A mathematical model for a series resonant converter

Analysis is presented of a linear dynamic model, around the static operation point, for a series resonant converter operating with small amplitude modulating signal and a modulation factor less than one. Comparison of the theoretical results with those found experimentally shows the validity of the proposed model also as regards the shift of the dominant pole with switching frequencies approximate to the resonance frequency. This happens to be particularly precise for values of Q greater than 1.5 where the first harmonic approach is much more valid. In conclusion, the proposed model approximates very closely to the behavior of the physical system for values of f/sub S//f/sub O/ greater than 0.6 and values of Q greater than 1.5.<>