Lucent Technologies Inc.

Netpower Technologies, Inc.

Other

Huawei Technologies Co., Limited

Hengchun Mao

Dianbo Fu

Yimin Jiang

Mark E Jacobs

Vijayan J Thottuvelil

Richard W Farrington

Rui Liu

Bing Cai

Feng Lin

Ning Sun

Yehoshua Mandelcorn

William P Gardiner

Circuit and method for controlling circuitry in a power converter device during a soft-start process is provided. Synchronous rectifier control circuitry is adapted to gradually apply a gate drive signal derived from the main switch of the power converter device to a freewheeling synchronous rectifier of the switching circuitry during the soft-start process. The control circuitry gradually releases the amplitude or the pulse-width of the gate drive signal to the freewheeling synchronous rectifier to avoid a large duty ratio in the synchronous rectifier during start-up so that a negative current does not build up in the output inductor.

Soft start for a synchronous rectifier in a power converter

A power converter device using synchronous rectifiers and method for controlling operation thereof are provided. A first synchronous rectifier is coupled to the secondary transformer winding to pass a voltage induced at the secondary winding in response to an input voltage supplied to the primary transformer winding during an on-state of a main power switch. A first drive circuit is coupled to the gate terminal of the first synchronous rectifier to selectively activate and deactivate the first rectifier in correspondence with the respective on and off states of the main power switch based on a gate voltage supplied by the first drive circuit, with at least one circuit parameter being selected in the first drive circuit for maintaining the gate voltage within a predefined range regardless of variation in the level of the input voltage.

Power converter including circuits for improved operational control of synchronous rectifiers therein

A power distribution system is provided including current sharing circuitry, current sensing and over-current protection. The system includes a plurality of power converter modules each having a current sharing signal terminal on an input side and power output terminals on an output side, the corresponding power output terminals of the several modules being connected together and adapted to power a common load; an interconnecting signal bus coupled across the current sharing signal terminals on the input side; a plurality of feedback circuits, each of which is associated with one of said modules, each feedback circuit including a comparator (error amplifier) for comparing a feedback voltage on the output side with a reference voltage to provide an error signal to the input side; the error signal conditioned to provide a current command signal to said signal bus, wherein the signal bus provides a common current command signal to drive the power converter modules.

Plural power converters with individual conditioned error signals shared on a current sharing bus

An energy recovery snubber circuit for a bidirectional power converter, a method of operation thereof and a power plant employing the bidirectional power converter. The bidirectional power converter has first and second inputs, an inductor coupled to the first input and a power switch coupled between the inductor and the second input. In one embodiment, the energy recovery snubber circuit includes: (1) a clamping capacitor coupled to the second input; (2) a clamping diode coupled between the clamping capacitor and the first input; and (3) a snubber inductor coupled to a node between the clamping capacitor and the clamping diode.

Energy recovery snubber circuit for bidirectional power converter and method of operation thereof

Circuit and method for reducing voltage level variation in a bias voltage generated in a power converter device are provided. The method allows providing a first voltage source configured to supply a first voltage during one respective mode of operation of the power converter, wherein the level of the voltage supplied by the first voltage source is directly proportional to variation in an input voltage of the converter device. The method further allows providing a second voltage source configured to supply a second voltage during another respective mode of operation of the power converter, wherein the level of the voltage supplied by the second voltage source has a generally inverse proportional relationship relative to variation in the input voltage of the converter device. At least one circuit parameter is selected in the voltage sources to adjust the respective levels of the first and second voltages. The first and second voltages are combined with one another to generate a combined voltage that comprises the bias voltage in the power converter device, the combined voltage resulting in a bias voltage level being relatively impervious to variation in the input voltage of the converter device.

Method and circuit for reducing voltage level variation in a bias voltage in a power converter

A controller for a power factor corrector (PFC), having a controllable switch and operable in a discontinuous conduction mode (DCM), and a method of controlling the controllable switch. In one embodiment, the controller includes: (1) a drive circuit adapted to drive the controllable switch and (2) a current mode control circuit adapted to sense a current of the PFC and develop a current control signal based thereon. The drive circuit reduces a duty cycle of the controllable switch based on the current control signal to reduce input current distortion in the PFC.

Controller for power factor corrector and method of operation thereof

A regulation circuit for a voltage-fed power converter, a method of operation thereof and a power converter employing the circuit or the method. The power converter has an inverter switch adapted to transfer power to a transformer. In one embodiment, the regulation circuit includes a switching network coupled to a tapped winding of the transformer. The switching network is operable to vary a turns ratio of the transformer, thereby regulating an output voltage of the power converter.

Regulation circuit for a power converter and method of operation thereof

A regulation circuit for a current-fed power converter having a power switch adapted to transfer power to a transformer. In one embodiment, the regulation circuit includes a switching network coupled to a tapped winding of the transformer and operable to vary a turns ratio of the transformer thereby regulating an output voltage of the power converter.

