The modeling and simulation of a simplified interconnection system consisting of a distributed generation (DG) unit connected to grid via inverter interface is addressed in this paper. The inverter interface is controlled with synchronous frame PI current controller. The task of tuning of controller is done with MATLAB. The current harmonics should be limited according to the requirement of relevant standards, such as IEEE Std. 1547. Theoretical calculations with Bessel function are performed to find suitable filter inductance values with reasonable switching frequency. The simplified interconnection model is realized and simulated in PSCAD. For validation of the method of filter inductance selection, the Matlab is used for analyzing current harmonics to improve the accuracy