On the Incorporation of Stability Constraints into Sequential Operational Scheduling

TL;DR

This paper investigates how incorporating stability constraints into sequential power system operations, specifically unit commitment and AC optimal power flow, affects overall grid stability, emphasizing the importance of including these constraints for reliable operation.

Contribution

It provides a thorough analysis of the interaction between stability constraints in sequential operational stages and demonstrates their impact on power system stability through simulations.

Findings

Including stability constraints in UC is essential for stability.

Adding stability constraints in AC OPF improves the stability index.

Simulations show the importance of stability constraints for reliable operation.

Abstract

With the increasing penetration of Inverter-Based Resources (IBRs), power system stability constraints must be incorporated into the operational framework, transforming it into stability-constrained optimization. Currently, there exist parallel research efforts on developing the stability constraints within DC power flow-based unit commitment (UC) and AC Optimal Power Flow (OPF). However, few studies discuss how including such constraints can interact with each other and eventually impact grid stability. In this context, this work simulates a realistic power system decision making framework and provides a thorough analysis on the necessity of incorporating frequency nadir and small signal stability constraints into these sequentially connected two operation stages. The simulation results demonstrate that including both stability constraints in the UC is essential to maintain power system stability, while the inclusion in AC OPF can further improve the stability index.