48results about "Efficient power electronics conversion" patented technology

The bridgeless boost topology reduces the power dissipation, cost, and size of prior PFC systems by eliminating the intrinsic loss of the input rectifier bridge. Sensing of the input line voltage by the controller is unnecessary. The use of One Cycle Control (also known as Single Cycle Control) allows the Power Factor Correction function to be performed without complex rectification networks to obtain the AC line voltage reference. The use of bi-directional switches makes it possible to control inrush current (the startup over-current due to the charging of the output bulk capacitor), which allows elimination of over-current limiting devices and reduction of the diode surge capability requirements. Moving the boost inductor to the system input adds an additional filtering function, reducing the cost of input EMI filtering.

A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.

An inverter (1) for a grounded direct voltage source, in particular for a photovoltaic generator (2), a battery or a fuel cell, for converting the direct voltage into an alternative voltage with a DC-DC converter (3) and a pulse inverter that is supplied by said DC-DC converter (3), said DC-DC converter (3) being configured to be an oscillating circuit inverter and comprising a series resonant oscillating circuit, said DC-DC converter (3), which is configured to be an oscillating circuit inverter, being configured to be a series-compensated oscillating circuit inverter with a choke (L1) and a series-mounted capacitor array consisting of two or several oscillating circuit capacitors, a rectifier bridge branch including 2 diodes (D3, D4; D5, D6, . . . ), being connected to each of the partial oscillating circuit capacitors, said rectifier bridge branch being connected with its positive or its negative pole to output side intermediate circuit capacitors which are preferably connected in series so that said DC-DC converter (3) delivers at least two bipolar output voltages and is combined with the pulse inverter (4) with a divided voltage intermediate circuit that is supplied from the oscillating circuit inverter.

Asynchronous rectifier controller is provided on a secondary side of an insulation-type synchronous DC/DC converter and controls the synchronous rectifier transistor. A driver circuit controls the synchronous rectifier transistor. A photo coupler connection terminal is coupled to an input side of the photo coupler. An error amplifier amplifies an error between a voltage detection signal according to an output voltage of the DC/DC converter and its target voltage, and to draw a current according to the error from an input side of the photo coupler via the photo coupler connection terminal.

A switching constant-current power device can stabilize current flowing to a load (e.g. a display device comprising an LED, or the like) even when the current is repeatedly interrupted. A voltage current detector is connected to the output side of a power converter and creates a voltage signal in accordance with the output voltage thereof; and a feedback circuit is provided between a controller for driving the power converter and a current detector, which generates a first feedback signal in accordance with the load current. The feedback circuit comprises a signal holding unit, which outputs a second feedback signal that was created by consulting the voltage signal at a given time, the feedback circuit supplying the first feedback signal, output by the current detector, to the controller when load current is flowing, and supplying the second feedback signal, output by the signal holding unit, to the controller when load current is not flowing.

A boost inductor value reduction circuit is integrated into a traditional boost power converter to greatly reduce undesirable high frequency harmonics from being fed back to the input side of the boost power converter. The boost inductor value reduction circuit is very small when compared with traditional filter techniques, is less costly than traditional filter techniques, and does not degrade the boost power converter control performance. It can also be used to reduce the size of the boost inductor without compromising the converter performance for use in energy efficient sensitive applications such as photovoltaic inverters.

An embodiment of a compound semiconductor device includes: a substrate; an electron channel layer and an electron supply layer formed over the substrate; a gate electrode, a source electrode and a drain electrode formed on or above the electron supply layer; a p-type semiconductor layer formed between the electron supply layer and the gate electrode; and a hole barrier layer formed between the electron supply layer and the p-type semiconductor layer, a band gap of the hole barrier layer being larger than that of the electron supply layer.

