The most advanced control systems for the dual active bridge (DAB) converter require many high-bandwidth measurement sensors, additional compensation controllers, and sophisticated mathematical calculations. Consequently, cutting down on the total number of sensors and eliminating the need for additional compensation controllers while preserving excellent dynamic performance are considered exciting research areas. Motivated by the abovementioned statements, this paper proposes an ultra-local model-based extended state observer (ESO) strategy for the single phase-shift (SPS)-modulated DAB converter. Because the linear ESO is able to provide accurate measurements of the current, the proposed method eliminates the need for two current sensors on either side of the DAB converter. In addition, only one control parameter is involved in the ultra-local model, which makes developing the controller substantially easier. The viability of the proposed method will be validated by simulations and experiments carried out in various operating circumstances. In addition, the robustness and adaptability of the proposed method will be tested under mismatched parameters.
