Power Utilities

BETTER TIMING AND FREQUENCY REQUIREMENT FOR SMART GRIDS

WHY TIMING IS REQUIRED AT A SUBSTATION:

Timing at substations has historically been provided by dedicated timing systems that use separate cabling and specific protocols such as IRIG-B. Such time code protocols deliver time information from a local clock, which physically connects with each intelligent electronic device (IED). The time is coded as a digital data stream frequently supported by a 1-PPS signal for precise alignment of the time code information.

Regulators are now categorizing power networks as critical infrastructures. Using a purely satellite-based sourcing of time to substations is creating an unacceptable risk. Interference, jamming and spoofing could degrade accuracy of time, with negative impact on the operational integrity of the power grid. In the worst case, this could lead to power outages.

HIGHEST TIME ACCURACY IS ESSENTIAL FOR EFFICIENT OPERATIONS:

With an increasing level of operational sophistication, greater accuracy is needed in power grid monitoring and localization of faults. Substations require microsecond accuracy with phasor measurement units as well as sample value merging units. Portable wave fault locators require a similar precision for accurate localization of any fault. Those requirements have been specified with IEC 61850, which addresses communication networks and systems for power utility automation.

THE IMPLEMENTATION METHOD OF TIMING AND FREQUENCY:

The requirement for time & frequency equipment in the power utility industry is twofold. First, as with any other modern business, there is the need to accurately and securely synchronize your IT network. Second, fault detection equipment, SCADA systems, protective relays, and remote terminal units all need to be synchronized.

Time synchronization is fundamental to the operation and control of modern generation, transmission and distribution substations. Protection relays, RTUs, PMUs, traveling wave fault location, and other IEDs require synchronization. Grid fault data, when accurately time stamped, can be efficiently analyzed to determine the root cause and sequence of events. Our products meet the North American Electric Reliability Council (NERC) recommendations that all power substation data recorders be time-synchronized with GPS.