The project focused on developing a hybrid direct‑current circuit breaker that can interrupt high‑current DC faults within a few hundred microseconds while preventing unwanted re‑closure of the contacts. The core technical effort involved measuring the properties of the residual plasma that remains after the arc is extinguished, determining the electrical strength of the contact gap, and characterizing the temperature of the electrodes. Spectroscopic analysis of the plasma provided insight into its composition and decay, while high‑speed voltage measurements captured the voltage drop that occurs when the electrodynamic forces—Holm’s force, gas‑dynamic pressure from the metal vapor, and the Lorentz force—separate the contacts. After roughly 100 µs a measurable voltage drop appears, which the detection electronics use to trigger the breaker’s closing circuit.

To validate the design, a modular model switch was built and tested under a range of conditions. The switch was operated at 400 V and 80 A with electrode gaps of 0.8 mm and 2.4 mm, demonstrating reliable arc suppression and contact separation. Impulse‑voltage tests confirmed that the contact gap could withstand transient currents up to 1 kA for a 1 µs pulse without damage. The hybrid switching concept was also evaluated at 400 V, 32 A for a 1 ms pulse, showing that the energy required to extinguish the arc is reduced compared to conventional breakers. These results confirm that the hybrid design can achieve fast, clean interruption while limiting the energy deposited in the contacts.

The project also produced a comprehensive simulation model that reproduces the arc dynamics, plasma decay, and contact motion. The model was calibrated against the experimental data and used to optimize the geometry of the contact system and the timing of the detection circuit. A dedicated measurement platform was qualified to capture the rapid voltage and current transients, and a functional demonstrator was assembled to verify the full system operation in a realistic environment.

Collaboration was essential to the success of the effort. The industrial partners, E‑T‑A Elektrotechnische Apparate GmbH and Dehn SE, supplied the expertise in high‑power switchgear and provided the production facilities for the model switch. Academic partners from the Technical University of Ilmenau (Electrical Devices and Systems group) and the Leibniz Institute for Plasma Research and Technology (INP) led the plasma diagnostics and theoretical analysis. The Physikalisch‑Technische Bundesanstalt (PTB) contributed to the qualification of the measurement equipment and supplied standards for electrical testing. The consortium worked together from the initial literature and patent survey through the design, construction, and testing phases, ensuring that the final demonstrator met both industrial performance requirements and scientific rigor. The project’s outcomes include a set of publications, a patent portfolio, and a validated prototype that demonstrates the feasibility of hybrid DC circuit breakers for future power systems.