Abstract: An improved full-bridge grid-connected inverter is proposed. In the inverter topology,an AC decoupling unit is used to isolate the PV source from the grid in the current freewheeling periods,and the common-mode voltage is clamped to one-half of the DC bus through a bi-directional clamping circuit. So that,the common-mode voltage is ensured to be constant,and the common-mode leakage current is suppressed effectively. In this paper,the operation principle,modulation strategy,and the clamping circuit of the proposed inverter are presented,and a comparative analysis is carried out between the proposed inverter and the existing typical topologies. Finally,the proposed inverter is verified through simulation and experiments.