Three-phase AC

An alternating current voltage that forms the basis of power transmission and distribution, composed of three phases with waveforms shifted by 120° each. Because it is the most efficient method for transmitting electricity over long distances from power plants to consumers, it has been the mainstream method since power transmission and distribution systems were established. When the transmission distance is long, high voltage such as extra-high voltage is used to reduce transmission losses. The system uses three wires (four if there is a neutral wire), with loads connected to each phase, and it is necessary to balance the load evenly across all phases.