State-Derivative Feedback Control for Damping Low-Frequency Oscillations in Bulk Power Systems

TL;DR

This paper proposes a state-derivative feedback control method that improves damping of low-frequency oscillations in power systems with high renewable energy, outperforming existing schemes in simulation.

Contribution

Introduction of a novel state-derivative feedback damping controller that enhances modal damping and frequency recovery in power grids with power electronics.

Findings

SDF controller improves damping of inter- and intra-area oscillations.

SDF matches state-feedback performance in simulations.

Outperforms frequency difference-based damping schemes.

Abstract

Low-frequency oscillations remain a major challenge in bulk power systems with high renewable penetration, long lines, and large loads. Existing damping strategies based on power modulation of high voltage DC (HVDC) or energy storage, are often limited by fixed control architectures, leaving some modes poorly damped. This paper introduces a state-derivative feedback (SDF) damping controller that uses both frequency and its rate of change as feedback signals. Incorporating state derivatives enhances modal damping and accelerates frequency recovery, enabling HVDC and energy storage to effectively stabilize the grid. We evaluate the SDF controller on two- and three-area systems and compare performance with a frequency difference-based damping scheme. Results show that the SDF control reproduces state-feedback performance while providing good damping of both inter- and intra-area oscillations compared to the frequency-difference method, highlighting its potential as a practical solution for stabilizing power-electronics-rich grids.