Patent ID: 11831271

Abstract:
A medium voltage inrush current (MVIC) regulator and interconnection control system for interposing between a distributed power generation facility and a utility grid. The facility has a designated generator step-up (GSU) transformer and is connected to the utility grid at a point of interconnect. The system includes a pre-insertion impedance injection transformer, a low voltage first switch connected between the pre-insertion transformer and secondary coils of the designated GSU transformer, a medium voltage second switch connected inline between the pre-insertion transformer and primary coils of the designated GSU transformer, and a controller. In response to restoration of the utility grid following a loss-of-grid event, the controller opens and closes the first and second switches according to an automated pre-energization switching sequence such that magnetic flux in the designated GSU transformer occurs at a reduced rate, thereby reducing inrush of current and undesirable power quality phenomena.