Sampling Rate Impact on Estimation of Untransposed Transmission Line Parameters Based on Fault Records

This paper highlights the sampling rate impact over an estimation method based on modal analysis techniques applied on untransposed three-phase transmission line. The analysed method represents a transmission system in the modal domain as three independent propagation modes that are modelled as three single-phase transmission lines using a suitable π equivalent. The estimation procedure is carried out in the modal domain, without the explicit modelling of the phase mutual parameters, which means a significant simplification on the calculation process using the least-square solution method. Since the modal parameters are identified, the self- and mutual parameters can be calculated using the same modal transformation matrix during the line decoupling. The method estimation accuracy is evaluated for a range of sampling rate associated with the relays records. © 2018, Brazilian Society for Automatics--SBA.