Last week I had a chance to talk to Manish Gupta, Symmetricom’s vice president of Marketing about smart grid technology. Normally we talk about timing in the telco infrastructure, however with less and less traffic being associated with channel banks the use of timing now seems less important. That is, except for with smart grid technology, where timing has become a critical factor, particularly in the new layer which adds intelligence to the transmission.
“This need is driven by Synchrophasors (phasor measurement units)and the SCADA system. The Precision Time Protocol (PTP), defined by IEEE 1588, is described, including the features which allow it to deliver the required time transfer accuracy. The IEEE Power and Energy Society sponsored the creation of IEEE C37.238-2011, a PTP profile for the Power Industry. The profile describes constraints on the use of PTP to make sure that Power Systems meet their timing requirements.”
All of this is discussed in Symmetricom’s white paper, “Profile for the Use of the Precision Time Protocol in Power Substations,” which underlines the main point: getting a control plane set up for two-way communication. Once that is accomplished, the network can reduce the impact of cascading failures.
During my previous interview with Manish we talked about timing being everything, and this time, in effect, we graduated that to timing being everywhere. I say this because the goal now is to have distributed clocks that synchronize the AC current.
Timing clocks are all over the grid. Masters, slaves, transparent clocks…all of them protecting the grid from surges while synchronizing the energy that makes the grid a resource to us all. The beauty of PTP is that when a clock is goes down, it allows other clocks to take over the role of master and to revert back when appropriate.
Today the grid has a tendency to overreact to a failure. As it becomes more distributed, though, it can eventually become self-healing, and if the substations can remain synchronized by reaching the clocks, they can blend the power from the subsystem to the existing grid. Without the clock, the AC currents can fall out of phase which normally results in substation failure.
In the long run, as more power sources come on the grid, synchrophasors are going to be referenced across companies sharing power. At this time, however, the timing remains somewhat off.
Edited by
Stefania Viscusi