Dong Yeob Han, Jun-Hyuk Park, and Kyo-Beum Lee, "DC offset Compensation Algorithm with Fast Response to the Grid Voltage in Single-phase Grid-connected Inverter," The Transactions of the Korean Institute of Electrical Engineers, vol. 64, no. 7, pp. 1005–1 > Paper

This paper proposes the DC offset compensation algorithm with fast response to the sensed grid voltage in the single-phase grid

connected inverter. If the sensor of the grid voltage has problems, the DC offset of the grid voltage can be generated. This error

must be resolved because the DC offset can generate the estimated grid frequency error of the phase-locked loop (PLL). In

conventional algorithm to compensate the DC offset, the DC offset is estimated by integrating the synchronous reference frame d-

axis voltage during one period of the grid voltage. The conventional algorithm has drawback that is a slow dynamic response 

because monitoring the one period of the grid voltage is required. The proposed algorithm has fast dynamic response because the 

DC offset is consecutively estimated by transforming the d-axis voltage to synchronous reference frame without monitoring one 

cycle time of the grid voltage. The proposed algorithm is verified from PSIM simulation and the experiment.