Patent ID: 8422249

Claim:
Apparatus for a microinverter which converts direct current (DC) input power into alternating current (AC) power for supply to an AC power grid, the apparatus comprising: a DC-to-current converter, connected to a DC power source and responsive to an error control signal, for producing a full-wave rectified output synchronized to an AC grid voltage then appearing on the power grid, the error control signal being responsive to a difference between a current command and an actual amount of AC output current then being supplied by the microinverter to the power grid; a commutator for converting the full-wave rectified output to the AC output current synchronized and phase-locked to the grid voltage, the commutator having switching components which are switched to a substantially on or off state substantially co-incident with zero crossings in the grid voltage, the commutator having a zero-crossing detector for detecting the zero crossings in the grid voltage so as to yield a zero crossing signal; and a controller, responsive to the zero crossing signal, for generating the current command and for synchronizing and phase-locking the operation of the commutator to the grid voltage.