Cascaded Multi-level Inverter

Project Graphic

Project Term:
12/15/2017 - 12/14/2020

Critical Need:

Electricity generation currently accounts for ~40% of primary energy consumption in the U.S. and continues to be the fastest growing form of end-use energy. Power electronics condition, control, and convert electrical power in order to provide optimal conditions for transmission, distribution, and load-side consumption. Most of today’s power electronics have limitations to their performance, temperature resilience, and size due to the circuit topology and semiconductor power devices used. Emerging semiconductor devices such as those based on wide-bandgap materials — along with transformative advances in circuit design and system architecture — present opportunities to dramatically improve power converter performance while reducing size and weight. Development of advanced power electronics with unprecedented functionality, efficiency, reliability, and form factor will help provide the U.S. a critical technological advantage in an increasingly electrified world economy.

Project Innovation + Advantages:

Virginia Polytechnic Institute and State University (Virginia Tech) will develop a wide-bandgap-based, high power (100 kW) DC-to-AC inverter that can receive power from sources like batteries or solar panels and transfer it directly to the medium voltage level of the utility grid. The team will also integrate the device with an existing medium voltage AC-to-DC converter to build a bidirectional solid-state transformer that converts low-voltage AC to high-voltage AC without using heavy, low-frequency materials such as copper and iron in its design. The hardware prototype will be packaged with a high power density design, having the potential to reduce size by two orders of magnitude over the current solid-state transformers. The cooling system is minimized due to the high efficiency and implementation of a convection-cooled heat sink. If successful, the project could lead to the first commercially viable medium voltage solid-state transformer, using just a single-stage process to obtain high efficiency power conversion.

Potential Impact:

If successful, CIRCUITS projects will enable further development of a new class of power converters suitable for a broad range of applications including motor drives for heavy equipment and consumer appliances, electric vehicle battery charging, high-performance computer data centers, grid applications for stability and resilience, and emerging electric propulsion systems.


More robust power electronics that withstand higher operating temperatures, have increased durability, a smaller form factor, and higher efficiency will significantly improve the reliability and security of a resilient electrical grid.


Low cost and highly efficient power electronics could lead to more affordable electric and hybrid-electric transportation, greater integration of renewable power sources, and higher efficiency electric motors for use in heavy industries and consumer applications.


Electricity is the fastest growing form of end-use energy in the United States. High performance, low cost power electronics would enable significant efficiency gains across the economy, reducing energy costs for businesses and families.


ARPA-E Program Director:
Dr. Isik Kizilyalli
Project Contact:
Prof. Jason Lai
Press and General Inquiries Email:
Project Contact Email:

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