Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Identification of Modals Parameters of Transmission Line Cable
Submission Author:
Mayara Calado , PR
Co-Authors:
Nilson Barbieri, Gabriel de Sant' Anna Vitor Barbieri, Marcos José Mannala, Mayara Calado
Presenter: Mayara Calado
doi://10.26678/ABCM.COBEM2017.COB17-1952
Abstract
The dynamics of electric transmission lines cables are induced by the action of the wind. Cyclic stresses not only lead to failure of the cables, but also of the structures and accessories installed on the lines. This way, it is important to analyse the dynamic behaviour of the system. Dynamic and structural test using three different cables: Greeley, Phosphorus and Tern with 54 meters span were conducted in an automatic testing bench using an impact hammer for system excitation and five accelerometers for obtaining the vibration data. At the same time, mathematical models obtained by the Finite Element Method were used to obtain corresponding numerical modal data. The modal parameters were identified using modal analysis and the Rational Fraction Polynomial method (RFPM) and were compared with numeric data obtained with linear and nonlinear mathematical models. The results showed that the linear model presents errors mainly when the cable span is large and with low mechanical traction (errors in the order of 20%), where the catenary is the large. The nonlinear model shows a better agreement between numerical and experimental results (errors in the order of 2.5%) for the entire range of mechanical traction variation used and for the three cable types. Best damping factor results were obtained by tuning the response individually for each vibration mode.
Keywords
Transmission line drivers, Self-damping, modal analysis, FEM, nonlinear model
