  Solar micro-inverters are becoming increasingly popular as they are modular,
and they posses the capability of extracting maximum available power from the
individual photovoltaic (PV) modules of a solar array. For realizing
micro-inverters single stage transformer-less topologies are preferred as they
offer better power evacuation efficacy. A SEPIC-\'Cuk based transformer-less
micro-inverter, having only one high frequency switch and four line frequency
switches, is proposed in this paper. The proposed converter can be employed to
interface a 35 V PV module to a 220 V single phase ac grid. As a very high gain
is required to be achieved for the converter, it is made to operate in
discontinuous conduction mode (DCM) for all possible operating conditions.
Since the ground of the each PV modules is connected to the ground of the
utility, there is no possibility of leakage current flow between the module and
the utility. Detailed simulation studies are carried out to ascertain the
efficacy of the proposed micro-inverter. A laboratory prototype of the inverter
is fabricated, and detailed experimental studies are carried out to confirm the
viability of the proposed scheme.
