Research of restraining harmonic circulating current in photovoltaic inverter wireless parallel system

In photovoltaic parallel inverters, the harmonic circulating currents caused by factors like the difference between the output voltage waveform, the dead time dispersion settings or nonlinear load have gained more importance. Based on the traditional droop and decoupling control method, the harmonic power control method which decoupling harmonic power from the total apparent power is proposed in this paper. And we add the harmonic power regulator to reduce harmonic power, so as to restrain the harmonic circulating currents. The experiment results demonstrate that harmonic power control can effectively suppress the harmonic circulating current between parallel inverters with nonlinear load, which ensure the stable operation of parallel system.