This article describes some fundamentals about the stability of a power system with asynchronous wind generators. In a well-known example from the literature (which only has synchronous generators), two cases of inclusion of asynchronous generators were analyzed: a) without control, b) doubly-fed induction generators. A computer program was coded, by applying a model of first order for the induction machine without control, and the results were verified with a commercial software which uses a model of third order. The case with doubly-fed induction generators only was analyzed with a commercial software. The results illustrate the effect of the induction wind generation on the power system oscillations.