ABSTRACT
Besides common and well-known types of use of the reed switches (RSs), a suggestion has been made to use them as sensitive elements of current and voltage in devices intended to decrease of vulnerability of digital protective relays (DPRs) to intentional remote destructive impacts (IRDIs). Accordingly, the input relays of the proposed protection device contain threshold elements for current, voltage, and angle between them. The starting element of the proposed DPR protection device requires no current-dependent time delay. In order to do this, the DPR manufacturer has to take these circuits out to a separate external connector so that RSs of the proposed protection device for the circuits can be connected through them. The authors describe a relay design to demonstrate its general concept only. It is obvious that the described device can be supplemented by signal relay registering the response, time delay device, RS sensitivity control unit, reinforced insulation, etc.
