IEEE Power & Energy Magazine - March/April 2018 - 30

grid modernization study funded through the Power systems
engineering research center by the U.s. department of
energy (dOe) in 2003, as depicted in Figure 4.
the most relevant implication of the proposed HcP ap proach is that the resiliency improvement in fast control actions
requires coordination among predictive, adaptive, and corrective protection actions. While adaptive protection has
been discussed for many years, particularly in two key initial studies funded by the dOe in the mid-1980s (led by
a.g. Phadke and g.d. rockefeller, respectively), it continues to be explored not only at the transmission level but also
for distribution systems and microgrids. corrective relaying actions are also being contemplated, as experience has
shown that relay misoperations can cause major blackouts.
the most promising, and least explored, option is to try to
predict faults based on historical data and prevailing weather
conditions, which will give operators an option to mitigate
consequences by undertaking various preemptive actions to
reduce risk of outages and major blackouts. the following
sections explore some innovative ways of getting control center operators involved in planning, tracking, and mitigating
unforeseen grid conditions that may impact the resiliency of
the physical system and electricity markets.

Legacy Protection
Inputs:
Fixed Settings
Local Measurements

Tripping for Faults
in the Protection
Zone Followed by
Reclosing

Resiliency in Planning: Using Rare Event
Criteria when developing Modeling
and Simulation Tools and Studies
resiliency starts with planning and design, answering the question of what needs to be done well ahead of any possible event
to reduce its adverse magnitude and duration. the electric utility industry has a long history of planning, and the high levels
of reliability today attest to its success in this area. However,
the majority of this work has been directed toward improving
system reliability, mostly focused on designing a system for
optimal operations during normal conditions and responding to
events similar to those previously encountered. Here, we present several ideas for increasing system resiliency by incorporating criteria that deal with rare events.
From the start of the power industry, modeling and simulation have played important roles. With the introduction of
digital computers, much of this power system understanding
has been integrated into software of increasing complexity, the
capabilities of which include short-circuit analysis, power flow,
contingency analysis, security-constrained optimal power
flow, and transient stability. modeling and simulation occur
over many time frames, ranging from decades in the future for
long-term planning to real-time for operations.

Before Fault Occurrence

During Fault Occurrence

Predictive Protection
Inputs (Historical):
Weather Data
Outage Data
Equipment
Deterioration Status

Adaptive Protection
Inputs:
Local Measurements
System Wide
Measurements

Corrective Protection
Inputs:
Relay Trip
Auto Reclosing Action
Fault Location

Adequacy
Check of
Existing
Settings

Learning
Process to
Adapt to
Prevailing
Conditions

Real-Time
Fault Analysis
to Determine
Accurate Fault
Location

Fast Recalculation of
Relay Settings

After Fault Occurrence

Supervised Operation
of Legacy Protection

Supervised Reclosing
Action

Relay Is Getting
Ready to Operate

After Relay Has
Operated

...
Before Relay Has
Operated

figure 4. HCP for improved resiliency.
30

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march/april 2018

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - March/April 2018