A novel single phase high step-up buck-boost inverter for PV AC module

A novel single phase buck-boost step-up inverter for PV AC module is presented in this paper. To begin with, the paper analyzes the inverter´s operation principle, control strategy and steady-state characteristics in detail. What´s more, the validity of the theoretical analysis has been verified by the simulation results of a 250W/40kHz prototype. The measured THD of grid-connected current is 4.01% and the maximum efficiency is 98.4%. The analytical and simulation investigations show that: if the unipolar frequency doubling SPWM method is adopted, the proposed inverter can effectively boost the DC link voltage to ensure the achievement of grid-connected power generation, and it has the advantages of simple structure, easy to control, and high efficiency.