OMICRON Magazine

CMC test set CMC test set Protection interface SPRECON-E-P DL6 SPRECON-E-P DL6 Protection data and additional services Laptop › Operation of the relay test set (local/remote) › Access to remote protection device › System-based testing via RelaySimTest Figure 1: Simplified, safe test set-up with remote control via Ethernet protection interface. allows us to guarantee that the differential and stabilization currents are calculated precisely. A connection is possible via optical fibers and an Ethernet-based communication network (e. g., an IP/MPLS network). The SPRECON-E-P DL6 doesn’t require a time source, elimi- nating the need for an external GPS receiver. There’s also no need for a separate protocol for transferring time informa- tion within the network. The data packages in the network can be prioritized, guaranteeing that the line differential protection can operate without disturbance. And – last but not least – system-based testing with RelaySimTest makes it possible to test the line differential protection system comprehensively with just a laptop (Figure 1). From an IT security perspective, how can you prevent unauthorized access? andreas: Inbound data from the protection interface is monitored by a firewall in the protection devices. The distant end only accepts and processes packages that comply with the firewall rules – otherwise, they are rejected and denied access. The data can also be protected with IPsec prior to modification by third parties. Is this solution suitable for existing systems? andreas: Of course. The protection interface on Sprecher line differential protection devices has always been Ethernet-based, which means that protection testing via a protection interface is also suitable for previously installed systems. All you need is an external switch for these systems configured according to the guidelines. How does it respond to repeat testing and firmware updates? Markus: This poses no problem, and neither do incident analyses nor other maintenance work. This is a good example of one of the device’s major strengths, as it allows users to save time and money. I’d also like to point out that there are currently no normative technical provisions for using different com- munication technologies for protection interfaces. That’s why Sprecher is working on creating guidelines from the general requirements. We hope that this will result in more Ethernet-based solutions in the future as well as higher interoperability. Thank you for the interview. «The data packages in the network can be prioritized, guaranteeing that the line differential protection can operate without disturbance.» andreas aichhorn, Product Manager, Sprecher Automation 28