CN208638248U - A kind of power supply unit and its power factor correction circuit - Google Patents
A kind of power supply unit and its power factor correction circuit Download PDFInfo
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- CN208638248U CN208638248U CN201821329561.6U CN201821329561U CN208638248U CN 208638248 U CN208638248 U CN 208638248U CN 201821329561 U CN201821329561 U CN 201821329561U CN 208638248 U CN208638248 U CN 208638248U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The utility model discloses a kind of circuit of power factor correction, comprising: the PFC front stage circuits including exchange input, rectification circuit and filter capacitor；The PFC main circuit being connect with PFC front stage circuits；The main control circuit that output end is connect with PFC main circuit；The feed circuit of the input terminal of output end and main control circuit connection；Output end is connect with feed circuit, for exporting thermal compensation signal in each pre-set interval, to improve the compensation circuit of the input current of PFC main circuit by feed circuit；Wherein, each pre-set interval is to exchange the input voltage zero passage period of input, each pre-set interval cyclically-varying, and the period is identical as the period of input voltage.It using scheme provided by the utility model, avoids near the alternating voltage zero-crossing of input, the current anomaly as caused by filter capacitor, so that the power factor of Switching Power Supply and harmonic wave total amount are met the requirements.The utility model additionally provides a kind of power supply unit, has corresponding effect.
Description
Technical field
The utility model relates to electronic circuit control technical fields, more particularly to a kind of power supply unit and its power factor (PF)
Correcting circuit.
Background technique
In power supply system, power factor and harmonic wave total amount are key factors in need of consideration, high power factor and
Low harmonic wave total amount, which is inhibited, endangers system itself and ambient enviroment bring due to current waveform distortion, has ensured confession significantly
The use environment of electric equipment and electrical equipment, power factor and harmonic wave total amount requirement of various countries' power grid to each electrical equipment
It is higher and higher.
Usually all comprising PFC (Power Factor Correction, PFC) electricity in existing Switching Power Supply
Road, common active PFC circuit generally include PFC main circuit and relevant control circuit, and the input current of itself can be made to have
Effect follows the variation of input voltage, so that the power factor of Switching Power Supply and harmonic wave total amount are met the requirements.But it is switching
It also include filter capacitor in the prime of pfc circuit in power supply, when the alternating voltage of power grid input was in the period of zero passage
When, the presence meeting of filter capacitor is so that the rear step voltage of rectifier bridge is higher than the input voltage of rectifier bridge, so that rectifier bridge is not at this time
Electric current is flowed through, the variation of input voltage can not be followed so as to cause the input current of rectifier bridge, and then also has led to switch electricity
The power factor and harmonic wave total amount in source are unable to satisfy requirement.
In conclusion filter capacitor caused current anomaly near network voltage zero passage how is avoided, so that opening
The power factor and harmonic wave total amount in powered-down source are met the requirements, and are current those skilled in the art technical problems urgently to be solved.
Utility model content
The purpose of the utility model is to provide a kind of power supply unit and its power factor correction circuits, to avoid the friendship of input
It flows near voltage zero-cross, the current anomaly as caused by filter capacitor, so that the power factor of Switching Power Supply and harmonic wave are total
Amount is met the requirements.
In order to solve the above technical problems, the utility model provides the following technical solutions:
A kind of circuit of power factor correction, comprising:
PFC front stage circuits including exchange input, rectification circuit and filter capacitor；
The PFC main circuit being connect with the PFC front stage circuits；
Output end is connect with the PFC main circuit, exports corresponding driving signal for feedback signal based on the received, with
Control the main control circuit of the switching tube on-off of the PFC main circuit；
Output end is connect with the input terminal of the main control circuit, for obtaining the output voltage of the PFC main circuit simultaneously
Export the feed circuit of the feedback signal；
Output end is connect with the feed circuit, for exporting thermal compensation signal in each pre-set interval, by described
Feed circuit improves the compensation circuit of the input current of the PFC main circuit in each pre-set interval；
Wherein, each pre-set interval is the input voltage zero passage period of the exchange input, each preset areas
Between cyclically-varying, and the period is identical as the period of the input voltage.
Preferably, the compensation circuit includes:
The first capacitor that first end is connect with the first output end of the rectification circuit；
First end is connect with the second end of the first capacitor, and common end is connect with the input terminal of reverse phase conversion circuit,
The first resistor of second end ground connection；
Output end of the output end as the compensation circuit, for by received voltage signal reverse phase, and by reverse phase
After signal afterwards subtracts preset value, the reverse phase of the signal as the output of the pre-set interval accordingly greater than zero is obtained
Conversion circuit.