Current-fed dc/dc converter with multilevel transformer and method of operation thereof

For use with a semiconductor switch that exhibits a temperature-dependent electrical characteristic and a current sense circuit that employs the characteristic of the switch to derive a switch current signal, a temperature compensation circuit, method of operation thereof and controller employing the same. In one embodiment, the circuit includes: (1) an electrical component, locatable in thermal communication with the switch and having a temperature-dependent electrical characteristic that bears an inverse relationship to the characteristic of the switch, that generates an intermediate signal based on an actual temperature of the switch and (2) a signal conditioning circuit, coupled to the electrical component, that scales the intermediate signal to yield a compensation signal that counteracts temperature-dependent variations in the switch current signal.

Temperature compensation circuit for semiconductor switch and method of operation thereof

For use with a power converter having an input, first and second capacitors and first and second switches, a mode selection circuit, having selectable modes of operation, a method of configuring a power converter, and power converter employing the mode selection circuit and method are provided. In one embodiment, the mode selection circuit may function in two modes of operation. In a first mode, based upon an input voltage, the mode selection circuit is adapted to couple the first and second capacitors and the first and second switches together as a half-bridge converter. In a second mode, based upon the input voltage, the mode selection circuit is adapted to couple the first switch and the first capacitor together as a forward-flyback converter and to further couple the second capacitor and the second switch as a clamp thereto. In another embodiment, the first mode is a high voltage mode, in response to a high input voltage and the second mode is a low voltage mode, in response to a low input voltage.

Power converter with voltage dependent switchable modes

A power supply that provides a source of backup AC voltage and a method of operating thereof. In one embodiment, the power supply includes a transformer having main power and backup power windings and a secondary winding. The power supply also includes multiple stages, namely, (1) a primary power stage coupled to the main power winding, (2) a backup power stage coupled to the backup power winding and having a backup battery, one of the primary and backup power stages acting as a current fed source and (3) an AC power stage, coupled to the secondary winding, that provides a source of AC voltage. The power supply is operable in a normal mode of operation in which the primary power stage supplies power to the secondary winding and further supplies power to the backup power winding to allow the backup power stage to charge the backup battery. The power supply is also operable in a backup mode of operation in which the backup power stage transfers power from the backup battery to the secondary winding via the backup power winding.

Power supply providing backup AC voltage and method of operation thereof

A power factor correcting eletrical converter apparatus receives an alternating electrical input signal from a power source. The apparatus preferably includes an input tracking circuit connected with the power source for tracking the input signal and providing the input signal at an input tracking node. The converter apparatus includes a rectifying circuit connected with the power source for receiving the input signal and generating a rectified input signal, and a filtering circuit connected with the rectifying circuit to filter and smooth the rectified input signal. An input sensing circuit is connected with the input tracking circuit for receiving the input signal and generating an input-indicating signal at an input-sensing node. An output circuit is connected with the filtering circuit for delivering the rectified boost signal to a load. The output circuit senses an electrical parameter associated with the load to produce an output-indicating signal at an output-sensing node. A feedback circuit is connected with the input-sensing node and with the output-sensing node for receiving the input-indicating signal and the output-indicating signal and generating a gating signal. The output circuit responds to the gating signal to switchingly control connection with the load. The input sensing circuit or the feedback circuit may be configured to impose a delay which causes the input-indicating signal to be out of phase with the input signal. The phase shift reduces input current distortion and increases input power factor.

Power factor correcting electrical converter apparatus

For use in a power converter having a power switch subject to switching losses and a rectifying diode subject to a reverse recovery condition, a snubber circuit and related method to mitigate adverse effects associated with the switching losses and the reverse recovery condition. In one embodiment, the snubber circuit includes a recovery circuit, having first and second energy storage devices and a snubber diode, coupled to the rectifying diode. The snubber circuit further includes a third energy storage device, coupled across the rectifying diode, configured to cooperate with the recovery circuit to mitigate adverse effects associated with the reverse recovery condition and reduce a rate of change of a voltage across the power switch to reduce the switching losses.

Snubber circuit for a power switch and recitifying diode and power converter employing the same

Temperature compensation circuit for semiconductor switch and method of

A backup power supply for use with a power plant having a primary power supply that provides primary power to an AC bus for subsequent conversion to DC power and a method of providing backup power to the AC bus. In one embodiment, the system includes a battery charger/inverter, coupled to the AC bus and couplable to a battery, that operates in a normal mode to convert a portion of the primary power to charge the battery and operates in a battery backup mode to convert DC power from the battery to provide the backup power to the AC bus.

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Plano, TX, United States of America

Hengchun Mao