Observer-based decoupling power control for frequency modulated Dual-Active-Bridge converter

This paper proposes a new control strategy to manage the active and reactive power within a single-phase frequency-modulated Dual-Active-Bridge converter individually. It is realized by decoupling control of the direct and quadrature current components, Id and Iq, as they are directly proportional to the active and reactive power, respectively. An observer is designed in order to observe the two current components since it is difficult to derive them directly from the measured transmission current. After that, based on the relative gain array, input-output pairing can be accomplished for lowest interaction between the d- and q-control channels. Simulation and experiment results show that, the proposed control strategy requires not very high sampling frequency but provides observed currents Îd and Îq with acceptable accuracy. As a consequence, active and reactive power are directly manipulated by two separate control loops with two simple PI regulators. The outcome of this paper allows to use a low-cost DSP platform to handle the active and reactive power within a high-frequency DAB converter individually.