A cornerstone of every utility’s operation is the communications network that enables continuous monitoring, control and management of the power grid. These real-time control and monitoring mechanisms, known as teleprotection, allow utilities to quickly isolate failures and reroute power, ensuring uninterrupted delivery.
For decades, SONET has been the foundation of utility networks, and while this has proven to be stable and dependable, legacy networks now present significant operational, management and budgetary challenges. Disunified networks, for instance, require multiple management system logins, which complicates recordkeeping and troubleshooting. The result is often abundant data with little insight.
Many utilities are now modernizing their networks by transitioning to packet-based networking. Migrating to packet technology will bring with it challenges, particularly in the form of issues involving jitter and delay. Packet networks introduce new causes of delay such as buffering that can cause inconsistencies in delay across the service, known as asymmetric delay variation. This phenomenon can adversely affect teleprotection, since this function depends on symmetrical delays in order to synchronize time accurately. Ultimately this can cause damaged power lines or unnecessary outages. Packet technologies also bring an increased vulnerability to “false trip” events caused by asymmetric delay variation. A teleprotection application must prevent these as far as possible, since false trips can lead to potentially costly downtime and troubleshooting.
Fujitsu’s utility teleprotection application is based on the vSure™ service assurance system. vSure centralizes and simplifies performance assurance functions for networks, services and applications. The system provides multilayer, multi-technology service assurance on Layer 0–3 devices, and monitors parameters important to teleprotection like delay, delay variation, packet loss, and jitter buffering. vSure also tracks and records historical trends and provides notification of any metrics that fall outside the designated thresholds.