Discrete time mapping modeling and bifurcation phenomenon study of a ZVS converter

The varying period and complex commutation conditions make the classic mapping modeling method based on fixed switching period no longer fit for soft switching circuit analysis. This paper proposes a discrete time mapping method for modeling variable frequency resonant circuits. The analysis begins with the derivation of a sixth-order iterative map for a ZVS converter used in ICPT (inductively coupled power transfer) systems and then the model developed is employed to analyze the instability and sub-harmonic operation of the converter.