An analogical distance relay for the 110kV electric lines
This article presents the basic principles of the analogical protections used for protecting the high-voltage electric lines (110 kV). A study for implementation of an analogical distance protection RD 110, for a high-voltage line is performed (a practical example). For the analogical relay the protection adjustment for an electric grid of 110 kV is presented. The distance relay is operating in association with the current-disconnecting delayed directional homopolar protection, with the automatic rapid reclosing protection and with the synchronism relay. An analysis is achieved upon these types of analogue protections for protecting the high-voltage grids, because they are still used in practice.