Open-end transformer-based power tap for interconnection of AC/DC micro-grids

This study proposes an open-end transformer-based power tap (OETPT) for the interconnection of the alternating current sub-grid and the direct current sub-grid of a hybrid micro-grid. Two topologies, topology-A and topology-B, were designed for OETPT, in which the primary or secondary windings of the transformer of OETPT are grounded, respectively. Steady-state and dynamic models were developed for OETPT, based on which a vector control system was designed for the coordinated control of OETPT with topology-A and topology-B, respectively. OETPT achieves the decoupled control of the active and reactive powers. Simulation studies and experimental validations were undertaken to manifest the coordinated power flow control performance of OETPT with topology-A and topology-B, respectively.