Prescriptive Grid-Tied Inverter Control

This article introduces a prescriptive control approach that improves the performance of grid-tied inverters. The current mainstream of contributions is predominantly based on combinations of canonical feedback actions, i.e., proportional (
${P}$
), integral (
${I}$
), derivative (
${D}$
), and resonant (
${R}$
). However, this classical view cannot synthesize suitable “intermediate” controller structures—which are not necessarily PIDR interconnections. In contrast, the proposed approach prescribes desired dynamics as initial step, and then synthesizes the exact feedback that enforces such prescription. It is also shown that prescriptive control is downward compatible with the popular PR control. The latter reaches only a narrow set of dynamical responses, since it is neglects crucial signal components, native to the proposed setting—which can improve the inverter performance in terms of achieving short settling times, small overshoots, robustness, and wide stability margins. Simulations and experiments are reported using a single-phase grid-tied inverter with an LCL filter.