A power combining technique includes receiving a first voltage at a first input and a second voltage at a second input. The power combining technique further includes combining, with at least two power converters, power received from the first and second inputs into a single power rail. A power balancing technique further includes controlling the at least two power converters such that a first one of the power converters outputs an amount of current to the single power rail that is proportional to and/or equal to the amount of current output by another of the power converters.

A converter includes two switching stages coupled in series between positive and negative input terminals. A control circuit is configured for driving the switching stages based on an output voltage of the converter. A first switching stage includes two switches coupled in series between a positive input terminal and a first node. A capacitor and an inductor are coupled in series between the two switches and a positive output terminal. A third switch is coupled between a node between the capacitor and the inductor and the negative input terminal. A second capacitor is coupled between the first node and the negative input terminal. A second switching stage includes a second node coupled to the first node. Two additional electronic switches are coupled in series between the second node and the negative input terminal. A second inductor is coupled between the two additional switches and the positive output terminal.

A method and apparatus for providing welding type power includes a phase shifted double forward converter having a first and second converter with a controller and an output rectifier. The output rectifier has at least one cathode current path that creates a cathode magnetic field when current flows in the cathode current path. The output rectifier also has at least one anode current path that creates an anode magnetic field when current flows in the anode current path. The cathode current path is disposed and oriented and the anode current path is disposed and oriented such that the cathode magnetic field acts to at least partially cancel the anode magnetic field.

A system of charging a battery of a vehicle is provided. The system includes a charger having a direct current (DC) capacitor to which a DC voltage converted from an AC charge voltage is applied and a first DC converter that converts a magnitude of a voltage of the DC capacitor. A first battery is connected to the first DC converter and is charged with a DC voltage converted by the first DC converter. A second DC converter is connected to the battery and converts a magnitude of a voltage of the battery. A second battery receives a DC voltage converted by the second DC converter. A controller charges the DC capacitor up to a predetermined initial charge voltage using power stored in the second battery by operating the second DC converter and the first DC converter in a backward direction before the AC charge voltage is provided to the charger.

The disclosure describes techniques to implement an isolated power converter circuit topology. The power converter circuit topology may include a level shifter or a low-side capacitor which may be configured to both provide capacitive isolation as well as clamping between power converter circuits arranged in a stacked or interleaved interconnection configuration. By controlling the drive signals to the power converter circuits, each power converter circuit, and the stacked interconnection of power converter circuits, may operate to convert power from one voltage level to a second voltage level in either a forward or reverse direction. In the example of a direct current (DC) battery, the stacked or interleaved interconnection of power converter circuits may be further configured to balance the charge level and amount of power drawn from each cell of a multi-cell DC battery.

A power conversion device includes a power supply, a converter, a current detection circuit, and a control circuit. The power supply includes positive and negative terminals. The converter includes a primary side and a secondary side. The converter is configured to output a first current to a load. The primary side is electrically connected to the positive terminal and the negative terminal of the power supply in parallel. The secondary side is electrically connected to the positive terminal of the power supply and the load in series. The current detection circuit is coupled between the secondary side and the load, and is configured to detect the first current to output a current detection signal. The control circuit is coupled to the current detection circuit for outputting a control signal to the converter according to the current detection signal and a reference current signal.

A multiwinding transformer includes a primary-side winding and a plurality of secondary-side windings. A primary-side bridge circuit is connected between a primary-side DC terminal and the primary-side winding. A plurality of secondary-side bridge circuits are connected between the plurality of secondary-side windings and a plurality of secondary-side DC terminals, respectively. A switching converter variably controls a first DC voltage of the primary-side DC terminal or a second DC voltage of a first secondary-side DC terminal among the plurality of secondary-side DC terminals such that a voltage ratio between the first DC voltage and the second DC voltage is controlled to a constant ratio in accordance with a turns ratio between the primary-side winding and the secondary-side winding corresponding to the first secondary-side DC terminal among the plurality of secondary-side windings.

A parallel power supply device according to the present invention includes: a plurality of DC/DC converters connected in parallel to perform power conversion between a DC power supply and a common load; a voltage detector to detect a voltage of the common load; and a plurality of control circuits each to control a corresponding one of the plurality of DC/DC converters, wherein during parallel operation of the plurality of DC/DC converters, the plurality of control circuits control the plurality of DC/DC converters by proportional control using a same target voltage value and a same proportional gain, based on a voltage value of the common load detected by the voltage detector. Therefore, in the parallel power supply device in which the plurality of DC/DC converters are connected in parallel, the individual DC/DC converters can supply electric power to the load independently and equally.

A display system is disclosed. The display system includes an electronic device including first and second interfaces and a display apparatus. The electronic device is configured to: rectify external alternating current (AC) power by direct current (DC) power based on a first ground, convert the DC power into power based on a second ground, provide the converted power to the display apparatus through a first interface connected to the second ground, and provide a signal received from an external device through a second interface connected to an earth ground to the display apparatus through the first interface, wherein a ground of the display apparatus is the same as the second ground and the second ground is different from the earth ground.

The present disclosure discloses a hybrid five-level bidirectional DC/DC converter and a voltage match modulation method thereof. The converter includes a first input filter capacitor C.sub.inp and a second input filter capacitor C.sub.inn, an output filter capacitor C.sub.o, a DC voltage source, a primary-side hybrid five-level unit, a primary-side two-level half bridge, a secondary-side single-phase full bridge H2, a high-frequency isolation transformer M.sub.1, a high-frequency inductor L.sub.s, and a controller. A positive pole of a DC bus of the primary-side hybrid five-level unit is coupled to a positive pole of the corresponding DC voltage source and to a positive pole of the input filter capacitor C.sub.inp respectively. A negative pole of the DC bus of the primary-side hybrid five-level unit is coupled to a negative pole of the corresponding DC voltage source and to a negative pole of the input filter capacitor C.sub.inn respectively. A terminal of the primary-side hybrid five-level unit is coupled to a midpoint between the first input filter capacitor C.sub.inp and the second input filter capacitor C.sub.inn connected in series. The primary-side hybrid five-level unit is coupled to a primary side of the high-frequency isolation transformer M.sub.1 through the high-frequency inductor L.sub.s, and a midpoint of the primary-side two-level half bridge is coupled to another terminal of the primary side of the high-frequency transformer.