Large-signal modeling and stability analysis of two-cascaded boost converters connected to a PV panel under SMC with MPPT

In this paper, a system consisting of two cascaded dc-dc boost converters under sliding-mode control, working as loss free resistors, connected to a PV panel is studied. The modeling, simulation and design of the system are addressed. First, an ideal reduced-order sliding-mode dynamics model is derived from the full-order switched model taking into account the sliding constraints and stability analysis is carried out. It is shown that the cascade connection of boost-based loss free resistors can be a good solution for the impedance matching in PV systems with the standard 380 V dc bus voltage.