According to at least one aspect of the disclosure, a bi-directional AC/DC converter is provided comprising a DC-power connection configured to be coupled to a DC-power source, an AC-power connection configured to be coupled to at least one of an AC-power source or a load, a multiplexer having a plurality of multiplexer switches, at least one interleaved bridge circuit having a plurality of bridge switches coupled to the multiplexer, and a positive DC node and a negative DC node coupled to the plurality of multiplexer switches, wherein the plurality of bridge switches includes at least two bridge switches coupled between the AC-power connection and at least one of the positive DC node or the negative DC node.

A resonant converter and a manufacturing method of a transformer thereof are provided. The resonant converter includes a full bridge circuit, an element, a first branch circuit, a second branch circuit and a secondary winding. The full bridge circuit includes a first node and a second node. The element includes an inductor or a capacitor. The first branch circuit includes a first primary winding. The second branch circuit includes a second primary winding, and the first and second primary windings have the same turn number. The transformer is constructed by the first and second primary windings and the secondary winding. The first branch circuit, the element and the second branch circuit are sequentially coupled in series between the first and second nodes. The first branch circuit and the second branch circuit are symmetrically located with respect to the element. The first and second branch circuits have the same impedance.

In a method for operating a controllable converter with an intermediate circuit capacitor, the control behavior can be improved by transmitting, depending on an intermediate circuit voltage applied to the intermediate circuit capacitor, an additional power component via the controllable converter such that the electric current that is generated by the controllable converter for the additional power component counteracts an oscillation of the intermediate circuit voltage. The additional power component is transmitted by the controllable converter to a connected motor as a pulsating additional torque. Also described is a controllable converter with a control unit for carrying out a method, wherein the controllable converter has semiconductors that can be switched off, and an intermediate circuit capacitor designed as a film-type capacitor.

A threshold detection system can be configured to monitor a location (e.g., a DC link) for overcurrent. The threshold detection system can be configured to generate a pulse width modulated signal with a duty cycle that is proportional to current through the DC link. The threshold detection system can be configured to determine whether the duty cycle exceeds a selected threshold.

A switching bridge for the DC-DC stage of a power converter, the switching bridge having one or more sets of upper and lower series-connected switches (S1, S2) connected across a DC bus and arranged to be switched to provide an output AC voltage, the switching bridge further comprising a voltage divider (C1) arranged to vary the output AC voltage level according to the switching state of the switches.

A power converter circuit includes a chopper circuit configured to receive an input voltage and generate a chopper voltage with an alternating voltage level based on the input voltage, an autotransformer including at least one tap, the autotransformer being coupled to the chopper circuit and configured to generate a tap voltage at the at least one tap, and a selector circuit configured to receive a plurality of voltage levels. At least one of these the voltage levels is based on the at least one tap voltage. The selector circuit is further configured to generate a selector output voltage based on the plurality of voltage levels such that the selector circuit selects two of the plurality of voltage levels and switches at a switching frequency between the two voltage levels.

This system for converting the electrical energy delivered by a supply network comprises of: a converter and at least one zero-sequence current limiting stage flowing in the converter. The or each limiting stage comprises an active compensation circuit comprising a magnetic component and a voltage source connected to the magnetic component, the voltage source and the magnetic component being adapted to serially inject with the converter an active compensation voltage of the zero-sequence voltages generated by the converter.

In a method for operating a controllable converter with an intermediate circuit capacitor, the control behavior can be improved by transmitting, depending on an intermediate circuit voltage applied to the intermediate circuit capacitor, an additional power component via the controllable converter such that the electric current that is generated by the controllable converter for the additional power component counteracts an oscillation of the intermediate circuit voltage. The additional power component is transmitted by the controllable converter to a connected motor as a pulsating additional torque. Also described is a controllable converter with a control unit for carrying out a method, wherein the controllable converter has semiconductors that can be switched off, and an intermediate circuit capacitor designed as a film-type capacitor.

A resonant inductive coupling extension cord and light emitting diode system having a plurality of light emitting diodes (LEDS) connected to a receiver coil designed to receive a pulsed DC current from a power supply by means of resonant inductive coupling. The power supply generates a pulsed DC current at a frequency of 0.8 KHz or greater, wherein the pulsed DC current is positive relative to ground. The power supply provides the pulsed DC current through a power coil and through the extension cords to the receiver coil. The (LEDs) are powered through resonant inductive coupling up to 160 volts. The light emitting diodes are self-limiting with respect to current. There is no potential for a spark or shock hazard when the extension cords are connected to the power supply, to the LED system or each other or whether the extension cords or LED are cut or broken.

The present disclosure is directed to an electric drive. The electric drive may include a first power inverter, a second power inverter, and a positive DC bus connecting the first power inverter and the second power inverter. The electric drive may also include a first switch connected to the positive DC bus between the first power inverter and the second power inverter. The electric drive may include a second switch connected to the positive DC bus between the first power inverter and the second power inverter. The electric drive may further include a control unit connected to the first switch and to the second switch. The control unit may be configured to selectively allow current to pass through the first switch and the second switch.