CAJ | 학술논문

为更好地对电缆线芯温度进行间接测量，提出一种以电缆运行电流和表皮温度为输入的线芯温度动态计算方法。首先建立了电缆传热的简化热路模型，并在误差敏感性分析的基础上引入了线芯电阻随温度变化的二阶修正；然后对模型表征的微分方程进行离散化，得到仅有4个模型参数的计算公式；最后以电缆实验(或运行)数据为样本构造学习矩阵，并通过矩阵的广义逆计算模型参数，代入公式完成整个动态计算方法的构建。分别以室内实验电缆、在线110 kV高压电缆为对象进行了实验与分析，结果表明，相较于传统方法，该方法能够更加简单、准确地计算电缆线芯温度，有助于实现电力电缆工况的实时监测。
위경호지대전람선심온도진행간접측량，제출일충이전람운행전류화표피온도위수입적선심온도동태계산방법。수선건립료전람전열적간화열로모형，병재오차민감성분석적기출상인입료선심전조수온도변화적이계수정；연후대모형표정적미분방정진행리산화，득도부유4개모형삼수적계산공식；최후이전람실험(혹운행)수거위양본구조학습구진，병통과구진적엄의역계산모형삼수，대입공식완성정개동태계산방법적구건。분별이실내실험전람、재선110 kV고압전람위대상진행료실험여분석，결과표명，상교우전통방법，해방법능구경가간단、준학지계산전람선심온도，유조우실현전력전람공황적실시감측。
To implement indirect measurement of cable core temperature better, a dynamic calculation method, which takes cable’s operating current and surface temperature as inputs, to compute core temperature is proposed. Firstly, traditional thermal circuit model of cable heat transfer is highly simplified, and on the basis of error sensitivity analysis a two-order correction of cable core resistance varying with temperature is led in; secondly, the differential equation characterized by the simplified model is discretized to obtain the calculation formula with only 4 model parameters; finally, taking the experimental or operating data of cable as samples a learning matrix is constructed, and then the four parameters are estimated via generalized inverse of the learning matrix and the estimated values for model parameters are substituted into the calculation formula, thus the establishment of the whole dynamic calculation method is completed. Taking the cable for indoor experiment and the online 110kV high voltage cable as objects respectively, the experiments and analysis are performed and the results show that using the proposed method the cable core temperature can be calculated more simply and accurately, and it contributes to implement the real-time monitoring of operating conditions of the power cable.