Page 103 - From Smart Grid to Internet of Energy

88 From smart grid to internet of energy

while transmitter and receiver uses public or private keys in asymmetric key
cryptography [5].
Attackers may perform cyber-attacks to generation, transmission, distribu-
tion and consumption levels of smart grid infrastructure. The most vulnerable
section of entire utility network is reported as distribution and control levels due
to numerous node deployments. The cyber-attacks specifically target consump-
tion level to manipulate load level and DSM operations. The internet-based
control and monitoring operations provide intrusion chance to attackers due
to previously discussed layer structure. The data manipulation of measurement
may include load rate increments, overflow alerts and malfunctions in monitor-
ing operation. These attack types are generally named as IP based load-altering
attacks that attempt to control and manage the load types. It is noted that IP
access to can be performed for three types of loads that are data centers and
server loads, direct load control (DLC), and indirect loads. The server type loads
are quite flexible and load rate depends on the operation load of data center.
Therefore, attackers target to reach server centers and to increase load rate
by producing overloaded traffic for increasing consumption. The DLC attacks
aim to access industrial and residential loads to cause malfunctions and chang-
ing operation conditions. The DLC is directly related with DSM operations such
as decreasing peak demand, load shedding, and valley filling and so on. There-
fore, DLC attacks seriously affect reliability and security of utility network.
The indirect load control attacks target IP based HEMS applications since con-
sumers control their residential loads to manage consumption data. The control
of smart appliances is essential to decrease energy costs but intrusions can dis-
turb control operations and may inject false command or price data to HEMS.
The attacks are prevented by using protection and authentication procedures
that are presented earlier [20].

2.5 PMU applications in smart grids

The PMUs are essential devices used in WAMS that provides real time moni-
toring of generation and transmission lines through wide areas. The WAMS
would prevent effects of major blackouts met in several countries if they had
used in utility grid. Smart grid infrastructure requires DA applications for
remote control and monitoring applications to take rapid action against grid dis-
turbances and to perform flexible power arrangements. The utility automation
facilitates DR applications during outages by routing generated energy from
various power plants. Thus, the critical load management can be accomplished
in a safer way. This management and control operation is known as self-healing
functionality of utility. Another key contribution of DA operation is effective
management of feeders and feeder networks to enable multiple stations and dis-
tribution lines to be used on demand. The global positioning system (GPS)
assisted PMUs have been introduced in Chapter 1 that first applications of these
devices date back to 1980s. Nowadays, PMUs are critical devices used in