Cooperative operation of inverters for grid-connected photovoltaic generation systems

This paper presents a three-phase cooperative power injection system for a grid-connected photovoltaic generation system that is based on the parallel association of two voltage source inverters: one is a multilevel neutral point clamped operated with a low switching frequency strategy and the other is a 2-level inverter which operates with a typical switching frequency deadbeat current control. The aim of this topology is to inject the power with the multilevel inverter and control the current quality with the traditional one. The proposal optimizes the system design, allowing high power injection into the three-phase grid, reducing the system losses and maintaining low harmonic distortion. The topology is validated through simulation and experimental results. (C) 2012 Elsevier B.V. All rights reserved.