Interconnection longitudinal differential protection using digital communications infrastructure WAN

The expansion tendencies of microelectronics, communications and information technology have led-in what it concerns the power field to the appearing a lot of opportunities concerning the IEDs (Intelligent Electronically Devices) LAN communication and interconnection, involved in the technological flux. The paper contain, approach the technical issues related to reliable interconnection and communication of LCDPR (Line Current Differential Protection Relays - F87/21/67N) using the WAN communication infrastructure, without taking in consideration the classical method of “relays direct connection”. The main disadvantage of “direct connection” is inefficient management of WAN and of optical fiber resources by using dedicated fibers (dedicated communication links). The FO can carry information up to G/Tbps, so, to dedicate FO cores only to inter-transfer of some particularly telegrams (kbps) between relays isn't a good practice. In that situation we will propose and practical prove that non classical interconnection between relays it is possible and reliable using logical channels defined in WAN infrastructure. Solution can create premises for a new strategy regarding protection philosophy and to streamline and optimize the Telecom infrastructure.