Characteristics Analysis of a Novel Air-Core High Frequency Transformer Based Dual Active Bridge Series Resonant Converter

A dual active bridge series resonant converter (DABSRC) is proposed with the isolation of an air-core high frequency transformer (ACT) in this paper. It reduces the weight of the transformer without the magnetic core which improves the gravimetric power density of DABSRC. It adopts crossed figure-eight shaped windings to ensure high coupling capability of ACT. In addition, the simplified ACT T-type equivalent model is established. Based on this model, the soft-switching characteristics of DABSRC are also analyzed in this paper. Simulations on a 100 kW 1kV / 750V DABSRC verify the validity of the proposed ACT-DABSRC.

I. Introduction

As a crore dc power conversion stage, DABSRC has been widely used in power electronics transformer (PET) and dc transformer (DCT). It has some overwhelming advantages of voltage conversion, high efficiency and galvanic isolation ^[1]. It is capable of fulfilling safe and flexible access of the multiple renewable resources and dc loads such as photovoltaics, storage, electric vehicles, data centers, and so on.