Inertia-aware Unit Commitment and Remuneration Methods for Decarbonized Power System

TL;DR

This paper develops an inertia-aware unit commitment model for decarbonized power systems, incorporating renewable uncertainty and proposing remuneration methods, with convex hull pricing emerging as the most effective for economic and frequency stability.

Contribution

It introduces a novel inertia-aware unit commitment model with joint chance constraints and evaluates multiple remuneration methods, highlighting convex hull pricing as optimal.

Findings

aCHP guarantees revenue adequacy without uplift

Model improves frequency stability during contingencies

MP requires high uplift due to inadequate price reflection

Abstract

To maintain frequency stability in decarbonized power systems, inertia services from synchronous generators (SGs) and inverter-based resources must be procured. However, designing an inertia-aware system operation poses significant challenges in considering the variability and uncertainty of renewable energy sources (RES) and adopting a remuneration method for inertia provision due to SG commitment variables. To address this research gap, we renovate the inertia-aware chance constraints unit commitment model by incorporating time-coupling constraints for SGs and joint chance constraints for RES uncertainty. We investigate remuneration methods for inertia provision, including uplift, marginal pricing (MP), approximated convex hull pricing (aCHP), and average incremental cost pricing (AIP), applying these to the renovated model. Numerical experiments show that the model enhances frequency stability during a contingency. Among the remuneration methods, only aCHP guarantees revenue adequacy without requiring uplift while maximizing economic welfare. However, the MP requires the highest level of uplift to adequately compensate generation costs, as the price function fails to account for inertia provision.