Modeling and control of a high boost ratio PV module DC-DC converter with double grid-line ripple rejection

This paper derives the small-signal model and designs the controller for a high boost ratio dc-dc converter with the application for PV modules. A voltage controller with proportional-integral (PI) cascaded quasi-resonant (QR) controllers is presented for an inner PV voltage loop of maximum power point tracking (MPPT) control. Here, PI controller provides fast-tracking of voltage reference and maintains zero steady-state error, while QR controller with resonant frequency equal to double grid-line (DGL) frequency provides high rejection capability of DGL oscillation of PV module voltage. As a result, the MPPT control algorithm can be free from DGL ripple oscillation and the MPPT efficiency can be improved. Experimental results based on a 250W prototype board confirm the effectiveness of the modeling and the proposed control method.