Enphase Energy, Inc.
Method and apparatus for balancing loads on split-phase islanded systems

Abstract:

A method and apparatus for balancing loads on a split-phase islanded system. In one embodiment, the apparatus comprises a device, coupled between a DG and a plurality of loads, comprising: an autotransformer coupled to first and second phase lines and a neutral line of the split-phase islanded system; a plurality of switches to switch between coupling a corresponding load to the first phase line and coupling the corresponding load to the second phase line; and a controller for determining, when a load imbalance is identified, at least one load to be switched from one of the first or second phase lines to the other of the first or second phase lines to reduce the load imbalance, and controlling at least one switch to switch the at least one load from the one of the first or second phase lines to the other of the first or second phase lines.