An Enhanced Generalized Average Modeling of Dual Active Bridge Converters

An enhanced generalized average modeling (GAM) method for a dual active bridge (DAB) converter is presented in this paper. Firstly, the conventional lossless model is introduced and it is shown that this model might cause a non-neglectable steady state error. In order to improve the modeling accuracy, a wide range of loss sources are involved in the proposed enhanced GAM model, such as conduction losses and core losses. On this basis, this paper further proves that the 3 ^rd-order harmonic component of the leakage inductance current should be considered to reduce steady state errors in light load conditions, while others might only consider the 1 ^st-order harmonic in the existing DAB models. Also, a universal form of the modeling equation to include up to any h ^th-order harmonic component is derived. Finally, comparative simulation and experimental results are presented to validate the feasibility of the analysis.