In a D.C. to D.C. converter, an input voltage is received via an inductor at an input terminal and stored onto a capacitor of an integrator. A first switch is coupled between the input terminal and a reference terminal such as ground and thereby fluxes the inductor. The input voltage stored on the capacitor falls at a rate determined by the integrator circuit and an initial value of the input voltage. After a time duration, the first switch becomes nonconductive. Current flows from the inductor through a diode to an output terminal until a second switch across the diode is made conductive. Stored voltage on the capacitor of the integrator increases in response to the second switch being conductive. The stored voltage on the capacitor is continuously compared with a reference voltage. The second switch is made nonconductive when the stored voltage on the capacitor exceeds the reference voltage.

The invention relates to a quasi-resonant push-pull converter and the method for controlling the same, said push-pull converter comprising: a direct current (DC) input power supply configured to supply DC input for the converter; a first power input unit and a second power input unit, connected to said DC input power supply, respectively and configured to supply input for the converter in different periods, comprising a first power switching tube and a second power switching tube, a first primary winding and a second primary winding; a power output circuit, configured to supply output of the converter, comprising secondary windings and full-bridge rectification circuits; a first output capacitor and a second output capacitor connected to said power output circuit and configured to store DC electric energy output by the power output circuit in which a resonant element is arranged to achieve a quasi-resonant switching circuit through voltage feedback; and a switching circuit being controlled through voltage feedback, whereby turns ratio of the primary windings and the secondary windings of the push-pull converter is controlled.

The invention provides a step-down DC-DC converter, which further comprises an output circuit, a voltage feedback circuit, a discharge path and a discharge control circuit, wherein the output circuitis used for converting an input voltage into an output voltage, and comprises a first power transistor and a second power transistor which are connected in series between an input end and a groundingend; the voltage feedback circuit is used for acquiring a feedback voltage based on the output voltage; the discharge path is coupled between the output circuit and the grounding end and is controlledin discharging; and the discharge control circuit controls the discharge path to discharge the output circuit when the feedback voltage obtained by the voltage feedback circuit is greater than a second reference voltage and the first power transistor is cut off, and controls the discharge path to prohibit discharge when the feedback voltage obtained by the voltage feedback circuit is smaller thanthe second reference voltage or the first power transistor is conducted. In this way, the problem that the overshoot duration of large-current transient response is long can be solved.

The invention discloses a DC transformer based on a centralized multi-winding high-frequency transformer, and a control method of the direct-current transformer. The transformer comprises M DC transformer units with input ends connected in series and output ends connected in parallel, wherein the medium-voltage DC side input ports of the M DC transformer units are connected in series to form a medium-voltage DC side port of the DC transformer, and low-voltage DC side output ports of the M DC transformer units are connected in parallel to form a low-voltage DC side port of the DC transformer. The multi-winding high-frequency transformers among the DC transformer units are mutually independent; each DC transformer unit comprises N submodules, the inputs of which are connected in series and the outputs of which are connected in parallel, wherein N is greater than or equal to 3; the input filter capacitors Cini of the submodules are connected in series to form a medium-voltage DC side input port of the unit, and the output filter capacitors Coi are connected in parallel to form a low-voltage DC side output port of the unit. According to the transformer, the bidirectional transmission of power between the medium-voltage DC side and the low-voltage DC side can be realized by controlling a phase shift angle between primary and secondary side bridge arms of the transformer in each sub-module, and zero-voltage switching-on of all switch tubes is realized.

A totem-pole power factor correction circuit (totem-pole PFC) is connected behind an input inductor receiving electric power from an alternating current (AC) power source. The totem-pole PFC is provided, in a high-frequency working area thereof, with at least two current transformer elements or a center-tapped current transformer element. The waveform of current flowing through the totem-pole PFC during positive and negative half cycles of AC power is sensed via the current transformer elements or the center-tapped current transformer element. Thereby, current waveform for the input inductor during positive and negative half cycles may be realized via the obtained current waveform completely, such that the practical problems originating from the conventional necessity for the establishment of bulky Hall device or another current-sensing unit are solved specifically.

