Observed Acceleration of Cascading Outages

Matthias Noebels,Mathaios Panteli,Ian Dobson

doi:10.1109/tpwrs.2021.3071028

Matthias Noebels, Mathaios Panteli + Show 1 more

Open Access

https://doi.org/10.1109/tpwrs.2021.3071028

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Abstract

Accounts of extreme power outages of transmission systems suggest the acceleration of cascading outage propagation over time and the splitting of the cascade into a slow phase and a subsequent fast phase. This is significant to network operators, as mitigation actions, such as load shedding, can only be effectively applied during the slow phase. During the fast phase, the network disintegrates too quickly for any manual intervention. To supplement the accounts of extreme outages, we describe the observed acceleration of smaller and more common cascading outages by analyzing transmission outage data published by one North American utility. Our results show that these common cascades accelerate much less than the extreme cascades. This justifies ongoing research in mitigation strategies.

Highlights

C ASCADING outages are widely seen as one of the main mechanisms causing widespread blackouts of power networks [1]–[3]
We analyzed the acceleration of cascading outages recorded for some worldwide extreme cascading outages and the more common cascades recorded by one USA utility
Some of the extreme outages had a slow phase followed by a fast phase that was at least an order of magnitude faster than the slow phase, whilst common cascades showed a much more modest acceleration of up to a factor of two

Summary

INTRODUCTION

C ASCADING outages are widely seen as one of the main mechanisms causing widespread blackouts of power networks [1]–[3]. A cascading outage is the uncontrolled and successive loss of parts of a power network, usually triggered by one or more disturbance events such as extreme weather, equipment failure, or operational errors [4]. Preventing and mitigating cascading outages is crucial for improving power transmission network resilience. This letter uses utility data to investigate, for the first time, whether the observed acceleration of extreme cascading outages can be observed in the more common, smaller cascading outages that occur more frequently. These more common cascading outages are extracted from line outage data reported by one Northern American transmission utility.

ACCELERATION OBSERVED IN EXTREME CASCADES

Line Outages Per Generation

Decrease of Time Between Generations

CONCLUSION

Findings

Weather-Related Cascades