Dynamic Estimation of Power System Inertia Distribution Using Synchrophasor Measurements

TL;DR

This paper introduces a real-time method for estimating power system inertia distribution using PMU data, accounting for measurement location and oscillations, to improve grid stability assessment.

Contribution

It presents a novel PMU-based dynamic inertia estimation technique that considers measurement location and oscillations, and identifies low inertia areas in real time.

Findings

Effective estimation of inertia distribution demonstrated on IEEE 24-bus system.

Identification of low inertia areas enhances grid stability monitoring.

Method accounts for measurement location and oscillations.

Abstract

Integration of intermittent renewable energy sources in modern power systems is increasing very fast. Replacement of synchronous generators with zero-to-low variable renewables substantially decreases the system inertia. In a large system, inertia distribution may vary significantly, areas of low inertia are more susceptible to frequency deviation, posing risks of load shedding and generation trip. Therefore, it is necessary for operators to evaluate and quantify the system inertia and its distribution in real time. This paper proposes a novel synchronized phasor measurement units (PMUs)-based dynamic system inertia estimation method. The proposed inertia estimation method is derived using electrical distance and clustering algorithm, which considers the impact of location of measurements relative to in-feed load and impact of oscillations. The center of inertia (COI) area and area of low inertia are also determined during the estimation. Numerical simulations are conducted on the IEEE 24-bus system with various load profiles using Transient Security Analysis Tools (TSAT), a core module of the DSATools, which demonstrate the efficacy of the proposed approach.