The invention relates to the field of power management, and provides a Buck type high power factor converter based on an integrated controller. In order to achieve high power factors, according to the technical scheme, the Buck type high power factor converter based on the integrated controller comprises a peripheral circuit, a rectifying bridge is composed of four diodes, and a partial voltage structure which is formed by two resistors which are in series connection is connected to the rear portion of the rectifying bridge in parallel; the positive output end of an AC input power source is connected to the negative electrode of one diode, the negative output end of the AC input power source is connected with an MOS switch through a current detecting resistor, and the other end of the MOS switch is connected with the positive electrode of the corresponding diode. The positive electrodes of the diodes are connected with one end of a voltage reduction inductor. An output load is connected with a difference partial voltage structure in parallel. Middle nodes of the two resistors are connected to the base electrode of a P-type audion, a high level end is connected to the emitting electrode of a secondary audion after passing through an emitting electrode resistor, a collector electrode is connected to the ground after passing through a collector electrode resistor, and a node between the collector electrode and the resistors outputs voltage feedback signals. The Buck type high power factor converter based on the integrated controller is mainly suitable for power source management.

A coil module includes a magnetic substance plate, a first coil, and a second coil. The magnetic substance plate includes a first area having a first magnetic permeability and a second area having a second magnetic permeability. The first coil is disposed on a surface of the magnetic substance plate. The second coil is disposed on the surface of the magnetic substance plate and partially overlapping the first coil. A portion of the first coil, not overlapping the second coil, is disposed on a surface of the first area, and a portion of the second coil, not overlapping the first coil, is disposed on a surface of the second area.

The invention discloses a power factor correction circuit. The power factor correction circuit comprises a rectifier circuit, a boost conversion circuit and a load circuit. The rectifier circuit is used for converting an alternating-current voltage into a direct-current voltage. The rectifier circuit comprises a first output end, a second output end and a third output end. The boost conversion circuit is used for boosting the direct-current voltage and outputting the direct-current voltage. The boost conversion circuit comprises a first input end, a second input end and a fourth output end. The fourth output end of the boost conversion circuit is connected with the first output end of the rectifier circuit. The first input end is connected with the second output end. The second input end is connected with the third output end. The load circuit is connected in series between the first output end of the rectifier circuit and the third output end. According to the technical scheme of the invention, the correction of the power factor is realized by adopting the boost conversion circuit, while the working efficiency is improved at the same time. The power factor value reaches more than 99%.

The invention discloses a power factor improver circuit with a function of PFC (power factor correction). The circuit comprises a control circuit and a switch circuit. By detecting the power, the switch circuit is controlled under light load, rectifier capacitance is decreased, the ability of the PFC circuit to correct waveform is greatly improved, a PF value of the PFC circuit being in light load is increased, and apparent power is decreased.

In a power conversion device, a power conversion unit includes a single-phase inverter on a secondary side of a resonant type converter that has an input of a direct current. A power conversion unit group is configured by connecting outputs of the single-phase inverters of a plurality of power conversion units in series. Respective phases of three phase alternate current are formed with the three power conversion unit groups housed in a power conversion device housing. The plurality of power conversion units constituting the power conversion unit group are disposed along a longitudinal direction of the power conversion device housing. The respective three power conversion unit groups are disposed at an upper stage, a middle stage, and a lower stage in a height direction of the power conversion device housing. The power conversion device housing has one end side in the longitudinal direction as output terminals of the three power conversion unit groups. The power conversion device housing has the other end side in the longitudinal direction where terminals of the three power conversion unit groups are connected in common.

A power converter and a control method thereof are provided. The power converter includes a primary side switching circuit, a secondary side switching circuit, a transformer, and a control circuit. The primary side switching circuit includes a first set of switches. The secondary side switching circuit includes a second set of switches. The transformer is coupled between the primary side switching circuit and the secondary side switching circuit. The control circuit is configured to control power transfer between the primary side switching circuit and the secondary side switching circuit by controlling the first and second sets of switches. The control circuit is adapted to enable and disable the first and second sets of switches in an enabling duration and a disabling duration respectively and alternatively.