Preferably, the compensation circuit includes:
The timing trigger circuit of the input terminal of output end and waveform generator connection；
Output end of the output end as the compensation circuit, for the output according to the timing trigger circuit, each
The waveform generator of the output thermal compensation signal in the pre-set interval.
Preferably, the feed circuit includes:
Positive input is for obtaining preset first voltage threshold value, and reverse input end is for obtaining the PFC main circuit
Output voltage transconductance type amplifier；
First end connect with the output end of the transconductance type amplifier, output end of the common end as the feed circuit
Second capacitor；
First end is connect with the second end of second capacitor, and common end is connect with the output end of the compensation circuit,
The second resistance of second end ground connection.
Preferably, the feed circuit includes:
Positive input is for obtaining preset second voltage threshold value, and reverse input end is for obtaining the PFC main circuit
Output voltage voltage amplification type amplifier；
First end is connect with the reverse input end of the voltage amplification type amplifier, and the first end of second end and third capacitor connects
The 3rd resistor connect；
Second end is connect with the first end of the 4th resistance, and common end is connect with the output end of the voltage amplification type amplifier
The third capacitor；
Second end is connect with the first end of the 5th resistance, common end as the feed circuit output end described
Four resistance；
The 5th resistance that second end is connect with the output end of the compensation circuit.
Preferably, the main control circuit includes:
First input end is connect with the first output end of the rectification circuit, and the of the second input terminal and the rectification circuit
The voltage sampling circuit of two output ends connection；
First input end is connect with the output end of the voltage sampling circuit, and the second input terminal is defeated with the feed circuit
The multiplier of outlet connection；
First input end is connect with the PFC main circuit, and the second input terminal is connect with the output end of the multiplier, is used for
The electric current of concatenated resistance and the voltage of multiplier output carry out on the main switch in the PFC main circuit that will acquire
Compare, to export the comparison circuit of different signals；
It is connect with the output end of the comparison circuit, for exporting corresponding institute according to the output signal of the comparison circuit
Driving signal is stated, to control the first drive control circuit of the switching tube on-off of the PFC main circuit.
Preferably, the main control circuit includes:
For exporting the saw-toothed wave generator of sawtooth wave；
First input end is connect with the output end of the feed circuit, and the second input terminal is defeated with the saw-toothed wave generator
Outlet connection, for the sawtooth wave to be compared with the feedback signal, to export the conversion circuit of different signals；
It is connect with the output end of the conversion circuit, for exporting corresponding institute according to the output signal of the conversion circuit
Driving signal is stated, to control the second drive control circuit of the switching tube on-off of the PFC main circuit.
Preferably, the compensation circuit are as follows: in each pre-set interval, the thermal compensation signal of output is amplitude
The electric signal being not zero, and be the compensation circuit for the electric signal that amplitude is zero except each pre-set interval.
Preferably, the PFC main circuit is DC-DC conversion circuit.
A kind of power supply unit, including circuit of power factor correction described in any of the above embodiments.
Using technical solution provided by the utility model, comprising: the PFC of exchange input, rectification circuit and filter capacitor
Front stage circuits；The PFC main circuit being connect with PFC front stage circuits；Output end is connect with PFC main circuit, for anti-based on the received
Feedback signal exports corresponding driving signal, to control the main control circuit of the switching tube on-off of PFC main circuit；Output end and master control
The input terminal of circuit processed connects, for obtaining the output voltage of PFC main circuit and exporting the feed circuit of feedback signal；Output end
It is connect with feed circuit, for exporting thermal compensation signal in each pre-set interval, to improve each preset areas by feed circuit
The compensation circuit of the input current of interior PFC main circuit；Wherein, when each pre-set interval is the input voltage zero passage of exchange input
Section, each pre-set interval cyclically-varying, and the period is identical as the period of input voltage.
The scheme of the application uses the design of compensation circuit.Each pre-set interval is the input voltage zero passage of exchange input
Period, each pre-set interval cyclically-varying, and the period is identical as the period of input voltage, i.e., what pre-set interval indicated is defeated
Enter to the alternating current of rectification circuit and is in the period of zero passage.Compensation circuit exports thermal compensation signal to feedback in pre-set interval
Circuit, feed circuit have responded thermal compensation signal, i.e., due to the presence of thermal compensation signal, the input signal of main control circuit is changed,
And then controlled by on-off of the corresponding driving signal to the switching tube in PFC main circuit, it improves in pre-set interval
The input current of PFC main circuit.That is, the scheme of the application is conducive to be in the alternating current for being input to rectification circuit
In zero period, the input current of rectification circuit can follow the variation of input voltage.Therefore, the scheme of the application avoids
Near the alternating voltage zero-crossing of input, the current anomaly as caused by filter capacitor, so that the power factor of Switching Power Supply
And harmonic wave total amount is met the requirements.
