Abstract: In the application of renewable energy power generation，multi-input-port power conversion system

is a high cost-effectiveness option. A multi-input-port DC-AC conversion system based on single-stage nonisolated

buck-boost power conversion cell was propsed . Each type of DC source flows into the full-bridge circuit

of corresponding input port and cascoded together，then，the total input voltage was processed by main conversion cell based on Buck-Boost topology and sinusoidal AC output was generated. Full-bridge circuit of master input port works in high frequency and full-bridge circuit of slave input port works in low frequency. Operation modes and steady-state characteristics of the proposed novel conversion system were analyzed. Furthermore，PSIM

simulation software was employed to verify the analysis results. A 500 W hardware prototype with 96.1% peak

efficiency was fabricated and tested. The experimental results demonstrate that the proposed multi-input-port DCAC

conversion system features of relatively high efficiency，wide gain range and simple system structure.

      Key words: multi-input-port；buck-boost；inverter；single-stage system；non-isolation