Control of a single-switch two-input buck converter for MPPT of two PV strings

Abstract

© 2014 ACPE. In this paper, the configuration composed by a Two-Input Buck (TIBuck) converter and a boost inverter is proposed for low-voltage grid-connected PV systems. This configuration is attractive for this application because it has high efficiency and can achieve dual maximum power point tracking (MPPT) with only one active switch. However, in this system, the nonlinear characteristics of the converter and the two PV arrays complicate the control. By means of a small-signal modeling, the control theme of the two PV voltages is formulated and the effect of the nonlinearities is presented. Simulation results are reported to validate the theoretical analysis, showing the dual MPPT capability