Three-Phase Photovoltaic Systems: Structures, Topologies, and Control

Photovoltaic (PV) technology has experienced an unprecedented growth in the last two decades, transforming from mainly an off-grid niche generation to a major renewable energy technology, reaching approximately 227 GW of capacity worldwide at the end of 2015 with a predicted extra 50 GW of new installations for 2016 [1]. Large PV power plants interfacing the grid through a three-phase power electronic converter are now well on the way to become a major player in the power system in many countries. Therefore, this chapter gives an overview of PV systems with a focus on three-phase applications from a hardware point of view, detailing the different PV inverter structures and topologies and discussing the different control layers within a grid-connected PV plant. Modulation schemes for various PV inverter topologies, grid synchronization, current control, active and reactive power control, maximum power point tracking, and grid integration requirements and support functions are also reviewed.