Parameter identification for dual-phase shift modulated DAB converters

Abstract

Deadbeat control is an effective method for controlling the output voltage of dual active bridge converters. However, its effectiveness depends on the model parameter accuracy. In practice, the model parameters of dual active bridge converters vary depending on the operation conditions, manufacturing tolerances, and calendar aging. This leads to performance degradation and causes steady-state errors of the output voltage. To overcome the effect of parameter mismatch, this study proposed an algorithm to achieve the online identification of two model parameters, i.e., the series inductor and the output capacitor. Based on a least-squares analysis, the online parameter identification of a dual active bridge converter under dual-phase shift modulation is implemented to obtain the actual values of model parameters. Consequently, the steady-state errors of the output voltage are immediately mitigated after every sampling period when the optimal predicted phase shift duty ratios are updated. The proposed algorithm was tested through both simulations and experiments to verify its effectiveness.