Detailed description of the invention
In order to illustrate the embodiment of the utility model or the technical proposal in the existing technology more clearly, below will be to embodiment
Or attached drawing needed to be used in the description of the prior art is briefly described, it should be apparent that, the accompanying drawings in the following description is only
It is some embodiments of the utility model, for those of ordinary skill in the art, in the premise not made the creative labor
Under, it is also possible to obtain other drawings based on these drawings.
Fig. 1 is the first structure diagram of circuit of power factor correction in the utility model；
Fig. 2 is the schematic diagram that rectifier bridge input current in the prior art can not follow input voltage；
Fig. 3 is a kind of waveform diagram of the thermal compensation signal in specific embodiment of the present invention；
Fig. 4 is the second structural schematic diagram of circuit of power factor correction in the utility model；
Fig. 5 a is the voltage waveform view of Waveform generating circuit output in specific embodiment of the present invention；
Fig. 5 b is another waveform diagram of thermal compensation signal in specific embodiment of the present invention；
Fig. 6 is the third structural schematic diagram of circuit of power factor correction in the utility model；
Fig. 7 is in the utility model using the structural schematic diagram of the circuit of power factor correction of transconductance type amplifier；
Fig. 8 is in the utility model using the structural schematic diagram of the circuit of power factor correction of voltage amplification type amplifier；
Fig. 9 is that main control circuit is shown using the structure of the circuit of power factor correction of voltage sample mode in the utility model
It is intended to；
Figure 10 is circuit of power factor correction of the main control circuit by the way of saw-toothed wave generator in the utility model
Structural schematic diagram.
Specific embodiment
The core of the utility model is to provide a kind of circuit of power factor correction, and the alternating voltage zero-crossing for avoiding input is attached
Closely, the current anomaly as caused by filter capacitor, so that the power factor of Switching Power Supply and harmonic wave total amount are met the requirements.
In order to make those skilled in the art better understand the scheme of the utility model, with reference to the accompanying drawing and specific implementation
The utility model is described in further detail for mode.Obviously, described embodiment is only the utility model a part
Embodiment, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art are not doing
Every other embodiment obtained under the premise of creative work out, fall within the protection scope of the utility model.
Referring to FIG. 1, Fig. 1 be the utility model in a kind of structural schematic diagram of circuit of power factor correction, the power because
Counting correcting circuit includes:
PFC front stage circuits 10 including exchange input 11, rectification circuit 12 and filter capacitor 13.
The typically network voltage of exchange input 11.Rectification circuit 12 is connect with exchange input 11, and rectification circuit 12 has
The structure of body can also be configured according to actual needs, such as common bridge-type all controlled rectifier circuit, single-phase half-wave are controllably whole
Current circuit etc..
Rectification circuit 12 is connected with filter capacitor 13, specifically, in the embodiment of figure 1, the first of filter capacitor 13
End is connect with the first output end of rectification circuit 12, and common end is connect with the first input end of PFC main circuit 20, filter capacitor
13 second end is connect with the second output terminal of rectification circuit 12, and common end is connect with the second input terminal of PFC main circuit 20.
When not using the scheme of the application, when the alternating voltage of 11 input of exchange input was in the period of zero passage, i.e. at Vin
When near zero passage, the presence meeting of filter capacitor 13 is so that the rear step voltage Vdc of rectification circuit 12 is higher than the defeated of rectification circuit 12
Enter voltage Vin, cause the input current of rectification circuit 12 that can not follow the variation of input voltage, so that the function of Switching Power Supply
Rate factor and harmonic wave total amount are unable to satisfy requirement.It can be found in Fig. 2, in the period of t1 to t2, lin can not follow the variation of Vin,
Especially in this section td wherein, lin electric current is 0, more influences the power factor and harmonic wave total amount of Switching Power Supply.
The PFC main circuit 20 being connect with PFC front stage circuits 10.
PFC main circuit 20 is used to adjust the voltage and current of output by the switching of switching tube on-off, in the specific implementation,
PFC main circuit 20 can be arbitrary DC-DC conversion circuit, such as common Boost circuit, Buck circuit, Flyback circuit
Deng.
Output end is connect with PFC main circuit 20, corresponding driving signal is exported for feedback signal based on the received, with control
The main control circuit 30 of the switching tube on-off of PFC main circuit 20 processed.
