The statistical spread of transmission outages on a fast protection time scale based on utility data

TL;DR

This paper analyzes the patterns of transmission line outages caused by protection systems, extracting statistical features from utility data and generating new outage patterns to improve large-grid disturbance simulations.

Contribution

It introduces a novel generative model for transmission outage patterns based on utility data, aiding in risk assessment of blackouts in large power systems.

Findings

Outage patterns follow identifiable statistical distributions.

A new index quantifies outage spread in the network.

Generated patterns match observed outage statistics.

Abstract

When there is a fault, the protection system automatically removes one or more transmission lines on a fast time scale of less than one minute. The outaged lines form a pattern in the transmission network. We extract these patterns from utility outage data, determine some key statistics of these patterns, and then show how to generate new patterns consistent with these statistics. The generated patterns provide a new and easily feasible way to model the overall effect of the protection system at the scale of a large transmission system. This new generative modeling of protection is expected to contribute to simulations of disturbances in large grids so that they can better quantify the risk of blackouts. Analysis of the pattern sizes suggests an index that describes how much outages spread in the transmission network at the fast timescale.