Inverse optimal control for angle stabilization in converters-based generation

TL;DR

This paper applies inverse optimal control to design a feedback controller for stabilizing phase angles in converter-based power systems, ensuring optimality and stability with practical implementation and simulation validation.

Contribution

It introduces a novel inverse optimal control approach for angle stabilization in converter-based systems, with a practical distributed controller design and comparative simulation results.

Findings

The inverse optimal controller stabilizes phase angles effectively.

The distributed angular droop controller achieves active power-angle droop behavior.

Simulation shows improved stability over standard frequency droop control.

Abstract

In inverse optimal control, the optimality of a given feedback stabilizing controller is a byproduct of the choice of a meaningful, a posteriori defined, cost functional. This allows for a simple tuning comparable to linear quadratic control, also for nonlinear controllers. Our work illustrates the usefulness of this approach in the control of converter-based power systems and networked systems in general, and thereby in finding controllers with topological structure and known optimality properties. In particular, we design an inverse optimal feedback controller that stabilizes the phase angles of voltage-source controlled DC/AC converters at an induced steady state with zero frequency error. The distributed angular droop controller yields active power to angle droop behavior at steady state. Moreover, we suggest a practical implementation of the controller and corroborate our results through simulations on a three-converter system and a numerical comparison with standard frequency droop control.