Remote Synchronization of the Microgrid to the Utility Grid Without Access to Point of Common Coupling in the Presence of Disturbances

The article presents the method of remote micro-grid synchronization with the utility grid in the presence of voltage disturbances. The proposed algorithm and control devices synchronize different power systems on the basis of the instantaneous voltage phase angle in spite of voltage quality problems and without need of access to point of common coupling. In the presence of grid voltage disturbances, instantaneous grid voltage phase angle is estimated and transmitted remotely with a certain accuracy, which is varies in presence of disturbances of grid voltages or depends on the synchronization algorithm and data transmission rate. The paper focuses on the influence of voltage disturbances on the proposed remote synchronization strategy and the shape of the output current of the synchronized power converter on the micro-grid. The four types of grid voltage disturbances are presented: harmonics, one-phase sag, two-phase sag, and phase voltage jump. The final conclusions present the possibility of using the proposed remote synchronizations algorithm in micro-grid power converter applications in the presence of typical utility grid voltage disturbances.