Joint Estimation of System Inertia and Load Relief

TL;DR

This paper introduces a new method for simultaneously estimating system inertia and load relief in power systems using a closed-form frequency response model, improving accuracy over traditional methods.

Contribution

A novel closed-form SFR-based procedure for joint estimation of system inertia and load relief, addressing limitations of conventional linear methods.

Findings

Method validated on Western Australia's power system data.

Outperforms traditional inertia estimation techniques.

Demonstrates improved accuracy in dynamic system assessment.

Abstract

Modern power systems with high share of renewable generation are at the risk of rapid changes in frequency and inertia resulting from contingencies. The importance of an accurate assessment of system and load relief, as well as frequency changes in the critical timescales is more pronounced in these power systems. This knowledge serves as an insight which will guide the solutions required for enhanced security and resilience. A novel procedure for simultaneously assessing system inertia and load relief using a closed-form system frequency response (SFR) model to fit measured disturbance data is presented. Results of applying the proposed approach on generator contingencies in the South West Interconnected System (SWIS) in Western Australia demonstrate the validity of the method and indicate that it can overcome some of the limitations observed in conventional inertia estimation methods based on the linearised swing equation, such as the sliding window and polynomial fit methods.