IEEE Power & Energy Magazine - March/April 2018 - 28

with which operators have the most experience. more rarely,
the system moves into the alert, emergency, and restorative states. However, such situations are encountered often
enough that control-room personnel train for them and, for
the most part, have adequate tools to deal with them. truly
enhancing grid resiliency requires tools to deal with the
much more difficult in extremis situations. as noted by the
north american electric reliability corporation (nerc)
in its 2012 report on resilience, during such an event, the
previously interconnected grid may be broken into a number
of electrical islands, and the operation of these islands may
need to be performed by entities not normally responsible
for grid operations.
the degree to which blackouts can be minimized or prevented during such in extremis situations depends on the
triggering event itself, as well as the availability of a combination of strategies ranging across time frames-from
real-time operations to asset and outage management to
potentially planning years ahead. a wide variety of different events can place a system in this operating state, each
having its own horizon of warning time. the most common
would be the more severe manifestations of relatively typical
weather conditions, which could induce large-scale storm
systems-potentially including tornados and ice storms.
Warning times in such situations would be, at most, hours.
Hurricanes can, of course, cause severe damage, but they
usually come with a longer warning period of at least a day
or more. in contrast, high-intensity earthquakes can cause
widespread damage with essentially no warning time.

Normal (N-1 Reliable)

Restorative

Alert

In Extremis

Emergency

figure 1. The power system operating states (adapted from
IEEE Spectrum, 1978).

Slow

Market
Incomplete

Normal
Market
Conditions

Fast

Slow

Market
Emergency

figure 2. Market operating states. (Source: EPRI.)
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ieee power & energy magazine

an emerging area of concern is what nerc calls highimpact, low-frequency (or HiLF) events. these are statistically unlikely but still plausible events that, should they
occur, could have catastrophic consequences on the grid and
thus many everyday lives. included in this group are largescale cyber or physical attacks, pandemics, electromagnetic
pulses (emPs), and geomagnetic disturbances (gmds). in
such cases, the length of warning time might be essentially
zero for cyber/physical attacks and emPs to hours for gmds
to potentially days or weeks for pandemics.
the following discussion focuses on time horizons for
which predictions are available within time frames that
allow operators or other utility staff to take actions that can
mitigate the impact of catastrophic events by reducing the
risk of incurring outages. to illustrate various applications
in the planning, operations, and asset and outage management time horizons, we provide examples of advanced ems
and dms tools that deal with risk reduction and mitigation.

Resiliency in the Economics of Energy
Exchange: The Market Operating States
the goal of resiliency for the physical electric grid is to
ensure continuous energy exchange between producers and
consumers. While the objective of reliability is to "keep the
lights on," the goal of resiliency in the context of energy
exchange is to "keep the markets on" at all times.
the history of market deregulation in the United states
is long, starting as early as 1935 when congress passed the
Public Utilities Holding company act. the act included
many new rules regarding the ways in which energy could
be sold. as the oil crisis hit in the 1970s, regulators began to
introduce energy conservation rules (up until 1974). despite
this, the price of oil remained high. as a result, much of the
legislation approved throughout this decade related to utilizing other forms of energy to reduce U.s. dependence on
oil or fossil fuels. in 1992, the national energy Policy act
allowed for private market competition within the wholesale
generation of electricity. this, in itself, helped pave the way
for true energy deregulation in the United states.
subsequently, Order 888 in 1996 and Order 2000 in 1999
assured "open-access nondiscriminatory transmission services" and further deregulation by "creating regional transmission Organizations" that replaced state operation and
control over the transmission grid. the energy Policy act of
2005 formed the U.s. Federal energy regulatory commission (Ferc) as the primary regulator for energy within every
state across the country. the energy independence and security act of 2009 helped further improve electricity delivery
to customers by assuring the development of a "smart grid."
all these efforts resulted in the creation of wholesale and
retail markets to allow electric energy producers and consumers to conduct the business of energy exchange for economic
benefits. the 2009 law imposed the not widely discussed resiliency requirement to "keep the markets on" at all times and
minimize the economic losses from grid interruptions. Figure 2,
march/april 2018

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