Optimizing Transmission Infrastructure Investments to Support Line De-energization for Mitigating Wildfire Ignition Risk

Abstract

Wildfires pose a growing risk to public safety in regions like the western United States, and, historically, electric power systems have ignited some of the most destructive wildfires. To reduce wildfire ignition risks, power system operators preemptively de-energize high-risk power lines during extreme wildfire conditions as part of "Public Safety Power Shutoff" (PSPS) events. While capable of substantially reducing acute wildfire risks, PSPS events can also result in significant amounts of load shedding as the partially de-energized system may not be able to supply all customer demands. In this work, we investigate the extent to which infrastructure investments can support system operations during PSPS events by enabling reduced load shedding and wildfire ignition risk. We consider the installation of grid-scale batteries, solar PV, and line hardening or maintenance measures (e.g., undergrounding or increased vegetation management). Optimally selecting the locations, types, and sizes of these infrastructure investments requires considering the line de-energizations associated with PSPS events. Accordingly, this paper proposes a multi-period optimization formulation that locates and sizes infrastructure investments while simultaneously choosing line de-energizations to minimize wildfire ignition risk and load shedding. The proposed formulation is evaluated using two geolocated test cases along with realistic infrastructure investment parameters and actual wildfire risk data from the US Geological Survey. We evaluate the performance of investment choices by simulating de-energization decisions for the entire 2021 wildfire season with optimized infrastructure placements. With investment decisions varying significantly for different test cases, budgets, and operator priorities, the numerical results demonstrate the proposed formulation's value in tailoring investment choices to different settings.

Managing Wildfire Risk and Promoting Equity through Optimal Configuration of Networked Microgrids

“…A framework to assess the wildfire risk of power lines and select overhead power lines to convert to underground cables is presented in [42]. Also, the authors of [25] optimize line undergrounding, in conjunction with vegetation management and placement of distributed energy resources, to reduce ignition risk and power shutoffs.…”

Sharing the Load: Considering Fairness in De-energization Scheduling to Mitigate Wildfire Ignition Risk using Rolling Optimization

“…In the third considered fairness method, we aim to minimize the range of load shed, which requires the introduction of two variables, S min and S max , for the minimum and maximum cumulative discounted load shed at a single bus, respectively. That is, we enforce constraint (11) and:…”

“…Results from [9] suggest that the optimized PSPS formulation allows system operators to evaluate the tradeoff between wildfire risk and system-wide load shedding, and potentially improve performance relative to a threshold-based approach. Building on this prior work, subsequent research has considered alternate wildfire risk models [7] and infrastructure investment plans to support optimized PSPS events [11].…”

Recursive restoration refinement: A fast heuristic for near-optimal restoration prioritization in power systems

“…Other research uses the Optimal Power Shutoff problem as a basis to plan infrastructure upgrades that minimize the impact of PSPS or reduce the need for PSPS in the future. Resilience through battery installations or under-grounding of lines is studied in [32]- [35], resilience through microgrid operations in [36], [37], and load shifting through energy storage to reduce power outages in [38]. Other OPS research considers extensions necessary for distribution grids [39], concurrent planning of PSPS and grid restoration [40], considerations of fairness for load outages [41], improved forecasting of wildfire ignition risk [31], [42], and dynamic line rating to reduce current rather than fully de-energize lines [43].…”

“…Refs. [11], [12], [22], [28]- [30], [32], [38], [40], [43], [44] all note the need for security constraints to ensure safe operations in future work, however, none of these works include such security constraints on grid operations.…”