An approach for modeling frequency-dependent apparent resistance of power transmission lines

A novel approach for modeling frequency-dependent impedance of a power transmission line is introduced and an analytical equation is derived. This paper focuses on the real part of this frequency-dependent impedance, which is referred to as apparent resistance; the imaginary part can then be treated in a similar manner. The apparent resistance is expressed in terms of frequency and line length, assuming all other influencing variables to be constant. Various numerical approximation techniques, which implement least square methods are applied to obtain a final approximated expression for this apparent resistance. Computational time and error between the analytical equation and the simplified approximated equation are compared. Results have shown that during the run of the digital simulation, the proposed equation is executed much faster than the analytical equations.