An Information Theoretic approach to identify Dominant Voltage Influencers for Unbalanced Distribution Systems

TL;DR

This paper introduces an information theoretic voltage influencing score (VIS) to efficiently identify dominant voltage influencer nodes in unbalanced distribution systems, aiding real-time voltage control with high accuracy.

Contribution

It proposes a novel, computationally efficient VIS metric based on information theory to identify DVI nodes, improving upon traditional power flow methods.

Findings

VIS accurately identifies DVI nodes with over 90% accuracy.

The method reduces computational burden by a factor of five.

Validated on IEEE 37-node system with effective results.

Abstract

Smart distribution grid with multiple renewable energy sources can experience random voltage fluctuations due to variable generation, which may result in voltage violations. Traditional voltage control algorithms are inadequate to handle fast voltage variations. Therefore, new dynamic control methods are being developed that can significantly benefit from the knowledge of dominant voltage influencer (DVI) nodes. DVI nodes for a particular node of interest refer to nodes that have a relatively high impact on the voltage fluctuations at that node. Conventional power flow-based algorithms to identify DVI nodes are computationally complex, which limits their use in real-time applications. This paper proposes a novel information theoretic voltage influencing score (VIS) that quantifies the voltage influencing capacity of nodes with DERs/active loads in a three phase unbalanced distribution system. VIS is then employed to rank the nodes and identify the DVI set. VIS is derived analytically in a computationally efficient manner and its efficacy to identify DVI nodes is validated using the IEEE 37-node test system. It is shown through experiments that KL divergence and Bhattacharyya distance are effective indicators of DVI nodes with an identifying accuracy of more than 90%. The computation burden is also reduced by an order of 5, thus providing the foundation for efficient voltage control.