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Power quality issues of smart microgrids Chapter | 4 93

reliability of the electrical system, if these storage units could be used as an
active demand-side management (DSM) tool. This needs the enactment of
ownership and utilization legislations for electrical vehicles storage units.
Also, distributed DSM and smart charging methods could be used to improve
the overall quality of the system.

4.2.1.3 Renewable energy sources integration
RES have changed the nature of the electricity generation from bulk genera-
tion units to DG units. This has helped one to improve the reliability of the
system, voltage profile and decreased the transmission line costs, losses, and
dependency on the main grid. These are the benefits of using RESs, while on
the other hand, these energy sources are not fully reliable because of the
probabilistic nature of the energy sources such as solar or wind power.
Another drawback of RES integration is that most of these sources have
power electronic based interfaces to convert the power; as mentioned
before, overusing of power electronic converters in the electricity grid will
cause lots of harmonic pollutions. Recently, researchers are working on
methods to make these RES multifunctional so that the integrated power
electronic converters could improve the power quality of the grid [7,14].

4.2.2 New tools of smart grids

As mentioned earlier, smart grids technology will bring new tools as well as
new challenges that are inevitable. These tools could be divided into several
categories such as technologies, concepts, and novel control methods. A
smarter grid requires the participation of the tools, which can deliver technol-
ogy solutions to assist utilities and engage consumers. In this section a brief
explanation of these tools and how they will affect the power quality of the
grid will be introduced.

4.2.2.1 Advanced metering infrastructure
AMI enables the application of technologies, such as smart meters and other
advanced metering devices, to enable a two-way flow of information
between customers and utility and to provide customers and utility with data
on consumption including time and amount of consumed energy and electric-
ity price. This will give the smart grids a wide range of functionalities, such
as remote consumption control, time-based pricing, consumption forecast,
fault and outage detection, remote connection and disconnection of users,
theft detection and loss measurements, and effective cash collection and debt
management. Meeting these goals means the progress to a smarter grid that
will have better control over power quality from different aspects. Logging
and reporting of any kind of disturbance and outage in a very fast way will
improve the power quality index in AMI-equipped grids.