Review and Comparison of Grid-Tied Inverter Controllers in Microgrids
- Tommaso Caldognetto
Abstract
Grid-tied inverters are widely used for interfacing renewable energy
sources or storage devices to low-voltage electrical power distribution
systems. Lately, a number of different control techniques have been
proposed to address the emerging requirements of the smart power system
scenario, in terms of both functionalities and performance. This paper
reviews the techniques proposed for the implementation of
current-controlled or voltage-controlled inverters in microgrids. By
referring to a voltage source inverter with LCL output filter, the
different control architectures are classified as single-, double-, and
triple- loop. Then, the functionalities that are needed or recommended
in the grid-connected, islanded, and autonomous operating modes of the
grid-tied inverter are identified and their implementation in the
different control structures is discussed. To validate the analysis and
to better illustrate the merits and limitations of the most effective
solutions, six control strategies are finally implemented and
experimentally compared on a single-phase, grid-connected inverter
setup.