Requirements for power supply for relay protection
This design guide provides details to design an auxiliary power supply for protection relay. The selection and applications of protective relays and their associated schemes shall achieve reliability, security, speed and properly coordinated. Meanwhile, protective devices have also gone through significant advancements from the electromechanical devices to the multifunctional, numerical. For example, unselective protection operation during a medium voltage network fault will cause an outage for an unnecessarily large number of consumers. Fingrid's application guideline for relay protection presents the operating principles of the relay protection in Fingrid's 110, 220 and 400 kV power networks and the requirements for operation of the protection systems of Fingrid customers (hereinafter referred to as 'customer').
Read More