Grid-connected inverter is better

Grid-connected PV inverters have traditionally been thought as active power sources with an emphasis on maximizing power extraction from the PV modules. While maximizing power transfer remains a top priority, utility grid stability is now widely acknowledged to benefit from several auxiliary services that grid-connected PV inverters may offer.

Beginning with an introduction to the fundamentals of grid-connected inverters, the paper elucidates the impact of unbalanced grid voltages on their performance. Various control strategies, including voltage and current control methods, are examined in detail, highlighting their strengths and limitations in mitigating the effects of grid imbalance.

For instance, a network of small solar panels might designate one of its inverters to operate in grid-forming mode while the rest follow its lead, like dance partners, forming a stable grid without any turbine-based generation. Reactive power is one of the most important grid services inverters can provide.

In the grid-connected inverter, the associated well-known variations can be classified in the unknown changing loads, distribution network uncertainties, and variations on the demanded reactive and active powers of the connected grid.

This review paper provides a comprehensive overview of grid-connected inverters and control methods tailored to address unbalanced grid conditions. Beginning with an introduction to the fundamentals of grid-connected inverters, the paper elucidates the impact of unbalanced grid voltages on their performance.

However, these methods may require accurate modelling and may have higher implementation complexity. Emerging and future trends in control strategies for photovoltaic (PV) grid-connected inverters are driven by the need for increased efficiency, grid integration, flexibility, and sustainability.