Selecting combinations of reinforcement actions to improve the reliability of distribution grids in the face of external hazards

Decisions concerning reinforcing distribution grids are complicated by the interaction of multiple hazards and reinforcement actions. This creates a need for a systemic approach to assessing how the system’s reliability depends on these interactions.

In this paper, we develop a systemic framework to support a distribution system operator to reinforce and protect multiple distribution grids. We address the problem of choosing between alternative combinations of reinforcement actions under budget constraints, minimum reliability standards, and different hazards. In the framework, this problem is structured as an influence diagram containing scenarios representing different combinations of hazards. The optimization problem is solved using techniques of Portfolio Decision Analysis (PDA) from a mixed integer linear problem which incorporates risk measures such as conditional value at risk (CVaR) to maximize reliability. We showcase the framework with an illustrative study case in which the operator considers several reinforcement actions to mitigate the risks posed by different hazards in two distribution grids.

The proposed approach is novel in combining the strengths of the PDA with existing reliability models and expert judgments to account for interactions between hazards and reinforcement actions. In particular, it exploits synergies to propose cost-efficient combinations of reinforcement actions.

Keywords: Decision analysis, Influence diagrams, System reliability, Risk management, Distribution grids.

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