When you have completed this chapter, you will be able to understand electric grid performance—conventional transmission technologies, smart transmission technologies, state-of-the-art (FACTS and HVDC) device operations and control, and the future outlook of smart device operations. You will be able to make smart and rigorous approach to calculate the operating conditions for an overcurrent protection system used for the protection of radial feeders and calculation for the settings of directional overcurrent relays in a ring distribution system. You will be able to use smart calculate conditions in distance protection system using stepped characteristics and calculate conditions in a current differential protection network used for unit protection.