How can protective relays improve system reliability?

Protective relays play a crucial role in enhancing system reliability by enabling rapid fault detection and isolation. When a fault occurs in an electrical system, such as a short circuit or overload, these relays detect the abnormal conditions almost instantaneously. This swift response is essential for minimizing the impact of the fault. By isolating only the affected sections, protective relays help to prevent cascading failures that can lead to widespread outages and potential damage to equipment.

Additionally, the ability of protective relays to act quickly helps limit the duration of disturbances, thereby preserving the integrity of the rest of the system and allowing normal operation to resume as quickly as possible. This proactive approach is fundamental in maintaining a stable and reliable electrical grid, ensuring continuous service and reducing downtime.

In contrast, the other options do not directly relate to the primary function of protective relays in enhancing reliability. For example, increasing the total power supply or providing redundant power sources does not address fault conditions. While aspects like software updates are important for overall system performance and security, they are not directly connected to the immediate response and isolation functions of protective relays.