A system includes a first circuit breaker comprising a first solid state switch, first mechanical contacts, and a current sensor structured to sense current flowing through the first circuit breaker, and a second circuit breaker electrically coupled to the first circuit breaker and being structured to interrupt current flowing to the first circuit breaker, wherein the first circuit breaker is structured to transmit, to the second circuit breaker, a request upon detecting a failure mode, and wherein the second circuit breaker is structured to interrupt current flowing to the first circuit breaker in response to receiving the request, and the first circuit breaker is further structured to open the first mechanical contacts when the current flowing through the first circuit breaker drops to a predetermined level.

A method of operating a Fault Current Limiter Circuit Breaker including a plurality of FLCB modules connected in series, including at least a first module and a second module. Each module has a plurality of parallel component legs including a mechanical switch leg having a mechanical switch, a semiconductor switch leg having a semiconductor switch, and a Metal Oxide Varistor leg having a MOV. The method includes, when the FLCB is in an open configuration, obtaining an indication that the FLCB should be closed; in response to the obtained indication, closing the semiconductor switch of each of the modules; and, after the closing of the semiconductor switches and while the mechanical switch of the second module remains open, closing the mechanical switch of the first module.

An electrical power system including: an electrical power source, a power electronics converter, an electrical network, a current limiting diode and a controllable circuit interruption device, wherein: the current limiting diode is configured to limit a fault current passing between the electrical power source and the electrical network in a fault condition; and the controllable circuit interruption device is configured to interrupt the fault current in response to a determination that the electrical power system is in the fault condition.

In an electrical distribution system including a solid-state circuit breaker (SSCB) and one or more downstream mechanical circuit breakers (CBs), a solid-state switching device in the SSCB is repeatedly switched ON and OFF during a short circuit event, to reduce a root-mean-square (RMS) value of the short circuit current. The resulting pulsed short circuit current is regulated in a hysteresis control loop, to limit the RMS to a value low enough to prevent the SSCB from tripping prematurely but high enough to allow one of the downstream mechanical CBs to trip and isolate the short circuit. Pulsing is allowed to continue for a maximum short circuit pulsing time. Only if none of the downstream mechanical CBs is able to trip to isolate the short circuit within the maximum short circuit pulsing time is the SSCB allowed to trip.

A system for overvoltage protection on loads for use in an electric aircraft is presented. The system includes an energy storage element configured to produce an electrical output, a bus element, wherein the bus is configured to transfer the electrical output from the energy storage element, a plurality of inverters, wherein each inverter is configured to generate a regulated output as a function of the electrical output and detect an overvoltage output as a function of the regulated output, and a plurality of load devices connected to the plurality of inverters, wherein each load device includes a fault protection device.

A circuit breaker distribution system is configured to provide selective coordination. The system comprises a solid-state switch disposed as a main or upstream breaker and a switch with an over current protection disposed as a branch or downstream breaker. The solid-state switch comprises a microcontroller including a processor and a memory, and computer-readable logic code stored in the memory which, when executed by the processor, causes the microcontroller to: allow repeated pulses of current through to the branch or downstream breaker in an event of an overload or short circuit, and choose a maximum current limit for the solid-state switch as a “chop level” such that the chop level is chosen higher than a rated current of the solid-state circuit breaker but low enough that the solid-state switch is not damaged from repeated pulses over a period of time needed to switch OFF the branch or downstream breaker.

A power supply delivery system is provided. The power supply delivery system includes a source module and a load module. The source module includes an input coupled to a Class 1 power source, plural outputs coupled to plural Class 2 cables, and circuitry coupled to the input and the plural outputs. The circuitry splits power received via the input into a plural Class 2 channels and conducts the plural Class 2 channels to the plurality of outputs. The load module includes plural inputs coupled to the plural Class 2 cables, an output coupled to a Class 1 load, and circuitry coupled to the plural inputs and the output. The circuitry combines the plurality of Class 2 channels received via the plural inputs into a single Class 1 channel and conducts the single Class 1 channel to the output.

An ERMS system and a method for implementing an ERMS system are disclosed. The ERMS system includes: a self-powered relay comprising a control circuit that controls the self-powered relay to work under one of a first mode and a second mode; a portable power box; and an electrical interface connecting the portable power box to the self-powered relay. Under the second mode, the self-powered relay is configured to reduce energy level in an arc flash event. Upon receiving a signal from the portable power box via the electrical interface, the control circuit controls the self-powered relay to work under the second mode.

A system includes a first circuit breaker comprising a first solid state switch, first mechanical contacts, and a current sensor structured to sense current flowing through the first circuit breaker, and a second circuit breaker electrically coupled to the first circuit breaker and being structured to interrupt current flowing to the first circuit breaker, wherein the first circuit breaker is structured to transmit, to the second circuit breaker, a request upon detecting a failure mode, and wherein the second circuit breaker is structured to interrupt current flowing to the first circuit breaker in response to receiving the request, and the first circuit breaker is further structured to open the first mechanical contacts when the current flowing through the first circuit breaker drops to a predetermined level.

Various embodiments include a device for coupling two DC grids comprising source-side and load-side capacitances comprising: a switching device for current regulation, the switching device including two series-connected switching modules; wherein each of the switching modules includes at least one controllable semiconductor switching element connected in parallel to a respective series circuit comprising a resistor and a capacitor; and a control unit. The control unit is programmed to: switch the controllable semiconductor switching element of one of the two switching modules on and at the same time switch the controllable semiconductor switching element of the other of the two switching modules off; switch the controllable semiconductor switching element of the other of the two switching modules on and at the same time switch the controllable semiconductor switching element of the one of the two switching modules off; repeat steps a) and b) until the voltages of the source-side and load-side capacitances have aligned with one another; and switch the controllable semiconductor switching elements of the two switching modules on.