A dc solid state circuit breaker and dc circuit breaker system

A DC solid-state circuit breaker (30), comprising:

• a first power terminal (31) and a second power terminal (32) connectable in series to terminals of a same first polarity of a DC source (10) and a DC load (20);
• a third power terminal (33) connectable to a terminal of a second polarity, opposite to the first polarity, or to an intermediate voltage of the DC source (10);
• a power module (40) connected between the first (31) and second (32) power terminals, the power module (40) comprising a first controlled semiconductor (41) configured to interrupt the current flow;
• a circuit (80) connected in parallel with the power module (40), the circuit (80) comprising a DC-Link (50) in series with a fault current module (60), wherein the DC-Link (50) comprises at least one capacitor (51) and the fault current module (60) comprises a semiconductor (61) configured to constrain the current flow to only one direction, wherein the fault current module (60) is connected between the second power terminal (32) and an intermediate node (34) of the circuit (80) arranged in between the DC-Link (50) and the fault current module (60);
• and
• a pre-charging system (70) connected between the third power terminal (33) and the intermediate node (34) of the circuit (80), wherein the pre-charging system (70) comprises a pre-charging impedance (71) through which the at least one capacitor (51) of the DC-Link (50) is pre-charged, wherein the pre-charging system (70) further comprises a first contactor (72) connected between the intermediate node (34) and the third power terminal (33) and in parallel with the pre-charging impedance (71).