Page 13 - Resilienza sistema elettrico

Summary

Several outages of the power system have occurred in recent
years, especially due to severe weather phenomena related to cli-
mate change. These events require a deep reflection on the criteria
adopted in the design and maintenance of power system compo-
nents, in system planning and operation, and in the organisation of
the recovery after the disruption.
This monograph develops the topic of resilience in the context
of the power system. Resilience is indicated as a key concept for an
actual improvement of the electric supply service, as it synthesises
and overcomes the traditional criteria to evaluate the performances
of the quality of supply: indeed, it shall characterise the future evo-
lution of the system.
Speaking of resilience means first to analyse in detail the critical-
ities of the system, namely the causes and circumstances that lead
to power outages: meteorological factors and other factors, of natural
or human origin, can threaten the system through the presence of
vulnerabilities in the individual components or in the operating condi-
tion of the system. The major threats are described, with special focus
on the weather conditions and their effect on system components.
Resilience must be measured: in fact, it is necessary to rely on
quantitative criteria for the monitoring of resilience levels and as a
decision support tool to select the most appropriate interventions
for its improvement. The monograph proposes some indicators that
characterize the different aspects of resilience, both ex-post (i.e. used
to characterise past operation) and ex-ante (i.e. model-based for pos-
sible prediction of future performances). In particular, a probabilistic
risk method is proposed, that combines models of threats, vulnera-
bilities, and power system response.
Resilience is increased through various types of intervention,
mostly based on special design and adaptation of network compo-
nents, aimed to enhance them with respect to threats; the introduc-
tion of redundancy at planning level is another typical criterion. In
addition to this, it is possible to identify system operating solutions
to be activated when the threat occurs. These solutions may require
to install dedicated control systems.
There are many activities carried out by RSE in the context of re-
silience: studies, methodologies, tools. The monograph gives some ex-
amples, focusing in particular on the climatic and environmental as-
pects, and on global assessment of the resilience of the power system.

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