Active and Reactive Power Control of Grid-Connected PV Power Systems based on HGNISS DC-DC Converter and SMDPC Strategy

In this paper, a complete model of the grid-connected photovoltaic (GCPV) system with the high-gain non-isolated single-switch DC-DC (HGNISS DC-DC) converter to extract the maximum power of PV panels and the nonlinear sliding mode direct power control (SMDPC) scheme to track of active and reactive power set-points is proposed. The applying of the HGNISS DC-DC converter covers the weakness of PV panels in supplying high voltage levels. In addition, the single switch structure of this converter simplified the applying of MPPT strategies and modified switched inductor (MSI) topology provides the high voltage gain with low output ripple. The improved Incremental conductance (INC) algorithm is used to extract the maximum power of PV panels. Also, the SMDPC strategy without any rotating coordinate transformation is applied to the DC-AC converter to track the instantaneous reference of active and reactive powers. The simulations are performed in three different scenarios to verify the performance of the GCPV system based on the HGNISS DC-DC converter and the proposed control strategy. These simulation results confirm the proper performance of the proposed system in transient and steady states condition with fast and precise tracking of active and reactive power.