Emulated Inertia and Damping of Converter-Interfaced Power Source

TL;DR

This paper presents a method to derive time-dependent emulated inertia and damping for converter-interfaced power sources, enhancing grid frequency support by modeling their dynamic response during frequency deviations.

Contribution

It introduces an analytical approach to explicitly calculate emulated inertia and damping from CIPS based on a linearized model of the power system.

Findings

Emulated inertia and damping are explicitly expressed as time-dependent functions.

The approach is based on a linearized model of CIPS and the power grid.

The method enhances understanding of CIPS dynamic response during frequency deviations.

Abstract

Converter-interfaced power sources (CIPSs), like wind turbine and energy storage, can be switched to the inertia emulation mode when the detected frequency deviation exceeds a pre-designed threshold, i.e. dead band, to support the frequency response of a power grid. This letter proposes an approach to derive the emulated inertia and damping from a CIPS based on the linearized model of the CIPS and the power grid, where the grid is represented by an equivalent single machine. The emulated inertia and damping can be explicitly expressed in time and turn out to be time-dependent.