The feedback signal that main control circuit 30 receives is different, can export different driving signals, driving signal is usual
It can be voltage signal, for determining the switching tube on-off of PFC main circuit 20.The specific structure of main control circuit 30, Ke Yigen
It is set and is adjusted according to actual conditions, have no effect on the implementation of the utility model.
Output end is connect with the input terminal of main control circuit 30, for obtaining output voltage and the output of PFC main circuit 20
The feed circuit 40 of feedback signal.
Feed circuit 40 is used to receive the output signal of PFC main circuit 20, it is compared with a preset reference signal,
Corresponding feedback signal is obtained, and is exported feedback signal as reference signal to main control circuit 30.
Output end is connect with feed circuit, for exporting thermal compensation signal in each pre-set interval, to pass through feed circuit
Improve the compensation circuit of the input current of PFC main circuit in each pre-set interval；
Wherein, each pre-set interval is to exchange the input voltage zero passage period of input, each pre-set interval cyclically-varying,
And the period is identical as the period of input voltage.
Each pre-set interval is the input voltage zero passage period of exchange input, that is to say, that pre-set interval indicated is to hand over
Near the output voltage zero passage of stream input 11, namely in the prior art due to the input current of rectifier bridge caused by filter capacitor
When input voltage can not be followed.In Fig. 3, t1 to t2 is a pre-set interval, and the specific range of pre-set interval is arranged,
That is the value of t1 and t2 usually can be set and be adjusted according to experimental data or theory analysis.For example, specific implementation
When the input current and input voltage of rectification circuit 12 are sampled, to determine the range of pre-set interval.For another example, it is contemplated that
The output power Po of the amplitude of input voltage vin, the capacitance of filter capacitor 13 and PFC main circuit 20 is to influence t1 and t2
Value three principal elements, therefore, can according to these three factors carry out pre-set interval range set.
In each pre-set interval, compensation circuit 50 can export thermal compensation signal, and thermal compensation signal can be voltage signal,
It can be current signal, be voltage signal shown in Fig. 3.The waveform of thermal compensation signal can be arbitrary the wave being not zero
It is successively shown from top to bottom in shape, such as Fig. 3: the waveform that amplitude gradually rises；The constant impulse waveform of amplitude；Amplitude first by
The waveform that the height that edges up keeps amplitude constant later；Amplitude first increases the waveform reduced afterwards.
Since compensation circuit 50 is connect with feed circuit 40, and thermal compensation signal is exported in each pre-set interval, inputted
Amplitude to the feedback signal of main control circuit 30 can respond thermal compensation signal, and then export corresponding driving signal to control
The switching tube on-off of PFC main circuit 20.Specifically, can be when thermal compensation signal improves, it is input to the anti-of main control circuit 30
Feedback signal is got higher, and the input current of PFC main circuit 20 is got higher, or when thermal compensation signal reduces, feedback signal is lower, PFC
The input current of main circuit 20 is lower.In the application, the input electricity of PFC main circuit 20 is improved due to being provided through feedback signal
The compensation circuit 50 of stream can change the switching tube on-off of PFC main circuit 20, so that PFC main circuit 20 in each pre-set interval
Input current changing.At the same time, when the input current of PFC main circuit 20 gets higher, it is more to be supplied to filter capacitor 13
Power is consumed, makes 13 repid discharge of filter capacitor, so that the input current of rectification circuit 12 improves, input voltage can be followed
Variation.In the fig. 3 embodiment, namely make t1 to t2 this period, Iin is improved, can be within this period of Vin zero passage
Follow the variation of Vin.
Using technical solution provided by the utility model, comprising: the PFC of exchange input, rectification circuit and filter capacitor
Front stage circuits；The PFC main circuit being connect with PFC front stage circuits；Output end is connect with PFC main circuit, for anti-based on the received
Feedback signal exports corresponding driving signal, to control the main control circuit of the switching tube on-off of PFC main circuit；Output end and master control
The input terminal of circuit processed connects, for obtaining the output voltage of PFC main circuit and exporting the feed circuit of feedback signal；Output end
It is connect with feed circuit, for exporting thermal compensation signal in each pre-set interval, to improve each preset areas by feed circuit
The compensation circuit of the input current of interior PFC main circuit；Wherein, when each pre-set interval is the input voltage zero passage of exchange input
Section, each pre-set interval cyclically-varying, and the period is identical as the period of input voltage.
