In August 2016, 2 500-kilovolt transmission lines successful San Bernardino County, California, tripped offline during a fire. As a result, immoderate region away, much than 1,000 megawatts of star procreation disconnected itself from the grid. Luckily, nary 1 mislaid power. In contrast, a 2003 constituent nonaccomplishment successful a generator adjacent Lake Erie led to a somewhat smaller nonaccomplishment of generation, but the ensuing blackout affected much than 50 cardinal people.
Why did 2 similar-sized events person specified a disparate interaction connected the power system?
The 2003 blackout and the disconnect successful 2016 had antithetic outcomes but, according to Pacific Northwest National Laboratory (PNNL) power systems adept Harold Kirkham, are conscionable 2 examples of however a tightly coupled strategy mightiness behave nether stress. And the effects of imaginable errors, combined with a strategy that's tightly coupled, could person much disruptive consequences arsenic the grid incorporates much diverse—and unpredictable—energy sources similar star and upwind power.
Energy successful the ecosystem of tightly coupled systems
When the California star procreation tripped offline, automated extortion and power systems maintained grid stability. But the star procreation should not person disconnected. It tripped due to the fact that of a atrocious measurement. That is, a measurement made by a perfectly functioning instrumentality doing precisely what it was designed to do.
The accidental of a ample star generator disconnecting connected a sunny time is not significant, but if it happens erstwhile the powerfulness transmission strategy is nether stress, determination mightiness beryllium a cascade of problems similar the 1 that led to the 2003 blackout successful the Northeast.
Kirkham said 1 effectual attack to ward disconnected these imaginable hazards is improving the methodology and meaningfulness of blase measurements communicated among antithetic parts of the grid. With backing from the U.S. Department of Energy's Office of Electricity and the enactment of an planetary radical of engineers and scientists, Kirkham is starring an effort to amended powerfulness measurements to supply a straighter way to a resilient and renewables-rich powerfulness grid.
Insight into energy measurement
"Measurement exists astatine the intersection of exertion and philosophy," said Kirkham, whose probe successful measuring energy goes backmost to an analog epoch of "instruments with pointers and scales, and bearings wherever particulate gets successful and screws things up." An Institute of Electrical and Electronics Engineers (IEEE) chap who came to PNNL successful 2010 from NASA's Jet Propulsion Laboratory, Kirkham's probe has paved the mode for advancements successful some fields during his 5 decades of powerfulness strategy engineering.
Kirkham's archetypal concerns astir shortcomings successful long-prevailing energy measurement approaches started successful 2010 erstwhile helium was portion of a squad moving to update the IEEE modular for instruments called phasor measurement units (PMUs). PMUs assistance lucifer the grid's proviso and request utilizing real-time information from aggregate points to springiness a "big picture" depiction of grid conditions. This depiction makes it imaginable to summation automation and integrate energy storage, electrical vehicles, and intermittent powerfulness from upwind oregon star panels into the powerfulness grid.
Early on, Kirkham was friends with the creators of PMUs erstwhile the measurements were being developed successful the 1980s, and he's seen their payment firsthand. Still, during immoderate of the meetings to update the standards, helium realized determination was thing fundamentally antithetic betwixt a PMU measurement and different measurements successful the powerfulness system. PMU measurements could beryllium utilized to measure measurement prime due to the fact that the PMU wholly characterizes the powerfulness strategy signal, wherever different measurements simply summarize it.
"I realized that this characterization would let america to spot wherefore the results of galore antithetic types of energy measurements bash not lucifer up with what we ideate we're describing," said Kirkham. "That mismatch means errors, powerfulness loss, and inefficiencies erstwhile some the halfway and the edges of the grid person galore devices and systems that respond faster than radical tin intervene."
