Robust control design for a boost converter in a photovoltaic system

A robust H_∞ control design based on linear matrix inequality (LMI) is presented in this paper to control a DC-DC boost converter in a photovoltaic system. The design method considers converter nonlinearities, modelled as a convex polytope, and achieves H_∞ performance, in terms of load disturbance rejection, as well as system stability. A 6kW PV system is considered as an application example to test the designed controller performance in presence and absence of parametric uncertainties. The results comparison shown the better performance and less power dissipation of this approach in compared with direct duty cycle control method. The proposed approach is also compared non-quantitatively and quantitatively with a non-linear LQR controller to elaborate performance superiority of the proposed method. This new approach achieves faster tracking of reference maximum power voltage provided by MPPT with less oscillation.