Switching function based modeling of flying capacitor DC-DC converters

This paper presents a new approach to the modeling and analysis of flying capacitor DC-DC converters using the switching function approach. This method helps to obtain the model dynamic equations which can be used in computer simulations to observe the response of the converter, voltages across the switching devices and the flying capacitors. The harmonic balance technique applied to the resulting model dynamic equations enables the determination of equations that predict the steady state variables and the peaks of the ripple quantities. The four-level DC-DC boost converter is analyzed to illustrate the utility of the proposed modeling approach which can be easily extended to other flying capacitor multilevel converter topologies.