CAREER Award to Aid Transition to Smarter, More Capable Power Grid

More than 130 years ago, Nikola Tesla and Thomas Edison engaged in the "War of the Currents" to determine whether Tesla's alternating current (AC) or Edison's direct current (DC) would be the preferred mode of power transmission. Tesla ultimately won the war due to AC's greater ability to transmit power over distance, but DC is making a late rally. Most modern electronics like cell phones, home computers and televisions run on DC, as do solar cells, wind farms and EV batteries. Data centers are also turning to DC due to its increased reliability and efficiency.  

The catch is that it often has to be converted from AC first, creating energy loss, inefficiencies and heat waste. As more and more industries and devices embrace DC current, power devices that can convert AC to DC efficiently, reliably and at high voltages will be critical.  

A U of A researcher, Xiaoqing Song, thinks he can build better conversion systems. The National Science Foundation thinks he can, too, and awarded Song, an assistant professor of electrical engineering, a $500,000 CAREER award to create more efficient, compact and high-voltage power conversion systems using wide bandgap (WBG) power devices.  

"WBG power devices will be critical to modernizing the power grid because they can better manage the rapidly increasing electricity demand driven by data centers and transportation electrification," Song stated. 

Higher Performance 

Wide bandgap devices outperform traditional silicon-based semiconductors that still dominate high voltage power conversion. These old technologies suffer from lower efficiency and limited voltage handling capability, hindering progress toward a cleaner, more capable grid.  

In contrast, WBG power devices use materials like silicon carbide and gallium nitride, enabling them to operate at higher voltages, higher temperatures and higher frequencies than silicon-based semiconductors. They are also more compact and more efficient.  

Song is specifically seeking to eliminate barriers to WBG adoption through the creation of aggregated WBG multi-chip modules, which leverage series and parallel interconnections of mature, lower-voltage WBG chips to achieve both high voltage and high current capability in a practical, scalable and cost-effective manner. Currently, WBG power devices struggle with currents over 100 amperes. 

Fundamental Challenges 

This project will tackle two fundamental challenges to achieving wider adoption of WGP devices: 

1. Achieving simultaneous voltage, current and thermal balancing across multiple series-parallel-connected WBG chips, and 

2. Overcoming limitations in current high-voltage, multi-chip packaging architectures. 

An improved WGB multi-chip module able to perform at higher amperages will also benefit a range of critical applications including large industrial drives, data centers, transportation electrification and high voltage direct current systems, offering simplified converter architectures, lower system losses and more compact system designs. 

This project supports Song's long-term vision of advancing WBG technology to improve energy efficiency, system reliability and power density. He hopes to pioneer high voltage packaging solutions that fully harness the advantages of WBG devices.