Abstract: Various embodiments of the teachings herein include a DC network comprising: an electrical conductor; a switching unit arranged at one end of the conductor to break the electrical connection via the conductor, the switching unit including a controllable power semiconductor connected in series in the current path of the conductor; wherein the conductor includes a first section and a second section starting from the switching unit with a connection point between the first section and the second section; a first overvoltage protection apparatus connected between the connecting point and a second pole of the DC network; and a second overvoltage protection apparatus connected between that end of the second section remote from the switching unit and the second pole. The overvoltage protection apparatuses each have a capacitor.

Abstract: A method is for precharging a second network section with electrical energy from a first network section of a DC network. In an initial state, an initial voltage prevailing in the second network section is lower than a DC voltage prevailing in the first network section. At a first point in time, the two network sections are connected via a resistor current path having a precharging resistor. At a subsequent second point in time, as soon as the voltage in the second network section is between the initial voltage and the DC voltage, the two network sections are connected via a semiconductor switch which is situated parallel to the resistor current path and is operated in a clocked mode or in a linear mode as a controllable resistor.

Abstract: A switching device for opening a current path of a direct-voltage network, which current path has source-side and load-side inductors, the switching device includes at least two switching modules, which are connected in series, each of the switching modules having at least one controllable semiconductor switching element, in parallel with which a series circuit of a resistor and a capacitor is connected. During operation of the switching device in order to open the current path, the controllable semiconductor switching element of at least one of the switching modules is switched into a conductive state with a duty cycle until the energy stored in the inductors has been dissipated, the duty cycle being dependent on the difference between the actual voltage and a target voltage across the semiconductor switching element, the target voltage being calculated at least from the system voltage of the direct-voltage network and the number of switching modules.

Abstract: A switching module a method for connecting a load to a DC network are disclosed. The switching module includes a first module connection, a second module connection, a third module connection, a first electronic switch connected between the first module connection and the second module connection, and a second electronic switch connected between the second module connection and the third module connection. The two electronic switches are connected in anti-series between the first module connection and the third module connection.

Abstract: Various embodiments of the teachings herein include a DC network comprising: an electrical conductor; a switching unit arranged at one end of the conductor to break the electrical connection via the conductor, the switching unit including a controllable power semiconductor connected in series in the current path of the conductor; wherein the conductor includes a first section and a second section starting from the switching unit with a connection point between the first section and the second section; a first overvoltage protection apparatus connected between the connecting point and a second pole of the DC network; and a second overvoltage protection apparatus connected between that end of the second section remote from the switching unit and the second pole. The overvoltage protection apparatuses each have a capacitor.

Abstract: Various embodiments of the teachings herein include a switching device for a DC voltage grid. The device may include: a first controllable semiconductor switch with a control contact and two load contacts; and a controller for the first switch using a control signal at the control contact. The controller is configured to: actuate the first switch using a control pulse that causes the electrical conductivity of the semiconductor switch to reduce for less than 1 ms; apply a current to a test circuit including the first switch; ascertain a first value representing the voltage or the change in voltage across the first switch as a result of the control pulse and the applied current; analyzing the first value; and generating a signal that represents the functionality of the first semiconductor switch.

Abstract: An energy supply network has a bus line with a line impedance for energy distribution. The energy supply network also includes a number of power-electronic converters having a respective commutation capacitor wherein the storage capacity thereof is selected in such a way that a controlling of the associated power-electronic converter is guaranteed during operation of the energy supply network and an excess of voltage is managed during a commutation. At least one energy accumulator is provided, which can be connected selectively to the bus line by controlling a switch device via a computer unit, wherein the storage capacity of the energy accumulator is substantially greater than the storage capacity of a respective commutation capacitor.

Abstract: Various embodiments include a DC switch for disconnecting a DC line. The switch may include: a power semiconductor switch arranged in a current path of the DC line; a first sensor for measuring the input and output voltages; a second sensor for measuring the current flowing through the DC line; and a controller for the power semiconductor switch. The control device is configured to: switch on the DC switch for a first time period; determine the input voltage present; determine the output voltage present at the end of the first time period; determine the current intensity present at the end of the first time period; and determine an inductance and/or capacitance from the determined values.

Abstract: An electronic switch is composed of two anti-serially connected turn-off semiconductor switches having at least four terminals and at least three terminals, respectively. A method for detecting a turn-off current through the electronic switch for a DC voltage grid includes measuring a first voltage between an emitter terminal and an auxiliary emitter terminal at the first switch, measuring a second voltage between a collector terminal and an emitter terminal or between a drain terminal and a source terminal at the second switch, comparing the first and second measured voltage or a time integral of the first and second measured voltage with a reference value, and turning off at least one of the two turn-off semiconductor switches when the reference value is exceeded. An electronic switch for performing the method and a DC voltage grid with such an electronic switch are also disclosed.

Abstract: Various embodiments include a DC switch for disconnecting a DC line. The switch may include: a power semiconductor switch arranged in a current path of the DC line; a first sensor for measuring the input and output voltages; a second sensor for measuring the current flowing through the DC line; and a controller for the power semiconductor switch. The control device is configured to: switch on the DC switch for a first time period; determine the input voltage present; determine the output voltage present at the end of the first time period; determine the current intensity present at the end of the first time period; and determine an inductance and/or capacitance from the determined values.

