CN220457290U - Power factor corrector, power factor correction circuit and power supply apparatus - Google Patents

Abstract

The utility model discloses a power factor corrector, a power factor correction circuit and a power supply device, wherein the power factor corrector is coupled with an alternating current voltage source, an output capacitor and a load, and comprises the following components: the first flyback converter comprises at least a first transformer, a first rectifying module, a first power switch, a second power switch and a third power switch; the second flyback converter at least comprises a second transformer, a second rectifying module, a first power switch, a second power switch and a fourth power switch.

Description

Power factor corrector, power factor correction circuit and power supply apparatus

Technical Field

The utility model relates to the technical field of power conversion, in particular to a power factor corrector, a power factor correction circuit and power equipment.

Background

In the prior art, high-power application needs to have a power factor requirement, for example, from 8 months of 2016, according to the requirements of IEC61000-3-2 and other standards, power application with power higher than 75W needs to increase Power Factor Correction (PFC), and power lower than 75W does not have the requirement. The power supply circuit commonly used realizes the function of power factor correction and obtains constant output electric signals, for example, the power supply circuit adopts the power factor correction circuit and outputs relatively stable direct current voltage; the post-stage power supply circuit adopts a direct current-direct current power supply circuit to realize constant and strobe-free output voltage or output current.

In the prior art power factor correction circuit, the power consumption of a diode rectifier bridge coupled with an ac voltage source is also a real problem that has to be considered.

Disclosure of Invention

First aspect

The utility model provides a power factor corrector coupled to an alternating voltage source and an output capacitor, the power factor corrector comprising:

the input end of the first flyback converter receives the first end of the alternating voltage source as an input voltage anode, the second end of the alternating voltage source as an input voltage cathode, and the output end of the first flyback converter is coupled with the output capacitor;

the input end of the second flyback converter receives the second end of the alternating voltage source as an input voltage anode, the first end of the alternating voltage source as an input voltage cathode, and the output end of the second flyback converter is coupled with the output capacitor;

the first flyback converter at least comprises a first transformer, a first rectifying module, a first power switch, a second power switch and a third power switch;

the second flyback converter at least comprises a second transformer, a second rectifying module, a first power switch, a second power switch and a fourth power switch.

Preferably, the power factor corrector further comprises a control module;

the 1 st end of the first transformer is coupled with the first end of the alternating current voltage source, the 2 nd end of the first transformer is coupled with the first end of the first power switch, the 3 rd end of the first transformer is coupled with the first end of the first rectifying module, the second end of the first rectifying module is coupled with the positive plate of the output capacitor, and the third power switch is coupled between the second end of the alternating current voltage source and the second end of the first power switch;

the 1 st end of the second transformer is coupled with the second end of the alternating current voltage source, the 2 nd end of the second transformer is coupled with the first end of the second power switch, the 3 rd end of the second transformer is coupled with the first end of the second rectifying module, the second end of the second rectifying module is coupled with the positive plate of the output capacitor, the fourth power switch is coupled between the first end of the alternating current voltage source and the second end of the second power switch, the negative plate of the output capacitor is coupled with the 4 th end of the first transformer and the 4 th end of the second transformer, and the output voltage is generated on the output capacitor;

the control module is coupled with the control end of the first power switch, the control end of the second power switch, the control end of the third power switch and the control end of the fourth power switch;

the power factor corrector controls the on and off of the first power switch, the second power switch, the third power switch and the fourth power switch through the control module, so that the same-phase change of the voltage and the current of the alternating-current voltage source is realized, and further, the power factor correction is realized.

Preferably, the power factor corrector further comprises a first detection resistor and a second detection resistor;

the first detection resistor is coupled between the second end of the first power switch and the ground and is used for detecting the current flowing through the first power switch and generating a first detection signal; the second detection resistor is coupled between the second end of the second power switch and the ground and is used for detecting the current flowing through the second power switch and generating a second detection signal; the control module is coupled with the first detection signal and the second detection signal and controls the on or off of the first power switch and the second power switch according to the detection signals;

the first rectifying module and the second rectifying module are diodes, or the first rectifying module and the second rectifying module are metal oxide semiconductor field effect transistors.