A power source circuit includes a first transistor as an output switch, a second transistor as a load switch, a reference voltage generating section, a soft start voltage generating section, a feedback voltage generating section, first and second error amplifiers, and first and second offset control sections. The first error amplifier controls a conduction state of the first transistor based on a difference between a soft start voltage obtained by adding an offset voltage to a soft start voltage or a reference voltage, whichever is smaller, and a feedback voltage. The second error amplifier controls a conduction state of the second transistor based on a difference between a soft start voltage obtained by adding an offset voltage to the soft start voltage and the feedback voltage.

The invention discloses a high- and low -voltage input balancing power factor correction circuit, which comprises a power factor correction (PFC) chip, wherein a feedback pin of the PFC chip is connected with a compensation circuit which comprises a remote control (RC) circuit formed by connecting a resistor R41 and a capacitor C21 in series, and a capacitor C10 connected with the RC circuit in parallel. The circuit of the invention has a simple structure, basically needs no extra circuit elements and is low in realization cost. In the invention, the traditional design bias is overcome, the resistor in the compensation circuit is replaced by the capacitor, and the RC circuit is used in combination to form a dual-electrode circuit; and thus, a loop bandwidth is greatly improved, a relatively high PF value can be kept at high-voltage input and low-voltage input, and the fluctuation range of voltage is expanded to 90 to 305V.

The invention relates to a power supply monitoring circuit and a control method thereof, and an AC/DC conversion apparatus. The power supply monitoring circuit that is provided includes a holding part holding, every time a local maximum value of a power supply voltage which fluctuates is detected, the local maximum value as a local maximum voltage value, a power stop detector detecting whether or not supply of the power supply voltage is stopped based on whether or not a state that a value of the power supply voltage is smaller than a first reference value according to the local maximum voltage value continues longer than a predetermined period, and a reference value controller decreasing the first reference value during a period in which the value of the power supply voltage exceeds a second reference value smaller than the first reference value and in which stop of the supply of the power supply voltage is detected.

The invention discloses a main/standby power conversion detection circuit capable of switching off a power supply IC for a power supply module. The main/standby power conversion detection circuit comprises an input voltage module, a reference voltage module, a comparator, an optocoupler module and a power supply IC control module, wherein the input voltage module is connected with the AC input endof the power supply module and is used for filtering and dividing the voltage of the AC input end, the comparator compares the output voltage of the input voltage module with the output voltage of the reference voltage module, the optocoupler module is disconnected when the output voltage of the input voltage module is too low, and the power supply IC is controlled to be disconnected through thepower supply IC control module. The main/standby power conversion detection circuit can continuously detect the input voltage of the AC input end, automatically turn off the power supply IC when the input voltage is under-voltage, and turn on the power supply IC when the input voltage is normal, thereby realizing the under-voltage protection of the power supply IC, and avoiding the problems of heating and even burnout caused by the long-term operation of the power supply IC under the condition of low voltage.

The invention discloses a driving method of a symmetrical half-bridge LC series resonance sine power conversion circuit. The driving method comprises the steps: S1, connecting a LC series resonance circuit between the primary end of a high-frequency transformer and a symmetrical half-bridge circuit in series; S2, determining the switching frequency of a symmetrical half-bridge sine power conversion circuit according to the resonance angular frequency of the LC series resonance circuit; and S3, according to the switching frequency, sending a transistor conduction instruction to the symmetricalhalf-bridge sine power conversion circuit, wherein the transistor conduction instruction is used for controlling the conduction or disconnection of a transistor in the symmetrical half-bridge sine power conversion circuit. According to the technical scheme, a symmetrical half-bridge circuit generates a fixed-width chopping voltage, so that a resonant tank circuit, the chopping voltage and the frequency of secondary synchronous rectification are matched, the voltage gain of a conversion circuit is kept constant under different load conditions, and the symmetrical half-bridge series resonance sine power conversion function is achieved.