Control of a three-phase grid-connected inverter for photovoltaic applications with a fuzzy MPPT under unbalanced conditions

Grid codes are being revised to include additional requirements for renewable energy, as the installed power increases. Therefore it is needed to develop control systems that are able to fulfil those new requirements, which usually include the ability to operate under unbalanced grid voltages without polluting the grid, among others. This paper presents a three-phase inverter for connection of photovoltaic generators to the grid, with a fuzzy maximum power point tracking and the ability to control reactive power. The main feature of the inverter is that the control system has been designed to deal with unbalanced voltage conditions.