Three-phase alternating current

This is the basic AC voltage used for power transmission and distribution, consisting of three phases with waveforms shifted by 120℃ from each other. Because it offers the highest efficiency when transmitting electricity over long distances from power plants to consumers, it has been the mainstream method from the establishment of power transmission and distribution systems to the present. When the transmission distance is long, high voltages such as extra-high voltage are used to reduce power loss in the lines. There are three wires (four when a neutral wire is included), and loads are connected to each phase, but the loads on each phase must be balanced.