IEEE Power & Energy Magazine - January/February 2015 - 74

To control power systems as efficiently as possible,
more real-time information about inertia
is needed.
by taking available operational measures (such as network
reconfiguration by switching and using flow control devices)
and then notifying market participants of the resulting available transfer capacity. at the same time, an efficient and
sustainable electricity system requires the efficient use of
existing and future transmission capacities to maximize
transportation possibilities. notably, new interconnections
and an increasing number of transmission devices allowing
for load flow control will be integrated in future transmission
networks and will offer new possibilities for network operation. further development of common tools for grid security
is therefore one of the major challenges european tSos will
face in the middle term. the methods to be applied have
to take into account all available technological measures to
enhance the flexibility of power system operations: flexible
ac transmission systems, pSts, real-time monitoring of thermal line ratings, battery energy storage systems for reactive
power support, and so on.
Innovative tools for the future coordinated and stable
operation of the pan-european electricity system have been
researched and developed by two projects, iteSLa and
umbrella, both of which are part of the european Commission's Seventh framework program (fp7). the aim of both
projects is to develop a simulation toolbox to support future
coordinated operation of the pan-european electricity transmission network. Besides this principal goal, the two projects
are cooperating and have jointly developed recommendations regarding operational rules for the future coordinated
operation of the pan-european electricity transmission network. Both projects are ongoing, providing information and
tools relevant for the future secure operation of the european
transmission system to deal with uncertainties, grid optimization and control, and dynamic security assessment.
for the grid operator, it is essential to have at hand a tool
that combines live power grid data (measurements and topology from SCaDa), live weather data, and real-time reliability
analyses along with short-term load flow forecasts, reliability
analyses, and detailed weather forecasts. the Sumo system,
an application for system security assessment, has so far shown
that with an open integration platform and a well-thought-out
architecture, diverse vendors' solutions can be integrated into
a useful tool for electric grid operational challenges.
a method of increasing ohL transmission capacity,
depending on ambient weather conditions, has been in operation in germany and Slovenia. for germany, a dynamic rating system has been incorporated into the operating process

ieee power & energy magazine

in the tennet control area, and relevant north-south transmission corridors in the country have been included in the
program. Special attention must be devoted to postfault
behavior to avoid a loss of stability in cases of severe disturbance. Countermeasures in the area of protection and control
as well as emergency control actions have been demonstrated
and have been in operation for a number of years.
to control power systems as efficiently as possible, more
real-time information about inertia is needed. possible countermeasures are being investigated in the nordic region, such as
real-time measurements of power plants to mitigate the impact
of future production and consumption on inertia and frequency.
further r&D work with a broader perspective will be necessary,
however, as foreseen in the development of a project devoted
to inertia, control, and protection of large power systems with
a large amount of inverter-based components that is part of the
horizon 2020 framework. this project is expected to cover
all issues related to the change in generation characteristics of
future power systems.

For Further Reading
itesla project. [online]. available: http://www.itesla-project.
eu/
umbrella project. [online]. available: http://www.eumbrella.eu/
D. roberts, p. taylor, and a. michiorri, "Dynamic thermal
rating for increasing network capacity and delaying network
reinforcements," in Proc. CIRED Seminar 2008: SmartGrids
Distribution, frankfurt, germany, paper 3, pp. 1-4.
D. a. Douglass, D. C. Lawry, a. a. edris, and e. C. Bascom, "Dynamic thermal ratings realize circuit load limits,"
IEEE Comput. Appl. Power, vol. 13, no. 1, pp. 38-44, 2000.
g. Lakota, J. Kosmacˇ, m. marinšek, B. Barl, and J.
Kostevc, "Comparison of overhead conductor temperature
measurements and estimations acquired from multiple systems installed on a single overhead line," in Proc. Int. Symp.
High Voltage Engineering, Seoul, Korea, 2013.

Biographies
Wilhelm Winter is with tennet, Bayreuth, germany.
Katherine Elkington is with Svenska Kraftnät, Stockholm, Sweden.
Gabriel Bareux is with rte, paris, france.
Jan Kostevc is with eLeS, Ljubljana, Slovenia.
p&e

january/february 2015

http://www.itesla-project http://www.e http://www.umbrella.eu/

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - January/February 2015