DC technologies will be essential building blocks for future DC distribution networks. As in any DC system

these networks will face crucial threats imposed by short-circuit DC faults. Protection is thus of great interest

and it will likely rely on DC circuit breakers (DCCBs). Among available configurations

<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Z$-source solid-state circuit breakers (Z-SSCBs) are promising candidates for protecting low and medium-voltage distribution networks

as well as DC equipment due to their structural and control simplicity and low cost. In this paper

start-of-the-art of Z-SSCBs topologies is reviewed. To set the context

the use of DC technologies for grid integration of renewables

DC power transmission

and the main types of DCCBs to protect DC transmission and distribution corridors are discussed. The Z-SSCB topologies are then classified into unidirectional and bidirectional. Advantages and disadvantages of different configurations are compared and analyzed based on existing research. Finally

a perspective on the future development of Z-SSCBs is discussed and potential challenges are elucidated.