Second aspect

The utility model also provides a power factor correction circuit coupled to an ac voltage source and an output capacitor, comprising:

the input end of the first flyback converter receives the first end of the alternating-current voltage source as an input voltage anode, the second end of the alternating-current voltage source as an input voltage cathode, and the output end of the first flyback converter is coupled with the output capacitor and comprises a first transformer;

the input end of the second flyback converter receives the second end of the alternating-current voltage source as an input voltage anode, the first end of the alternating-current voltage source as an input voltage cathode, and the output end of the second flyback converter is coupled with the output capacitor, and the second flyback converter comprises a second transformer;

in a first half period of an alternating current voltage source, in a first working state, a first path receives voltage of the first half period of the alternating current voltage source to store energy of the first transformer, and first current flowing through the first transformer rises; in a second operating state, the first transformer discharges energy to the output capacitor through a second path to generate an output voltage on the output capacitor, and the first current drops; in the second half period of the alternating current voltage source, in a third working state, the third path receives the voltage of the second half period of the alternating current voltage source to store energy for the second transformer, and the second current flowing through the second transformer rises; in a fourth operating state, the second transformer discharges energy to the output capacitor through a fourth path to generate the output voltage on the output capacitor, and the second current drops.

Preferably, the power factor correction circuit comprises a first power switch, a second power switch, a third power switch and a fourth power switch;

when the first working state of the first half cycle of the alternating-current voltage source is in a conducting state, the second power switch is in a conducting state, the third power switch is in a conducting state, the fourth power switch is in a cut-off state, and a first current of the first working state flows through the alternating-current voltage source, the first transformer, the first power switch, the second power switch, the third power switch and the second transformer;

when the first power switch is in an off state in a second working state of a first half period of the alternating-current voltage source, at least one of the second power switch and the third power switch is in an on state, the fourth power switch is in an off state, and a first current in the second working state flows through the first transformer, the first rectifying module and the output capacitor;

in a third working state of a second half period of the alternating-current voltage source, the first power switch is in a conducting state, the second power switch is in a conducting state, the third power switch is in a cut-off state, the fourth power switch is in a conducting state, and a second current in the third working state flows through the alternating-current voltage source, the second transformer, the second power switch, the first power switch, the fourth power switch and the first transformer;

in a fourth operating state of the second half period of the alternating voltage source, at least one of the first power switch and the fourth power switch is in an on state, the third power switch is in an off state, the second power switch is in an off state, and a second current in the fourth operating state flows through the second transformer, the second rectifying module and the output capacitor.

Preferably, in the first working state and the second working state, the first path and the second path through which the first current flows, and components except the alternating current voltage source form a first flyback converter;

in the third and fourth operating states, the third and fourth paths through which the second current flows, components other than the ac voltage source constitute the second flyback converter.

Preferably, the power factor correction circuit comprises a control module;

the first flyback converter further comprises a first detection resistor connected in series between the second end of the first power switch and the ground, and is used for detecting a first current and generating a first detection signal;

the second flyback converter further comprises a second detection resistor connected in series between the second end of the second power switch and ground, and is used for detecting a second current and generating a second detection signal;

the control module is coupled with the first detection signal and the second detection signal and is used for generating a first control signal to drive the first power switch to be turned on or off according to the received detection signal and generating a second control signal to drive the second power switch to be turned on or off.

Preferably, the power factor correction circuit further comprises a control chip, a first rectifying module and a second rectifying module;

the first rectifying module and the second rectifying module are diodes or metal oxide semiconductor field effect transistors;

the control chip is integrated with the control module; the control chip is combined with the first transformer, the second transformer, the first rectifying module and the second rectifying module to realize the same-phase change of the input voltage and the input current of the alternating-current voltage source, and further realize the power factor correction.

Preferably, part or all of the third power switch and the fourth power switch are diodes.

Third aspect of the utility model

An embodiment of the present utility model provides a power supply device, including the power factor corrector according to any one of the first aspect or the power factor correction circuit according to any one of the second aspect.

The utility model has the following advantages:

according to the power factor corrector, a diode rectifier bridge coupled with an alternating voltage source is eliminated, and the efficiency and the performance are improved.

