Exact-order Discrete-Time Modeling of a DAB Derived Hybrid Switched-Capacitor Converter

Modeling of the switched-capacitor based converters has been quite challenging due to the considerable voltage and current ripples associated with them and/or the complete alternating nature of one or more states which make the state-space averaging technique inapplicable. The discrete-time modeling approach does not use any “small/linear ripple” approximation and hence is widely preferred for modeling such converters. However, due to the presence of singular state matrices, the conventional discrete-time modeling approach is unsuitable for deriving the exact order model of most of these converters. Since the reduced order models of such converters lack accuracy, this article proposes an exact-order discrete modeling technique for them. The proposed method, applicable to a wide variety of standard and hybrid switched-capacitor converters, removes the singularity from the state matrices through shrinking and helps to derive their most accurate exact-order models. The exact order model of a dual active bridge derived hybrid Dickson switched-capacitor converter is developed and verified through simulation. Then, the experimental results are provided to verify the dynamic response of the closed-loop control system designed using the developed model.