A Bidirectional Isolated Integrated AC-DC Converter Based on an Interleaved 3-Level T-Type Power Converters

Abstract

This paper presents an integrated single-phase bidirectional ac-dc converter based on a dual-active-bridge (DAB) topology. The primary side is based on a multi-state switching cell (MSSC) with a T-type (TNPC) cell, which is composed of two three-level interleaved legs and coupled inductor, while the secondary side is a single-phase full-bridge (FB). Moreover, a comparative analysis between an isolated ac-dc converter with a neutral point clamped (NPC) converter on the primary side is presented. The basic converter operating principles and experimental results of a 850 W prototype are presented in order to validate the theoretical analysis. The control strategy is implemented on the TMS320F28379D DSP. The proposed topology achieves a maximum efficiency of 91.40% at 300 W output power, and 89.40% at rated power. From the experimental results, it can be stated that the converter based on the T-type topology is more efficient than the structure based on the NPC.