Drawings

FIGS. 1A-1B are schematic illustrations of 4 operational states of one embodiment of the present utility model;

FIG. 2 is a block diagram of the structure of the present utility model;

fig. 3 is an embodiment of the present utility model.

Various features and elements are not drawn to scale in accordance with conventional practice in the drawings in order to best illustrate the specific features and elements associated with the utility model. In addition, like elements/components are referred to by the same or similar reference numerals among the different drawings.

[ reference numerals description ]

210: first flyback converter

220: second flyback converter

[ symbolic description ]

L1: first transformer

L2: second transformer

P (1) -P (4): first path-fourth path

ICh1-ICh2: first current-second current

MP1-MP4: first power switch-fourth power switch

GP1-GP4: first control signal-fourth control signal

DX (x=1-2): rectifying module

RCS1: first detection resistor

VCS1: first detection signal

RCS2: second detection resistor

VCS2: second detection signal

o1-o4: 1 st end to 4 th end

VAC: AC voltage source

VAC1: first end

VAC2: second end

CO: output capacitor

VO: and outputting the voltage.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

First aspect

The present utility model provides a power factor corrector, as shown in fig. 2, coupled with an ac voltage source VAC and an output capacitor CO, comprising: a first flyback converter 210 having an input terminal receiving a first terminal VAC1 of an ac voltage source VAC as an input voltage anode, a second terminal VAC2 of the ac voltage source VAC as an input voltage cathode, and an output terminal coupled to an output capacitor CO; a second flyback converter 220 having an input terminal receiving a second terminal VAC2 of the ac voltage source VAC as an input voltage anode, a first terminal VAC1 of the ac voltage source VAC as an input voltage cathode, and an output terminal coupled to the output capacitor CO; the first flyback converter 210 at least comprises a first transformer L1, a first rectifying module D1, a first power switch MP1, a second power switch MP2 and a third power switch MP3; the second flyback converter 220 at least includes a second transformer L2, a second rectifying module D2, a first power switch MP1, a second power switch MP2 and a fourth power switch MP4.

In one embodiment, as shown in fig. 1A, the power factor corrector further comprises a control module; the 1 st end o1 of the first transformer L1 is coupled to the first end VAC1 of the ac voltage source VAC, the 2 nd end o2 of the first transformer L1 is coupled to the first end of the first power switch MP1, the 3 rd end o3 of the first transformer L1 is coupled to the first end of the first rectifying module D1, the second end of the first rectifying module D1 is coupled to the positive plate of the output capacitor CO, and the third power switch MP3 is coupled between the second end VAC2 of the ac voltage source VAC and the second end of the first power switch MP1; the 1 st end o1 of the second transformer L2 is coupled to the second end VAC2 of the ac voltage source VAC, the 2 nd end o2 of the second transformer L2 is coupled to the first end of the second power switch MP2, the 3 rd end o3 of the second transformer L2 is coupled to the first end of the second rectifying module D2, the second end of the second rectifying module D2 is coupled to the positive plate of the output capacitor CO, the fourth power switch MP4 is coupled between the first end VAC1 of the ac voltage source VAC and the second end of the second power switch MP2, the negative plate of the output capacitor CO is coupled to the 4 th end o4 of the first transformer L1 and the 4 th end o4 of the second transformer L2, and the output voltage VO is generated on the output capacitor CO; the control module is coupled with the control end of the first power switch MP1, the control end of the second power switch MP2, the control end of the third power switch MP3 and the control end of the fourth power switch MP4; the power factor corrector controls the on and off of the first power switch MP1, the second power switch MP2, the third power switch MP3 and the fourth power switch MP4 through the control module, so as to realize the same phase change of the voltage and the current of the alternating-current voltage source VAC, and further realize the power factor correction.

In one embodiment, the first rectifying module D1 and the second rectifying module D2 are diodes, and the first flyback converter 210 and the second flyback converter 220 in the pfc circuit are diode rectifying structures.

In one embodiment, the first rectifying module D1 and the second rectifying module D2 are Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), and the first flyback converter 210 and the second flyback converter 220 in the pfc are Metal Oxide Semiconductor Field Effect Transistor (MOSFET) synchronous rectifying structures.

