What happens to the dielectric breakdown voltage of a line as its power angle increases infinitely?

As the power angle increases infinitely, the dielectric breakdown voltage of a power line decreases. This phenomenon can be attributed to the fact that the power angle reflects the phase difference between the voltage and current in an electrical system.

When the power angle increases, it typically indicates that the system is operating further from its optimal condition. In practical terms, this can lead to increased electric field strength across the insulation of the line. A stronger electric field can ultimately lead to the point where the dielectric material can no longer withstand the electrical stress, causing breakdown.

Therefore, as the angle approaches larger values, the ability of the dielectric to withstand the voltage decreases, resulting in a lower breakdown voltage. This understanding is critical when analyzing the operational limits and safety of electrical systems, particularly in high-voltage lines and transmission systems. Thus, while the system is expected to operate effectively within certain limits, excessively increasing the power angle compromises the insulation ability, leading to a decrease in dielectric breakdown voltage.