An alternative technique to obtain the ABCD matrices of the transmission lines: application in the representation of the transmission lines in electromagnetic transient simulations

Abstract

This project will be developed a methodology for obtaining ABCD matrices of transmission lines. These matrices will be used as a transmission line model to represent the line in simulations of the electromagnetic transients in electric power systems. The proposal of the project is to find the elements of the ABCD matrix of the line starting from its frequency response which will be obtained from classical models used to represent transmission lines in electromagnetic transient conditions. In order to obtain the ABCD matrix will be necessary to perform simulations considering several configurations of the sending and receiving ends of the line. The number of configurations is a function of the number of phases of the line and therefore, initially, it will be is necessary to define a relationship among the number of the phases of the line and the number of the configurations of the line. The main advantage of the proposed method is that it can be applied to represent a generic transmission line, whereas the methods available in the literature are restricted to two-phase lines and three-phase lines with a vertical symmetry plane. The representation of the transmission lines by its ABCD matrix will result in a model developed directly in the phase domain, which takes into account the distributed nature of the line parameters and the effect of the frequency on the longitudinal parameters. Because the ABCD matrix will be a line model directly in the time domain it will be easily inserted in the software packages used in electromagnetic transient simulations (such as EMTP and ATP). The proposed technique for obtaining transmission line models will result in a reliable and efficient option to represent transmission lines in electromagnetic transient studies in electric power systems. (AU)