Advanced nonlinear control of photovoltaic system connected to the grid

This paper presents the nonlinear control of single-phase grid connected to the photovoltaic system through an adaptation circuit and LCL filter. The control objective is threefold i) regulating the DC voltage to a desired value (VR) ii) supply a current with sinusoidal form and in phase with the grid voltage by controlling DC/AC converter (power factor correction: PFC) iii) extracting the maximum power from the PV array by acting on the DC/DC converter (MPPT)). The whole system is described by 5^th order nonlinear mathematical model and controlled by using the backstepping technique and its tools from Lyapunov stability. The simulation results have been performed through Matlab/Simulink environment and show that the designed controller meets its objective.