What does power factor indicate in a 3-phase system?

Power factor in a 3-phase system specifically represents the ratio of real power (measured in watts) to apparent power (measured in volt-amperes). This ratio is critical in assessing the efficiency of the electrical system because it indicates how effectively the current is being converted into useful work output.

A power factor of 1 (or unity) signifies that all the power is being effectively used for productive work, while lower values indicate that some power is being wasted, often due to reactive power caused by inductive loads. Understanding power factor is essential, as it directly affects the overall performance and efficiency of power systems, potentially leading to increased operating costs and the capacity limitations of the power supply.

In contrast, the other options do not accurately capture the essence of what power factor indicates. The frequency stability, total voltage, and load capacity pertain to different aspects of system operation and performance but do not relate directly to the efficiency of power usage as reflected by the power factor.