Development of a generalized switched-capacitor DC/DC converter with bi-directional power flow

This paper presents the generalized circuit structure of a switched-capacitor dc/dc converter that can offer features of voltage step-down, voltage step-up, and bi-directional power flow. Starting with the derivation of a single-capacitor bidirectional converter cell, a converter string is created by cascading a required number of cells, which is determined by the input and output conversion ratio for optimizing the conversion efficiency. The input current is made continuous by operating two strings in parallel and in anti-phase. State-space averaging technique is applied to study the static and dynamic behaviors.