A comparative theoretical analysis of distributed ladder converters for sub-module PV energy optimization

This paper presents a theoretical framework to compare DC-DC ladder converter topologies applied to series stacked configurations of DC `cells.' In a range of applications including photovoltaics and battery management, the practice of stacking cells in series is common, but leads to limitations in performance and reliability due to mismatch among series stacked units. Ladder converters operate in parallel with series-stacked cells to balance power flow and can achieve low insertion loss and high efficiency. A general theory and implementation details of different ladder converters is presented. Figures of merit relevant to ladder converters are derived and tabulated.