Page 67 - From Smart Grid to Internet of Energy

Introduction to smart grid and internet of energy systems Chapter 1 53

transceiver mode as transmitter and receiver to increase transmission distances.
Thus, each sensor receives transmitted data from previous one and forwards to
next sensor until data reaches to gateway. The WSNs ensure this operation by
their self-organization, self-adaption, limited node energy, and unstable trans-
mission links as expressed in [41]. The placements of nodes along a WSN are
random and each node may be replaced to another location, protected or may be
interfered by any noise source. The network topology also affects the efficiency
and reliability while mesh topology ensures more flexible and reliable operation
among others. The self-organization of network nodes provide better manage-
ment and smart mesh networking structure where nodes initially monitor the
neighbor nodes and detect signal strength to select the most suitable node for
communicating. The time synchronization is established throughout nodes to
gateway by this way. When the gateway receives request of nodes, it assigns
network resources for nodes and two or more transmission paths are assigned
to ensure network reliability.
The recent advances in WSN have promoted its widespread use in smart grid
applications including power generation, transmission, distribution and power
consumption levels for monitoring and control processes in efficient and reli-
able ways. The WSNs are suitable for smart grid applications such as AMI,
DR and DSM, dynamic pricing, fault detection and prevention, distributed gen-
eration control, and remote detection. Since the CPS of smart grid is completed
by communication networks, selecting the proper communication method is
primarily effective on the performance of WSN associated smart grid applica-
tions. The requirements of each application are depending to its data transmis-
sion and latency rates, i.e. distribution feeder automations require higher data
rates with low latency communications since they should immediately detect
the faults and protect the system by isolating. The smart metering and monitor-
ing applications are not sensitive to latencies since they transmit measurement
data to MDMS in predefined intervals. It is noted by several studies that the
improvements of WSN will improve efficiency and reliability of smart grid
applications by the enhancement of distributed automation, dynamic load
and source control, advanced management systems and smart sensors with
energy harvesting capabilities. The WSN applications can be classified into
three levels of smart grid as given in Table 1.7 as generation, transmission
and distribution, and consumption levels [42].
The generation level applications include remote monitoring of conven-
tional and RESs such as wind and solar plants and even ESSs. The related mea-
surement and monitoring data may be wind speed, wind direction, temperature,
irradiation and humidity for RESs while others are electrical such as voltage,
current, power and power factor of generation plant. The distributed generation
is another aspect of generation level since small scale and micro plants can be
considered in the context of generation level. The security and reliability of gen-
eration level is directly affected by the reliability of distributed generation and
microgrid plant. Therefore, grid-connected and island mode operations should