In one embodiment, as shown in fig. 3, the power factor corrector further includes a first detection resistor RCS1 and a second detection resistor RCS2; the first detection resistor RCS1 is coupled between the second end of the first power switch MP1 and ground, and is configured to detect a current flowing through the first power switch MP1 and generate a first detection signal VCS1; the second detection resistor RCS2 is coupled between the second end of the second power switch MP2 and ground, and is configured to detect a current flowing through the second power switch MP2 and generate a second detection signal VCS2; the control module is coupled to the first detection signal VCS1 and the second detection signal VCS2, and controls the on or off of the first power switch MP1 and the second power switch MP2 according to the detection signals.

In one embodiment, as shown in fig. 1A, in a first half-period of the ac voltage source VAC, if the voltage at the first end VAC1 is higher than the voltage at the second end VAC2 (which is assumed but not limited to be described for convenience of description), the third power switch MP3 is turned on, which corresponds to zero voltage of VAC2, and at this time, the fourth power switch MP4 is turned off, the first power switch MP1, the second power switch MP2, the first transformer L1, the second transformer L2, and the first rectification module D1 form an independent flyback converter, the sinusoidal half-wave voltage of the ac voltage source VAC charges and stores the first transformer L1 through the first power switch MP1, and after the first path P (1) of the first current Ich1 flowing from the first end VAC1 of the ac voltage source VAC passes through the first transformer L1 and the first power switch MP1, the two paths of the third power switch MP3 and the second power switch MP2 are respectively turned back to the second end VAC2 of the ac voltage source, and the two paths of the second power switch MP2 are respectively turned back to the second end VAC2, and the current factor of the second power switch MP2 is reduced, and the current factor of the correction path is formed by the two paths of the third power switch MP3; as shown in fig. 1A, after the first power switch MP1 is turned off, the first transformer L1 starts to discharge, at this time, at least one of the second power switch MP2 and the third power switch MP3 is in a conductive state, and preferably, both the second power switch MP2 and the third power switch MP3 are in a conductive state; after the first current Ich1 is transformed by the first transformer L1, the first current Ich1 is coupled from the primary winding of the first transformer L1 to the secondary winding of the first transformer L1, the first current Ich1 of the secondary winding and the first current Ich1 of the primary winding have a turns ratio relationship (ich1_secondary= Nps ×ich1_primary) of the first transformer L1, wherein Nps is the turns ratio of the primary winding and the secondary winding, and the second path P (2) of the first current Ich1 passes through the first transformer L1, the first rectifying module D1, and the output capacitor CO; the control module controls the on and off of the first power switch MP1, and the first flyback converter 210 achieves the transfer of the energy of the first half period of the ac voltage source VAC to the output capacitor CO, and achieves the power factor correction function.

In the second half period of the ac voltage source VAC, the voltage of the second end VAC2 is higher than that of the first end VAC1, the fourth power switch MP4 is turned on, the third power switch MP3 is turned off, which corresponds to zero voltage VAC1, and the analysis process is similar to that of fig. 1A, and the description is not repeated with reference to the third path P (3) of the second current Ich2 and the fourth path P (4) of the second current Ich2 in fig. 1B; the control module, by controlling the on and off of the second power switch MP2, the second flyback converter 220 effects transfer of energy from the second half-cycle of the ac voltage source VAC to the output capacitor CO and effects a power factor correction function.

By the combined operation of the first flyback converter 210 and the second flyback converter 220, the power factor corrector achieves power factor correction for the entire cycle of the alternating voltage source VAC.

According to the operating principle of the flyback converter, the input current peak value Iinpk of the ac voltage source VAC can be calculated by the formula: iinpk=vin/l×ton, where Iinpk represents an input current peak value, vin represents a sinusoidal half-wave dc input voltage, L represents inductance values of primary windings of the transformers L1 and L2, where primary inductance values L of the transformers L1 and L2 are constants, and when the control module controls the on time ton to be constant, the input current peak value Iinpk is in a proportional relationship with the sinusoidal half-wave dc input voltage Vin, so that the input current peak value Iinpk follows the sinusoidal half-wave dc input voltage Vin, thereby obtaining a higher power factor.

