With increasing emphasis on non-conventional energy systems and autonomous power generation, development of improved and appropriate generating systems has recently taken on greater significance. This paper describes the performance analysis of a single phase self-excited induction generator (SEIG), suitable for autonomous/standby power systems. The system is also appropriate for wind energy systems and small portable systems. Both windings of the induction machine, the main and the auxiliary, are utilized. One winding will be devoted to the supply excitation current only, by being connected to the excitation capacitor, while the load is connected across the other winding. As the design of excitation, the minimum of self-excited capacitor connected auxiliary winding is determined as the suitable value using a circuit equation of auxiliary winding. For the steady state analysis, the equivalent circuit of the single-phase induction generators is used as a basis for modeling using the double-revolving field theory. The validity of the designed generator system is confirmed by experimental and computed results.