Distance protection and the importance of precision measuring equipment

As we know short circuits are an inevitable phenomenon for the electrical power system. These damages must be quickly detected by the relay protection system and the damaged part must be isolated quickly. The defense of a line is of particular importance. When a defense system is designed, a compromise must be made between economics and performance, independence and security, complexity and simplicity, accuracy and speed. From a technical point of view, the correct performance of the relay protection has been of particular importance over the years. It is not desirable for a node of the system to be taken out of service due to a wrong action of the relay protection leading to energy faults, accompanied by penalties to consumers and disadvantages vis-à-vis competitors for companies operating in the energy market. In some case’s the local backup protection is combined with the remote backup protection which is defined as a backup of the backup. In numerical relays, often at the software level, the user can implement functions based on logical mathematical blocks. In this combination with the rapid developments in information technology with applications in the system in the electrical power system made the relay protection quite efficient and powerful, any error in the communication channels or human errors can cause the relay protection to malfunction or malfunction