Ingeniare. Revista chilena de ingeniería
On-line version ISSN 0718-3305
MACRI, M.G and BENEDETTI, M. Triphasic induction motor multiresolution analysis on voltage sags. Ingeniare. Rev. chil. ing. [online]. 2012, vol.20, n.1, pp.66-78. ISSN 0718-3305. http://dx.doi.org/10.4067/S0718-33052012000100007.
This document presents the study results of the wavelet 1D multi-level decomposition of perturbed electromagnetic torque and shaft speed signals, of the three-phase induction motor, when it is subjected to different types of voltage sags, as characterization ABC, Bollen (2000). The three-phase voltage sags (3 variables) are analyzed in the effect on a perturbed variable (the electromagnetic torque and mechanical speed) that contains indirect information from the voltage sag occurred in the stator. The study examines seven different types of voltage sags, also considering the influence of duration and retained voltage. For each case, a vector whose elements are the energy levels at different wavelet decomposition levels of the analyzed variable is obtained, showing that the way 1D signal energy is distributed at different levels of decomposition set a unique signature for each case. Thisform of description of the voltage sags, produced in the stator, based on the multi-level decomposition, reduces the amount of variables to be analyzed and subsequently allows the classification of the disturbances using artificial intelligence techniques; storage is advantageous because the vectors of energy levels of approximation in databases used less amount of space required for a temporary signal, and employing a reversible DWT, it's also possible to reconstruct the state variable.
Keywords : Power quality; voltage sags; wavelet analysis; electric machines; AC motors.