IEEE Power & Energy Magazine - September/October 2019 - 28

Modernization Initiative, which includes the Grid Modernization Laboratory Consortium (GMLC) program. This
program encompasses a wide range of projects, and among
them are several cross-cutting efforts. One of these is the
Grid Architecture project, a multiyear, multilab effort to
advance the discipline of Grid Architecture, develop tools
for use by anyone doing this type of work, and, most importantly, develop five reference architectures that illustrate
the use of this discipline and use wide stakeholder input to
help develop a national consensus on grid modernization, as
expressed through the reference architectures. The work we
do on the GMLC Grid Architecture project also supports
aspects of several other GMLC projects.
The five reference architectures are
✔ high-resilience grids
✔ high penetration of DERs with high usage of distribution automation
✔ advanced bulk energy systems
✔ flexible and agile/fractal grids and microgrids
✔ converged networks (e.g., electric, gas, water, and
transportation) for smart urban environments.
These reference architectures are models that we hope
will inform thinking in the industry about grid modernization. We do not expect that anyone would take one of these
as a blueprint but, rather, would adopt and adapt them for
use according to his or her unique requirements and constraints. All of the architecture specification packages and
the tools developed for this article will be available to the
industry via the PNNL grid architecture website (https://
gridarchitecture.pnnl.gov/).
The other major DOE program that uses the methods
outlined in this article is the DSPx Project of the Transmission Planning and Technical Assistance Division of the
DOE Office of Electricity. This project provides technical
assistance for state electricity utility regulators and has had
extensive uptake across the United States, with regulators
working on electric grid modernization issues. Much of the
content produced by this effort and contained in guidebooks
is based on our grid architecture work. The guidebooks are
posted on the grid architecture website given previously. We
also make use of this discipline in the ongoing activity to
develop a revised guide document for phasor measurement
unit networks in work being done for the North American
SynchroPhasor Initiative

Summary
Grid Architecture is a discipline for understanding the
multiple structures that comprise the whole electric grid
and determining how to modify or extend those structures
to relieve old constraints, improve grid characteristics,
and enable new capabilities. By understanding the grid as
a network of structures and focusing on structural issues,
we can enable stakeholders to make superior decisions
about grid evolution, investment, and usage. The discipline of grid architecture provides principles, methods,
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tools, concepts, and reference models to support a wide
range of grid modernization stakeholders. Grid architecture is not just for use by deep architecture experts; some
of the best uses to date have been by regulators and utility
planning groups.
Grid Architecture provides valuable new insights into
grid modernization planning and design as well as the
means to future-proof technological investments and reduce
integration costs-two issues that concern regulators and
utility executives alike. Proper structure creates intrinsic
grid characteristics that bolster resilience, capability, and
affordability, which help safeguard investments by limiting change effects. Well-planned grid structure simplifies
downstream decisions and frees up architects and engineers
working on individual components or systems to employ
creativity with the assurance that unintended consequences
will not crop up to hamper or even invalidate their work.
For these reasons, it is not just important but crucial that
the structural issues addressed by grid architecture be
considered before other aspects of grid modernization are
undertaken. Ultimately, the discipline of Grid Architecture
provides a new and better way to think about the whole grid
as it has evolved in the United States and most of the world
and to manage the otherwise overwhelming complexity of
grid modernization.

For Further Reading
J. Taft and A. Becker-Dippmann, "Grid architecture," Pacific Northwest Nat. Lab., Richland, WA, Rep. PNNL-24044,
2015.
M. Chiang, S. Low, A. Calderbank, and J. Doyle "Layering as optimization decomposition: A mathematical theory
of network architectures," Proc. IEEE, vol. 95, no. 1, pp.
255-312, 2007.
L. Northrup et. al. "Ultra-large-scale systems," Carnegie Mellon Univ. Pittsburgh, PA, 2006. [Online]. Available: https://resources.sei.cmu.edu/asset_files/Book/2006_
014_001_30542.pdf
J. Taft, "Architectural basis for highly distributed transactive power grids: Frameworks, networks, and grid codes,"
Pacific Northwest Nat. Lab., Richland, WA, Rep. PNNL25480, 2016
P. De Martini, L. Kristov, and L. Schwartz, "Distribution systems in a high distributed energy resources future:
Planning, market design, operation and oversight," California Institute of Technology, California ISO, and Lawrence
Berkeley Nat. Lab., FEUR Rep. No. 2, Oct. 2015. [Online].
Available: https://gridarchitecture.pnnl.gov/media/advanced/
FEUR_2%20distribution%20systems%2020151022.pdf

Biography
Jeffrey D. Taft is with Pacific Northwest National Laboratory, Richland, Washington.
p&e
september/october 2019

https://gridarchitecture.pnnl.gov/ httpS://gridarchitecture.pnnl.gov/ https://resources.sei.cmu.edu/asset_files/Book/2006_014_001_30542.pdf https://resources.sei.cmu.edu/asset_files/Book/2006_014_001_30542.pdf https://gridarchitecture.pnnl.gov/media/advanced/FEUR_2%20distribution%20systems%2020151022.pdf https://gridarchitecture.pnnl.gov/media/advanced/FEUR_2%20distribution%20systems%2020151022.pdf

IEEE Power & Energy Magazine - September/October 2019

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