摘要：AbstractThe present paper discusses the modelling and the nonlinear control of a DC/AC conversion system composed of photovoltaic arrays, boost converters, DC bus capacitors, N-cascaded H-bridge multilevel inverters (CHBMI) and an L-filter linked to a single-phase grid. This work aims at achieving threefold control objectives: i) regulating the voltages across the PV panels in order to extract the available maximum power, ii) guaranteeing a unitary power factor (UPF) by forcing the grid current to be sinusoidal and in phase with the electric network voltage, iii) controlling the DC-link voltages to track their given references. The achievement of these objectives is done thanks to a regulator based on a multi-loop structure. Indeed, on one hand, each panel is individually controlled to track the maximum power point; on the other hand, two cascaded loops aim at ensuring a satisfactory power factor correction and DC-link voltages regulation. The proposed regulator is developed using the nonlinear backstepping approach and some tools from Lyapunov stability. The simulation results, obtained using MATLAB/SIMULINK/ SimPower Systems environment, prove that the synthesized regulator meets its objectives and presents interesting performance in terms of tracking and regulation.
