What defines a three-phase power system?

A three-phase power system is defined by its use of three alternating currents, each individually offset by 120 degrees from one another. This configuration is crucial because it allows for a more efficient transmission of power compared to single-phase systems, which typically rely on one alternating current.

The three-phase system achieves a continuous power supply, as at any given time one of the three phases is at its peak voltage, ensuring that power delivery is smooth and stable. This is particularly advantageous for industrial applications where large motors and equipment are used, as it results in reduced vibration, increased efficiency, and better load balance.

This system is fundamental in electrical engineering and is widely adopted for power distribution due to its ability to provide more power with fewer conductors. Each phase can carry a portion of the total load, allowing for optimal use of infrastructure. In contrast, other options describe alternatives that do not support the same level of efficiency or power continuity as a three-phase system.