The grid, it's reliablity, why they 'go down'
To the un-initiated, Electrical System design (power grid/generation design) with an eye towards 'reliability' falls in the category of 'moving target'; correct one aspect of 'system failure' and, given time, another un-addressed facet will rear it's ugly head ...
Why is this so the layman asks?
We continue to build larger systems and more interconnected systems as well as experience different circumstances thrown at us from mother nature's direction, both in terms of events (like ice storms, electrical storms, ion storms) but also from the unpredictability of how materials/equipment react sometimes in adverse and severe environment as when stressed during unforseen circumstances
From: http://eetd.lbl.gov/certs/pdf/Dobson_4.pdf
Blackout Mitigation Assessment in Power Transmission Systems Electric power transmission systems are a key infra- structure and blackouts of these systems have major direct and indirect consequences on the economy and national security.
Analysis of North American Electrical Reliability Council blackout data suggests the existence of blackout size distributions [are proportional or related with] with power tails [system size or complexity]. This is an indication that blackout dynamics behave as a complex dynamical system. Here, we investigate how these complex system dynamics impact the assessment and mitigation of blackout risk.
The mitigation of failures in complex systems needs to be approached with care. The mitigation efforts can move the system to a new dynamic equilibrium while remaining near criticality and preserving the power tails.
Thus, while the absolute frequency of disruptions of all sizes may be reduced, the underlying forces can still cause the relative frequency of large disruptions to small disruptions to remain the same.
Moreover, in some cases, efforts to mitigate small disruptions can even increase the frequency of large disruptions. This occurs because the large and small disruptions are not independent but are strongly coupled by the dynamics.
...
In this paper, we focus on the intrinsic dynamics of blackouts and how complex system dynamics affect both blackout risk assessment and the impact of mitigation techniques on blackout risk. It is found, perhaps counterintuitively, that apparently sensible attempts to mitigate failures in complex systems can have adverse effects and therefore must be approached with care.