The scheme of the application uses the design of compensation circuit.Each pre-set interval is the input voltage zero passage of exchange input
Period, each pre-set interval cyclically-varying, and the period is identical as the period of input voltage, i.e., what pre-set interval indicated is defeated
Enter to the alternating current of rectification circuit and is in the period of zero passage.Compensation circuit exports thermal compensation signal to feedback in pre-set interval
Circuit, feed circuit have responded thermal compensation signal, i.e., due to the presence of thermal compensation signal, the input signal of main control circuit is changed,
And then controlled by on-off of the corresponding driving signal to the switching tube in PFC main circuit, it improves in pre-set interval
The input current of PFC main circuit.That is, the scheme of the application is conducive to be in the alternating current for being input to rectification circuit
In zero period, the input current of rectification circuit can follow the variation of input voltage.Therefore, the scheme of the application avoids
Near the alternating voltage zero-crossing of input, the current anomaly as caused by filter capacitor, so that the power factor of Switching Power Supply
And harmonic wave total amount is met the requirements.
In a kind of specific embodiment of the utility model, referring to fig. 4, compensation circuit 50 includes:
The first capacitor C1 that first end is connect with the first output end of rectification circuit 12；
First end is connect with the second end of first capacitor C1, and common end is connect with the input terminal of reverse phase conversion circuit 51,
The first resistor R1 of second end ground connection；
Output end of the output end as compensation circuit 50 is used for received voltage signal reverse phase, and after by reverse phase
Signal subtract preset value after, obtain greater than zero signal as corresponding pre-set interval output reverse phase conversion circuit
51, this preset value can be zero, not handle the signal after reverse phase.
The first end of first capacitor C1 is connect with the first end of rectification circuit 12, is adopted to the electric current of rectification circuit 12
Sample obtains the positively related current waveform of electric signal with first capacitor C1.The current waveform of first capacitor C1 passes through first
Resistance R1 can be converted to corresponding voltage waveform, be expressed as Va in fig 5 a.The voltage waveform is input to reverse phase conversion circuit
51 input terminal, the output end of reverse phase conversion circuit 51 can be used as the output end of compensation circuit 50.Reverse phase conversion circuit 51 has
Body can be made of an inverter cricuit and a conversion circuit, and inverter cricuit is used for the phase of received voltage signal Va
180 ° of reversion, the signal after reverse phase can be subtracted preset value by conversion circuit, obtain the signal greater than zero again later as phase
The output for the pre-set interval answered, reference can be made to Fig. 5 b, the signal Vx that reverse phase conversion circuit 51 exports is the compensation circuit 50 pre-
If the thermal compensation signal exported in section.
The capacitance of first capacitor C1, the preset value being arranged in the resistance value and reverse phase conversion circuit of first resistor R1,
To be set and be adjusted according to the actual situation, such as it is adjusted according to the mode of experimental data and theory analysis, so that
It obtains 12 input current of rectification circuit and follows input voltage.And it is pointed out that in this kind of embodiment, by taking the first electricity
Hold C1 electric current, and then generate corresponding thermal compensation signal, the thermal compensation signal generated can be made more accurate.In this kind of embodiment
In, in each pre-set interval, the thermal compensation signal that compensation circuit 50 exports is the signal that amplitude is not zero, specifically, for example
It can be amplitude and first increase the signal reduced afterwards.And except pre-set interval, it is normal that compensation circuit 50 should not influence PFC main circuit 20
Switching tube on-off, therefore except each pre-set interval, compensation circuit 50 usually should not export thermal compensation signal, export in other words
Thermal compensation signal amplitude be 0.
In a kind of specific embodiment of the utility model, referring to Fig. 6, compensation circuit 50 includes:
The timing trigger circuit 52 that output end is connect with the input terminal of waveform generator 53；
Output end of the output end as compensation circuit 50, for the output according to timing trigger circuit 52, each default
The waveform generator 53 of thermal compensation signal is exported in section.
In view of pre-set interval can be obtained by experimental data, a number of factors for influencing pre-set interval can also be carried out
Theoretical calculation and obtain, therefore in this kind of embodiment, refering to Fig. 6, made using timing trigger circuit 52 and waveform generator 53
For compensation circuit 50.Specifically, timing trigger circuit 52 can be made of timing circuit and corresponding trigger circuit.It can lead to
It crosses timing trigger circuit 52 to set pre-set interval, that is to say, that generate thermal compensation signal by timing trigger circuit 52
Period set, so that waveform generator 53 compensates in the corresponding period output of signal.In general, by fixed
When trigger circuit 52 setting, the compensation circuit 50 output thermal compensation signal period and rectification circuit 12 input voltage vin
Identical, in pre-set interval, the thermal compensation signal that waveform generator 53 exports can be arbitrary waveform, such as shown in Fig. 3
Waveform, certainly, the thermal compensation signal are required to change the input current of PFC main circuit 20.Using timing trigger circuit 52 and
The design of waveform generator 53, since device count is few, so that the reliability of compensation circuit 50 is higher.
