Sorry, you need to enable JavaScript to visit this website.

Transformerless Converter Topology

Opcondys

A Bidirectional, Transformerless Converter Topology for Grid-Tied Energy Storage Systems 

Program: 
ARPA-E Award: 
$2,956,351
Location: 
Manteca, CA
Project Term: 
01/17/2018 to 01/16/2021
Project Status: 
ACTIVE
Technical Categories: 
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: 

Opcondys will develop a high-voltage power converter design for energy storage systems connected directly to the power grid. Opcondys' converter design will use a modified switched multiplier topology that will allow connection to utility transmission lines without intervening step-up transformers. It uses a photonic, wide bandgap power switching device called the Optical Transconductance Varistor. This is a fast, high-voltage, bidirectional device which reduces the number of circuit elements required for charging and discharging the storage element. By operating at 100 kHz it is possible to increase efficiency to 99% compared to 95-98% efficiency of traditional converters. The system also reduces the size of the passive elements by 50% and, because of the optical control, mitigates electromagnetic interference issues. The elimination of step-up transformers further reduces system size, and can enable a lower cost than existing systems. If successful, project developments could open the door to increased integration of grid-level energy storage.

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.

Security: 

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.

Environment: 

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.

Economy: 

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.

Contacts
ARPA-E Program Director: 
Dr. Isik Kizilyalli
Project Contact: 
Kristin Sampayan
Release Date: 
8/23/2017