On the Phase Plane Stability Analysis for DC to DC Series Resonant Converters

In this note we present a novel stability analysis method for DC to DC series resonant converters which relies on the phase plane technique. We compare our results with those presented in previous works. Our method gives more insight in the rationale behind the stability conditions because these are ensured in terms of geometrical considerations instead of eigenvalues of linear discrete time approximations as presented in previous works. Further, this note is motivated because we have found that several authors avoid the stability analysis based in eigenvalues because this concept obscures the comprehension of the stability conditions