Page 18 - PEN eBook May 2022

SEMICONDUCTORS Semiconductors

However, the electrification agenda will not begin and end with cars. Wider transport applications
will soon come into view, including trucks and buses, marine and shipping, the further electrification
of trains, and even airplanes. On the supply side, grid-connected solar power systems and the

transport of energy via high-voltage DC (HVDC) links will also be critical to the generation and
distribution of low-carbon energy.

A common theme across these applications is the potential role for higher system voltages
and, hence, higher-voltage power devices. In EVs, the benefit of the shift from 400 to 800 V is
predominantly the faster charging rate possible. In solar inverters, an ongoing shift from 1,000-V to
1,500-V systems is reducing the number of PV strings, inverters, cables, and DC junction boxes, all
of which result in efficiency and cost savings. In gigawatt HVDC installations, in which the nominal
voltage is several hundred kilovolts, a higher individual device rating reduces the number of devices

required in a multilevel stack, reducing maintenance and overall system size.

SiC power devices have the potential to be a key enabler in each of these areas. However,
today, the range of SiC devices available on the market is incredibly narrow, from just 650 V to
1,200 V, with just a smattering of 1,700-V devices available, and while 3,300 V looks well within reach
technologically, only GeneSiC supplies devices at this voltage level.

This singular focus on the automotive prizes on offer is, of course, understandable. The race to
capture market share of this industry has led to companies fighting to drive up capacity, adopt
200-mm wafers, and drive up yields. This leaves scant room for the substantial R&D activities
necessary to open up the high-voltage markets, which are relatively small in comparison.
SiC Power Electronics:

Looking Beyond

Automotive

By Peter Gammon, professor of SiC Power Devices at the University of Warwick
and founder of PGC Consultancy; Arne Benjamin Renz, researcher at the
University of Warwick; and Guy Baker, researcher at the University of Warwick

There remains little doubt that silicon carbide, a so-called third-generation, wide-bandgap
semiconductor is fulfilling its long-known potential, with the automotive industry having been the
very public proving ground for the material in the last five years. SiC-based drivetrain inverters —
power converters that convert DC electricity from the battery side into AC required from the motor
side — are smaller, lighter, and more efficient than their Si IGBT–based ancestors.
Figure 1: The current Si and SiC device landscape, alongside a projection to SiC’s future potential market

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