Page 293 - From Smart Grid to Internet of Energy

Internet of things for smart grid applications Chapter 7 261

sources usage. Therefore, it is called as distribution system automation (DSA)
which controls the DSM. This automation system is based on smart meter con-
trol, communication control, and multi-agent controls. These control mecha-
nisms provide fault detection, isolation of fault points, reconfiguration of
distribution system and restoration that all enables to have a self-healing
system.
Another novel research area in the smart grid control of distribution level is
smart transformers, which are inherited from conventional line frequency trans-
formers. This new transformer type called solid state transformers (SST) or
bidirectional intelligent semiconductor transformer (BIST) is an emerging tech-
nology. The researches have shown that this technology improves the reliability
and stability of the electric distribution grid even in high frequency (HF) con-
versions. Now, the smart transformers (ST) compete with SST and conventional
transformers in reliability and efficiency issues. The ST can be easily interfaced
with microgrid generators to adjust the line frequency. Besides, ST manages
active power request by controlling the current fluctuations on the medium volt-
age (MV) side, and the reactive power can be handled independently by ST to
enable unity power factor [18, 19].
The DLC is a featured control method used in smart grid for power resil-
iency at distribution level. The penetration of photovoltaics (PVs), wind tur-
bines, combined heat and power (CHP), fuel cells and even EVs to the
distribution system have introduced several challenges on system reliability
and resiliency. This challenge is handled by using VPP design that allows
assembling the capacity of these DERs into a single source profile. The reliabil-
ity of distribution system is not only based on automation and control but also on
the measurement and metering that provide the required monitoring data. A
robust measured infrastructure minimizes the fault and outage probability on
the transmission and distribution levels. The measurement infrastructure quality
is related to a number of standards where some of them are IEC61000-4-30 for
supply quality, IEEE Std. 1588 for precision time protocol in distributions sys-
tems, IEEE Std. 2030-2011 for the smart grid interoperability references, IEEE
Std. 1547.4 for planned islands/micro-grids and IEEE Std. 1547.6 for intercon-
nection to distribution secondary networks [1].
The improvement of AMI that is also listed in Table 7.2 as a featured appli-
cation of smart grid is one of the most important technological challenge in
energy monitoring. The AMI has brought bidirectional communication and
metering capability to distribution service providers and consumers and thus,
the mechanical electricity meters have been converted to smart meters
(SMs). The communication medium used by AMI can be selected from numer-
ous variety of wired or wireless communication methods such as PLC, IEEE
802.15.4 based wireless schemes, Worldwide Interoperability for Microwave
Access (WiMAX), and even satellite communication.
Inga et al. presented wireless heterogeneous network architecture in [20]
similar to shown in Fig. 7.3 where multi-hop capabilities for routing traffic from
the SMs to the universal data aggregation points (UDAP) are considered. The