Page 46 - From Smart Grid to Internet of Energy

Introduction to smart grid and internet of energy systems Chapter 1 35

whole grid infrastructure by observing power quality, load demand amounts,
and performing estimation algorithms in the system [1, 4].
The control and interoperability of Smart Grid can be performed by a wide
variety of communication system but complying with IEC 61850 standard that
is an open system standard regardless to type of vendor or infrastructure. The
standard communication interface enables interaction between MDMS and dif-
ferent field devices such as IEDs, power plants, feeders, substations, and power
system utilities installed at any DER. PEVs and ESSs are also integrated to
utility grid in addition to power plants installed at any microgrid along a Smart
Grid infrastructure. Therefore, any device or micro resource penetrated to Smart
Gris is handled in a “plug and play” structure due to IEC 61850 standard [4].
Another major control strategy used in distributed system automation and
control is agent-based control approach. In this strategy, each DER has a local
controller agent (LCA) that is responsible to monitor and to control distributed
source in remote areas. Each LCA communicates with other LCAs throughout
microgrid and comprises a global control agent (GCA) infrastructure.
When any DER faces with any fault during operation, it is disconnected
from grid and LCA transmits an emergency signal to other LCAs and GCA
to express that its DER has been disconnected. Afterwards, multiagent based
system rearranges new operation conditions regarding to instant generation
capacity and load demand. The GCA runs the control algorithm procedures
to response the fault and recovers the disconnected DER in a short while. In this
step, GCA uses offline calculation and tries to find an optimized solution to
operate self-healing procedure of microgrid structure [25].

1.3 Fundamental components of smart grids
The Smart Grid infrastructure is defined as system of systems and includes
many analog and digital technologies altogether due to its complex structure.
The fundamental components of Smart Grid infrastructure are new and
advanced grid sections, integrated communication systems, advanced control
systems, smart devices and smart metering, and decision support environment
with HMI. These components are presented in following topics as smart sensors
and sensor networks, phasor measurement units, smart meters, and wireless sen-
sor networks. The smart metering, management, and control infrastructures
require smart devices that are equipped with sensors and sensor networks. Sen-
sors can be used at any location throughout Smart Grid infrastructure from
generation level to customer sides and play crucial role for monitoring and data
acquisition. The sensor infrastructure provides required measurement data to
control generation and consumption rates instantly to transmit actual situation
data of utility grid. Thus, several management processes such as DSM, demand
response and generation planning can be performed. The developed sensor net-
works facilitate management issues of TSO and DSOs to detect faults and