Effect of Voltage Source Converters with Electrochemical Storage Systems on Dynamics of Reduced-inertia Bulk Power Grids

TL;DR

This paper investigates how voltage source converters with battery energy storage systems influence the dynamic stability of power grids with reduced inertia, using a modified IEEE 39-bus test system and real-time simulations.

Contribution

It extends the IEEE 39-bus test network to include VSC-based BESS in a reduced-inertia grid, analyzing their impact on system dynamics and control strategies.

Findings

VSC-BESS can improve stability in reduced-inertia grids.

Different VSC control strategies have distinct effects on system response.

Real-time simulation validates the impact of VSCs on grid dynamics.

Abstract

A major concern associated to the massive connection of distributed energy resources is the increasing share of power electronic interfaces resulting in the global inertia reduction of power systems. The recent literature advocated the use of voltage source converter (VSC) interfaced battery energy storage system (BESS) as a potential way to counterbalance this lack of inertia. However, the impact of VSCs on the dynamics of reduced-inertia grids is not well understood especially with respect to large transmission grids interfacing a mix of rotating machines and resources interfaced with power electronics. In this regards, we propose an extension of the IEEE 39-bus test network used to quantify the impact of VSCs on reduced-inertia grids. In this respect, a reduced-inertia 39-bus system is obtained by replacing 4 synchronous generators in the original 10-synchronous machine system, with 4 wind power plants modeled as aggregated type-3 wind turbines. Then, a large-scale BESS is integrated into the reduced-inertia network via a three-level neutral-point clamped (NPC) converter, thereby to be used for studying the impact of VSC on the dynamics of the inertia-reduced power system, as well as for comparing different VSC controls. The proposed models are implemented on a real-time simulator to conduct post-contingency analysis, respectively, for the original power system and the reduced-inertia one, with and without the BESS-VSC.