Research on control strategy of a single-phase inverter with good output voltage quality

Abstract

As for the off-grid distributed power generation system, basic working principle of a single-phase inverter composed of the quasi-Z source inverter and the single-phase full-bridge inverter is studied in this paper. In terms of the former Quasi-Z source inverter, direct sample and control method of DC-link peak voltage is discussed. The PWM modulation strategy of the shoot-through duty cycle with no zero state is also analyzed, and make the Quasi-Z source inverter achieve the voltage-boosted function. For the latter single-phase full-bridge inverter, repetitive control and proportional control are combined to control the voltage loop, the THD of output voltage under a nonlinear load may be improved and the inverter has good output voltage quality, in the meanwhile, the quick dynamic response of the system is increased. The experimental results verify that the presented control strategy is valid and feasible.