A transmission line model with non-uniformly distributed line impedance

This paper discusses an extension of the conventional single-phase transmission line model with uniformly distributed parameters. The derived model can additionally account for non-uniformities of line impedance along the transmission line which may be due to non-uniformities in external conditions along the line (e.g. wind) affecting electrical parameters. In order to provide understanding of the resulting equations, the model derivation is briefly described. The results are validated by mathematical proof against the case of uniformly distributed line impedance. As the results are available in a non-closed form solution, a possible procedure of application is proposed. The equations are applied to study cases with non-uniform line impedance caused by conductor temperature gradients along the line, demonstrating the impact of considering parameter non-uniformities.