Minimum airgap flux linkage requirement for self-excitation in stand-alone induction generators

A minimum airgap flux linkage is required for the self-excitation and stable operation of an isolated induction generator feeding an impedance load. With the aid of bifurcation theory, it is shown that the minimum airgap flux linkage requirement is the value at which the derivative of the magnetizing inductance with respect to the airgap flux linkage is zero. This minimum airgap flux linkage determines the minimum or maximum load impedance and minimum excitation capacitance requirements. This result is demonstrated using single-phase and three-phase induction generators