Second aspect

The utility model also provides a power factor correction circuit coupled to an ac voltage source VAC and an output capacitor CO, comprising: a first flyback converter 210, the input end of which receives the first end of the alternating voltage source VAC as an input voltage anode, the second end of the alternating voltage source VAC as an input voltage cathode, and the output end of which is coupled with the output capacitor CO, wherein the first flyback converter 210 comprises a first transformer L1; a second flyback converter 220, the input end of which receives the second end of the alternating voltage source VAC as an input voltage anode, the first end of the alternating voltage source VAC as an input voltage cathode, and the output end of which is coupled with the output capacitor CO, wherein the second flyback converter 220 comprises a second transformer L2; the power circuit further comprises a first power switch MP1, a second power switch MP2, a third power switch MP3 and a fourth power switch MP4; in a first half cycle of the ac voltage source VAC, in a first operating state, as shown in fig. 1A, the first power switch MP1 is in an on state, the second power switch MP2 is in an on state, the third power switch MP3 is in an on state, the fourth power switch MP4 is in an off state, the first path P (1) receives a voltage of the first half cycle of the ac voltage source VAC to store energy in the first transformer L1, and the first current Ich1 flowing through the first transformer L1 rises; the first current Ich1 of the first path P (1) flows through the alternating voltage source VAC, the first transformer L1, the first power switch MP1, the third power switch MP3, the second power switch MP2 and the second transformer L2; after the first current Ich1 flowing from the first end VAC1 of the alternating-current voltage source VAC passes through the first transformer L1 and the first power switch MP1, the first current flows back to the second end VAC2 of the alternating-current voltage source VAC through two paths of the third power switch MP3, the second power switch MP2 and the second transformer L2 respectively, and the two current paths formed by the second power switch MP2 and the third power switch MP3 reduce the resistance on the charging current path, so that the efficiency of the power factor correction circuit is improved.

In the second operating state, as shown in fig. 1A, the first power switch MP1 is in an off state, at least one of the second power switch MP2 and the third power switch MP3 is in an on state, and preferably, both the second power switch MP2 and the third power switch MP3 are in an on state; the fourth power switch MP4 is in an off state, the first transformer L1 discharges energy to the output capacitor CO through the second path P (2) to generate an output voltage VO on the output capacitor CO, and the first current Ich1 drops; after the first current Ich1 is converted by the first transformer L1, the first current Ich1 is coupled from the primary winding of the first transformer L1 to the secondary winding of the first transformer L1, the first current Ich1 of the secondary winding and the first current Ich1 of the primary winding have a turns ratio relationship (ich1_secondary= Nps1 ×ich1_primary of the first transformer, where Nps1 is the turns ratio of the primary winding and the secondary winding of the first transformer), and the second path P (2) of the first current Ich1 passes through the first transformer L1, the first rectifying module D1, and the output capacitor CO.

In the second half period of the ac voltage source VAC, in the third operating state, as shown in fig. 1B, the first power switch MP1 is in an on state, the second power switch MP2 is in an on state, the third power switch MP3 is in an off state, and the fourth power switch MP4 is in an on state; the third path P (3) receives the voltage of the second half period of the ac voltage source VAC to store energy in the second transformer L2, the second current Ich2 flowing through the second transformer L2 rises, the second current Ich2 of the third path P (3) flows through the ac voltage source VAC, the second transformer L2, the second power switch MP2, the fourth power switch MP4, the first power switch MP1 and the first transformer L1; after the second current Ich2 flowing from the second end VAC2 of the alternating voltage source VAC passes through the second transformer L2 and the second power switch MP2, the second current flows back to the first end VAC1 of the alternating voltage source VAC through two paths of the fourth power switch MP4, the first power switch MP1 and the first transformer L1 respectively, and the two current paths formed by the first power switch MP1 and the fourth power switch MP4 reduce the resistance on the charging current path, thereby improving the efficiency of the power factor correction circuit.

