This paper proposes a compensation method for the 2nd harmonics of grid-connected small wind power generation systems.
Theoretically, a single-phase grid-connected inverter system has no choice but to cause the 2nd harmonics to DC-link voltage. The
reference active current is affected by the DC-link voltage. The output current from the reference active current is distorted by 2nd
harmonics. Unlike existing methods which compensates the reference of DC-link voltage, the proposed method can compensate,
conveniently, the reference active current with the 2nd harmonics. The proposed method takes a PR controller as a feed-forward
compensator to reduce the 2nd harmonics in the reference active current. The PR controller can implement selective harmonic
compensation without excessive computational requirements; the use of these controllers simplifies the method. The simulation
results agree well with the theoretical analysis.