Abstract: A switching module a method for connecting a load to a DC network are disclosed. The switching module includes a first module connection, a second module connection, a third module connection, a first electronic switch connected between the first module connection and the second module connection, and a second electronic switch connected between the second module connection and the third module connection. The two electronic switches are connected in anti-series between the first module connection and the third module connection.

Abstract: A switching device for opening a current path of a direct-voltage network, which current path has source-side and load-side inductors, the switching device includes at least two switching modules, which are connected in series, each of the switching modules having at least one controllable semiconductor switching element, in parallel with which a series circuit of a resistor and a capacitor is connected. During operation of the switching device in order to open the current path, the controllable semiconductor switching element of at least one of the switching modules is switched into a conductive state with a duty cycle until the energy stored in the inductors has been dissipated, the duty cycle being dependent on the difference between the actual voltage and a target voltage across the semiconductor switching element, the target voltage being calculated at least from the system voltage of the direct-voltage network and the number of switching modules.

Abstract: An energy supply network has a bus line with a line impedance for energy distribution. The energy supply network also includes a number of power-electronic converters having a respective commutation capacitor wherein the storage capacity thereof is selected in such a way that a controlling of the associated power-electronic converter is guaranteed during operation of the energy supply network and an excess of voltage is managed during a commutation. At least one energy accumulator is provided, which can be connected selectively to the bus line by controlling a switch device via a computer unit, wherein the storage capacity of the energy accumulator is substantially greater than the storage capacity of a respective commutation capacitor.

Abstract: A method is for precharging a second network section with electrical energy from a first network section of a DC network. In an initial state, an initial voltage prevailing in the second network section is lower than a DC voltage prevailing in the first network section. At a first point in time, the two network sections are connected via a resistor current path having a precharging resistor. At a subsequent second point in time, as soon as the voltage in the second network section is between the initial voltage and the DC voltage, the two network sections are connected via a semiconductor switch which is situated parallel to the resistor current path and is operated in a clocked mode or in a linear mode as a controllable resistor.

Abstract: An electronic switch is composed of two anti-serially connected turn-off semiconductor switches having at least four terminals and at least three terminals, respectively. A method for detecting a turn-off current through the electronic switch for a DC voltage grid includes measuring a first voltage between an emitter terminal and an auxiliary emitter terminal at the first switch, measuring a second voltage between a collector terminal and an emitter terminal or between a drain terminal and a source terminal at the second switch, comparing the first and second measured voltage or a time integral of the first and second measured voltage with a reference value, and turning off at least one of the two turn-off semiconductor switches when the reference value is exceeded. An electronic switch for performing the method and a DC voltage grid with such an electronic switch are also disclosed.

Abstract: An electronic switch includes a turn-off semiconductor switch, a capacitor, a varistor, with the capacitor and the varistor being arranged in a first series circuit which is arranged in parallel with the turn-off semiconductor switch, a switch, and a resistor, with the switch and the resistor being arranged in parallel with the turn-off semiconductor switch and with the first series circuit.

Abstract: A DC voltage switch may include: a first node and a second node for series integration into a pole of a DC voltage line; a third node for the other pole of the line; a mechanical switch between the first and second nodes; a pulse-current module in parallel with the switch; four semiconductor switches connected as bridges comprising two series of two semiconductor switches; a pulse-current capacitor in parallel with the two series; and a switchable semiconductor element. The pulse-current module includes three module nodes. Potential points between the semiconductor switches of the two series correspond to the first and second module node and the outer ends of the two series of in each case two of the semiconductor switches are connected in pairs to a fourth module node and a fifth module node and the semiconductor element is between the fifth and third module node.

Abstract: A DC voltage switch may include: a first node and a second node for series integration into a pole of a DC voltage line; a third node for the other pole of the line; a mechanical switch between the first and second nodes; a pulse-current module in parallel with the switch; four semiconductor switches connected as bridges comprising two series of two semiconductor switches; a pulse-current capacitor in parallel with the two series; and a switchable semiconductor element. The pulse-current module includes three module nodes. Potential points between the semiconductor switches of the two series correspond to the first and second module node and the outer ends of the two series of in each case two of the semiconductor switches are connected in pairs to a fourth module node and a fifth module node and the semiconductor element is between the fifth and third module node.

Abstract: A detector apparatus includes a number of detectors for assigned radiation sources of a computed tomography system, wherein each detector may require a constant input voltage in a range between 900 V and 1200 V. During operation of the detector apparatus, an auxiliary voltage is fed to a high voltage source to supply power to the input terminals on the number of detectors. The high voltage source includes a central first DC-DC converter, to which the auxiliary voltage is fed, and a number of second DC-DC converters arranged downstream of the first DC-DC converter. The first and the second DC-DC converter are based on different power supply topologies, wherein each second DC-DC converter generates the constant input voltage in the predetermined range from a central output voltage provided by the first DC-DC converter and supplies the constant input voltage to a corresponding detector.