Enhanced Modeling of Contingency Response in Security-constrained Optimal Power Flow

TL;DR

This paper introduces a smooth, physically accurate model for contingency response in security-constrained optimal power flow, improving the representation of generator behavior during contingencies.

Contribution

It presents a novel continuously-differentiable model that captures generator switching and response characteristics, enhancing the realism of contingency modeling in SCOPF.

Findings

Validated on IEEE test systems with multiple contingencies

Demonstrated improved modeling accuracy and operational limits

Showed computational feasibility for large-scale systems

Abstract

This paper provides an enhanced modeling of the contingency response that collectively reflects high-fidelity physical and operational characteristics of power grids. Integrating active and reactive power contingency responses into the security-constrained optimal power flow (SCOPF) problem is challenging, due to the nonsmoothness and nonconvexity of feasible sets in consequence of piece-wise curves representing generator characteristics. We introduce a continuously-differentiable model using functions that closely resemble PV/PQ switching and the generator contingency response. These models enforce physical and operational limits by optimally allocating active power imbalances among available generators and deciding the bus type to switch from the PV type to the PQ type. The efficacy of this method is numerically validated on the IEEE 30-bus, 300-bus, and 118-bus systems with 12, 10, and 100 contingencies, respectively.