Sampled-Data Modeling, Analysis and Control of Load-Resonant DC-DC Converters in Variable Frequency Operation

Abstract

Sampled-data modeling, analysis and control of load-resonant DC-DCconverters in variable frequency operation are considered. A generalblock diagram model is given and then used to obtain a nonlinearsampled-data model reflecting cycle-to-cycle dynamics. An alternativemodel that reflects half-cycle dynamics is also obtained. Thehalf-cycle model is more compact than the full cycle dynamic model.Because of this, it is used as the basis for the other derivationsin the paper. These include: a linearizedhalf-cycle dynamic model, open-loop stability conditions, control-to-outputtransfer function, open-loop audio-susceptibility, open-loop outputimpedance, anddiscrete-time integralcontrollers achieving line regulation and load regulation.