This project proposes the development of an estimation method for the transmission line parameters based on the phase current and voltage measurements at the sending and receiving ends in fault situations. Considering that a small three-phase line can be represented by a lumped element (denominated three-phase À circuit), the total three-phase line length can be represented by two or more three-phase À circuits connected in cascade. From the current and voltage measurements at the line terminals, and representing the line by a cascade with two or more À circuits, the equations associated with the currents and voltages of the line as a function of the longitudinal and transversal parameters can be obtained. From these equations, a system is obtained with number of variables (line parameters) minor than the number of equations, where the solution can be obtained by a proper solution methodology. The proposed method can be used for estimation of asymmetrical transmission lines parameters with short, medium and long lengths. Thus, a major accuracy is expected in the parameters estimation of three-phase lines. Considering that most of the system operations, short-circuit evaluations, faults and settings of the protection system are dependent of the line parameters, the procedures proposed in this research can significantly improve the reliability and general performance of electrical systems.
News published in Agência FAPESP Newsletter about the scholarship: