FPGA-based real time incremental conductance maximum power point tracking controller for photovoltaic systems

Maximum power point tracking (MPPT) is an important issue in photovoltaic (PV) systems. Hence, we need to design an efficient and cost-effective system which is able to transfer the maximum power received from PV cell to the load. This study describes the hardware implementation of a real time incremental conductance (INC) MPPT algorithm for a PV module. According to the PV dynamic model, a criterion is presented that by modifying the original algorithm, an adaptive variable step size INC algorithm is realised and efficiently is implemented on XILINX XC3S400 field programmable gate array (FPGA). At first, the PV model characteristics and the proposed algorithm with the mathematical equations are modelled and simulated using `MATLAB/Simulink-system generator' environment; then the system performance is examined. It is worth that some solutions are proposed to simplify the system based on the design constraints for hardware implementation of digital controller on FPGA. The optimised design of hardware architecture and the high processing speed of FPGA have enhanced the performance of digital controller in designed MPPT system. The experimental results show the proposed method provides a good tracking speed and also mitigation of fluctuation output power.