T&D World Magazine

Dynamic Monitoring, Diagnostics and Control Are Here to Stay

Today, we know so much about all aspects of the power grid, and, more importantly, we can access so much of this data in real time. With data on the condition of the grid, the operating characteristics of the components and the capacity of the devices, we are rapidly moving to an era where we can act in real time.

Of course, many advances today have their roots in the not-too-distant past. Remember when everyone was scratching their collective heads trying to understand the phasor measurement unit (PMU) technology? I was working for Public Service New Mexico as a senior substation engineer when PMUs first came on the scene. They were heralded as the next powerful tool for mitigation of blackouts.

The North American Electric Reliability Corp. (NERC) went so far as to intonate that the massive 2003 blackout would have been a nonevent if PMUs had been widely deployed. NERC said that if these devices had been installed in sufficient numbers, the operators would have seen the instability developing. At that point, they would have been able to take action and prevent the excursion. That may have been a bit of a stretch, considering how primitive the other tools available to us were back then.

After the blackout, utilities began to investigate PMUs, and the utility I worked at was no exception. On staff, we had Abe Ellis, a brilliant Ph.D. who grasped the significance at once. Ellis also predicted a wide-area snapshot of the grid that would one day provide us with very useful real-time behavior of the power system. Like most visionaries, he spent a great deal of time trying to show the rest of us how these devices fit into the future of our industry.

Luckily for me, early PMUs were huge devices and had to be installed in the substation’s bus work. Because of this, I was able to work closely with Ellis installing PMUs on the utility’s system and reviewing the data they produced.

After the installations, he showed me the data pouring into his computer. It was both a eureka moment and an uh-oh moment. I saw our network in real time and it made sense, but the amount of data flooding his computer was unbelievable. How would the industry handle all the data if we had PMUs on every line in every substation?

These early installations were the beginnings of a wide-area measurement system. They started people developing the tools for analyzing this real-time, large-scale data into usable information. Prior to that, the only view we had of the network was a simulation run on an electromagnetic transient program — and that was only a simulation. No one knew this early work would set the stage for the dynamic grid monitoring systems being developed today.

Fast-forward to the present, my friend Abe was so correct. PMUs are still with us, pumping out network data, but that is only part of the available technology. A plethora of sensors have spread over the grid since those early days. Today, just about every device in the substation is self-monitoring and equipped with some sort of diagnostics to make them better, but this isn’t happening just in the substation.

The transmission and distribution lines have been the focus of recent technological advancements. The towers, poles and conductors are being made smarter — or, using today’s vernacular, wired. Technology improves and sensors become smaller and cheaper, which means we find more uses for them. These wonders of miniaturization are being attached to the structures, hung on the lines and embedded in the hardware — all of which has brought about the next great evolution in smart grid equipment. In effect, we are at a point where we redefine those sacred cows of operating criteria.

Utilities now have the ability to really rate their line’s capacity. Dynamic line ratings are based on real-time measurements of sag, conductor temperature and weather conditions rather than old-school methods of selecting static conditions by committee. In addition, as more lines become brainy, the grid is morphing into a dynamic system with real-time energy management systems. These systems are capable of optimizing the electrical grid. Power flows can be monitored to avoid congestion, and software predicts the network’s behavior.

Tomorrow’s system operators will have dynamic views of their entire system on their console with event-driven functionality, which is just in time since utilities are operating their facilities closer and closer to capacity limits. Our industry has been moving at an unbelievable pace as we pack more brainpower into every device. It’s a challenging future where diagnostics monitoring and intelligent control systems are fused into a tool set that allows us to get the most out of our aging infrastructure while building out the smart grid of the future.

We now have tools that have been decades in the making. It is the confluence of smart grid software and hardware technologies making this one of the most dynamic epochs of our industry. But we have to be ready for it!



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