Topologies and Controls for Optimal Energy Bifurcation in an AC DC and Hybrid Microgrid

Abstract

The study has explored the perspective of the hybrid microgrid. The layout newlineof the study follows a specific hierarchical structure of the hybrid microgrid newlinewhere the functional blocks like distributed generators, energy storage units and newlinedc/ac sub-grids have been explored, analysed and amended to attain the objective, newlineensuring an operationally stable hybrid microgrid. The storage components in the newlinemicrogrid have been mathematically designed at the initial stage and the statespace newlinemodel of the storage elements have been obtained. Further, a self-tuned newlinedynamic exponent based control scheme has been designed to improve the stateof- newlinecharge management along with the improvement in the state-of-power of the newlinedc microgrid. To ensure the suitable energy bifurcation between the energy-dense newlineand the power-dense storage units, a pseudo power decomposition filter has been newlineintroduced for the dc microgrid framework. Further, to improve the transient newlinepower-sharing among the distributed generators in the dc microgrid, the concept newlineof frequency superimposed power bifurcation technique has been introduced. newlineWith the concept of the conditional drooping, the frequency superimposition newlinetechnique has been further introduced to ensure robust coordination between the newlinedc and ac sub-grids in the framework of a hybrid microgrid. To improve the newlinestability of the ac sub-grid, an improved auxiliary dynamic damping loop has been newlineintroduced. The concept of the non-directional virtual inertial loop has been newlinepresented for the islanded microgrid to improve the stability of the system to a newlinecertain extend. Finally, the concept of the direction sensitive synthetic inertial newlinescheme for the hybrid microgrid has been introduced to ensure a robust hybrid newlinemicrogrid framework. The perspective of the electric vehicle has been showcased newlinein the study as the potential distributed loads in the hybrid microgrid and a duallayer newlinecascaded torque control mechanism has been developed for the newlineimprovement in the torque response. Finally, the concept of the single-phase newlinevirtual