Backstepping Control for Maximum Power Tracking in Single- Phase Grid-Connected Photovoltaic Systems

摘要

The problem of maximum power point tracking (MPPT) in photovoltaic (PV) arrays is addressed considering a PV system including a PV panel, a PWM DC/AC inverter connected to single-phase grid. The maximum power point (MPP) of PV generators varies with solar radiation and temperature. To reduce the PV system cost, the MPPT is presently achieved without, chopper, resorting to solar radiation and temperature sensors. The proposed strategy involves a multi-loop nonlinear controller designed, using the backstepping design technique, to meet the three main control objectives i.e. (i) voltage reference generator designed to meet maximum power point tracking (MPPT), (ii) tight DC Link voltage regulation for a wide range voltage-reference variation and power factor correction (PFC) requirement must be satisfactorily realized. A formal analysis based on Lyapunov stability is developed to describe the control system performances. It is formally shown that the developed strategy control actually meets the MPPT requirement.