Relay protection and automatic devices should meet those requirements
Relay protection and automatic devices shall meet the requirements of reliability, selectivity, sensitivity and quickness, and shall meet the following requirements:
1) The relay protection and automatic device should be simple and reliable, the components and contacts used should be as few as possible, the wiring circuit is simple, the operation and maintenance are convenient, and the simplest protection should be adopted under the premise of meeting the requirements.
2) The protection required for coordination of adjacent equipment and lines, the sensitivity and action time between the two levels should be coordinated with each other.
3) When a fault occurs within the scope of the protected equipment or line, it should have the necessary sensitivity coefficient.
4) The protection device should be able to remove the short-circuit fault as soon as possible. When it is necessary to accelerate the removal of the short-circuit fault, the protection device can be allowed to act without selectivity, but automatic reclosing or automatic power supply of the backup power supply should be used to reduce the power outage range.