A semiconductor switching circuit, for use in a HVDC power converter, comprising: a main semiconductor switching element, including first and second connection terminals between which current flows from the first connection terminal to the second connection terminal and an auxiliary semiconductor switching element electrically connected between the first and second connection terminals thereof, and a control unit, operatively connected to auxiliary semiconductor switching element and programmed to control the switching element to create an alternative current path between the first and second connection terminals by at least two of: a fully-on mode in which the switching element is operated at its maximum rated base current or gate voltage; a pulsed switched mode in which the switching element is turned on and off; and an active mode in which the switching element is operated with a continuously variable base current or gate voltage.

An inductive power transfer transmitter 200 comprising: a transmitting coil 7; a main flyback switch S1 in series with the transmitting coil 7; and an active snubber circuit 202 connected in parallel with the main flyback switch S1; wherein the main flyback switch S1 and the active snubber circuit 202 are configured to provide substantially zero voltage switching

A DC-DC converter includes a filter circuit, a full-bridge circuit connected to the filter circuit, and a transformer having a primary winding and a secondary winding, the primary winding being connected to the full-bridge circuit. The full-bridge circuit includes first to fourth semiconductor switches. First to fourth overvoltage protection circuits are associated with the first to fourth semiconductor switches, respectively. Each of the overvoltage protection circuits is connected in parallel its associated semiconductor switch.

A method includes determining that a current at an inductor in a series transfer capacitor buck converter is decaying to zero during a first cycle. The method also includes, in response to determining that the current at the inductor is decaying to zero, enabling an electrostatic discharge (ESD) structure and turning off a low side transistor. The ESD structure is disposed at a node connecting the low side transistor, a high side transistor and the inductor. The method further includes disabling the ESD structure before the high side transistor is turned on during a next cycle following the first cycle.

A control module for a flyback power converting device is coupled between a primary side winding of the flyback power converting device and a power end and includes a switch unit coupled to the primary side winding; wherein the control module conducts a connection between the primary side winding and the power end when the switch unit is disconnected; wherein the power end is able to provide an operation current to the control module.

A drive includes an inverter power circuit that applies power to an electric motor of a compressor from a direct current (DC) voltage bus. A power factor correction (PFC) circuit outputs power to the DC voltage bus based on input alternating current (AC) power. The PFC circuit includes: (i) a switch having a first terminal, a second terminal, and a control terminal; (ii) a driver that switches the switch between open and closed states based on a control signal; (iii) an inductor that charges and discharges based on switching of the switch; and (iv) a circuit that outputs a signal indicating whether the switch is in the open state or the closed state based on a voltage across the first and second terminals of the switch.

The present disclosure provides a snubber circuit, wherein the snubber circuit is used to an electronic equipment including a pulse signal generator, a driving power source and a load, and the snubber circuit includes a current detection module, a control module and a snubber module. The current detection module is connected to the driving power source and detects the driving current of the driving power source. The control module is connected to the current detection module and the snubber module and adjusts a center frequency of the snubber module according to the driving current detected by the current detection module. The snubber module is connected to an output terminal of the pulse signal generator and filters the noise of the pulse signal. Therefore, the present disclosure may dynamically adjust a center frequency of a filtering, so as to increase a filtering performance and increase an efficiency of suppressing EMI.

A T-breaker is an all-in-one solution for dc microgrid fault protection, power flow control, and power quality improvement. A T-breaker features a modular multilevel “T” structure with integrated energy storage devices. The two horizontal arms of the T-breaker realize fault current breaking, load voltage compensation, and power flow control; and the vertical arm of the T-breaker realizes shunt compensation. The configuration provides excellent voltage scalability and relaxes the requirements on the switching signal synchronization during fault transients. The local energy storage in sub-modules eases the fault energy dissipation requirement placed on the traditionally-adopted surge arrestors. The modular multilevel structure also offers immense control flexibility for all types of targeted functions of the provided T-breaker.

A DC/DC converter has an active energy store, such as an inductance, which can be periodically charged and discharged by one or more semiconductor switches, such as transistors. To avoid voltage overshoot, an RCD element is provided for at least one semiconductor switch, wherein a capacitor and a diode of the RCD element are connected in series, and a resistor of the RCD element can be connected either in parallel with the diode or disconnected from the diode by a switch. The diode of the RCD element is arranged so as to be blocking in the conducting direction of the semiconductor switch.

A method for controlling an active snubber circuit includes measuring a gate voltage at a first transistor and measuring a gate voltage at a second transistor. The method also includes determining whether the first transistor and the second transistor are in the same state based on the gate voltage measured at the first transistor and the gate voltage measured at the second transistor. The method also includes, in response to a determination that the first transistor and the second transistor are in the same state, enabling the active snubber circuit. The method also includes, in response to a determination that the first transistor and the second transistor are not in the same state, disabling the enable signal. The method also includes disabling the active snubber circuit in response to the enable signal being disabled.