Phase shifting transformer is a special form of transformer which is used to control power flow in power system network by changing phase of line voltage. In phase shifting transformer, power flow is controlled by regulating the phase displacement between the input and the output voltages of the transmission lines that are internally connected through the phase shifting transformer. The direction and magnitude of power flow is controlled by changing the phase shift. In the area of complex power generation, such as power plant, phase shifting transformers are increasingly used as they make power grid more reliable, reduces transmission losses, and protect transmission lines. Another factor influencing the growth of phase shifting transformer in power system network is its cost efficiency over other solutions. Phase shifting transformers are primarily used in transmission lines and power plants.