Patent ID: 8670249

Claim:
A circuit for use with an inverter and a distributed power generator, comprising: a high side input point and a low side input point for the distributed power generator; and (i) a parallel input capacitor connected across the high side input point and the low side input point; a first regulating circuit connected in parallel with the parallel input capacitor, the first regulating circuit having a high side output point and a low side output point for connection to an input of the inverter; and a first controller that controls the first regulating circuit so that voltage oscillation at twice a grid frequency across the parallel input capacitor is substantially removed; wherein the parallel input capacitor has a small value such that voltage oscillation at twice the grid frequency at the first regulating circuit high side and low side output points is not substantially removed; or (ii) a series input inductor having a first terminal and a second terminal, the first terminal connected to one of the high side input point and the low side input point; a second regulating circuit connected between the second terminal of the series input inductor and the other of the high side input point and the low side input point, the second regulating circuit having a high side output point and a low side output point for connection to an input of the inverter; and a second controller that controls the second regulating circuit so that current oscillation at twice a grid frequency through the series input inductor is substantially removed; wherein the series input inductor has a small value such that current oscillation at twice a grid frequency at the second regulating circuit high side and low side output points is not substantially removed.