A switching device is for coupling a DC voltage branch to a DC voltage bus. The switching device includes a series circuit including a first switching module and a second switching module. A first diode is connected in parallel with the first semiconductor switching element and a second diode is connected in parallel with the second semiconductor switching element. A third semiconductor switching element is connected in parallel with the series circuit. A control device is connected to the first and second semiconductor switching elements, to the bridging semiconductor switching element, to the voltage sensor and to the current sensor. The control device is configured to, upon a first threshold value of the voltage being undershot and current flowing in an exceptional case, switch the bridging semiconductor switching element to the conducting state in order to facilitate a current flow from the DC voltage branch to the DC voltage bus.

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 DC voltage switch includes a first switch arranged at a first potential between a first terminal of the first switch and a second terminal of the first switch, a first discharging device which is arranged between the first terminal at the first potential and a third terminal at a second potential and includes a first switching element designed as a thyristor, and a second discharging device which is arranged between the second terminal and a fourth terminal at the second potential and includes a second switching element designed as a semiconductor switch that can be switched off. The respective discharging devices connect the first terminal and the third terminal and/or the second terminal and the fourth terminal, at least temporarily, when the DC voltage switch is being or has been switched off.

Embodiments described include hybrid power connections between a drilling rig and a power grid. A hybrid energy controller can provide the ability to connect a high horse-power micro-grid with a drilling rig to a normal utility grid and mitigate any power surges. The micro-grid can comprise battery units capable of providing power when generator sets (gensets) don't meet load demands and storing excess power when supplied power exceeds demand.

A method for controlling a solid state circuit breaker includes detecting a direction of a current flowing through the solid state circuit breaker, obtaining a breaking current value of the solid state circuit breaker according to the detected direction of the current, obtaining a value of a maximum threshold current to flow through the solid state circuit breaker, obtaining a predicted current value within a next sampling period of a present sampling period of the solid state circuit breaker, comparing the predicted current value with the breaking current value, and upon the predicted current value being greater than the breaking current value, delaying the solid state circuit breaker, and upon the predicted current value being greater than the maximum threshold current value, controlling the solid state circuit breaker to disconnect a circuit in which the solid state circuit breaker resides.

A battery inverter system includes a plurality of battery inverter units, wherein each of the battery inverter units includes a multiphase inverter and a battery unit connected to the inverter on the DC side. The battery unit includes a plurality of individual units connected in parallel to one another and protected against overcurrent by means of rack fuses, and the battery inverter units are connected in parallel on the AC side and are configured to operate with a common drive pulse pattern. The battery inverter units are interconnected on the DC side via compensation fuses, wherein the compensation fuses are provided such that in the event of a short circuit in one of the inverters, the compensation fuses are triggered faster than the rack fuses.

A vehicle electrical system, particularly for a motor vehicle. The vehicle electrical system has at least two electrical system branches, a disconnecting switch device between the two electrical system branches, wherein the disconnecting switch device has a first controllable switch unit and a series circuit having a second controllable switch unit and an overcurrent protection unit, wherein the first switch unit and the series circuit are electrically connected to each other in parallel between the two electrical system branches, and a control unit which in an idle mode of the vehicle electrical system, is equipped to switch the first switch unit into an open, current-disconnecting switching state and to keep it in the current-disconnecting switching state and to switch the second switch unit into a closed, current-carrying switching state and to keep it in this current-carrying switching state. A motor vehicle with the above-mentioned vehicle electrical system is also disclosed.

Disclosed is a fault current controller for a direct current power grid, which includes a primary circuit and a controller. The primary circuit includes an inductor, a filter capacitor, a resistor, an IGBT switch, a diode, a contactor and a Hall current sensor. The inductor, a first resistor and a second contactor are connected in series and are connected to a first contactor in parallel. A first branch including a second resistor and a first diode, a second branch including a third resistor and a second diode, and the inductor are connected in parallel; the filter capacitor, the IGBT switch and the first resistor are connected in parallel. The Hall current sensor is arranged in the series circuit. The controller controls the IGBT switch and the two contactors in the primary circuit to form different on-off combinations.

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.

A multi-line supply unit for a vehicle control unit, including at least two supply lines each connected to a vehicle voltage source at the input and brought together at a common node at the output; and a protective device, including, in each of the supply lines, at least one first damping diode looped into the supply lines in the forward direction, between the vehicle voltage source and the node; and an operating method for such a multi-line supply unit. At least one switch element is looped into each of the supply lines, respectively, in parallel with the damping diode, respectively; an evaluation and control unit measuring and evaluating a line voltage at the inputs of the supply lines, respectively, and measuring and evaluating a reverse-polarity-protected supply voltage at the common node, and controlling the switch elements in the supply lines as a function of the evaluation, using corresponding control signals.