Current Vector Oriented Control Scheme for Power Sharing in Open-End Winding Transformer Based Microgrids

A new control scheme for sharing of power between two energy sources integrated to form a microgrid using a transformer with open-end primary windings is proposed in this paper. The microgrid's power circuit, developed for the proposed scheme, consists of two three-phase voltage source inverters (VSIs), each connected to opposite ends of the open-end primary windings of a three-phase transformer. The transformer's secondary windings, arranged in a star configuration, supply power directly to the loads or feed it into the grid. The control scheme allows flexible sharing of both active and reactive power between the two inverters in any proportion, depending on the availability of power from the sources supplying the inverters. This flexibility is crucial for optimizing resource utilization and maintaining power balance. The power-sharing mechanism is based on a current vector-oriented synchronous reference frame, making it simpler and more efficient than conventional schemes used in microgrids. The effectiveness and validity of the proposed control approach are demonstrated through detailed simulations conducted in MATLAB Simulink, highlighting its practicality in managing power distribution in microgrids and enhancing system reliability.