Variable-Gain Decentralized Input Voltage Sharing for ISOP DC–DC Converters

It is a critical challenge in modular input-seriesoutput-parallel (ISOP) conversion systems without input voltage monitor and interconnected lines to achieve balanced input voltage sharing (IVS) and output voltage regulation (OVR) under wide load variation. A novel variable-gain decentralized inverse-droop control method supporting full modularity design is proposed to address this issue in this paper. By designing the inverse-droop gain as a function of each converter module's average inductor current, the proposed method can eliminate the requirements for input voltage sampling, high-voltage galvanic isolation of control circuits, and interconnected lines, which are very essential for ISOP converter modularity design. Furthermore, it can effectively extend the operation area with excellent IVS performance, while the OVR of the ISOP converter can also be effectively guaranteed. The principle of the proposed method is elaborated, and the smallsignal-based stability analysis for the IVS control system along with the output voltage control system design of the ISOP converter is also investigated. The experimental results validate the effectiveness of the proposed control method.