的地埋电力电缆动态增容

Dynamic capacity-increase of buried cable based on BP network forecasting

为挖掘现行电缆输送容量,可根据需要在一定范围内动态增加运行电缆的实际输送容量。根据电缆温升特性以及电缆导体最高允许温度(90℃),利用BP神经网络建立预测模型并结合插值计算,最终实现地埋电缆的动态增容。通过66 kV交联聚乙烯单芯电力电缆暂态温升试验结果表明:未满额运行的电缆增容至满负荷(额定容量)时,缆芯稳态温度为81.5℃,低于电缆设计满负荷时,最高允许温度为90℃;增容至过负荷,以120%额定容量运行时,缆芯最高温度达到100.47℃,但是若增容后运行时间不超过可安全运行最大时间23 h,其缆芯温度不会超过90℃。建立的预测模型并结合插值计算可以给出地埋电缆允许的增容值,并满足预测精度要求。

In order to dig the cable transmission capacity, the practical transmission capacity should be increased dynamically within certain range according to requirements. On the basis of the characteristic of cable temperature rise and the highest permitted temperature （90 ℃ ） of cable conductor, BP neural network forecasting is adopted to establish forecasting model, together with interpolation calculation, dynamic capacity-increase of buried cable being realized. Through the transient temperature rise test of 66 kV single-core XLPE cables, it is proved that the stable temperature of cable core reaches to 81.5 ℃ when the cable capacity increases to full load （ rated capacity） ; the highest permitted temperature is 90 ℃ when the load is below designed full load; the temperature reaches to 100. 47 ℃ when the cable runs under over Ioad,120% of rated capacity; the temperature will be under 90 ℃, if running time is within 23 h, the longest safe running time, after capacity increase. In other words, the established forecasting model with interpolation calculation is able to work out the permitted capacity increase for buried cable, which meets the requirement of forecasting accuracy.