Patent ID: 8482947

Claim:
An apparatus for controlling the delivery of power from a photovoltaic (“PV”) cell to an alternating-current (AC) grid at a grid voltage and grid frequency, the apparatus comprising: an inverter comprising: an input converter configured to deliver power from the PV cell to a galvanically isolated unipolar bus, the input converter comprising a maximum-power-point-tracking (“MPPT”) device configured to determine the maximum amount of power that may be withdrawn from the photovoltaic cell and deliver a setpoint value, i SIC , for the current that is drawn by the input converter from the PV cell, wherein the input converter is further to receive a measurement of the voltage of the PV cell, V I , and to calculate and deliver a power delivery setpoint P s =V I ·i SIC ; an active filter configured to supply energy to and absorb energy from the unipolar bus; and an output converter configured to deliver power from the unipolar bus to the AC grid, and an inverter controller configured to maintain a voltage of the unipolar bus at a pre-determined value, the inverter controller comprising: an input converter controller to control a current delivered by the input converter to the unipolar bus; an output converter controller to control the output converter to deliver power to the AC grid; and an active filter controller to control the active filter to supply time-varying power to the output converter.