Pricing inertia and Frequency Response with diverse dynamics in a Mixed-Integer Second-Order Cone Programming formulation

TL;DR

This paper introduces a novel optimization framework using MISOCP to procure and value diverse frequency response services, including multi-speed FR, in power grids with low inertia and high renewable penetration.

Contribution

It presents the first MISOCP-based approach to optimally value multi-speed frequency response and inertia services in frequency-secured power system operation.

Findings

Effective procurement of inertia and FR with diverse dynamics.

Marginal pricing scheme for multi-speed FR.

Enhanced frequency security in low-inertia grids.

Abstract

Low levels of system inertia in power grids with significant penetration of non-synchronous Renewable Energy Sources (RES) have increased the risk of frequency instability. The provision of a certain type of ancillary services such as inertia and Frequency Response (FR) is needed at all times, to maintain system frequency within secure limits if the loss of a large power infeed were to occur. In this paper we propose a frequency-secured optimisation framework for the procurement of inertia and FR with diverse dynamics, which enables to apply a marginal-pricing scheme for these services. This pricing scheme, deduced from a Mixed-Integer Second-Order Cone Program (MISOCP) formulation that represents frequency-security constraints, allows for the first time to appropriately value multi-speed FR.