Asymmetrical Bidirectional Converter for Economic Integration of PV-Storage Generation

In this article, the concept of asymmetrical bidirectional converter (ABC) is proposed for PV-storage generation station. The asymmetrical power flow is introduced by the massive PV power generation during the daytime and relatively smaller load supply/energy storage requirement at the night. To meet the asymmetrical bidirectional power flow need, the ABC topology is proposed with different forward/backward power rating. As a result, the backward power rating can be saved and the total component cost can be reduced. The zero-voltage soft-switching characteristic of ABC is analyzed under both forward mode and backward mode. The circuit parameter design process has been discussed considering the two working modes. The equivalent phase-shift angle is proposed for smooth mode switching and bidirectional power regulation. The proposed ABC converter is comparatively evaluated with traditional bidirectional converter in terms of cost, voltage/current stress, and efficiency. Both bidirectional power conversion capability and soft-switching operation has been validated through simulations and experimental results.