Discrete time domain small-signal modeling of full-bridge phase-shifted series resonant converter

This paper provides an analytical discrete small-signal state-space model of the phase-shift modulated series resonant converter used to obtain an explicit linearized phase-shift to output voltage transfer function. This transfer function is useful for linear closed loop control design. Initially, the effective duty-ratio to output voltage transfer function is derived. It is then proven, analytically and through results, that it is linearly related to the phase-shift to output voltage which is the main research concern. The analysis is carried out using state-plane diagrams. Small-signal state-space model representation is derived which is used for closed loop controller gain calculations. Results validate the calculated control gains based on the proposed linearized model.