1. Introduction

The latest revolution in the electricity network technology is called smart grid (SG). Smart grid term describes the future intelligent electric power that using digital technology to monitor and control. In other words, smart grids integrate information and communication intelligently to improve the electricity delivered to customers. It will also enhance safety and reliability, and financial control services in the system. A smart grid is a version of the future power grid that employs advanced equipment and services together with intelligent monitoring, control, communication, and intellectual protection. It is referred to as a revolution in the future of electric power grids because by using applicable technologies, it is a modern and integrated system. With increased energy demands and the expansion of renewable energy sources, power grid systems must be moderated and improved. The smart grid will integrate all types of electric power sources, and accommodate

all means of energy generation and distribution to meet the future demands of energy and its technologies [1].

Quality of power delivery is a significant goal of the smart grid that will provide a variety of needs and options at different costs. Furthermore, smart grids will provide advanced monitoring and control by employing intelligent equipment such as digital sensors, electronic switches, smart energy metering, and creative and advanced communication systems. Its data acquisition and control systems include interactive software, real-time control, and power flow analysis. All different types of renewable energy sources will be interconnected with the energy grid system to improve quality, reliability, and stability by using intelligent and advanced devices. Providing advanced technology such as the smart grid requires a smart and intelligent protection system to improve the efficiency of power delivery to customers, and to reduce outages. Employing the smart grid allows energy consumers to be active participants by providing information and options to control the electric demand balance [2].

The microgrid is used to provide customers with economical and reliable power resources and to make effective use of them through the formation of a smart grid structure during the disturbance. However, the protection of microgrid is a challenging task [3–5]. This chapter discusses the application of differential protection schemes. Issues related to protection include bidirectional power flow; it also handles the decrease in fault current levels [6–8]. The power system must operate safely at all times. The main requirements for power system protection include speed, selectivity, sensitivity, safety, reliability and dependability. The reliability requirements of the protection system ensure that appropriate and operable protective measures taken even when certain parts of the protective device may fail [9].
