DC solid state circuit breakers for bidirectional applications

A direct current (DC) solid state circuit breaker, comprising:

• a first DC solid state circuit breaker module including a first power electronics section, a first airgap section, a first current sensing device, and a first controller;
• and
• a second DC solid state circuit breaker module including a second power electronics section comprising, a second airgap section, a second current sensing device, and a second controller, wherein:
• the first controller is configured to, when a fault is detected, operate the first DC solid state circuit breaker module to provide current interruption or maintain the first DC solid state circuit breaker module in a conducting state based on a direction of current flow sensed by the first current sensing device, and
• the second controller is configured to, when the fault is detected, operate the second DC solid state circuit breaker module to provide current interruption or maintain the second DC solid state circuit breaker module in a conducting state based on a direction of current flow sensed by the second current sensing device.

A method for interrupting current in a direct current (DC) solid state circuit breaker, the method comprising:

• setting a power electronics section to operate in a conducting state, the power electronics section comprising at least a first transistor switch;
• setting one or more airgap sections to operate in the conducting state, the one or more airgap sections comprising at least a second transistor switch and a third transistor switch, the second transistor switch and the third transistor switch arranged in back to back configuration such that i) the second transistor switch is configured to interrupt current flowing in a first direction from a first terminal of the DC solid state circuit breaker to a second terminal of the DC solid state circuit breaker and ii) the third transistor switch is configured to interrupt current flowing in a second direction from the second terminal of the DC solid state circuit breaker to the first terminal of the DC solid state circuit breaker;
• while the power electronics section and the one or more airgap sections are operating in the conducting state, detecting a fault condition;
• and
• in response to detecting the fault condition, controlling operation of the power electronics section and the one or more airgap sections to interrupt current flowing in the first direction or in the second direction through the DC solid state circuit breaker.