A method based on evolutionary algorithms for the estimation of parameters in excitation systems is shown. Usually, for these parameters, typical values or values provided by the manufacturer are used. These values do not reflect the recent conditions of operation of the system. When estimation of parameters is confronted, this is done based on methods supported on the domain of frequency, which demand an arduous work of adjustment, also can be based on methods that force to linearize the model around an operation point and omitting certain types of non-linearities like limiters. The evolutionary method presented estimates parameters with signals in the time domain. It can use real data originated in the operation of the system, and directly executes the adjustment of the results. This evolutionary method may be applied for specific functions of the system or in the whole excitation system. It can include the non-linear properties of the system, such as the saturation in the case of an operation that reaches the limits. The evolutionary method was applied to the model of an excitation system in the hydroelectric plant of Salvajina in Colombia