Dynamic line rating current calculation without ambient parameters inputs

摘要

Dynamic line rating current is widely used in the smart grid for improving the efficiency and economy of the power transmission and distribution. The rating current is determined by the ambient parameters such as convection heat loss rate, solar radiation, wind power, wind direction, etc. This paper proposes a method for calculating dynamic rating current only by means of the measurement of voltage and current of the two ends of the line free from any ambient parameter inputs. The instantaneous temperature can be estimated by calculating the variation of the line parameters, and subsequently the steady state conductor temperature can be obtained. The rating current is calculated by curve fitting of the dissipating power curve based on the steady state conductor temperature obtained and the conductor current. The scientific model of this technique, which is implementable into products, is constructed using Matlab/Simulink. Simulation tests show that the calculated dynamic line rating current is reliable and accurate.