Assessing Zonal System Inconsistencies on Power Network Security in Real-Time Operations

Zonal market systems encounter numerous challenges associated with network congestion. Controlling cross-border power flows at the zonal level further exacerbates issues such as unexpected violations of capacity limits on both intra- and inter-zonal transmission lines. In day-ahead markets, re-dispatch processes can alleviate some of these problems. However, in balancing markets, there is no time to address these inconsistencies. Such discrepancies in real-time operations are directly related to the safety concerns of the network. In this talk, we introduce a method for analyzing the discrepancy between nodal and zonal systems. Nonlinear behaviors of zonal systems, due to the merit order for each zone, are captured using merit-order constraints with binary variables. This allows us to represent the true feasible region of zonal net positions that ensures security in real-time operations. By comparing this feasible region subject to merit-order constraints with the one derived from existing zonal models, one can determine the extent of system distortion in terms of feasibility. We analyze the conditions under which zonal systems can avoid congestion and evaluate the impact and usefulness of the minimum cross-border capacity policy.

About Jehum

Jehum Cho is an assistant professor at the Erasmus University of Rotterdam. His current research focuses on energy systems optimization, electricity market designs and optimization under uncertainty.