In the fourth operating state, as shown in fig. 1B, the first power switch MP1 is in an off state, at least one of the second power switch MP2 and the third power switch MP3 is in an on state, and preferably, both the second power switch MP2 and the third power switch MP3 are in an on state; the fourth power switch MP4 is in an off state, the second transformer L2 discharges energy to the output capacitor CO through the fourth path P (4) to generate an output voltage VO on the output capacitor CO, and the second current Ich2 drops; after the second current ICh2 is transformed by the second transformer L2, the second current ICh2 is coupled from the primary winding of the second transformer L2 to the secondary winding of the second transformer L2, the second current ICh2 of the secondary winding and the primary winding

= Nps2×ibh2_primary, wherein Nps2 is the turns ratio of the primary winding and the secondary winding of the second transformer, preferably Nps 2= Nps 1), the fourth path P (4) of the second current Ich2 passes through the second transformer L2, the second rectifying module D2, and the output capacitor CO.

In the power factor correction circuit of fig. 1A, in the first operation state and the second operation state, the first current Ich1 flows through the first path P (1) and the second path P (2), respectively, and the components other than the ac voltage source VAC constitute the first flyback converter 210.

In the pfc circuit of fig. 1B, in the third operating state and the fourth operating state, the second current Ich2 flows through the third path P (3) and the fourth path P (4), respectively, and components other than the ac voltage source VAC constitute the second flyback converter 220.

According to the operating principle of the flyback converter, the input current peak value Iinpk of the ac voltage source VAC can be calculated by the formula: iinpk=vin/l×ton, where Iinpk represents an input current peak value, vin represents a sinusoidal half-wave dc input voltage, L represents inductance values of primary windings of the transformers L1 and L2, where primary inductance values L of the transformers L1 and L2 are constants, and when the control module controls the on time ton to be constant, the input current peak value Iinpk is in a proportional relationship with the sinusoidal half-wave dc input voltage Vin, so that the input current peak value Iinpk follows the sinusoidal half-wave dc input voltage Vin, thereby obtaining a higher power factor.

In the power factor correction circuit shown in fig. 3, the power factor correction circuit further includes a control module; the first flyback converter 210 further includes a first detection resistor RCS1 connected in series between the second terminal of the first power switch MP1 and ground, for detecting the first current Ich1 and generating a first detection signal VCS1; the second flyback converter 220 further includes a second detection resistor RCS2 connected in series between the second terminal of the second power switch MP2 and ground, for detecting the second current Ich2 and generating a second detection signal VCS2; the control module is coupled to the first detection signal VCS1 and the second detection signal VCS2, and is configured to generate a first control signal GP1 according to the received detection signal to drive the first power switch MP1 to be turned on or off, and generate a second control signal GP2 to drive the second power switch MP2 to be turned on or off.

In one embodiment, as shown in fig. 1A-1B, the power factor correction circuit further includes a first rectifying module D1 and a second rectifying module D2; when the first rectifying module D1 and the second rectifying module D2 are diodes, the first flyback converter 210 and the second flyback converter 220 in the pfc circuit are diode rectifying structures.

In one embodiment, as shown in fig. 1A-1B, the power factor correction circuit further includes a first rectifying module D1 and a second rectifying module D2; when the first rectifying module D1 and the second rectifying module D2 are Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), the first flyback converter 210 and the second flyback converter 220 in the pfc circuit are synchronous rectifying structures of the MOSFETs.

In one embodiment, as shown in fig. 1A-1B, the power factor correction circuit further includes a control chip, the control chip is integrated with a control module, and the control chip outputs a first control signal GP1 to control the first power switch MP1; outputting a second control signal GP2 to control a second power switch MP2; outputting a third control signal GP3 to control a third power switch MP3; outputting a fourth control signal GP4 to control a fourth power switch MP4; by controlling the on and off of the first power switch MP1, the second power switch MP2, the third power switch MP3 and the fourth power switch MP4, a stable voltage VO is generated on the output capacitor CO, and simultaneously, the same phase change of the voltage and the current of the ac voltage source VAC is realized, thereby realizing the power factor correction.

In one embodiment, as shown in fig. 3, the pfc circuit further includes a feedback module, an input terminal is coupled to the output voltage VO on the output capacitor CO, the sampled output voltage VO is fed back, the feedback signal FB is output to the control module, the control module integrates the error between the feedback signal FB and the reference voltage, and then controls the first power switch MP1 and the second power switch MP2 to be turned on or off, so as to control the output voltage VO, where the feedback module includes an isolated feedback mode of resistor voltage division, or optocoupler isolation, transformer isolation, or capacitor isolation, and the feedback control will not be described in detail in the specification because the feedback control is in the prior art.

