Nonlinear effects due to electromechanical interaction in generators with smooth poles

Abstract Electromechanical interaction in rotating machinery is an interesting nonlinear phenomenon. The methods used to analyze this phenomenon depend on the type of the electrical machine, synchronous or asynchronous, and on its size, but they are often related to the study of the unbalanced magnetic pull (UMP). In this paper the nonlinear behavior of generators with smooth poles of high-speed turbogenerators is presented during and after the excitation of the magnetic field in the air-gap in order to fully exploit the effect of the UMP. In the first part of the paper a method, which allows the simulation of the dynamical behavior of a flexible rotor caused by the UMP, is presented. In the second part, the simulation of a magnetic field excitation transient in a turbogenerator is presented and the nonlinear aspects in the system response and forcing are highlighted.