Abstract: The output current quality of grid-connected inverters is affected by grid voltage disturbance or uncertainty of inverter circuit parameters. According to the disturbance observer control principle, the model of current control based on disturbance observers is established to design current disturbance observing controllers in this paper. This method makes the variation of grid voltages and DC voltages as external disturbance, and improves the anti-interference ability of current control. In addition, compensation control is involved to reduce the difference of circuit parameters when real power is changed. This method can improve the dynamic response speed of current control and decrease output current harmonics of grid-connected inverters. The results of simulations and experiments show that this method obviously restrains current harmonics caused by unbalanced grid voltages or voltage distortion, and improves the output current quality in low power conditions. When the input real power of grid-connected inverters changes rapidly, both the response speed and quality of currents are improved by this method,which can indirectly reduce the time of maximum power point tracking for photovoltaic inverters.