The paper presents the new, enhanced way of the use of Prony analysis, combined with Padé approximation, for the transfer functions identification. Transfer functions of interests are related to automatic voltage regulator (AVR) and excitation system. In the presented analysis the influence of field voltage recorded signal corruption with noise is successfully overcame. By the use of standard first order synchronous generator model, it is possible to extract exact generator model parameters, using Padé approximation. After that step, the transfer function of automatic voltage regulator (AVR) is derived using similar technique. Finally, derived generator and AVR transfer functions are verified by Matlab/Simulink simulation.