To suppress the leakage current of traditional dual-buck grid-connected inverters

a novel non-isolated cascaded dual-buck grid-connected inverter topology（CDBGCI） and dual-carrier sinusoidal pulse width modulation（DCSPWM） strategy were proposed. The high-frequency and low-frequency common-mode equivalent models of CDBGCI were established by the method of common-mode equivalent circuit

and the high-frequency and low-frequency common-mode leakage currents of the inverters are analyzed in detail

respectively. The research results show the high-frequency common-mode voltage of the novel cascaded inverter keeps a constant value during a power frequency period

and the leakage current is less than 300 mA

so the high-frequency common-mode current is effectively suppressed. Meanwhile

compared with asymmetric CDBGCI

symmetric CDBGCI has a smaller low-frequency common-mode leakage current

and the high-frequency common-mode leakage current can be suppressed when n dual buck grid-connected inverters are cascaded. Finally

the results can provide references for the research of cascade grid-connected inverter topology and leakage current suppression.