智能配电系统电缆导体温度推算与应急能力评估

摘要

在电缆暂态热路模型的基础上,运用连续系统离散化处理方法,建立一种电缆导体温度实时推算方法:依据输入的负荷电流和电缆外表面温度数据,实时推算电缆导体温度.给出了一种载流量动态应急评估方法:将阶跃电流作用下的电缆暂态温升分为稳态部分和4个热时间常数不等的暂态分量.利用数据拟合的方法确定各温升暂态分量的参数,得到阶跃温升表达式.依据该表达式即可进行电缆线路应急能力评估,即评估不同情况下导体温度达到稳定限额所需的应急时间.通过实验验证了所提方法的准确性和可行性,并进行了简单的定量和误差分析.%Based on the transient thermal circuit model of power cable and by the dispersed processing of continuous system,a real-time method is proposed to calculate the power cable conductor temperature according to its load current and outside surface temperature.A dynamic ampacity assessment method is also given,which divide the transient temperature rise caused by the step current into the steady state component and four transient components with different time constants.Data fitting is applied to obtain the parameters of transient components and a step temperature rise expression is thus achieved,based on which,the emergency capability of power cable line can be assessed,i.e,the time required to reach the stable limit of temperature rise under different conditions.The feasibility and accuracy of the proposed methods are verified by experiments,and simple quantitative analysis and error analysis are also carried out.