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Inside the Lab That Pushes Supergrid Circuit Breakers to the Limit

Tomorrow’s megavolt transmission lines need breakers that can withstand titanic forces

10 min read
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photo of KEMA Laboratories

The Guardian: KEMA Laboratories tests a circuit breaker under extreme conditions to ensure it won't fail when it really matters.

Photo: KEMA Laboratories

Imagine a blazingly hot day in central China, when all the air conditioners in every megacity are running at full blast. Through the remote mountains of Shanxi province, the major transmission lines that carry ultrahigh-voltage electricity to the cities are operating at close to maximum capacity. Heated by the sunshine and the flowing current, the transmission lines sag dangerously close to the treetops. Suddenly the current jumps from line to tree branch, finding the path of least resistance and pouring through the tree into the ground. There's a bright flash as the current ionizes the air.

During this short circuit, the abruptly unleashed current reaches 10 to 20 times its normal level within a blink of an eye. Now the power grid's protection system must act fast. Within milliseconds, protection relays must recognize the fault and command the circuit breakers at both ends of the line to switch off the current, isolating the faulted line. The stakes are high: A sustained short-circuit current can trigger a chain reaction of failures throughout the grid and cause widespread blackouts, severely damaging expensive equipment in the process. The 2003 blackout in northeast North America was set off by a tree's contact with transmission lines in Ohio, which caused a cascade of failures that shut down more than 260 power plants, stopped the flow of 60,000 megawatts throughout the northeast grid, and darkened New York City.

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Inside the Universe Machine: The Webb Space Telescope’s Trailblazing Optics

As NASA’s newest Big Science project opens its eyes, IEEESpectrum reflects on JWST’s groundbreaking engineering

9 min read
Fourteen technicians in clean-room suits guide the hoisting of a honeycombed, hexagon-mirrored telescope inside a giant cleanroom construction space

The James Webb Space Telescope’s 18-segment gold mirror enables it to see a penny 40 kilometers away, or a football 550 kilometers away.

NASA/Desiree Stover

“Build something that will absolutely, positively work.” This was the mandate from NASA for designing and building the James Webb Space Telescope—at 6.5 meters wide the largest space telescope in history. Last December, JWST launched famously and successfully to its observing station out beyond the moon. And now according to NASA, as soon as next week, the JWST will at long last begin releasing scientific images and data.

Mark Kahan, on JWST’s product integrity team, recalls NASA’s engineering challenge as a call to arms for a worldwide team of thousands that set out to create one of the most ambitious scientific instruments in human history. Kahan—chief electro-optical systems engineer at Mountain View, Calif.–based Synopsys—and many others in JWST’s “pit crew” (as he calls the team) drew hard lessons from three decades ago, having helped repair another world-class space telescope with a debilitating case of flawed optics. Of course the Hubble Space Telescope is in low Earth orbit, and so a special space-shuttle mission to install corrective optics ( as happened in 1993) was entirely possible.

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This Startup Is Using AI to Help Keep Store Shelves Stocked

Wisy’s platform eases supply-chain issues by tracking inventory

4 min read
Phone screen with Wisy platform on black background

Store employees take a picture of a product on display using Wisy's platform, and the AI records information based on the photo.

Wisy Platforms

Shoppers are seeing more and more empty shelves, as stores around the world struggle to keep products stocked. The situation is the result of supply-chain issues caused in part by the COVID-19 pandemic. The product-unavailability rate increased from 5 percent to 15 percent during the past three years, according to the Consumer Brands Association.

To make it easier for stores to track inventory, startup Wisy developed an AI platform that uses image recognition to detect which products are out of stock or running low, as well as those that are available but haven’t yet been put on display.

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A Multiphysics Approach to Designing Fuel Cells for Electric Vehicles

White paper on fuel cell modeling and simulation

1 min read
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Comsol

Fuel cell electric vehicles (FCEVs) often reach higher energy density and exhibit greater efficiency than battery EVs; however, they also have high manufacturing costs, limited service life, and relatively low power density.

Modeling and simulation can improve fuel cell design and optimize EV performance. Learn more in this white paper.