The present invention discloses a DC solid-state circuit breaker with self-adapt fault current limiting capability. The topology of the DC solid-state circuit breaker is a H-bridge circuit consisting of two unidirectional breakable bridge arms and two series-connected diode bridge arms, wherein the two unidirectional breakable bridge arms are connected in series to the two series-connected diode bridge arms in a same direction to form two series branches, respectively; the series branches are connected in parallel; a series branch formed by a DC reactor L and a DC biased power supply is connected to the PCC between the two unidirectional breakable bridge arms and the PCC between the two series-connected diode bridge arms; the DC line is connected to the two PCCs, respectively.

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 power supply box includes: a first terminal that is configured to be connected to a first power storage device that supplies power to a first load; a second terminal that is configured to be connected to an alternator and a second load; a normally-off switch that is configured to be connected between the first terminal and the second terminal; and a bypass that is configured to be connected in parallel with the switch between the first and second terminals. The bypass includes a diode that has a forward direction that is from the first terminal toward the second terminal, and a resistor that is connected in series with the diode between the first and second terminals.

Example systems, apparatuses, methods, and computer program products are disclosed for electroporating cells in a tissue using a set of voltage pulses generated by capacitor charge circuitry based on a voltage supply. An example method includes continuously monitoring a set of characteristics of the voltage supply and the set of voltage pulses; generating a first set of monitor signals based on the set of characteristics; detecting a first fault condition based on the first set of monitor signals; and generating a first crowbar trigger activation signal. The example computer method further includes: detecting a second fault condition based on a second set of monitor signals generated based on the first set of monitor signals; and generating a second crowbar trigger activation signal. Subsequently, the example computer method includes electrically disconnecting the capacitor charge circuitry from electroporation electrode circuitry based on either the first or second crowbar trigger activation signal.

A surge protection device includes a surge protection circuit, a controller, and a wireless module. The surge protection circuit has a plurality of surge protection elements, receives a power source and correspondingly generates a sampling signal according to the power source. The controller compares a representative voltage value of the power source corresponding to the sampling signal with a first reference value to determine a using state of the surge protection circuit. The wireless module correspondingly transmits the using state to a remote server.

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 system is disclosed which eliminates problems caused by surges of electric energy which is generated on a utility customer's property and which is fed back onto a utility-owned service line by maintaining a minimum utility provided percentage (MUPP) of power being provided onto a customer-owned dead-end service line. Where the electric energy generated by a utility customer is incrementally excluded from the customer-owned dead-end service line through a plurality of contactors which are controlled by a 120 volt command line.

A fast-operating AC fault current limiter, to limit the fault current let through to downstream equipment during short circuit or low-impedance faults, comprises a series inductor to limit current rise time, a current sensor to sense the instantaneous current, a series AC semiconductor switch to interrupt current flow when it exceeds the maximum desired fault current, and a shunt AC semiconductor switch to catch inductor flyback voltage when the series semiconductor switch is opened. Each of the series and the shunt AC switches comprises two back-to-back MOSFETs. Inventive control of timing of the individual MOSFETs obviates the need for exact simultaneous timing of opening the series switch and closing the shunt switch, which is otherwise required to avoid short circuits.

The present disclosure provides a system, apparatus and method for providing rapid shutdown for photovoltaic power systems and provides a system, apparatus and method for providing arc sensing for photovoltaic power systems. An AC current can be put on the DC bus to control PV panel shutdown. Local mean decomposition can be used to sense arcing on the DC bus.

A fault clearing circuitry provided for connecting to at least one electrical line transmitting power includes: an electrical energy storage; at least one controllable switch connectable between the electrical energy storage and at least one electric line; and a control circuit for monitoring the at least one electric line for a fault and to close the at least one controllable switch if a fault is detected. The electrical energy storage stores an amount of electrical energy dimensioned to be sufficient for releasing one or more circuit breakers or clearing one or more fuses in the at least one electrical line in order to clear the fault. The control circuit closes the at least one controllable switch if a fault is detected such that a discharging of the electrical energy stored in the electrical energy storage is incurred injecting a current pulse in the at least one electrical line.