In one embodiment, part or all of the third power switch MP3 and the fourth power switch MP4 in the pfc circuit are diodes, and do not affect the current flowing in the first path P (1), and the third path P (3).

In a third aspect, the present utility model also provides a power supply device, including the power factor corrector of any one of the first aspects, or the power factor correction circuit of any one of the second aspects.

From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

according to the power factor corrector, the power factor correction circuit and the power supply equipment, the diode rectifier bridge coupled with the alternating voltage source is removed, so that the loss of the power factor corrector or the power factor correction circuit can be obviously reduced, and the efficiency and the performance are improved.

It should be noted that, in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described as different from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other. It should also be noted that, in this document, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Moreover, relational terms such as "first" and "second" may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions, or order, and without necessarily being construed as indicating or implying any relative importance. "and/or" means either or both of which may be selected. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or terminal device comprising the element.

The foregoing has outlined rather broadly the more detailed description of the utility model in order that the detailed description of the utility model that follows may be better understood, and in order that the present contribution to the art may be better appreciated. While various modifications of the embodiments and applications of the utility model will occur to those skilled in the art, it is not necessary and not intended to be exhaustive of all embodiments, and obvious modifications or variations of the utility model are within the scope of the utility model.

Claims (11)

1. A power factor corrector coupled to an ac voltage source and an output capacitor, the power factor corrector comprising:

the input end of the first flyback converter receives the first end of the alternating voltage source as an input voltage anode, the second end of the alternating voltage source as an input voltage cathode, and the output end of the first flyback converter is coupled with the output capacitor;

the input end of the second flyback converter receives the second end of the alternating voltage source as an input voltage anode, the first end of the alternating voltage source as an input voltage cathode, and the output end of the second flyback converter is coupled with the output capacitor;

the first flyback converter at least comprises a first transformer, a first rectifying module, a first power switch, a second power switch and a third power switch;

the second flyback converter at least comprises a second transformer, a second rectifying module, a first power switch, a second power switch and a fourth power switch.

2. The power factor corrector of claim 1, further comprising a control module;

the 1 st end of the first transformer is coupled with the first end of the alternating current voltage source, the 2 nd end of the first transformer is coupled with the first end of the first power switch, the 3 rd end of the first transformer is coupled with the first end of the first rectifying module, the second end of the first rectifying module is coupled with the positive plate of the output capacitor, and the third power switch is coupled between the second end of the alternating current voltage source and the second end of the first power switch;

the 1 st end of the second transformer is coupled with the second end of the alternating current voltage source, the 2 nd end of the second transformer is coupled with the first end of the second power switch, the 3 rd end of the second transformer is coupled with the first end of the second rectifying module, the second end of the second rectifying module is coupled with the positive plate of the output capacitor, the fourth power switch is coupled between the first end of the alternating current voltage source and the second end of the second power switch, the negative plate of the output capacitor is coupled with the 4 th end of the first transformer and the 4 th end of the second transformer, and the output voltage is generated on the output capacitor;

the control module is coupled with the control end of the first power switch, the control end of the second power switch, the control end of the third power switch and the control end of the fourth power switch;

the power factor corrector controls the on and off of the first power switch, the second power switch, the third power switch and the fourth power switch through the control module, so that the same-phase change of the voltage and the current of the alternating-current voltage source is realized, and further, the power factor correction is realized.

3. The power factor corrector of claim 2, further comprising a first sense resistor and a second sense resistor;

the first detection resistor is coupled between the second end of the first power switch and the ground and is used for detecting the current flowing through the first power switch and generating a first detection signal; the second detection resistor is coupled between the second end of the second power switch and the ground and is used for detecting the current flowing through the second power switch and generating a second detection signal; the control module is coupled with the first detection signal and the second detection signal and controls the on or off of the first power switch and the second power switch according to the detection signals;

the first rectifying module and the second rectifying module are diodes, or the first rectifying module and the second rectifying module are metal oxide semiconductor field effect transistors.

