2-DOF based novel controller design for DC voltage regulation of LCL interfaced three phase grid connected solar PV system

The dedicated PI controller for dc voltage regulation and control has been implemented with control technique for operation of grid-connected PV system. Generally, dedicated PI controller have been used for the dc link voltage control due to ease of implementation. The PI controller is having constraint regarding response time and overshoot with only proportional and one integral gain. The conventional PI controller is having one degree of freedom (DOF). In this paper the 2-DOF PI controller in PI-P configuration is been proposed for the dc link voltage control. It is based upon the concept to increase the DOF in the system. The system with PI-P controller with 2 DOF having two proportional gains and one integral gain. The performance of the PI-P controller is compared with the PI controller while PV system connected to grid (considering grid current response) and under disturbance in reference dc voltage. The system transient during interconnection have been improved and showing better response for dc voltage control.