In a kind of specific embodiment of the utility model, refering to Fig. 7, feed circuit 40 includes:
Positive input is for obtaining preset first voltage threshold value, and reverse input end is for obtaining PFC main circuit 20
The transconductance type amplifier of output voltage；
First end is connect with the output end of transconductance type amplifier, second electricity of the common end as the output end of feed circuit 40
Hold C2；
First end is connect with the second end of the second capacitor C2, and common end is connect with the output end of compensation circuit 50, and second
Hold the second resistance R2 of ground connection.
The input signal of transconductance type amplifier is voltage signal, and output signal is current signal, specifically, Fig. 7 is seen, it can
First voltage threshold value is arranged in the positive input of transconductance type amplifier, it is used for and the received PFC main circuit 20 of reverse input end
Output voltage Vo be compared, the specific value of first voltage threshold value can be set and be adjusted according to the actual situation.It adopts
With in the feed circuit 40 of transconductance type amplifier, the first end of the second capacitor C2 in compensation network and the output end of transconductance type amplifier
Connection, output end of the common end as feed circuit 40, the second end of the second capacitor C2 and the first end of second resistance R2 connect
It connects, common end is connect with the output end of compensation circuit 50, the second end ground connection of second resistance R2.
It should be pointed out that in this embodiment, the thermal compensation signal that compensation circuit 50 exports is voltage signal, at it
In his embodiment, compensation circuit 50 can be with output current signal, then the tie point of compensation circuit 50 and feed circuit 40 should
Adaptably adjust.Such as in embodiment of this kind using transconductance type amplifier, when the thermal compensation signal that compensation circuit 50 exports
When for current signal, the output end of compensation circuit 50 can be connect with the output end of transconductance type amplifier, i.e., it directly will compensation letter
It number is superimposed with the output signal of feed circuit 40.The high frequency performance of transconductance type amplifier is good, and the conversion rate under big signal is also higher,
Circuit structure is simple simultaneously, and supply voltage and power consumption are all lower.
In a kind of specific embodiment of the utility model, refering to Fig. 8, feed circuit 40 includes:
Positive input is for obtaining preset second voltage threshold value, and reverse input end is for obtaining PFC main circuit 20
The voltage amplification type amplifier of output voltage；
First end is connect with the reverse input end of voltage amplification type amplifier, and second end is connect with the first end of third capacitor C3
3rd resistor R3；
Second end is connect with the first end of the 4th resistance R4, and common end is connect with the output end of voltage amplification type amplifier
Third capacitor C3；
Second end is connect with the first end of the 5th resistance R5, fourth electricity of the common end as the output end of feed circuit 40
Hinder R4；
The 5th resistance R5 that second end is connect with the output end of compensation circuit 50.
The input signal of voltage amplification type amplifier is voltage signal, and output signal is also voltage signal, specifically, seeing
Second voltage threshold value can be arranged in the positive input of voltage amplification type amplifier, for received with reverse input end in Fig. 8
The output voltage Vo of PFC main circuit 20 is compared, and the specific value of second voltage threshold value can be set according to the actual situation
Fixed and adjustment.In feed circuit 40 using voltage amplification type amplifier, the first end of the third capacitor C3 in compensation network and the
The second end of three resistance R3 connects, and the second end of third capacitor C3 is connect with the output end of voltage amplification type amplifier, 3rd resistor
The first end of R3 is connect with the reverse input end of voltage amplification type amplifier.The resistance value of 3rd resistor R3, the capacitor of third capacitor C3
Value, the resistance value of the 4th resistance R4 and the resistance value of the 5th resistance R5 can be set and be adjusted according to actual needs.Voltage
Scale-up version amplifier is more common amplifier, convenient to carry out.
In a kind of specific embodiment of the utility model, refering to Fig. 9, main control circuit 30 includes:
First input end is connect with the first output end of rectification circuit 12, and the second of the second input terminal and rectification circuit 12 is defeated
The voltage sampling circuit 31 of outlet connection；
First input end is connect with the output end of voltage sampling circuit 31, the output end of the second input terminal and feed circuit 40
The multiplier 32 of connection；
First input end is connect with PFC main circuit 20, and the second input terminal is connect with the output end of multiplier 32, for that will obtain
The electric current of concatenated resistance is compared with the voltage that multiplier 32 exports on the main switch in PFC main circuit 20 taken, with
Export the comparison circuit 33 of different signals；
It is connect with the output end of comparison circuit 33, for exporting corresponding driving letter according to the output signal of comparison circuit 33
Number, to control the first drive control circuit 34 of the switching tube on-off of PFC main circuit 20.
