Loss Estimation of a Dual Active Bridge as part of a Solid State Transformer using Frequency Domain Modelling

This paper proposes an improved method for the loss estimation of a Dual Active Bridge (DAB) using frequency domain modelling. The method uses a detailed, frequency depending transformer model to describe even highly utilized DABs. The model is used to estimate the occurring losses of a DAB as part of an modular Solid State Transformer (SST). The influence of the SST's phase power ripple is considered for the loss estimation. The results of the frequency domain model and the loss calculation are validated using measurement data of an SST-cell prototype.