APPLICATIONS FOR POWER ELECTRONICS: SMALL, RELIABLE, AND ENERGY EFFICIENT

Power electronics convert and control electrical power across the grid and in a growing array of products used by industry, consumers, the military, and utilities. Wide bandgap (WBG) semiconductors—the same materials used in LED light fixtures and many flat screen TVs—can improve energy efficiency in the next generation of power electronics while also reducing cost and system size. WBG semiconductors used in variable frequency drives (VFDs), for example, increase the efficiency of industrial motor systems and expand the range of motor applications in which these energy-efficient drives are cost-effective. Moreover, WBG-based power electronics are more compact and reliable—even as they function at higher power loads, operating temperatures, and frequencies than today’s widely used, silicon-based power electronics.

WBG: ENHANCED CAPABILITIES

control of electrons graphic

Current applied to WBG semiconductors will not excite as many electrons across the gap (compared to silicon semiconductors), enabling finer control over the flow of electrons. This and other properties of WBG semiconductors enable faster, smaller, more reliable and efficient power electronic devices Semiconductors are materials that can allow electricity to flow more readily than insulators—but less readily than conductors. This property makes semiconductors extremely useful for fabricating power electronic chips that control and convert electrical power (i.e., adjust the voltage, current, and frequency as required by various types of equipment and applications).

A bandgap is the term used for the amount of energy needed to release electrons in semiconductor materials so that the electrons can move freely, enabling the flow of electricity. WBG semiconductors have bandgaps significantly greater than those of silicon semiconductors. Electrical current applied to WBG semiconductors will excite fewer electrons across the gap, enabling superior current control and reducing energy losses.

WBG semiconductors are able to operate at higher voltages and power densities than silicon-based semiconductors, allowing the same amount of power to be delivered with fewer chips and smaller components. In addition, these more powerful WBG semiconductors can operate at higher frequencies, which helps to simplify system circuitry and reduce system costs. Furthermore, WBG semiconductors tolerate heat better than silicon. As a result, WBG-based power electronic chips can operate in harsher conditions without degrading the semiconductor material. This greater thermal tolerance (300°C vs. 150°C) reduces the need for bulky insulation and additional cooling equipment, allowing for more compact system designs. Collectively, these performance properties of WBG semiconductors will enable technology developers to continue designing increasingly more compact, efficient, reliable, and affordable power electronics in the decades ahead.

BUILDING MORE COST-EFFICIENT POWER ELECTRONIC SYSTEMS

Graphic to depict share of electricity flowing through power electronics to increase from 30% in 2005The share of electricity flowing through power electronics is expected to increase rapidly. By 2030, an estimated 80% of all U.S. electricity is expected to flow through power electronics Semiconductor chips. They are fabricated by creating complex circuits on a thin, circular wafer (substrate) using a series of iterative processing steps (e.g., oxidizing, etching, doping, etc.). These fabrication processes are automated to produce multiple, integrated circuits or chips on a single wafer. The wafers are then sliced apart to create a number of identical chips. As WBG wafers become available in larger sizes compatible with the automated equipment and infrastructure used by the silicon industry, WBG chip production will scale up substantially.

As shown in the above graphic, chips perform critical power conditioning functions in devices like rectifiers (convert AC electricity to DC), inverters (convert DC electricity to AC), and variable frequency drives (which include both inverters and rectifiers). WBG semiconductor-based devices perform these functions more efficiently, yielding significant energy savings:

  • Industrial Motor Systems: Motor systems use nearly 70% of the electricity consumed in U.S. manufacturing today. Many manufacturers size their motors to handle peak demand, so these motors often use more power than is actually needed. Some motor systems use a variable-frequency drive (VFD) to dynamically adjust motor speed to match power requirements and save energy. VFDs that take advantage of WBG power chips can directly save the energy equivalent of the electricity used by 1 million homes annually. More efficient and compact WBG-based VFDs are also likely to expand the range of motors in which VFDs are cost-effective.
    • Graphic of small house representing 1M homes growing into a big house representing 6.9M homesCost and performance benefits of WBG-based VFDs are expected to expand the existing VFD market (where savings equal the electricity used by 1 million households) into a wider range of industrial motor system sizes and applications. Expanded use of VFDs in industrial motor systems can boost savings by the equivalent of the annual electricity needed to power up to 5.9 million U.S. homes
    • Consumer Electronics and Data Centers: Power converters for data centers and consumer electronics (such as laptops, smart phones, and tablets) account for nearly 4% of U.S. electricity use today, and the demand for these facilities and products continues to rise. The small converter on the cord of your laptop computer, for example, converts the AC power from your wall outlet into the DC power used by your laptop. Similarly, data centers need to convert power to meet the needs of the diverse components of modern data center systems. WBG chips will eliminate up to 90% of the energy losses in today’s rectifiers that perform these conversions. WBG-based power electronics in consumer electronics and data centers can save enough electricity annually to power over 1.3 million homes.
    • Conversion of Renewable Power: Renewable energy generated by wind turbines and solar photovoltaic systems must be converted from DC to AC prior to upload to the electric grid. The WBG chip provides the required conversion in the inverter. More efficient WBG-based power electronics for solar and wind energy conversion can annually save enough electricity to power more than 700,000 homes.

Please watch the video below created by PowerAmerica member, Atom Power, about potentials and capabilities of using SiC in solid-state circuit breaker applications.

For more information about wide bandgap semiconductors, please click here!