Gate control of power semiconductor devices using reduced gate drivers is disclosed. A circuit breaker may include a multitude of transistors, such as insulated gate bipolar transistors (IGBTs), connected in series with one another. Each transistor may be connected to a respective gate resistor. Diodes may be connected between various gate resistors. One or more resistor-capacitor (RC) snubber circuits may be provided in parallel with one or more of the transistors. Likewise, one or more metal-oxide varistors (MOVs) may be connected in parallel to one or more of the transistors. A gate driver (e.g., a single gate drive) may be connected to the one or more diodes and an emitter of at least one of transistors.

A system includes a contactor operatively connected to a coil for actuating the contactor to open and close a circuit. A pass element includes a source, a drain, and a gate, wherein the drain is electrically connected to the coil, and wherein the coil is in series between the pass element and ground. A voltage source is connected to the source of the pass element to pass current into the coil when the pass element is in a pass state. A current source control circuit with economizer is operatively connected to the gate of the pass element. A delay circuit is operatively connected to the current source control circuit with economizer and to a command line to command a lower current for holding the contactor closed after a delay has expired for the contactor to transition.

A low-voltage protection switch unit, such as a motor protection switch, includes: at least an external conductor line, from an external line supply terminal of the low-voltage protection switch unit to an external line load terminal of the low-voltage protection switch unit; a neutral conductor line, from a neutral conductor terminal of the low-voltage protection switch unit to a neutral conductor load terminal of the low-voltage protection switch unit; a mechanical bypass switch arranged in the external conductor line; a semiconductor circuit arrangement connected in parallel with the mechanical bypass switch; an electronic control unit for actuating the mechanical bypass switch and the semiconductor circuit arrangement in a specifiable manner; and a current measurement arrangement connected to the electronic control unit, the current measurement arrangement being arranged at least in the external conductor line. The electronic control unit switches the semiconductor circuit arrangement on/off in a specifiable clocked manner.

The disclosure relates to a circuit breaker with a monitoring device having an electronic switch and a mechanical changeover switch, where the mechanical changeover switch has a first terminal, a second terminal and a third terminal, where in a neutral position of the mechanical changeover switch the first terminal is connected to the third terminal and where in an operating position of the mechanical changeover switch the second terminal is connected to the third terminal, where the electronic switch is connected to the third terminal of the mechanical changeover switch as a series circuit, where when switching on the circuit breaker in a first switching state, initially the electronic switch is activated, where a measurement is taken at the first terminal using the monitoring device to determine whether essentially the same potential is present at the first terminal as at the third terminal and, it this is the case, the electronic switch is activated and the mechanical changeover switch is in an operating position in a subsequent additional switching state. Furthermore, the disclosure relates to methods for the circuit breaker.

Compliant electrical circuit protection devices are described for use in hazardous environments without presenting ignition risks for potentially explosive environmental conditions. Sensing features and systems may evaluate wiring limits and user selected settings for compatibility, detect loose connections and operating parameters to ensure safe operation of the device, and to intelligently diagnose and manage issues of concern for the circuit protection devices as well as the larger electrical power system.

A switch system includes a mechanical switch for switching electrical currents, the mechanical switch operating in one of a closed state and an open state; the system further including an actuator configured to change the state of the mechanical switch, wherein the actuator comprises a Thomson-coil system including a Thomson coil, and wherein the mechanical switch and the Thomson coil are electrically connected in series.

There is disclosed a circuit breaker arrangement for interrupting a current flowing through a direct current (DC) transmission line including a semiconductor switching device and a pulse injection circuit configured to inductively inject into the transmission line a pulse current that opposes the current flowing through the transmission line to thereby reduce the current in the transmission line to cause the semiconductor switching device to turn-off to interrupt the path for the current flow through the transmission line.

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 includes a plurality of parallel component legs including a mechanical switch leg including a mechanical switch, a semiconductor switch leg including a semiconductor switch, and a Metal Oxide Varistor leg including a MOV. The method includes, when the FLBC 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.

A switch system includes a mechanical switch for electrical currents. The mechanical switch operates in a conductive state and in a non-conductive state. A first actuator is configured to change the state of the mechanical switch, wherein an actuation of the first actuator is based on a Thomson coil system. A second actuator is also configured to change the state of the mechanical switch and includes a loaded spring system locked by a latch system. Each of the first and second actuators is configured to change the state of the mechanical switch depending on a property of an electrical current passing through the mechanical switch.

An on-load tap-changer for switching, without interruption, between winding taps of a tap-changing transformer, including a diverter switch for performing a switch-over from a first to a second fixed contact, a selector for preselecting, without power, the first and second fixed contact, and a first controller, wherein the diverter switch has a plurality of semiconductor and mechanical switching elements, the selector has a first and second selector arm, which are actuatable independently of one another and can contact each of the fixed contacts, and the first controller is configured to trigger a switch command and to actuate the first and second selector arm and the plurality of mechanical switching elements by a motor drive, wherein the on-load tap changer includes a second controller to actuate the plurality of semiconductor switching elements, and wherein during the switch-over the first controller actuates the motor drive depending on the second controller.