Fig. 9 is seen, voltage sampling circuit 31 can obtain the output voltage of rectification circuit 12, and the voltage of sampling is defeated
Enter to the first input end of multiplier 32, the feedback signal that feed circuit 40 exports is input to the second input terminal of multiplier 32.
For multiplier 32 by received two signal multiplications, the result obtained is expressed as Vb.Comparison circuit 33 obtains the Vb and Is respectively,
That Is is indicated is the electric current of concatenated resistance Rs on main switch in PFC main circuit 20, different Vb and Is it can be concluded that
Different comparison results, i.e. comparison circuit 33 can export different electric signals, and the first drive control circuit 34 receives more electric
When the electric signal that road 33 exports, the switching tube on-off of corresponding driving signal control PFC main circuit 20 is exported.
In a kind of specific embodiment of the utility model, refering to fig. 10, main control circuit 30 includes:
For exporting the saw-toothed wave generator 35 of sawtooth wave；
First input end is connect with the output end of feed circuit 40, the output end of the second input terminal and saw-toothed wave generator 35
Connection, for sawtooth wave to be compared with feedback signal, to export the conversion circuit 36 of different signals；
It is connect with the output end of conversion circuit 36, for exporting corresponding driving letter according to the output signal of conversion circuit 36
Number, to control the second drive control circuit 37 of the switching tube on-off of PFC main circuit 20.
Conversion circuit 36 can receive the sawtooth voltage signal Vt of the output of saw-toothed wave generator 35, and receive feedback letter
Number Ve, Vt is compared with Ve, exports corresponding switch control signal Vc, and then 37 output phase of the second drive control circuit is answered
Driving signal, control PFC main circuit 20 switching tube on-off.It in this embodiment, can be with since device count is less
So that the reliability of main controller circuit is higher.
Corresponding to the embodiment of circuit of power factor correction above, the utility model embodiment additionally provides a kind of power supply
Equipment may include circuit of power factor correction described in any of the above-described embodiment on the power supply unit, not repeat to say herein
It is bright.
It should also be noted that, herein, relational terms such as first and second and the like are used merely to one
Entity or operation are distinguished with another entity or operation, without necessarily requiring or implying between these entities or operation
There are any actual relationship or orders.Moreover, the terms "include", "comprise" or its any other variant are intended to contain
Lid non-exclusive inclusion, so that the process, method, article or equipment including a series of elements is not only wanted including those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or equipment
Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
There is also other identical elements in process, method, article or equipment including element.
Each embodiment in this specification is described in a progressive manner, the highlights of each of the examples are with it is other
The difference of embodiment, same or similar part may refer to each other between each embodiment.For being used disclosed in embodiment
For electric equipment, since it is corresponding with circuit of power factor correction disclosed in embodiment, so be described relatively simple, it is related
Place referring to circuit of power factor correction part explanation.
Specific case used herein is expounded the principles of the present invention and embodiment, above embodiments
Explanation be merely used to help understand the technical solution of the utility model and its core concept.It should be pointed out that being led for this technology
For the those of ordinary skill in domain, without departing from the principle of this utility model, if can also be carried out to the utility model
Dry improvement and modification, modifications and modifications also fall within the protection scope of the claims of the utility model.
Claims (10)
1. a kind of circuit of power factor correction characterized by comprising
PFC front stage circuits including exchange input, rectification circuit and filter capacitor；
The PFC main circuit being connect with the PFC front stage circuits；
Output end is connect with the PFC main circuit, corresponding driving signal is exported for feedback signal based on the received, with control
The main control circuit of the switching tube on-off of the PFC main circuit；
Output end is connect with the input terminal of the main control circuit, for obtaining output voltage and the output of the PFC main circuit
The feed circuit of the feedback signal；
Output end is connect with the feed circuit, for exporting thermal compensation signal in each pre-set interval, to pass through the feedback
Circuit improves the compensation circuit of the input current of the PFC main circuit in each pre-set interval；
Wherein, each pre-set interval is the input voltage zero passage period of the exchange input, each pre-set interval week
The variation of phase property, and the period is identical as the period of the input voltage.
2. circuit of power factor correction according to claim 1, which is characterized in that the compensation circuit includes:
The first capacitor that first end is connect with the first output end of the rectification circuit；
First end is connect with the second end of the first capacitor, and common end is connect with the input terminal of reverse phase conversion circuit, and second
Hold the first resistor of ground connection；
Output end of the output end as the compensation circuit is used for received voltage signal reverse phase, and after by reverse phase
After signal subtracts preset value, obtains the signal greater than zero and converted as the reverse phase of the output of the corresponding pre-set interval
Circuit.
