Analysis of the Behavior of the 3rd Harmonic over Power Transmission Lines

Due to a large use of power electronics devices, the power grid has experienced increasing harmonic pollution that has started to interfere in the performance of power transmission lines. For correctly evaluating how this interference can be, analytical modelling of transmission lines can play a very important role for serving as an alternative to computer tools. This is what is shown in this work for the 3^rd power harmonic, based on a methodology developed by the authors that have already proofed as being satisfactory for the power frequency and for the 5^th power harmonic. For better illustrating the application of the developed methodology, some key representative cases are presented as happening in a practical 230 kV power transmission line.