Voltage-mode grid-tie inverter with active power factor correction

Presented herein is a power and control system architecture of a voltage-mode inverter that is interfaced between a DC power source and an AC utility grid. Utilizing an inverter power stage of a full-bridge switching configuration, the single stage of DC-to-AC power conversion is innovatively controlled to achieve maximum power tracking from the power source and a driving sinusoidal output voltage with a proper phase-shift with respect to the utility grid voltage such that the utility grid current contains no reactive component at the utility grid frequency regardless of the load type (resistive, capacitive, or inductive). In addition to various protection features, a particular novel feature is the harmonic-cancellation capability that eliminates most or all of harmonic content in the inverter output voltage. The overall system of power and control results in either an in-phase (absorbing power) or out-of-phase (providing power) utility-grid current (unity power factor) with respect to the utility grid voltage while absorbing either maximum power available from the DC power source or limiting the delivered AC output power to not exceed either the inverter rated power or the maximum rated output voltage.