On the capacitor voltage needed to trigger self-excitation in induction generators

The paper analyzes the phenomenon of self-excitation in induction generators. A nonlinear state-space model is obtained based on a magnetization curve that is nonlinear at high and low currents. The model was used previously to characterize the steady-state regimes of self-excited induction generators, including the number of possible regimes and their stability properties. In this paper, the model is used to find boundaries for spontaneous and triggered self-excitation, and to derive a remarkably simple formula that specifies the initial voltage to be applied to the capacitors to trigger self-excitation. The results are validated in simulations and experiments, and a very good agreement is observed overall between the computational, simulated, and experimental data.