Application of a combined electro-thermal overhead line model in power flow and time-domain power system simulations

摘要

This study presents a combined electro-thermal overhead line (OHL) model for power flow and time-domain power system simulations. It originally enables the combined dynamic simulation of thermal as well as electrical characteristics of OHLs. The thermal behaviour of OHLs is replicated according to IEEE Std.738-2012 considering time-varying weather variables and is incorporated as controllable resistance into a traditional electrical OHL model. Therewith, simulating the dynamic influence of conductor temperatures on electrical quantities is enabled. The impact of the electro-thermal OHL model is evaluated based on the analysis of bus voltages, line currents, losses, reactive power flows, cumulated generation and consumption in a small radial as well as in a meshed power system. Therefore, a method for estimating line lengths from given system data and a process for the calculation of mutually depending initial line conductor temperatures for power flow and time-domain simulations is presented. The results show high deviations in active power line losses (up to 33.34%) and reactive power flows (up to 11.43%) compared with the traditional electrical OHL modelling approach. Thus, the relevance for considering electro-thermal line models in power system simulations with special emphasis on the assessment of line losses and reactive power flows is demonstrated.