High-Efficiency Floating Bidirectional Power Flow Controller for Next-Generation DC Power Network

Abstract

To realize flexible power flow control for DC power networks, we have proposed a bidirectional power flow controller (BPFC) based on a bidirectional buck-boost converter. It is possible to control the power flow by intentionally introducing additional voltage difference between two terminals. However, we have not investigated the efficiency of BPFC for power flow control in detail so far (in previous papers). Because many power converters are expected to be installed in future DC power networks, efficiency investigation is vital. In this paper, we first reveal the energy efficiency of BPFC and study ways to improve the efficiency. Then, we propose a novel structure of the BPFC, which drastically improves its efficiency. We call the proposed structure floating bidirectional power flow controller (F-BPFC). The efficiency and characteristics of the F-BPFC are experimentally compared with those of the BPFC and its superiority is clarified in this paper.