Review of Dual-Buck-Type Single-Phase Grid-Connected Inverters

Shoot-through issue of traditional bridge-type grid-connected inverters (GCIs) imposes a risk to GCIs' reliability and efficiency, so dual-buck-type single-phase GCIs are widely used in the applications requiring high reliability and high efficiency. These types of GCIs are reviewed in this article. As there is no shoot-through issue in the reviewed inverters, reliability of the inverters is improved. The dead time between switches are not required, so quality of the grid current is high. Freewheeling current flows through the independent freewheeling diode instead of the body diode of the switch, so efficiency of the system can be improved. Topologies of the dual-buck-type single-phase GCIs can be divided into two categories, i.e., buck and boost GCIs. Derivation of the reviewed topologies is given. Modulation strategies of the presented GCIs are illustrated. Different dual-buck-type topologies are compared. Finally, applications of the dual-buck-type single-phase GCIs are given.