Experimental Verification of the z-Domain Model for Digitally Controlled Converters

The small-signal z-domain model for digitally controlled converters was presented before. Though simulation results showed that the theoretical predictions were valid, no experimental results were at hand. In this paper experimental evidence is provided that proves the accuracy of the small-signal z-domain model. For that purpose the z-domain model is applied to the input current control loop of a boost power factor correction converter. The accuracy of the z-domain model is studied by comparing the theoretical and experimental closed-loop step response of the current control loop for different initial conditions and current compensators. After filtering out the effects of quantization, this study reveals the good accuracy of the small-signal z-domain models for digitally controlled converters