Argonne is developing ultra-fast protection technology for next-generation charging infrastructure
Research demonstrates a high-speed direct current (DC) protection approach designed to enable safer operation of emerging heavy-duty electric vehicle (EV) charging systems and other large-scale power infrastructures.
Why this research matters
- Problem: Emerging megawatt-scale DC charging systems for heavy-duty electric vehicles require new protection technologies capable of responding to faults much faster than conventional systems.
- Argonne contribution: Researchers developed and tested an ultra-fast hybrid DC circuit breaker concept designed to interrupt high DC fault currents in less than 500 microseconds.
- Outcome: The work could help support safer and more reliable deployment of high-power DC infrastructure for heavy-duty EV charging, hyperscale data centers and other next-generation energy systems.
As heavy-duty EVs become more common, charging infrastructure must deliver much higher levels of power to reduce charging times and support commercial operations. Emerging megawatt-scale direct current (DC) fast charging systems can help meet that demand, but they also create new safety and reliability challenges that differ from traditional alternating current (AC) systems.
Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory developed and tested an ultra-fast DC circuit breaker concept designed to help protect high-power charging infrastructure. Circuit breakers are designed to quickly stop electrical faults before they can damage equipment or disrupt operation. In high-power DC systems, however, interrupting faults is more difficult because the electrical current flows continuously in one direction, unlike in AC systems where the current periodically reverses direction and passes through zero.
To address this challenge, the Argonne team developed an Ultra-Fast Active Resonance Current Source-Based Hybrid DC Circuit Breaker, or UFRDCB. The system combines multiple protection technologies to rapidly interrupt fault currents in high-power DC systems.
As an initial proof-of-concept, researchers developed and experimentally validated a 10-kW prototype. During testing, the prototype successfully interrupted a continuous 1-kA DC current in less than 500 microseconds. The research also examined broader protection gaps in low- and medium-voltage DC systems and identified future research directions for improving the safe and reliable operation of megawatt-scale charging infrastructure.
The work represents one approach for protecting emerging DC distribution systems used in applications such as heavy-duty EV charging infrastructure and hyperscale data centers. Researchers are continuing to investigate additional approaches that could provide even faster protection performance for these types of systems. Knowledge gained from this effort is helping guide ongoing research and development activities supported by DOE’s Office of Critical Minerals and Energy Innovation Transportation Technologies Office.
Beyond charging infrastructure, the research helps improve understanding of protection challenges in next-generation DC power systems and contributes technical insight that could support future code and standards development. The work also supports collaboration with organizations such as Underwriters Laboratories and the Institute of Electrical and Electronics Engineers to help inform safer deployment of high-power DC infrastructure across the United States.
Publication
The study, “Protection of Megawatt-Scale DC Fast Charging Infrastructure for Heavy-Duty Vehicles: Ultra-Fast DC Breaker Development, Testing, and Future Roadmap,” was published as SAE Technical Paper 2026-01-0400. Authors include Md Rakib-Ur Rahman and Daniel Dobrzynski of Argonne. DOI: 10.4271/2026-01-0400.