Short Circuit Current Constrained UC in High IBG-Penetrated Power Systems

TL;DR

This paper introduces a unit commitment model with explicit short circuit current constraints tailored for high inverter-based generator penetration, aiming to enhance system protection and stability while minimizing operational costs.

Contribution

It develops a novel SCC-constrained UC model incorporating decision-dependent matrix inverse and linear reformulation, addressing challenges posed by inverter-based generators.

Findings

SCC constraints impact system operation and cost.

The model effectively maintains SCC levels in high IBG scenarios.

Simulation results demonstrate improved system stability.

Abstract

Inverter Based Generators (IBGs) have been increasing significantly in power systems. Due to the demanding thermal rating of Power Electronics (PE), their contribution to the system Short Circuit Current (SCC) is much less than that from the conventional Synchronous Generators (SGs) thus reducing the system strength and posing challenges to system protection and stability. This paper proposes a Unit Commitment (UC) model with SCC constraint in high IBG-penetrated systems to ensure minimum operation cost while maintaining the SCC level at each bus in the system. The SCC from synchronous generators as well as the IBGs are explicitly modeled in the formulation leading to an SCC constraint involving decision-dependent matrix inverse. This highly nonlinear constraint is further reformulated into linear form conservatively. The influence of the SCC constraint on the system operation and its interaction with the frequency regulation are demonstrated through simulations on IEEE 30- and 118-bus systems.