Page 31 - EE Times Europe March 2022

EE|Times EUROPE 31

Nuclear Fusion Research Looks to Secure the Future of Energy

The MTF plasma injector is powered by • Fuel production. The fusion process starts perature for a longer period of time, especially
electromagnets. Because of the swirling by filling a tank with liquid metal, spin- if the atoms must remain at that temperature
motion, an injector creates a ring of plasma ning the metal until a cavity is formed. for extended periods. First Light cuts the time
that creates a magnetic field, which forms General Fusion injects hydrogen plasma it takes to keep the temperature constant by
a cloud of particles. The plasma ring is into the cavity. directing the fuel toward a rapid projectile;
squeezed to temperatures and pressures at • Energy conversion. In the pilot plant, heat as a result, the fusion process occurs in a
which nuclear fusion should occur. Plasma would be extracted from metal and used fraction of a second. First Light thinks that its
particles move along magnetic field lines, to make steam. The steam would drive a method will avoid some of the most difficult
which then circulate without ever colliding turbine and produce electricity. aspects of fusion-reactor construction.
with the wall. The magnetic field prevents • Energy economics. General Fusion claims
the hot fusion plasma from colliding with the that MTF is straightforward to manu- TIMETABLE
liquid metal and cooling. As the plasma core facture and scale because it uses simple Proceeding along several research routes, as
heats up, the magnetic field functions as a electromagnets and does not require described here, the global effort to achieve
good thermal insulator. expensive lasers. viable fusion-based power is projected to
According to General Fusion, MTF has four First Light, meanwhile, uses a technique succeed within one or two decades. That’s a
key advantages: based on inertial confinement, with the goal rather short time when we remember that the
• Material durability. The liquid metal of achieving fusion conditions by rapidly com- earliest scientific investigations into fusion
liner shields the MTF structure from pressing the fusion fuel and using the inertia date back to the 1930s and the tokamak solu-
neutrons released by the fusion of the fuel to sustain those conditions long tion was born in the 1950s. ■
reaction, overcoming the problem of enough to activate the fusion reaction.
structural damage to plasma-facing It’s difficult to perfect a process that Maurizio Di Paolo Emilio is editor-in-chief of
materials. requires atoms to be heated to the sun’s tem- Power Electronics News and EEWeb.

POWERING THE FUTURE
SiC and GaN: A Tale of Two Semiconductors

By Ezgi Dogmus, Poshun Chiu, and Taha Ayari, Yole Développement

ver the last several decades, advances in silicon carbide and booster power modules from Denso in its Mirai fuel-cell EVs. And GM
gallium nitride technologies have been characterized by has signed up Wolfspeed to supply SiC for its EV power electronics.
development, growing industry acceptance, and the prom- European car manufacturers have been slower to embrace SiC, but
Oise of billion-dollar revenues. The first commercial SiC change is afoot. In June, Renault and STMicroelectronics joined forces
device arrived in 2001 in the form of a Schottky diode from Germany’s to develop SiC and GaN devices for EVs and HEVs. More announce-
Infineon. Rapid development has followed, and the industry sector is ments are expected soon from Daimler, Audi, and Volkswagen.
now poised to exceed US$4 billion by 2026. Importantly for Wolfspeed, Infineon, STMicroelectronics, Rohm,
GaN first wowed the industry in 2010, when U.S.-based Efficient and onsemi, automotive OEMs also prefer to buy wafers and devices
Power Conversion (EPC) delivered its super-fast switching transis- from multiple sources to ensure reliable supply. Factor in the vast
tors. Market adoption hasn’t yet matched that of SiC, but come 2026, sums that China and others are pouring into the SiC supply chain, and
power GaN revenues could hit more than US$1 billion. volume sales will only continue to rise.
The secret to future market success for each technology rests with Along the way, the thorny issue of cost is also being addressed. At
electric and hybrid electric vehicles. For SiC, the EV/HEV market is the component level, silicon IGBTs are vastly cheaper than the SiC
truly the sweet spot; at least 60% of the more than US$3 billion equivalent and are not going to disappear from power applications
market is expected to come from this sector. anytime soon. But Tier 1 manufacturers and OEMs have indicated
Tesla kickstarted the SiC power device market in 2017, when it that implementing high-power–density SiC in an inverter design, for
became the first automaker to use SiC MOSFETs in a car (the Model 3). example, cuts costs at the system level because the design will require
Sourced from STMicroelectronics, the device was integrated with an fewer components, yielding space and weight savings.
in-house main inverter design. Other automakers have been quick to But where does this leave GaN? This wide-bandgap semiconductor
follow, including Hyundai, BYD, Nio, General Motors, and others. has yet to witness the success of SiC in the EV sector. Thanks to GaN’s
China’s Geely Automobile recently announced that it was collab- high-frequency operation and efficiencies, however, OEMs are either
orating with Rohm Japan on SiC-based traction inverters for its EVs. eyeing the technology with intense interest or have development
NIO, China’s answer to Tesla, will implement a SiC-based electric programs under way.
drive system in its vehicles. At the same time, automaker and semi-
conductor manufacturer BYD has been developing SiC modules for its EARLY DAYS
entire line of EVs. GaN power devices can already be found in low-volume, high-end
Last year, China-based electric bus manufacturer Yutong revealed photovoltaic inverters and increasingly are being used in fast chargers
that it would use SiC power modules manufactured by StarPower China for a range of mobile devices, including smartphones. Indeed, Ireland’s
in bus powertrains. The modules use SiC devices from Wolfspeed. Navitas Semiconductor, the U.S.’s Power Integrations, and China’s
Hyundai will integrate Infineon’s SiC-based power module for Innoscience are all manufacturing GaN power ICs for the burgeoning
800-V battery platforms into EVs. In Japan, Toyota is using SiC fast-charger market.

www.eetimes.eu | MARCH 2022