Comparison of Voltage Balance and State Estimation Dynamics for Hybrid Switched-Capacitor Converter Topologies

Abstract

This work develops a general analytical framework to understand and quantity state estimation and flying capacitor voltage balance dynamics in hybrid switched-capacitor converter topologies. We expand a state-space modelling framework previously only applied to flying-capacitor multilevel (FCML) converters to treat other topology classes including Dickson-based, series-parallel (SP), Fibonacci, and exponential (doubler) converters. In the generalized treatment, it is shown that many topologies undergo order-reduction which provides significant simplification compared to the FCML case. To compare the relative difficulty of estimating or balancing flying capacitor voltages, we introduce the concept of condition number to better quantity observability and controllability. A hardware prototype consisting of Series-Parallel and FCML topologies is used to verify the model and illustrate topology differences.