Patent ID: 8369113

Claim:
A photovoltaic power conditioning unit for delivering power from a photovoltaic dc power source to a grid mains utility supply, the power conditioning unit comprising: a plurality of input terminals for connecting to the dc power source; a plurality of output terminals for connecting to the grid mains utility supply; a voltage increasing converter connected to the input terminals; a voltage reducing converter connected to the voltage increasing converter; a dc-to-ac converter connected to the voltage reducing converter and to the output terminals and comprising a current source inverter; a synchronization circuit coupled to the output terminals configured to generate a synchronization signal that is synchronized with the grid mains utility supply; a reference signal generation circuit that is coupled to the synchronization circuit and configured to generate a sinusoidal reference signal template in synchronism with the grid mains utility supply based on the synchronization signal; a current sensor configured to sense a current flowing through the voltage reducing converter and to provide a current sense signal; and a comparator configured to compare an instantaneous value of the sinusoidal reference signal template with an instantaneous value of the current sense signal and to provide an output to control the voltage reducing converter to regulate sinusoidal current injection by the current source inverter into the grid mains utility supply.