Uncertainty Quantification in LV State Estimation Under High Shares of Flexible Resources

Abstract

The ongoing electrification introduces new challenges to distribution system operators (DSOs). Controllable resources may simultaneously react to price signals, potentially leading to network violations. DSOs require reliable and accurate low-voltage state estimation (LVSE) to improve awareness and mitigate such events. However, the influence of flexibility activations on LVSE has not been addressed yet. It remains unclear if flexibility-induced uncertainty can be reliably quantified to enable robust DSO decision-making. In this work, uncertainty quantification in LVSE is systematically investigated for multiple scenarios of input availability and flexibility utilization, using real data. For that purpose, a Bayesian neural network (BNN) is compared to quantile regression. Results show that frequent flexibility activations can significantly deteriorate LVSE performance, unless secondary substation measurements are available. Moreover, it is demonstrated that the BNN captures flexibility-induced voltage drops by dynamically extending the prediction interval during activation periods, and that it improves interpretability regarding the cause of uncertainty.

Threat Scenarios and Monitoring Requirements for Cyber-Physical Systems of Flexibility Markets

“…However, frequent activations may break correlation between the few available measurements (e.g. primary substation and weather data) and power system states at the end of LV feeders [25]. Thus, the implementation of FMs might deteriorate the accuracy of LV state estimation, making critical states potentially unobservable to DSOs.…”