Nonlinear Control of Three Phase Single Stage Grid Connected PV System Through Half Bridge Power Inverter

This paper presents a new controller design method based on a hybrid automaton approach to address the control problem of a three-phase PV system. The PV system architecture consists of two PV panels, a single-phase half-bridge inverter employing two DC link capacitors, and an LCL filter on the grid side. The control objective is two-fold: (i) to achieve satisfactory power factor correction (PFC) and (ii) to ensure that the PV panels provide the maximum power output. In the inner loop, the hybrid automaton technique is used to ensure the operating modes of the switching architecture to achieve unity power factor. In the outer loop, a PI regulator is employed to regulate the capacitor voltage. The simulation results, obtained using the MATLAB/SimPowerSystems environment, demonstrate that the developed controller achieves its objectives. Keywords: PV system; Nonlinear control; MPPT; PFC; Hybrid automaton model; Grid-connected system.