Static state stability analysis of AC-excited generators

The most significant difference between the ac-exited generator and the traditional synchronous generator is the adjustable speed. A detail analysis of the static state stability of the ac-excited generator is present. The stability of the ac-excited generator is limit not only by the static state stability limit as synchronous machine but also by the breakdown torque as asynchronous machine. The relation between static state stability limits and rotor speed is derived from the mathematic model, thereby the law of static state stability at any speed is presented and these have been tested by dynamic physical simulative experiment.