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.