Current Decoupling Method Using a Repetitive Controller for DC-AC-DC Converter Using Single Transformer

Abstract

The use of triple active bridge (TAB) converters in distributed electric grids has attracted considerable attention because of their multi-directional power connection, insulation performance, and small size. However, there remains a problem with respect to the interaction between two current loops with TABs, and there are few solutions to this problem when an AC supply is connected to the system. In this paper, we propose a method to suppress the interference by using iterative control as the main approach, taking into account the occurrence of periodic disturbance in the TAB converter when connected to an AC system. In order to estimate the characteristics of the proposed method, a prototype is built and tested experimentally. As a result, it is confirmed that the measured grid current THD is within 5% and that he battery current ripple decreased by 84% at a maximum.