A Parameter Estimator for Inductance within a Dual Active Bridge Converter

This paper presents a method for a real-time estimate of the primary winding inductance value within the transformer of a dual active bridge converter. The technique requires measurements of the primary and secondary dc bus voltages and of the primary winding current. An application is presented with an externally tunable inductor used in series with the leakage inductance of the transformer. In the application, the external inductance value will dynamically adjust per the performance needs of the converter. An augmented control strategy is proposed, which will detect a deviation in inductance above a certain threshold then re-tune the gains of the controller. To demonstrate the performance of the proposed controller, a real-time digital simulation of the converter and tunable inductor is employed using control hardware-in-the-loop. The large signal transient response is analyzed to evaluate the performance improvement provided by the augmented controller as the tunable inductor dynamically changes during the operation of the converter.