The present paper describes a novelty approach to detect structural changes in the generating units of Itaipu power plant. The methodology is based solely on output time series measured in the rotating electric machine. The method deals with the application of time-series analysis through auto-regressive moving average models (ARMA) and statistical modeling for the linear prediction of damage diagnosis. In order to illustrate the procedure proposed is employed a simplified mathematical model regarding shaft radial vibrations in the generating unit 18A of Itaipu power plant. Several parameters variations are imposed in the system to simulate real damages conditions in the electrical machine. The approach is also evaluated with experimental data. The efficacy, advantages and drawbacks of the proposed method are demonstrated through these numerical and experimental tests.

**Setki tysięcy abstraktów z prac naukowych, które ukazały się w okresie styczeń 2014 r. - 5 października 2014 r. i wiele więcej.**