Can Smarter Solar Inverters Save the Grid?

A new technique called virtual oscillator control lets solar inverters help stabilize the power grid

10 min read
Photo of a SolarCity worker installing photovoltaic panels on a house in Hawaii.
Aloha, Solar: A worker from SolarCity installs photovoltaic panels on a house in Hawaii, the U.S. state with the highest penetration of rooftop solar systems connected to the grid.
Photo: SolarCity

When Steve Johnson had solar panels installed on the roof of his Boulder, Colo., home several years ago, he considered it his personal contribution to making the world a little cleaner. And if his grid-connected photovoltaic (PV) system would occasionally cause his electricity meter to spin backward during the day and trim his utility bills, so much the better.

It was only later, during a tour of the National Renewable Energy Laboratory (NREL), in nearby Golden, that he learned about solar’s potential downside: Most PV systems are set up to disconnect from the grid whenever they detect a significant fault. If a single home’s PV system trips off-line, it’s only a headache for the owner. But if hundreds or thousands of them do so simultaneously, it could upset the network’s delicate balance, turning an otherwise small disturbance into an outage blacking out an entire city or county.

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A Diamond "Blanket" Can Cool the Transistors Needed for 6G

Gallium nitride transistors have struggled to handle the thermal load of high-frequency electronics

4 min read
blue mountain of crystals with an inset of molecules on a pink background
Srabanti Chowdhury/Stanford

High-power radio-frequency electronics are a hot commodity, both figuratively and literally. The transistors needed to amplify 5G and future 6G signals are struggling to handle the thermal load, causing a bottleneck in development. Engineers in the United States and England have teamed up to demonstrate a promising solution—swaddling individual transistors in a blanket of thermally conductive diamond to keep them cool.

“Thermal issues are currently one of the biggest bottlenecks that are plaguing any kind of microelectronics,” says team lead Srabanti Chowdhury, professor of electrical engineering at Stanford University. “We asked ourselves ‘can we perform device cooling at the very material level without paying a penalty in electrical performance?’”

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New Contactless ECG Continuously Monitors the Heart

Millimeter-wave radar device make electrode-less cardiovascular health tech possible

3 min read
Video still of a man lying down. A box shaped device on a pole sits above his body. To the left, a monitor displays ECG readings.

The researchers demonstrated an experimental setup for contactless ECG monitoring using millimeter-wave radar.

University of Science and Technology Of China/IEEE

This article is part of our exclusive IEEE Journal Watch series in partnership with IEEE Xplore.

More than 100 years after the technology was first developed, the electrocardiogram (ECG) remains the gold standard for measuring the electrical activity of the heart. However, an ECG currently requires electrodes to be attached on a person’s skin. Even the latest consumer technologies like the Apple Watch require a user seeking an ECG to touch a finger to the device’s protruding “digital crown,” forming a circuit across the user’s body, thereby enabling electrical signals across the heart to be measured.

However, researchers in China have reported the invention of a novel ECG technology that uses millimeter-wave radar and AI to infer an ECG signal, making the system completely contactless. Should the researchers’ initial promising results bear out, the millimeter-wave tech could inspire new applications based on a reliable and uninterrupted stream of heart health data.

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Designing Fuel Cell Systems Using System-Level Design

Modeling and simulation in Simulink and Simscape

1 min read
Designing Fuel Cell Systems Using System-Level Design

Design and simulate a fuel cell system for electric mobility. See by example how Simulink® and Simscape™ support multidomain physical modeling and simulation of fuel cell systems including thermal, gas, and liquid systems. Learn how to select levels of modeling fidelities to meet your needs at different development stages.