Photovoltaic (PV) energy has grown at an average annual rate of 60% in the last five years, surpassing one third of the cumulative wind energy installed capacity, and is quickly becoming an important part of the energy mix in some regions and power systems. This has been driven by a reduction in the cost of PV modules. This growth has also triggered
the evolution of classic PV power converters from conventional single-phase grid-tied inverters to more complex topologies to increase efficiency, power extraction from the modules, and reliability without impacting the cost. This article
presents an overview of the existing PV energy conversion systems, addressing the system configuration of different PV plants and the PV converter topologies that have found practical applications for grid-connected systems. In addition, the recent research and emerging PV con-
verter technology are discussed, highlighting their possible advan-
tages compared with the present technology.Solar PV energy conversion systems have had a huge growth
from an accumulative total power equal to approximately 1.2 GW in 1992 to 136 GW in 2013 (36 GW during 2013) [1]. This phenomenon has been possible because of several factors all working together to push the PV energy to cope with one important position today (and
potentially a fundamental position in the near future). Among these factors are the cost reduction and increase in efficiency of the PV modules, the
search for alternative clean energy sources (not based on fossil fuels), increased environmental awareness, and favorable political regulations from local governments (establishing feed-in tariffs designed to accelerate investment in renewable energy technologies). It has become usual to see PV systems installed on the roofs of houses or PV farms next to the roads in the countryside.Grid-connected PV systems account for more than 99% of the
PV installed capacity compared to