This paper presents a desaturation-based technique for short-circuit protection in quasi-two-level converters. The proposed design enables a cost-effective implementation of this protection scheme in a flying capacitor multilevel converter operating as a quasi-two-level converter, requiring only two detection circuits for n series-connected switches. Detailed design guidelines for the protection circuit are provided, along with simulations that illustrate its operational boundaries and experimental verification of the proposed scheme.

The development of DC protection systems is an enabler of widespread adoption of DC microgrids. This paper introduces a three-level gate driver that provides the latching current limiter functionality in a solid-state circuit breaker with unidirectional protection. The proposed gate driver combines the output port description of a well-known, enabled gate driver with a soft turn-off network. The corresponding circuit can be adapted to well-established SSCBs, requiring few modifications which could allow for quick development. The concept, simulation, implementation and experimental validation of the gate driver are in the scope of the paper. The gate driver is implemented and tested in a solid-state circuit breaker prototype, showing the potential to develop further DC protection devices.