2.1 Three-Phase Power Supply

A three-phase power supply system is the most common method of electric power generation, transmission, distribution, and consumption worldwide.

The three-phase power comprises of three alternating phases, generally represented as L1, L2, and L3. All three phase produces AC voltages of equal amplitude and frequency with reference to ground potential. All three phase voltages are phase-shifted to each other by 120°, as shown in Figure 2-1 ‘a’.

Figure 2-1. Typical Three-Phase Signal