The 'how' is arsenic important arsenic the 'what'
Kirkham's decades-long exploration revealed conscionable however acold the fields of energy and measurement had advanced, though sometimes on abstracted pathways. It's easier to hold connected however to measurement magnitude oregon value due to the fact that humans tin interaction and consciousness the circumstantial things they privation to measure, adjacent if they take a kilogram alternatively of a lb to quantify it. But measurements autumn abbreviated erstwhile it comes to quantifying abstract concepts similar beauty, intelligence, oregon adjacent immoderate of the things of involvement successful the powerfulness system.
"It utilized to beryllium astir a joke," said Kirkham, "that we did not cognize however to specify concepts similar IQ, but we surely knew however to measurement it." But it's not a joke—it's an illustration of a antithetic benignant of measurement.
Over the years, researchers had learned that measuring an abstract conception similar quality could beryllium untrustworthy if antithetic approaches were utilized successful IQ tests. The solution was ever to usage the aforesaid approach. Standardization was needed. And the aforesaid inconsistencies came up successful measurements for concepts that look to person lone 1 ft successful the worldly world. Although the hardness of metals, the octane worth of gasoline, and the eyeball unit captured by glaucoma tests each look to quantify a chiseled carnal thing, the "thing" is really ne'er defined, lone the method by which it is measured. To get accordant results, each of these measurements trust connected a prescribed process.
"You conscionable travel the recipe," said Kirkham. "Air temperature, nutrient calories, upwind speed, and galore different measurements of this kind."
These measurements are called pragmatic oregon operational measurements, wherever the method of measurement is intimately defined, due to the fact that it's hard to specify precisely what it is you're trying to quantify.
Take, for example, the reactive powerfulness imagined to beryllium consumed by electrical motors successful their alternating current's magnetic field. Originally described arsenic the "wattless watt" driven by an "idle current," the conception of reactive powerfulness has been truthful hard to specify that it led to arsenic galore arsenic 10 antithetic operational measurements successful usage today. These antithetic measurements pb to discrepancies and miscommunications that could outgo some wealth and reliability without humans to construe measurement results for automated grid devices.
Kirkham saw the imaginable successful creating energy measurement processes that springiness azygous answers crossed the powerfulness strategy alternatively of continuing to constitute caller definitions for things that defy definition. As portion of an ongoing planetary collaboration, helium and PNNL electrical technologist Artis Riepnieks developed their ain method of implementing PMUs to region measurement errors caused by real-world distortions.
That improvement made imaginable a method to bespeak to devices successful the powerfulness strategy erstwhile to trust—and erstwhile to distrust—measurement results.
"Lines and connections are tripping connected and disconnected each the time," said Kirkham. "The powerfulness strategy keeps going due to the fact that it was built to beryllium robust. Integrating a measurement prime appraisal would let automated devices to appropriately suffer spot successful the measured effect earlier they react, bringing their show person to what quality operators expect. There should beryllium less examples of what happened successful San Bernardino backmost successful 2016."
A powerfulness measurement recalibration
The measurement occupation is solvable, but Kirkham says convincing the powerfulness assemblage could beryllium tricky due to the fact that the radical practicing powerfulness engineering contiguous don't needfully presumption the contented done the mentation of measurement. The solution volition necessitate a cadre of multidisciplinary researchers, powerfulness engineers, measurement experts, and operators to attack issues with precocious measurement knowing and rotation everything retired successful logical, enforceable standards. Kirkham and his squad are putting the finishing touches connected standards for the astir pressing areas.
"As distributed resources nutrient vigor faster, with little country for mistake margins successful a much divers vigor ecosystem, there's a immense upside to making definite those assets are participating successful a unchangeable way," Kirkham said. "We indispensable person measurements that tin uncover wherever we request other cushions, however large those cushions are, and however overmuch we tin spot them. Our strategy volition ever beryllium tightly coupled but trusting successful the fundamentals of our measurements could forestall a big of problems."
Citation: New attack to energy measurement could mean less blackouts, amended automation and much cleanable vigor resources (2021, August 4) retrieved 4 August 2021 from https://techxplore.com/news/2021-08-approach-electricity-blackouts-automation-energy.html
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