Three-Phase Current - Definition and Generation
Three-phase current or 3-phase AC voltage plays a fundamental role in the transmission and distribution of electrical energy, as the energy can be transmitted with less material and power losses than, for example, with single-phase AC voltage. Three-phase AC is mainly used in industrial medium- and low-voltage networks, especially for supplying electric motors and other loads with higher power. But three-phase current can also be used in households, e.g. for an electric stove.
Definition: Three-phase alternating current is understood to be three alternating currents (or alternating voltages) of the same frequency, which are which are phase shifted to each other by 120°.
Three-phase current - definition and generation
Three-phase current can be represented both in a line chart and as a pointer diagram. In the pointer diagram, the 3 pointers rotate counterclockwise. The pointer length corresponds to the peak value of one phase.
Three-Phase current - Pointer-diagram
As you can see from the line chart, the sum of the three voltages is zero at any time. However, this means that if a load with 3 string resistors of the same size is connected to, the N-conductor (neutral conductor) can be omitted. More about this later.
Another advantage of a Three-Phase system is that it can supply both single-phase and three-phase loads.