Review and Comparison of Single-Phase Grid-Tied Photovoltaic Microinverters

The presence of the electrical isolation between the PV module and the grid is very crucial aspect in determining the performance requirement as well as the utility operator's specs of the PV microinverter design. The grid-connected PV microinverter design can be classified into transformer-less and transformer-based topologies in regard to the galvanic isolation. Typically, a microinverter's performance can be enhanced with the use of transformer-less topologies to be more efficient, compact, less bulky, and costly than the transformer-based topologies. Whereas, the use of transformer in microinverter topologies provides high power quality as well as galvanic isolation to eliminate the safety issues which in return meet the grid standards. In this paper, to address the various challenges of microinverters, a number of experimentally verified non-isolated and isolated microinverters have been carefully reviewed and compared in terms of their corresponding efficiency, power density, reliability, and cost.