IEEE Power & Energy Magazine - May/June 2017 - 40

Distribution network operators require more advanced
planning and asset management tools to deal with
challenges in the near future.
connection of the generator as requested, leading to a violation
of its planning rules but keeping the right to curtail the injection of the generator for a given number of hours per year to
prevent constraints on the distribution network. This allows the
DRESs to connect to the distribution network while minimizing
its connection costs and time. Consumers, prosumers, or generators connected to the grid could obtain an advantage from this
contractual flexibility.
Other technologies involving consumers or prosumers
are under development. DG units could contribute to voltage control by modifying their reactive power following the
DSO's instructions. Smart-charging flexibility for electric
vehicles can be used to balance supply and demand, reducing the need for investment in grid reinforcements. Electric
vehicle charging connection can be incentivized or penalized by the market through price signals. Energy storage
solutions can be used to provide power when conditions are
not favorable and to store power when there is a generation
excess. Until now, economic factors and regulatory issues
have hindered the application of these technologies.
A standard, completely interoperable interface between
DSOs and customers will facilitate active demand management and DRES participation in grid operation and reliability, promoting its own integration into the system. The
development of this standard and the interoperability should
be promoted as a basis for the transition to SGs.
Harmonized connection rules are urgently needed to
facilitate a massive integration of DRESs. A uniform and
clear regulatory framework for distribution grid connection,
independent of country or utility, will facilitate the process.
DSOs can contribute to this framework by implementing
solutions for voltage control based on the reactive power
control of DRESs and providing the right balance at TSO/
DSO connection nodes.
The observability and control of distribution networks
need to be improved for the future. Variable generation
must be predicted and managed by improving the prognosis of consumption and DRES production as well as using
sophisticated algorithms to better estimate and control the
status of the grid (state estimators and OPF-based products).
Distribution network operators require more advanced
planning and asset management tools to deal with challenges in the near future (probabilistic methods, OPF-based
techniques, ICT infrastructure, and flexibility services and
products). Additionally, the cost recovery framework for
DSOs should be modified to foster innovation. Pioneering initiatives should receive some revenue during their
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progress to enable the widespread connection of DRESs
using SG solutions. When they become routine solutions,
the costs must be allocated among all the agents (DRES
generators, DSOs, and TSOs) in a fair way.
Many SG solutions will become business as usual as
soon as the regulatory framework allows it. A balance
between new approaches and traditional reinforcement
will be found depending on technical aspects, the residual
lifespan of assets, persistence and urgency of the problem,
complexity of available solutions, and especially costs and
recoupment. The digitalization and cost-effective decarbonization of the modern world makes the transition to
SGs critical.

For Further Reading
M. Sebastián-Viana, et al. (2013). IGREENGrid Project [Online]. Available: http://www.igreengrid-fp7.eu/
Commission regulation (EU) 2016/631. (2016, Apr.). Establishing a network code on requirements for grid connection of generators [Online]. Available: http://eur-lex
.europa.eu/legal-content/EN/TXT/?uri=OJ:JOL_2016_112
_R_0001
A. Keane, L. F. Ochoa, C. L. T. Borges, G. W. Ault, A.
D. Alarcon-Rodriguez, R. A. F. Currie, F. Pilo, C. Dent, and
G. P. Harrison, "State-of-the-art techniques and challenges
ahead for distributed generation planning and optimization,"
IEEE Trans. Power Syst., vol. 28, no. 2, pp. 1493-1502,
May 2013.
G. P. Harrison and A. R. Wallace, "Optimal power flow
evaluation of distribution network capacity for the connection of distributed generation," IET Proc. Generat. Transm.
Distrib., vol. 152, no. 1, pp. 115-122, Jan. 2005.

Biographies
Jesús Varela is with Iberdrola Distribución Eléctrica S.A.U.,
Spain.
Nikos Hatziargyriou is with the Hellenic Distribution
Network Operator, Greece.
Lisandro J. Puglisi is with Iberdrola Ingeniería S.A.U.,
Spain.
Marco Rossi is with Ricerca Sul Sistema Energetico, Italy.
Andreas Abart is with Netz Oberösterreich GmbH,
Austria.
Benoît Bletterie is with the Austrian Institute of Technology, Austria.
p&e
may/june 2017

http://www.igreengrid-fp7.eu/ http://eur-lex http://www.europa.eu/legal-content/EN/TXT/?uri=OJ:JOL_2016_112

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - May/June 2017