IEEE Power & Energy Magazine - November/December 2017 - 60

by the Electric Power Research Institute in a white paper
published in 2015. Based on discussions among various stake-
holder groups during a period of over three years, the ride-
through requirements have been carefully balanced with valid
distribution impact concerns such as the need for effective anti-
islanding detection, safety during distribution circuit mainte-
nance, and reclosing coordination.
The proposed 1547 also includes requirements for ride-
through of consecutive voltage disturbances and frequency-
droop (frequency/active power) capability with a default dead-
band of 36 mHz. Regarding dynamic voltage support, the new
1547 standard is intentionally not overly prescriptive, and that
capability remains optional.
The transformation of today's power system toward an
integrated grid with high connectivity requires interoperabil-
ity and communication capability from DERs. Hence, the pro-
posed 1547 requires a standardized communication interface,
locally available at all DERs, that will enable monitoring,
control, and information exchange. Proprietary communica-
tion interfaces in addition to the 1547-compliant interface may
also exist and could be used by some manufacturers or third-
party aggregators.
The large number of new performance and functional
requirements put forth in the proposed 1547 requires careful
consideration of how these functions may interact with one
another. While active and reactive power controls are largely
decoupled, 1547 specifies a priority order that determines which
of the potentially conflicting requirements would take prece-
dence. In general, distribution safety and reliability require-
ments (e.g., cease-to-energize command, undervoltage trip for
distribution circuit faults, and anti-islanding prevention) precede
bulk system reliability requirements (e.g., ride-through), fol-
lowed by autonomous voltage real-power and frequency-droop
functions, followed by the response to a remotely commanded
active power limit.
The AGIR will have discretion in assigning performance
categories based on technical conditions such as DER tech-
nology, application, location, or penetration levels. The frame-
work is flexible enough so that nontechnical issues-such as
societal benefits or the broader impacts of DER on the envi-
ronment, emissions, and sustainability-may be considered.
An example is the conversion of landfill methane to energy
using a synchronous generator that may have less voltage ride-
through capability than a solar PV inverter.

Conclusions
High penetrations of DPVs in areas such as California and
Hawaii illustrate the myriad impacts on BPS reliability, sta-
bility, system balancing, and load forecasting. DPVs continues
to grow rapidly, and there is likely to be a proliferation of
other types of DERs that may impact the BPS. Aggregation
of DERs, such as Germany's VPPs, are a promising solu-

ieee power & energy magazine

tion to some of these system balancing and load forecasting
issues. The new interconnection and interoperability require-
ments for DERs specified in the proposed 1547 revision are
intended to resolve most of the known bulk system reliabil-
ity and stability issues. Thought leadership and commitment
across multiple stakeholders in the power industry are needed
as we transition the power system toward an integrated grid.

For Further Reading
J. C. Boemer, K. Burges, P. Zolotarev, J. Lehner, P. Wajant,
and M. Fürst, "Overview of German grid issues and retrofit of
German photovoltaic power plants for the prevention of fre-
quency stability problems in abnormal system conditions of the
ENTSO-E Region Continental Europe," in Proc. 1st Int. Workshop Integration of Solar Power into Power Systems, Aarhus,
Denmark, Oct. 24, 2011.
J. C. Boemer, "Recommended settings for voltage and fre-
quency ride-through of distributed energy resources," EPRI,
Palo Alto, CA, Tech. Rep. 3002006203, 2015.
Sponsor-Ballot Draft Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems, IEEE P1547/D6.7.2, May 2017.
F. A. Monforte, C. Fordham, J. Blanco, S. Barsun, A.
Kankiewicz, and B. Norris. (2016). Improving short-term load
forecasts by incorporating solar PV generation. Itron, Califor-
nia Energy Commission. [Online]. Available: https://www1.
itron.com/PublishedContent/101525WP-01%20Forecast%20
Simulations.pdf
NERC Distributed Energy Resources Task Force. (Feb.
2017). "Distributed energy resources: Connection modeling
and reliability considerations," NERC. [Online]. Available:
http://www.nerc.com/comm/Other/essntlrlbltysrvcstskfrcDL/
Distributed_Energy_Resources_Report.pdf

Biographies
Debra Lew is with GE Energy Consulting, Boulder,
Colorado.
Marc Asano is with the Hawaiian Electric Company,
Honolulu, Hawaii.
Jens Boemer is with the Electric Power Research Insti-
tute, Seattle, Washington.
Colton Ching is with the Hawaiian Electric Company,
Honolulu, Hawaii.
Ulrich Focken is with Energy and Meteo Systems, Old-
enburg, Germany.
Richard Hydzik is with Avista Corporation, Spokane,
Washington.
Matthias Lange is with Energy and Meteo Systems, Old-
enburg, Germany.
Amber Motley is with the California Independent System
Operator, Folsom, California.
p&e

november/december 2017

https://www1 http://www.itron.com/PublishedContent/101525WP-01 Forecast http://www.nerc.com/comm/Other/essntlrlbltysrvcstskfrcDL/

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2017