Disclosed are a fault current-suppressing damper topology circuit and a control method thereof and a converter. An anode of a separate diode is connected to a positive electrode of a second switch module, a cathode of the separate diode is connected to one end of an energy storage capacitor, and the other end of the energy storage capacitor is connected to a negative electrode of a first switch module; a damping resistor is connected in parallel with an arrester and then with the first switch module; a bypass switch is connected in parallel between a terminal x1 and a terminal x2 of the damper topology circuit; a power supply system acquires energy from the energy storage capacitor and supplies power to a control system; and the control system controls an operating state of the damper topology circuit by controlling the bypass switch, the first switch module and the second switch module. The fault current-suppressing damper topology circuit is applied to voltage source converters. In case of a DC fault, stress resulting from fault currents is reduced by use of a damping resistor, thereby avoiding damages to a device and achieving self-power supply, modularization and independent control. The fault current-suppressing damper topology circuit can be flexibly applied to various types of voltage source converters and has outstanding economic efficiency and technicality.

An alternating current circuit breaker has a series circuit of bipolar switching modules which are inserted in series into a phase line of an alternating current line. Each switching module has an energy storage device and actuatable power semiconductors that can be activated and deactivated. Each switching module can be driven such that a switching module voltage that corresponds to a positive or negative energy storage device voltage or a zero voltage can be generated at the poles of the switching module. A controller is configured to actuate the switching modules based on a polarity change of a phase current such that the switching module voltage switches polarity, wherein a switching module voltage opposite the phase voltage can be generated. A method for switching alternating currents is effected with the alternating current circuit breaker.

A motor driving circuit for receiving a control signal to output at least one output current for driving a motor is provided. The motor driving circuit includes an input module, a gain module, an output module, a first slew rate limiting module, and a second slew rate limiting module. The first slew rate limiting module has a first limiting parameter. The second slew rate includes a second limiting parameter. An output current is outputted by the output terminal. When a rising slew rate of the output current is less than a first slew rate value, the first slew rate limiting module does not operate. When the rising slew rate of the output current is greater than the first slew rate value, the motor driving circuit limits the rising slew rate of the output current based on the first limiting parameter of the first slew rate limiting module.

A motor driving circuit includes a first output switch, a second output switch, a first adjusting module, and a second adjusting module. A rising slew rate of the first output current along the first direction is adjusted according to the first adjusting parameter of the first adjusting module. A falling slew rate of the first output current along the first direction is adjusted according to the second adjusting parameter of the second adjusting module.

The fan driving circuit includes a processing module providing a fan phase signal; a speed signal providing module electrically connected to the processing module; a first switch, wherein the third terminal of the first switch is electrically connected to a ground voltage, the second terminal of the first switch receives the fan phase signal; a second switch, wherein the first terminal of the second switch is electrically connected to the third terminal of the fan driving circuit and the first terminal of the first impendence, the second terminal of the second switch is electrically connected to the second terminal of the first impendence and the second terminal of the first diode, the third terminal of the second switch of is electrically connected to the first terminal of the first switch; and a third switch, wherein the second terminal of the third switch is electrically connected to a bias voltage.

Disclosed are a fault current-suppressing damper topology circuit and a control method thereof and a converter. An anode of a separate diode is connected to a positive electrode of a second switch module, a cathode of the separate diode is connected to one end of an energy storage capacitor, and the other end of the energy storage capacitor is connected to a negative electrode of a first switch module; a damping resistor is connected in parallel with an arrester and then with the first switch module; a bypass switch is connected in parallel between a terminal x1 and a terminal x2 of the damper topology circuit; a power supply system acquires energy from the energy storage capacitor and supplies power to a control system; and the control system controls an operating state of the damper topology circuit by controlling the bypass switch, the first switch module and the second switch module. The fault current-suppressing damper topology circuit is applied to voltage source converters. In case of a DC fault, stress resulting from fault currents is reduced by use of a damping resistor, thereby avoiding damages to a device and achieving self-power supply, modularization and independent control. The fault current-suppressing damper topology circuit can be flexibly applied to various types of voltage source converters and has outstanding economic efficiency and technicality.

A discharge circuit for demagnetizing an inductive load includes a first switch comprising a control terminal and first and second terminals. The first terminal is connected to a voltage supply. A second switch includes a control terminal and first and second terminals. The second terminal of the first switch and the second terminal of the second switch are connected to the inductive load. A third switch includes a control terminal and first and second terminals. The first terminal of the third switch is connected to the first terminal of the second switch. A first Zener diode includes an anode connected to the control terminal of the second switch and a cathode connected to the voltage supply. A first temperature sensing circuit generates a first sensed temperature signal based on a temperature of at least one component of the circuit. A first comparing circuit receives a first reference temperature signal and the first sensed temperature signal and that generates a first output.

A protection circuit for an electric motor with a single phase winding, consisting of two coil sections with central tapping, wherein the two coil ends of the coil sections are each connected to ground via a switching element. The task of the invention is for an electric motor of this type to ensure a thermal relief for the switching elements, improved and smoother running, reduced warming of the printed circuit board, improved EMC characteristics, a more robust design of the overall switching, a focused conduction of the losses and an extra protection against any surge impulses from a mains network.

Triac controlled dimmers and switches often employ a snubber circuit to prevent self-tripping and to reduce radio frequency emissions. Standard snubber circuits allow small amounts of AC current to reach the load even when the dimmer or switch is set to the off position, thereby causing unwanted illumination in certain high efficiency LED lighting. A load-side dynamic snubber circuit is provided for use in dimmers, switches, and similar applications which only activates the snubber circuit when the dimmer or switch is active, thereby preventing current from reaching the load when the dimmer or switch is in the off position.

A sensor excitation circuit includes a voltage driver circuit and a short-circuit protection circuit. The voltage driver circuit selectively conducts electrical current via a driver output in response to a first operating voltage exceeding a driver voltage threshold (V1be). The short-circuit protection circuit includes a protection semiconductor switching device and a temperature compensation circuit. The protection semiconductor switching device limits the electrical current through the voltage driver circuit in response to switching on when a second operating voltage exceeds a protection voltage threshold (V2be). The temperature compensation circuit is connected to the protection semiconductor switching device, and is configured to limit a variation of the protection threshold voltage (V2be) in response to exposing the protection semiconductor switching device to different temperatures.