Methods of balancing reactive power in multi-level motor drives with active front ends

Abstract

A method of balancing reactive power at a power delivery system is disclosed. The method may include operating a power delivery system that may have a plurality of power cells that are electrically connected to a first transformer comprising one or more primary windings and a plurality of secondary windings such that each cell is electrically connected to one of the secondary windings and a plurality of the secondary windings are phase-shifted with respect to the primary windings. The method may further include controlling the reactive current flow at each power cell by calculating, at a first controller, a reactive current flow adjustment for at least one power cell so that reactive current flow is balanced among each of the plurality of power cells. Each cell may include a plurality of switching devices.

Dependencies are inferred from the claim text.