Model predictive control of input‐series output‐parallel dual active bridge converters based DC transformer

Abstract

DC transformer (DCT) which is composed of dual active bridge (DAB) converters, is capable of fulfiling high‐ratio voltage conversion between the medium‐voltage dc distribution and low‐voltage dc distribution. A model predictive control (MPC) strategy was proposed for the DAB‐DCT to improve dynamic performance and achieve a proper power distribution, considering the bidirectional power of DCT. The traditional voltage closed‐loop control scheme with the single‐phase shift (SPS) and the MPC scheme with SPS are compared on a downscale DAB‐DCT laboratory prototype, using PowerPC P2020 + FPGA_6SL X45 as the core controller. The excellent dynamic characteristics of DCT with proposed MPC strategy is verified by extensive experimental results.