ISSN 2515-0855
doi: 10.1049/oap-cired.2017.0374
www.ietdl.org
Challenges and opportunities of 5G in
power grids
Gargi Bag
1
✉
, Linus Thrybom
1
, Petri Hovila
2
1
ABB Corporate Research, IIoT group, Vasteras, Sweden
2
ABB Medium Voltage Products, Vaasa, Finland
✉ E-mail: gargi.bag@se.abb.com
Abstract: This study is based on the ongoing evolution of the power grid for supporting a much more flexible and dynamic
grid with a high penetration of renewable energy sources and storages. The foreseen applications required for controlling
and protecting this new grid are further mapped against the emerging 5G technology, identifying both the challenges as
well as the opportunities, by assessing the power grid requirements versus the envisioned 5G technology and
functionality.
1 Introduction
The power grid which we know today as a traditional one way power
flow, where the power is generated by a few large power plants,
transferred via high-voltage (HV) transmission and finally
transformed and distributed to the consumers in the end of the
grid, is now fast evolving. The new power grid needs to support a
bi-directional power flow due to the increasing number of both
small scale as well as large-scale distributed energy resources (DER).
This paper uses the evolving power grid as a starting point for
identifying the new control, protection and monitoring applications
needed, and focuses the analysis on the derived communication
aspects and requirements. Especially the emerging fifth generation
of mobile networks, 5G, is targeted in the analysis since it is just
being defined, with the expressed vision to support vertical
industry needs in e.g. the energy domain. This concurrent
evolution gives a good opportunity to synchronise these two
domains, providing use cases and requirements from the energy
domain, into the 5G domain. In this paper, the communication
requirements related to power grid protection, control as well as
monitoring are presented, identifying the challenges such as
latency, reliability and time synchronisation that need to be
addressed. The paper also discusses the opportunities that open up
due to the flexibility, which is provided by wireless technologies.
2 From traditional to smart grids
The power grid is transforming into a bi-directional power flow,
whereby some of the traditional consumers are also becoming
producers i.e. prosumers. The new grid has a large quantity of
DER, typically renewable energy sources which often are
intermittent by nature. Small-scale DER units are mainly
connected to the distribution grids and larger wind/solar parks
with multiple DER units to the transmission grids.
This evolving new power grid provides also the basis for a
large-scale deployment of microgrids, where a part of the grid,
with DER, is disconnected for example in case of disturbances
from the main grid and operated intentionally as an islanded grid.
Fig 1 shows the power grid with addition of DER.
Within the distribution grid there will be need of wide area
monitoring using for example phasor measurement units (PMUs)
and additional types of sensors, for monitoring not only the
phasors but also information such as temperature, vibration etc. for
the devices in the grid. Similarly, with addition of renewables in
the grid, more and more control functions related to power
balancing, voltage and frequency control are also required from
the DER units by the grid codes or in the future by technical
service markets. These DER units need to communicate
decentrally or centrally to execute the control applications.
However, it is not only the infrastructure of the grid that is
changing, but also its electrical characteristics (e.g. dynamics due
to less inertia) is changing due to the fact that modern power
electronics are used in connecting the DER units with different
fault behaviour and fault current feeding capability than traditional
synchronous generators. Therefore, new protection methods and
schemes need to be developed for both grid-connected and
islanded operation in order to detect the limited fault current.
Since the current flow will be bi-directional, directional protection
will be needed in many cases. In addition, other schemes, such as
line differential protection, can be used to enhance the protection
sensitivity.
The conclusion is that the transformed power grid will necessitate
more control, coordination, and monitoring functionalities, thus a
higher degree of grid automation including communication [1].
Due to its scalability and flexibility, as well as cost efficient
deployment, wireless communication is a suitable candidate for
providing the communication infrastructure for the emerging
power grid. The need for wide area coverage, as well as high
performance are two identified reasons [2] why cellular
technologies are suitable to facilitate the communication needs for
the power grid. The use of the emerging 5G, which is envisioned
to support both massive machine type communication as well as
ultra-reliable and low latency communication, will further make
the case stronger for using wireless communication for grid
automation.
2.1 Use cases and requirements
Table 1 gives a high-level overview of different application
requirements in terms of latency and availability in grid
automation. However, it is to be noted that the figures for latency
presented below are generalised and the exact requirements are
application dependent.
2.1.1 Protection: For protection applications, the limited fault
current of the used power electronics converters is a challenge to
detect using existing methods. Line differential protection can be
considered in this case as one very potential alternative, relying on
high-speed communication of measurements between two points
of the distribution or transmission line to detect a fault. As Fig 2
shows, in line differential protection, two relays monitors, and a
24th International Conference & Exhibition on Electricity Distribution (CIRED)
12-15 June 2017
Session 5: Planning of power distribution systems
CIRED, Open Access Proc. J., 2017, Vol. 2017, Iss. 1, pp. 2145–2148
2145This is an open access article published by the IET under the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/3.0/)