Numerical Simulation And Analysis Of Temperature Field Of Overhead Conductors

The temperature limit of overhead conductors is important in the transmission line sag, the dynamic capacity-increase technology and the thermal melting ice technology of iced conductor.In order to control the distribution of the radial temperature distribution of the overhead conductors, a theoretical analysis method and the finite element numerical simulation method are used to analyze the radial temperature field of the steel core aluminum wire.Firstly, the current density distribution of each layer in the overhead conductors is derived by considering the skin effect of the alternating current.Based on the relationship of the dynamic thermal equilibrium in the air, the surface temperature of the conductor is iterative calculated, and the internal temperature of the conductor is calculated by the contact heat transfer coefficient.A finite element model for the analysis of the two dimensional temperature field of steel core aluminum strand is established, and the distribution law of temperature field inside the steel core aluminum wire is calculated accurately.The numerical results of the theoretical analysis and the numerical results are compared with the results of the finite element method, and the influence of various environmental parameters and factors on the internal temperature field is discussed.Analysis results show that:(1)Conductor temperature increases with the decrease of wind speed, the increase of ambient temperature, and the increase of sunshine intensity.In the larger wind speed, low temperature environment, the maximum allowable current of the transmission line can be improved.(2)The internal maximum temperature occurs in the inner layer of them contact with the least of other strands,the internal temperature decreases with the increase of the contact area and the contact number with other strands,so the maximum allowable current value can be improved by using the conductor which have large contact area and small pore in wire strands.(3)The conductor temperature increases with the increase of the current rate, and the rate is increasing rapidly, and the maximum temperature difference is increasing,so there is a large error in the use of the surface temperature which is used to measure the surface temperature in a high current,method of monitoring the internal temperature of the wire should be sought.