## 2 Definition and Motivation behind Building Smart Grid  
There are yet no unanimous agreement on the standard definition of a Smart Grid, for it is a concept which is still under development. The definition of smart grid varies from experts to experts creating a wide technical outlook of the whole system, considering all the definitions that are available. For example, The European Union has defined a smart grid as \"an electricity network that can cost efficiently integrate the behavior and actions of all users connected to it--generators, consumers and those that do both--in order to ensure economically efficient, sustainable power system with low losses and high levels of quality and security of supply and safety\" [17]. Electric Power Research Institute (EPRI) website offers the following definition \"A SG is one that incorporates information and communications technology into every aspect of electricity generation, delivery and consumption in order to minimize environmental impact, enhance markets, improve reliability and service, and reduce costs and improve efficiency\" [18]. The International Electro-Technical Commission (IEC) definition states that \"The SG is integrating the electrical and information technologies in between any point of generation and any point of consumption\" [19]. International Energy Agency (IEA) defines \"A SG is an electricity network that uses digital and other advanced technologies to monitor and manage the \begin{table}
\begin{tabular}{c c} \hline \hline
**Conventional Grid** & **Smart Grid (SG)** \\ \hline Hierarchical structure & Network structure \\ \hline Less feasible for feedback network & The inherent and real-time control \\ \hline Wide area interrupts at the time of outage & Filtering and islanding disconnection \\ \hline Network restriction control & Network comprehensive control \\ \hline Customers and subscriptions provided with limited services & Customers and subscriptions provided with various services \\ \hline Radial Network & Dispersed Network \\ \hline Slower in response during emergencies & Quicker in response during emergencies \\ \hline Small volumes of data available & Large quantities of data available \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cont. transport of electricity from all generation sources to meet the varying electricity demands of end-users. Smart grids co-ordinate the needs and capabilities of all generators, grid operators, end-users and electricity market stakeholders to operate all parts of the system as efficiently as possible, minimizing costs and environmental impacts while maximizing system reliability, resilience and stability\" [20]. Australian Government New Direction Report defines SG as \"the application of information and communications technology to improve the efficiency and effectiveness of the generation, transmission and distribution, and usage of power\" [21]. In Australia, the smart grid system primarily includes distribution and retail value chain elements, although transmission and generation (both distributed and centralized) are also affected. In general, the primary smart grid technologies considered as part of this study reside on the distribution network, within/around the home, with the information being processed in a data center [21]. An overview of the smart grid concept is shown in Figure 1[22]. The electric power industry stakeholders realize the need to address diverse challenges relevant to the present power network. Such challenges are the gap between supply and demand; low system efficacy; rising cost; and global warming, to name a few. Some of the key drivers that motivates the researchers, developers, and policy makers to pay attention towards the smart grid development are:  
* Increasing electricity demand: According to the International Energy Agency, the world energy consumption will be increased by 48% compared to the 2012 energy demand [1]. Rising electricity demand requires more reserve margins for unexpected outages.