Control design and operation of photovoltaic systems in low voltage AC MicroGrid

MicroGrid (MG) is becoming an important system for a massive and reliable integration of renewable energy sources. Hence, due to its benefits, photovoltaic (PV) systems are the most suitable and widely used in MGs. However, for a reliable integration of PV panels, they must be interfaced by smart power electronics devices that allow the implementation of advanced control solutions. In addition to operating as active power generator with maximum power point tracking (MPPT), the new PV systems (PVS) should behave as ancillary services providers by participating to the grid regulation, such as frequency stabilization, voltage profile control, harmonics compensation and so forth. This paper aims at reviewing the control and operation of PVS in AC MG. Control structures, active power control, MPPT and inner loops are presented and discussed. Design, analysis and control of single-stage three phase PVS in AC MG that is able to operate at MPP or as a dispatchable source are made. The control structure is validated through dynamic simulations.