Modeling and design of a new bi-directional buck-boost cascade inverter

This paper concentrates on the modeling and design of a new bi-directional buck-boost cascade inverter. The proposed inverter can be seen as the cascade of a Buck converter and a Boost converter, both with bipolar outputs. First, The operation principle of the proposed inverter is explained. With detailed analysis, the switching function model is established. Then, the averaged model for control purpose is given. Afterwards, a decoupled control scheme is presented. Device-level simulations and experiments verify that the proposed system can not only perform bi-directional operation with bipolar buck/boost output voltage, but also achieve good steady-state and dynamic performance.