Three-phase grid connected inverter for photovoltaic systems, a review

The inverter is an essential element in a photovoltaic system. It exists as different topologies. This review-paper focuses on different technologies for connecting photovoltaic (PV) modules to a three-phase-grid. The inverters are categorized into some classifications: the number of power processing stages; the use of decoupling capacitors and their locations; the use or no of the transformers; the type of three phase inverter; whether they are preceded by a DC/DC converter or not. Some of three-phase topologies are presented, compared according to the type of control (i.e. the PWM method; the bang-bang method or the fuzzy logic method or numerical control); and a comparison with single-phase inverters is given.