4. The pfc of claim 1 wherein the third and fourth power switches are partially or fully diodes.

5. A power factor correction circuit coupled to an ac voltage source and an output capacitor, comprising:

the input end of the first flyback converter receives the first end of the alternating-current voltage source as an input voltage anode, the second end of the alternating-current voltage source as an input voltage cathode, and the output end of the first flyback converter is coupled with the output capacitor and comprises a first transformer;

the input end of the second flyback converter receives the second end of the alternating-current voltage source as an input voltage anode, the first end of the alternating-current voltage source as an input voltage cathode, and the output end of the second flyback converter is coupled with the output capacitor, and the second flyback converter comprises a second transformer;

in a first half period of an alternating current voltage source, in a first working state, a first path receives voltage of the first half period of the alternating current voltage source to store energy of the first transformer, and first current flowing through the first transformer rises; in a second operating state, the first transformer discharges energy to the output capacitor through a second path to generate an output voltage on the output capacitor, and the first current drops; in the second half period of the alternating current voltage source, in a third working state, the third path receives the voltage of the second half period of the alternating current voltage source to store energy for the second transformer, and the second current flowing through the second transformer rises; in a fourth operating state, the second transformer discharges energy to the output capacitor through a fourth path to generate the output voltage on the output capacitor, and the second current drops.

6. The power factor correction circuit of claim 5, wherein the power factor correction circuit comprises a first power switch, a second power switch, a third power switch, and a fourth power switch;

when the first working state of the first half cycle of the alternating-current voltage source is in a conducting state, the second power switch is in a conducting state, the third power switch is in a conducting state, the fourth power switch is in a cut-off state, and a first current of the first working state flows through the alternating-current voltage source, the first transformer, the first power switch, the second power switch, the third power switch and the second transformer;

when the first power switch is in an off state in a second working state of a first half period of the alternating-current voltage source, at least one of the second power switch and the third power switch is in an on state, the fourth power switch is in an off state, and a first current in the second working state flows through the first transformer, the first rectifying module and the output capacitor;

in a third working state of a second half period of the alternating-current voltage source, the first power switch is in a conducting state, the second power switch is in a conducting state, the third power switch is in a cut-off state, the fourth power switch is in a conducting state, and a second current in the third working state flows through the alternating-current voltage source, the second transformer, the second power switch, the first power switch, the fourth power switch and the first transformer;

in a fourth operating state of the second half period of the alternating voltage source, at least one of the first power switch and the fourth power switch is in an on state, the third power switch is in an off state, the second power switch is in an off state, and a second current in the fourth operating state flows through the second transformer, the second rectifying module and the output capacitor.

7. The power factor correction circuit of claim 6, wherein,

in the first working state and the second working state, a first path and a second path through which a first current flows, and components except an alternating current voltage source form a first flyback converter;

in the third and fourth operating states, the third and fourth paths through which the second current flows, components other than the ac voltage source constitute the second flyback converter.

8. The power factor correction circuit of claim 7, wherein the power factor correction circuit comprises a control module;

the first flyback converter further comprises a first detection resistor connected in series between the second end of the first power switch and the ground, and is used for detecting a first current and generating a first detection signal;

the second flyback converter further comprises a second detection resistor connected in series between the second end of the second power switch and ground, and is used for detecting a second current and generating a second detection signal;

the control module is coupled with the first detection signal and the second detection signal and is used for generating a first control signal to drive the first power switch to be turned on or off according to the received detection signal and generating a second control signal to drive the second power switch to be turned on or off.

9. The power factor correction circuit of claim 8, further comprising a control chip, a first rectifying module, and a second rectifying module;

the first rectifying module and the second rectifying module are diodes or metal oxide semiconductor field effect transistors;

the control chip is integrated with the control module; the control chip is combined with the first transformer, the second transformer, the first rectifying module and the second rectifying module to realize the same-phase change of the input voltage and the input current of the alternating-current voltage source, and further realize the power factor correction.

10. The power factor correction circuit of claim 6, wherein the third and fourth power switches are partially or fully diodes.

11. A power supply apparatus comprising the power factor corrector or power factor correction circuit of any one of claims 1 to 10.