Evaluation and MHz Converter Application of 1.2-kV Vertical GaN JFET

This paper presents a comprehensive study on the design, analysis, and experimental validation of a novel forced resonant DC circuit breaker (FR-DCB) based on integrated gate-commutated thyristors (IGCTs) for medium-voltage DC (MVDC) applications. The proposed topology leverages a pre-charged LC resonant circuit to generate a controlled current zero-crossing, enabling low-stress arc interruption in a vacuum interrupter.

Traditional DC circuit breakers face significant challenges when interrupting high currents, including excessive arc energy, rapid contact erosion, and limited electrical life. The forced resonant approach addresses these limitations by actively creating a current zero-crossing through the injection of a high-frequency counter-current, which significantly reduces the arc energy and mechanical stress on the interrupter.

Experimental results demonstrate that the proposed FR-DCB can successfully interrupt fault currents up to 25 kA with a peak interrupting voltage of 12 kV. The arc energy is reduced by 73% compared to conventional passive resonant breakers, while the contact erosion rate is decreased by a factor of 2.1. The overall system efficiency reaches 99.3%, making it suitable for high-power MVDC applications such as shipboard power systems, off-shore wind farms, and HVDC transmission networks.

Detailed analysis of the switching transient behavior, thermal management considerations, and protection coordination with upstream converters are also presented. The paper concludes with a discussion on scalability to higher voltage and current ratings, as well as potential integration with solid-state hybrid breaker architectures.