The power system protection can not prevent system faults, but it can limit the damage caused by short circuits while protecting people and equipment from damage. Goals are to selectively clearing faults in milliseconds and protecting equipments from overload conditions. The damages are due to short circuits in a system, abnormal conditions in the system and majorly human mistakes.
The basic purpose of installation of protective relays are:
1. To protect very expensive equipment like transformers, generators, motors, cables and other installed components.
2. To ensure the interruption of supply to minimum number of consumers in case of system fault.
3. To minimize the production losses of the factories.
4. To avoid major shutdowns.
Since the protection system limits the damages/losses and keeps the system running therefore it is considered a vital importance for the system.
