Solid-state aided airgap for dc circuit breakers

Abstract

A DC solid-state circuit breaker includes a power electronics section, an airgap section, and a sensing and control circuit. The power electronics section includes a first solid-state switching component. The airgap section is connected in series with the power electronics section to establish a main current path. The airgap section implements an isolation switch connected in series with a fail-safe interruption circuit that includes a current commutation switch, a second solid-state switching component, and an overvoltage protection device connected in parallel with one another. In response to detecting a fault event and/or an opening command, the sensing and control circuit performs a fail-safe operation that controls the isolation switch at a time period, and controls the current commutation switch and the second solid-state switching component at a delayed time period that occurs after controlling the isolation switch.