| The temperature of power cable is an important basis to judge the reliability,safety and capacity increase of power cable.The environment of cable laying is complicated,and the traditional calculation methods can no longer meet the needs of daily management in terms of calculation speed and accuracy.Therefore,it is urgent to find an algorithm that can meet the requirements of both speed and precision.According to the characteristics of the cable load,we studied the steady state thermal field and transient state thermal field of buried power cables and provided a heat transfer matrix to calculate the steady state temperature rise of buried power cables and a transient thermal circuit model based on time-response of thermal field to calculate the transient temperature rise of buried power cables.The cable temperature obtained by the finite element methods(FEM)was taken as the control group data to verify the effectiveness of the method.The specific research of this article includes:1)The steady-state temperature rise and transient temperature rise of the power cable are modeled and calculated by the FEM.The steady-state temperature field distribution and the transient temperature rise curve of the power cable are obtained respectively as the data basis for the study of fast algorithms.2)Based on the thermal resistance of transfer matrix method of power cable,each cable from the thermal resistance and heat resistance,and considering the environment temperature,cable buried depth,soil thermal resistance coefficient and the distance between cable and other factors on the cable and transition matrix elements,the influence of temperature was given power cable core analytic formula of steady state temperature rise fast algorithm.3)Proposed a transient thermal path model on the basis of the principle of time domain response,the cable group of dispersed into the sum of many cable.Put a single function superposition,respectively with the genetic algorithm of model parameters extracted from response model through the cable node coupling method to calculate the integrated temperature rise of cables,so as to realize the fast calculation of the transient temperature rise.4)The fast algorithm is used to simulate the working conditions of the cables which are in steady state operation,intermittent operation and periodic operation in the actual power load.The calculation results are compared with the finite element calculation results to verify the feasibility.The fast calculation method of steady-state temperature rise and transient temperature rise of power cable cores proposed in the article has great advantages in calculation speed,and provides convenience for the daily management of loads in the power sector. |
PDF Full Text Request