Finite Element Analysis of Self-Excited Induction Generator for Isolated Small Power Wind Turbines

This paper deals with the field-circuit type finite element analysis of the dynamic regimes of the three-phase squirrel cage induction generator used in the isolated small power wind conversion systems. The numerical analysis of the squirrel cage induction generator using circuit models may lead to inaccurate results due to the usual simplifying hypotheses. This paper proposes a field-circuit model of the machine that is much more elaborated, being able to successfully take into account the complex specific phenomena such as: magnetic saturation, skin effect in the rotor bars, teeth harmonics etc. Among the dynamic regimes specific to the operation of the induction generator integrated in the isolated wind conversion systems, this paper is focused on the following aspects: self excitation phenomenon in case of open-circuit, three-phase short-circuit and dynamic response of the generator in case of load variations.