In our latest installment of the BaSiCs of SiC, we are delving into the world of power electronics as we investigate how SiC components have come to define the industry.
Research into SiC as a semiconductor has directly supported the evolution of even more efficient, reliable, wide bandgap power electronics. But what exactly are power electronics, and why are they important?
What Are Power Electronics?
The term power electronics refers to solid-state electronic devices used for the conversion and control of electric power. Modern power electronics includes devices such as MOSFETs (Metal-oxide Semiconducting Field-Effect Transistors) and IGBTs (Insulated-Gate Bipolar Transistor) as well as inverters (DC to AC), rectifiers (AC to DC), and converters (AC to AC, DC to DC). These power electronics are an indispensable part of modern technology, but the earliest form of these components could well be unrecognizable to most engineers today.
First Power Electronics
Early power electronics were far different from what we see today in terms of size, capability, and functionality. One of the earliest examples of power electronics was the mercury-arc value developed in 1902 to convert AC to DC. Mercury continued in wide use for rectifiers and power transmission until the introduction of Selenium electronics in the early 1930s.
Selenium (Se) began to be replaced by Silicon (Si) in power electronics around the mid-1950s.
In fact, Silicon, Gallium Arsenide (GaAs), and Gallium Nitride (GaN) were the primary semiconductors used in power electronics for many years. The next big change in power electronics would be the use of Silicon Carbide (SiC).
MOSFETs were originally developed in the late 1950s but were not suitable for use in power electronics until the 1970s. IGBTs were then introduced in the early 1980s but did not become widely available until the 1990s.
Silicon Carbide Comes into Its Own
NASA was looking at using Silicon Carbide (SiC) semiconductors as early as the 1990s, but the major hurdle to widespread acceptance of SiC in place of Si was the actual fabrication of these devices, including identifying effective ways to grow pure SiC crystals. However, in the early 2010s, SiC power electronics truly came into their own (and continue to evolve today).
In 2011, Cree (the parent company of Wolfspeed) launched the first commercial SiC power MOSFET. Then, in 2016, Wolfspeed released an all-SiC high-performance commercial half-bridge power module and gate driver combination. Wolfspeed now makes SiC, SiC MOSFETS, and SiC power modules.
SiC power electronics support emerging industries such as renewable power (including solar, thermal, and wind power), EV/HEV power systems, and electric trains, buses, and other types of public transportation. They can also be found on uninterruptible power supplies (UPS), industrial electronics, and motor drives. In addition, devices made with SiC components exhibit greater efficiency, take up less space, weigh less, and do not require extensive cooling systems.
Why Silicon Carbide is Important to Power Electronics
The introduction of SiC as a semiconductor has significantly impacted power electronics, including higher voltages, higher switching frequencies, a wider bandgap, extreme temperature tolerance, and low resistance -- all of which are key to the continued development of effective power electronics and the designs that depend on them.
With some of the most BaSiC parts of SiC discussed over these last few blogs, we’ll now start taking a look at some specific applications in our next few posts!