Hybrid controller topology for large solar PV installations in high-voltage DC grid-connected applications

In this work, a new topology is proposed to integrate large solar photovoltaic installations to high-voltage DC grid, which is efficient, economical and flexible in its operation. The proposed system consists of a PV array-fed DC–DC boost converter, grid-connected DC–DC boost converter circuits and hybrid controller. The hybrid controller proposed here consists of the random search method (RSM)-based MPPT controller along with the RSM-based two-loop average current controller, and the MPPT controller helps in harnessing the maximum power at varying weather conditions, whereas the voltage controller helps in reducing the distortion in output voltage. RSM method is chosen here for the design of controllers, as it has simple computational steps, is derivative-free, guarantees global convergence and requires less memory. The performance of the proposed system is studied in the continuous conduction mode. The performance of the chosen MPPT controller is compared with the incremental conductance technique to validate the performance of the proposed system. The proposed topology along with hybrid controller used here extracts the maximum power operating point and can achieve stable DC output according to grid requirement. Matlab/Simulink environment is chosen for simulation of the proposed topology.