3. circuit of power factor correction according to claim 1, which is characterized in that the compensation circuit includes:
The timing trigger circuit of the input terminal of output end and waveform generator connection；
Output end of the output end as the compensation circuit, for the output according to the timing trigger circuit, each described
The waveform generator of the output thermal compensation signal in pre-set interval.
4. circuit of power factor correction according to claim 1, which is characterized in that the feed circuit includes:
Positive input is for obtaining preset first voltage threshold value, and reverse input end is for obtaining the defeated of the PFC main circuit
The transconductance type amplifier of voltage out；
First end is connect with the output end of the transconductance type amplifier, common end as the feed circuit output end second
Capacitor；
First end is connect with the second end of second capacitor, and common end is connect with the output end of the compensation circuit, and second
Hold the second resistance of ground connection.
5. circuit of power factor correction according to claim 1, which is characterized in that the feed circuit includes:
Positive input is for obtaining preset second voltage threshold value, and reverse input end is for obtaining the defeated of the PFC main circuit
The voltage amplification type amplifier of voltage out；
First end is connect with the reverse input end of the voltage amplification type amplifier, and second end is connect with the first end of third capacitor
3rd resistor；
Second end is connect with the first end of the 4th resistance, the institute that common end is connect with the output end of the voltage amplification type amplifier
State third capacitor；
Second end is connect with the first end of the 5th resistance, fourth electricity of the common end as the output end of the feed circuit
Resistance；
The 5th resistance that second end is connect with the output end of the compensation circuit.
6. circuit of power factor correction according to claim 1, which is characterized in that the main control circuit includes:
First input end is connect with the first output end of the rectification circuit, and the second of the second input terminal and the rectification circuit is defeated
The voltage sampling circuit of outlet connection；
First input end is connect with the output end of the voltage sampling circuit, the output end of the second input terminal and the feed circuit
The multiplier of connection；
First input end is connect with the PFC main circuit, and the second input terminal is connect with the output end of the multiplier, for that will obtain
The voltage that the electric current of concatenated resistance is exported with the multiplier on the main switch in the PFC main circuit taken is compared
Compared with to export the comparison circuit of different signals；
It is connect with the output end of the comparison circuit, for exporting the corresponding drive according to the output signal of the comparison circuit
Dynamic signal, to control the first drive control circuit of the switching tube on-off of the PFC main circuit.
7. circuit of power factor correction according to claim 1, which is characterized in that the main control circuit includes:
For exporting the saw-toothed wave generator of sawtooth wave；
First input end is connect with the output end of the feed circuit, the output end of the second input terminal and the saw-toothed wave generator
Connection, for the sawtooth wave to be compared with the feedback signal, to export the conversion circuit of different signals；
It is connect with the output end of the conversion circuit, for exporting the corresponding drive according to the output signal of the conversion circuit
Dynamic signal, to control the second drive control circuit of the switching tube on-off of the PFC main circuit.
8. circuit of power factor correction according to any one of claims 1 to 7, which is characterized in that the compensation circuit are as follows:
In each pre-set interval, the thermal compensation signal of output is the electric signal that amplitude is not zero, and each described pre-
If except section being the compensation circuit for the electric signal that amplitude is zero.
9. circuit of power factor correction according to claim 8, which is characterized in that the PFC main circuit is DC-DC transformation
Circuit.
10. a kind of power supply unit, which is characterized in that including PFC electricity as described in any one of claim 1 to 9
Road.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821329561.6U CN208638248U (en) | 2018-08-17 | 2018-08-17 | A kind of power supply unit and its power factor correction circuit |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201821329561.6U CN208638248U (en) | 2018-08-17 | 2018-08-17 | A kind of power supply unit and its power factor correction circuit |
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| CN208638248U true CN208638248U (en) | 2019-03-22 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023000348A1 (en) * | 2021-07-23 | 2023-01-26 | 深圳汝原科技有限公司 | Power supply circuit structure, drying device, power supply kit and power supply method |
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2018
- 2018-08-17 CN CN201821329561.6U patent/CN208638248U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023000348A1 (en) * | 2021-07-23 | 2023-01-26 | 深圳汝原科技有限公司 | Power supply circuit structure, drying device, power supply kit and power supply method |
| GB2624326A (en) * | 2021-07-23 | 2024-05-15 | Sz Zuvi Tech Co Ltd | Power supply circuit structure, drying device, power supply kit and power supply method |
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