Robust Dynamic Operating Envelopes for Flexibility Operation Using Only Local Voltage Measurement

Locational marginal prices (LMP) are the dual variables associated with the power balance constraint of the optimal power flow (OPF) problem. Prior works on LMP calculation and forecasting shows that LMP is composed of generation cost, marginal loss cost and distribution network (DN) congestion cost. The focus of this work is to estimate the congestion component of LMP for radial DNs with only local parameter measurements. The true congestion component of LMP is derived by solving an OPF without penalizing the DN loss or generation cost. The estimated component of the LMP, referred to as the flexibility activation signal (FAS), is derived as a function of the nodal voltage profile at the point of common coupling (PCC) and the line loading of incoming and outgoing branches from PCC. The estimated and true congestion components of LMP for all nodes are analyzed via time series analysis using Granger causality and sensitivity and specificity of estimation output. Numerical case studies provide statistical evidence that voltage times series can be utilized to estimate congestion component of DN OPF. Further, we also show that with local parameter measurements such as line loading and/or voltage measurements can accurately estimate DN congestion incidents with an accuracy exceeding 95%. Although, localized congestion estimation is not entirely accurate, however, such a method is privacy-preserving, desired for autonomous operation without the need for centralized communication. Thus, proposed decentralized FAS estimation is inherently cyber-secure and resilient to external attacks, while mitigating DN congestion.

show abstract

Identifying Secure Operating Ranges for DER Control Using Bilevel Optimization

Girigoudar,

Roald

2024

IEEE Trans. Smart Grid

View full text Add to dashboard Cite

Active distribution grids are accommodating an increasing number of controllable electric loads and distributed energy resources (DERs). A majority of these DERs are managed by entities other than the distribution utility, such as individual customers or third-party aggregators, who control the loads and DERs without consideration of any distribution grid constraints. This makes it challenging for a distribution system operator (DSO) to allow third-party aggregators and transmission operators to fully exploit the flexibility offered by these resources while also ensuring that distribution grid constraints such as voltage magnitude limits are not violated. In this paper, we develop a bilevel optimization-based framework to determine the aggregate power flexibility that can be obtained from an unbalanced distribution grid while ensuring that there is no disaggregation solution that leads to grid constraint violations. The results are a set of constraints and operating rules that are easy to communicate, and which provide the entities that procure flexibility from DERs (e.g. transmission operators or third-party aggregators) with the ability to freely implement their own disaggregation strategy without intervention from the DSO. The proposed approach is tested on two unbalanced distribution feeders and our simulation results indicate that it is possible to determine a wide range of aggregate power flexibility, as long as a simple set of rules for DER control activation are followed.

show abstract

Robust Dynamic Operating Envelopes for Flexibility Operation Using Only Local Voltage Measurement

Cited by 3 publications

References 22 publications

Comparison of market designs ensuring network integrity in low voltage distribution systems with high DER penetration

Comparison of market designs ensuring network integrity in low voltage distribution systems with high DER penetration

Estimation of congestion component of LMP using only local measurements for flexibility markets

Identifying Secure Operating Ranges for DER Control Using Bilevel Optimization

Contact Info

Product

Resources

About