FPGA-based real time simulation and control of grid-connected photovoltaic systems

• An effective control strategy for grid-connected photovoltaic (PV) systems is presented.
• The simulation results confirm the accuracy of the adopted control strategy.
• The feasibility of the overall FPGA based control circuit is proved.

Nowadays, FPGA devices are widely used to build control platforms in various fields of real time applications such as wireless telecommunications, image and signal processing, robotics and renewable energy systems. In grid-connected photovoltaic (PV) systems, an effective control strategy is needed for an efficiently use of solar energy as well as for energy supplies optimization. This paper presents an investigation, modelling and FPGA based digital controller design of a two-stage grid connected photovoltaic (GCPV) system. The basic idea of the proposed control structure is to operate the PV system as an active power generator and reactive power regulator. Firstly, a comprehensive study of dynamic behaviour of a two-stage GCPV system using Matlab/Simulink was presented. Subsequently, a digital circuit design of Incremental Conductance (IncCond) algorithm and decoupled active–reactive power control algorithm is carried out using the Hardware Description Language (VHDL). The simulation results confirm the accuracy of the adopted control strategy as well as the feasibility of the overall FPGA based control circuit.