A direct current circuit breaker includes: a positive supply line between a positive input terminal and a positive output terminal; a negative supply line between a negative input terminal and a negative output terminal connecting a direct current load to a supply; a series connection of a first galvanic separation switch and a bypass switch in the positive supply line, and a second galvanic separation switch in the negative supply line; a semiconductor switch element connected parallel to the bypass switch; and a series connected inductor in the positive supply line. The first and second galvanic separation switch, the bypass switch, and the semiconductor switch element are controlled using a processing unit.

A separating device for interrupting a direct current of a current path, in particular for an on-board electrical system of a motor vehicle. The separating device has a hybrid switch with a current-conducting mechanical contact system and a first semiconductor switch connected to the hybrid switch in parallel and having a switchable resistance cascade with at least one ohmic resistor which is connected to the contact system of the hybrid switch in parallel.

Various examples are provided related to direct current circuit breakers and their control methods. In one example, among others, a hybrid direct current circuit breaker (DCCB) includes an ultrafast mechanical switch (UFMS) connected in series with a commutating switch (CS) or auxiliary circuit breaker (ACB); a main breaker (MB) including a series of η semiconductor switching stages in parallel with the UFMS and CS or ACB; and control circuitry that can turn off individual switching stages in a defined order in response to opening contacts of the UFMS. The switching stages can be turned off based upon a dielectric strength across the contacts as they open. In another example, a method includes opening contacts of an UFMS connected in series with a CS or ACB; and turning off individual switching stages of a series of η semiconductor switching stages connected across the UFMS and the CS or ACB.

Provided is an arc suppression device including one or more current-limiting circuits provided in parallel with a circuit breaker that switches between feeding and shutoff of power from a power supply. The current-limiting circuit shuts off a current from the power supply when the power from the power supply is fed to a load through a circuit breaker. The current from the power supply is shut off when a voltage generated by a potential difference between contacts of the circuit breaker becomes a predetermined voltage or higher in a case where feeding of the power from the power supply to the load is shut off by the circuit breaker. The potential difference is generated upon shutoff.

A circuit assembly includes a first signal branch connecting a signal connection to an electrical load via a semiconductor switch and a second signal branch connecting the signal connection to the electrical load via a relay. When a sensor detects a polarity change in an electrical signal within a test time interval, a controller may close the semiconductor switch at a first signal time such that electrical energy is supplied to the electrical load, actuate the relay at a second signal time after the semiconductor switch has been closed, and open the semiconductor switch after the relay has been closed such that electrical energy is supplied to the electrical load solely via the second signal branch.

A hybrid load protection apparatus (1) comprises a primary power supply path (1A) provided between an input terminal (2) and output terminals (2, 3) and a controllable mechanical switch (5A) connected in series with a primary coil (4A-1) coupled inductively to a secondary coil (4A-2) providing a voltage, U.sub.A, corresponding to a current rise speed of the electrical current flowing through the primary path (1A). The voltage, U.sub.A, is applied directly to a driver input (IN) of a first driver circuit (6A) to trigger automatically a switch-off of the mechanical switch (5A) within a first switch-off period (Δt1) to interrupt the primary power supply path (1A), A secondary power supply path (1B) is provided in parallel to the primary path (1A) and having a further coil (4B) connected in series with a semiconductor power switch (5B). wherein a second driver circuit (6B) associated with the secondary path (1B) detects an increasing electrical current, I, flowing through the secondary path (1B) caused by the interruption of the primary current path (1A) on the basis of a voltage drop (ΔU.sub.4) generated by the further coil (4B) and a non-linear voltage drop (ΔU.sub.5) along the semiconductor power switch (5B) applied as a sum voltage (U.sub.B) directly to a driver input (DESAT) at a high voltage side of the second analog driver circuit (6B) to trigger automatically a switch-off of the semiconductor power switch (5B) within a second switch-off period (Δt2) to interrupt the secondary power supply path (1B).

A switching apparatus for conducting and interrupting electrical currents includes: a first mechanical contact arrangement; a semiconductor switch which is connected in parallel to the first mechanical contact arrangement; a second mechanical contact arrangement connected in series to the first mechanical contact arrangement; an auxiliary coil electrically isolated from a circuit of a switching drive used to move contacts of the first and second mechanical contact arrangements, and which is electromagnetically coupled to a coil of the switching drive such that a voltage is generated therein when a voltage supply of the switching drive is switched off; and a switching electronics for switching the semiconductor switch on and off, and which is supplied with the voltage generated in the auxiliary coil when the voltage supply of the switching drive is switched off. The switching electronics switches the semiconductor switch on and off multiple times according to a prespecified sequence.

A changeover apparatus for interruption-free changeover between two energy supply systems includes: at least one first outer conductor section and one second outer conductor section; a first mechanical bypass switch arranged in the first outer conductor section; a first semiconductor circuit arrangement connected in parallel with the first mechanical bypass switch; a first measuring device for recording a first voltage and/or a first mains frequency, which first measuring device is connected to the first outer conductor section; a second mechanical bypass switch arranged in the second outer conductor section; a second semiconductor circuit arrangement connected in parallel with the second mechanical bypass switch; and an electronic control unit for actuating, in a predeterminable manner, the first mechanical bypass switch, the first semiconductor circuit arrangement, the second mechanical bypass switch, and the second semiconductor circuit arrangement. The first measuring device is connected for communication with the electronic control unit.

Within a direct current hybrid circuit breaker (DC HCB), a capacitance is provided in a semiconductor switch path in series with a semiconductor switch and the semiconductor switch is in parallel with a surge arrestor to facilitate opening the DC HCB. The semiconductor switch path is connected in parallel with a mechanical switch path that includes a mechanical switch. The circuit causes the current through the mechanical switch to ramp down while the current through the semiconductor switch ramps up to a supply current. The mechanical switch can open without current and against no recovery voltage.

A device is for opening or closing a DC circuit with at least one busbar. The device includes an electric switch for opening or closing the DC circuit; a fault current detector; a trigger unit and a precharging device. The electric switch opens the DC circuit via the trigger unit upon a fault current being detected by the fault current detector. Further, the precharging device restores the voltage on the busbar prior to closing the electric switch. The device further includes a control unit for automatically closing the electric switch after the pre-charging process.