Abstract:
A DC-DC converter for connecting high-voltage DC networks has series-connected sub-converters. The high-voltage DC networks which can be connected to the DC-DC converter can have different transmission symmetries by way of power exchanging devices and additional power exchanging devices. Thus, a symmetrical monopole can be connected to an asymmetrical bipolar network using the invention.
Abstract:
A submodule for a modular multilevel converter has nine semiconductor switches that can be switched off, four capacitors, six network nodes, and two terminals. The components are mounted such that different voltages are generated between the terminals of the submodule by controlling the semiconductor switches. This arrangement of components substantially improves the behavior of the converter and of the submodule in the event of a fault.
Abstract:
The invention relates to a method and an actuating arrangement for controlling a MOSFET, in particular wide-bandgap MOSFET. A change of an actuating variable, which actuates the MOSFET as a function of an operating characteristic variable that influences the switching behavior of the MOSFET is stored in a characteristic block. The change counteracts a reference actuating value of the actuating variable. An actual value of the operating characteristic variable is determined during operation of the MOSFET, The actuating variable is changed from the reference actuating value as a function of the actual value commensurate with the change of the actuating variable stored in the characteristic block. The change stored in the characteristic block can include a change in the switch-on or switch-off voltage or gate resistance of the MOSFET as a function of the operating temperature or the operating voltage of the MOSFET.
Abstract:
A switching half-bridge has two field-effect transistors and a supplementary circuit arranged upstream of a gate terminal of a first field-effect transistor and formed of a first circuit branch having a damping resistor and an inductor connected in series with the damping resistor and a second circuit branch being connected in parallel with the first circuit branch and having a series resistor and an auxiliary switch connected in series with the series resistor. The half-bridge can be switched from a first switching state to a second switching state, wherein while the auxiliary switch is open, a change in the control voltage causes the first circuit branch to temporarily change the gate-source voltage of the first field-effect transistor from the switch-on level to a second switch-off level greater than a first switch-off level, with the gate-source voltage thereafter returning to the first switch-off level.
Abstract:
A device switches a direct current in a branch of a direct current voltage network node. The device contains a constant current path extending between two connection terminals, in which a mechanical switch is disposed. The device further has a switching current path bridging the constant current path and a power switching unit is disposed therein. The power switching unit has power semiconductor switches which can be switched on and off and configured to interrupt a short-circuit current in the event of a fault. The device contains a longitudinal voltage source for generating a counter-voltage in a loop formed by the constant current path and the switching current path. The device can be used economically over long periods of time to control the load flow on a network node. Accordingly, the longitudinal voltage source has a circuit for connecting and disconnecting the electrical power.
Abstract:
A modular power converter with wide-bandgap semiconductors, in particular SiC semiconductors. The modular power converter has at least two base units. The base units are connected together on the input side, and each base unit has an input circuit on the input side and an output circuit on the output side. The input circuit and the output circuit are each formed by the wide-bandgap semiconductors arranged in a B6-bridge circuit. An intermediate circuit capacitor is connected in parallel with the input circuit and the output circuit forming an intermediate circuit. The input circuits of the base units or a sub-quantity of the base units are arranged in a series circuit. At least one inductor is arranged between each pair of input circuits.
Abstract:
In a method for protecting a field-effect transistor, which is operated in a switching mode, against an overload current in a switched-on switching state, an electric drain-source voltage between a drain connection and a source connection of the field-effect transistor is detected. The drain-source voltage is compared with a predefined voltage comparison value, and the field-effect transistor is switched into a switched-off switching state in the event that the drain-source voltage is greater than the voltage comparison value. For the purpose of providing a temperature compensation of the protection, the temperature of the field-effect transistor is detected; and the voltage comparison value is adjusted depending on the temperature. The voltage comparison value is, in addition, also dependent on time during the switched-on switching state.
Abstract:
A device for monitoring a power semiconductor switch includes a circuit section for applying to the power semiconductor switch an HF voltage having a frequency above a switching threshold of the power semiconductor switch, a shunt resistor for detecting an actual HF current resulting from application of the HF voltage to the power semiconductor switch, a monitoring circuit for comparing the actual HF current with an expected HF current that depends on a switching state of the power semiconductor switch when the HF voltage is applied to the power semiconductor switch, and a comparator for generating a power semiconductor status signal depending on a result of the comparison. A corresponding method for monitoring a power semiconductor switch of this type is also described.
Abstract:
A DC converter is suitable for continuous operation for connecting high-voltage DC networks having different voltages. The DC converter has a first partial converter and a second partial converter, which are connected in series with each other, forming a converter series circuit. The converter series circuit extends between the DC terminals of a DC connection. The second partial converter extends between the DC terminals of a second DC connection. The first partial converter and the second partial converter are connected to each other via a power exchange device, such that the exchange of electrical power between the first partial converter and the second partial converter is made possible via the power exchange device.
Abstract:
A longitudinal voltage source interconnects into a first line and a second line and feeds a longitudinal voltage into each of the two lines. The voltage source has first and second H-bridge circuits, each with four switches, and with outer terminals and center terminals. The center terminals are connectable to disconnected locations of the first and second lines. A capacitor has a first capacitor terminal connected to the two first output terminals of the two H-bridge circuits and a second capacitor terminal connected to the two second output terminals of the two H-bridge circuits. One or more switching modules are connected between the first capacitor terminal and the first output terminals of the first and second H-bridge circuits, and one or more switching modules are connected between the second capacitor terminal and the second output terminals of the first and second H-bridge circuits.