This invention is concerning a secondary side reflux circuit having a series circuit that is formed by connecting a secondary side reflux diode and a reflux reactor in series, the secondary side reflux circuit being provided on a secondary side of a DC/DC converter that subjects DC power from a DC power supply to DC/DC conversion and outputs the converted power to a load connected in series to a smoothing reactor connected to an output side of a rectifier circuit having a plurality of rectifying semiconductor switching elements. During a period in which a voltage from the DC power supply is not applied to a primary side of a transformer, the secondary side reflux circuit diverts a load current flowing through a load so as to return the load current to the load.

A spike suppression circuit includes a wide bandgap transistor, a first transistor, a clamping circuit, and a capacitor. The wide bandgap transistor is depletion-type. The first transistor is coupled in series with the wide bandgap transistor. The clamping circuit provides a voltage difference, and is coupled to a common node between the wide bandgap transistor and the first transistor. The capacitor provides a supply voltage for the clamping circuit. When the first transistor is turned off, the capacitor can recycle spike energy at the common node.

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.

A semiconductor device includes: semiconductor layer having surface and rear surface; insulating film formed on the surface; first and second surface electrode layers formed on the insulating film; rear electrode layer formed on the rear surface; active region set in region of the surface covered with the first surface electrode layer; capacitor region set in region of the surface covered with the second surface electrode layer; first trench formed in the active region; first insulating film formed on inner surface of the first trench; first embedded electrode embedded in the first trench and controlling ON/OFF of current flowing between the first surface electrode layer and the rear electrode layer; second trench formed in the capacitor region; second insulating film formed on inner surface of the second trench; and second embedded electrode embedded in the second trench and electrically connected to the first surface electrode layer.

A power conversion device includes first and second terminals connected to a DC power source, third and fourth terminals connected to a commercial power system or a load, a transformer including a primary winding having seventh and eighth terminals and a secondary winding having fifth and sixth terminals, an inverter circuit connected between the first and second terminals and the seventh and eighth terminals, a converter circuit connected between the fifth and sixth terminals and the third and fourth terminals, a diode bridge including first and second AC input terminals connected to the fifth and sixth terminals, respectively, and first and second DC output terminals, a first capacitor connected between the first and second DC output terminals, and a first resistor connected in parallel with the first capacitor between the first and second DC output terminals.

Passive filters, line replaceable units and a modular power supply are provided. In one example the modular power supply has a DC bus link having a positive line and a negative line with at least one passive filter and an inductor having a first end and a second end, the first end coupleable to a phase output. A diode bridge having at least a first diode and a second diode, with an anode of the first diode coupleable to the second end of the inductor and a cathode of the first diode coupleable to the positive line, wherein a cathode of the second diode is coupleable to the second end of the inductor and an anode of the second diode is coupleable to the negative line, and wherein the first diode and the second diode are each configured to produce a combined reverse recovery charge that achieves a target DV/DT for an output voltage of the at least one passive filter.

An energy recovery snubber circuit for a power converter which includes a flyback transformer driven by a converter switch is disclosed. The snubber circuit includes two capacitors which are connected such that, when the snubber circuit is connected to a primary winding of the flyback transformer, the capacitors are charged in series by current flowing in a first direction in the primary winding when the converted switch is turned OFF, to recover energy stored in the leakage inductance of the transformer, and discharged in parallel to cause current flow in a second direction in the primary winding of the transformer, to thereby transfer the recovered energy to the transformer.

An object of the present invention is to provide a semiconductor oscillation suppression circuit capable of suppressing voltage oscillation of a switching element with low loss. A semiconductor oscillation suppression circuit includes a wide-bandgap semiconductor element and a capacitor connected to the wide-bandgap semiconductor element in parallel and having a larger capacity than a junction capacitance of the wide-bandgap semiconductor element.

An apparatus (400A, 400B, 400C, 400D, 500A, 500B, 800) supplies power to an output thereof. The apparatus includes: an isolation transformer (110) and a rectifier (120). The isolation transformer has a parasitic capacitance (Cp) between one of its input terminals (1S/1F) and one of its output terminals (2S/2F). The rectifier has a pair of input terminals connected to the output plurality of diodes (D1/D2/D3/D4) connected in a bridge. The apparatus also includes a compensation device for compensating for an increase in an output voltage across the output of the apparatus due to a charge pump effect of the parasitic capacitance. The compensation device includes at least one compensation capacitor (410, 510/520, 810/812) connected across one of the diodes of the bridge.

A power converter circuit includes a switching circuit with at least one electronic switch, a capacitor configured to provide or receive a voltage with a predefined voltage level, at least one first inductor, and a snubber circuit. The snubber circuit includes at least one second inductor inductively coupled to the at least one first inductor and electrically coupled to the capacitor.