CN110289755A - High power factor DCM Buck-Flyback pfc converter - Google Patents

High power factor DCM Buck-Flyback pfc converter Download PDF

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Publication number
CN110289755A
CN110289755A CN201910561135.8A CN201910561135A CN110289755A CN 110289755 A CN110289755 A CN 110289755A CN 201910561135 A CN201910561135 A CN 201910561135A CN 110289755 A CN110289755 A CN 110289755A
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circuit
output
input
buck
voltage
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CN110289755B (en
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张震
姚凯
邬程健
管婵波
李凌格
陈杰楠
马春伟
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Nanjing University of Science and Technology
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Nanjing University of Science and Technology
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/12—Arrangements for reducing harmonics from ac input or output
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/14—Arrangements for reducing ripples from dc input or output
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • H02M1/4208—Arrangements for improving power factor of AC input
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • 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

Abstract

The present invention provides a kind of high power factor DCM Buck-Flyback pfc converter, design circuit includes main power circuit, output voltage sampling circuit, output voltage feedback control circuit, sawtooth wave compares and switch tube driving circuit, input voltage comparison circuit, logic switching circuit.Traditional DCM Buck pfc converter is using duty ratio control is determined, and input power factor increases, but input current has intrinsic dead zone, and inductive current peak is big, and EMI differential-mode characteristic is poor, and switching tube conduction loss is big, and efficiency cannot optimize.

Description

High power factor DCM Buck-Flyback pfc converter
Technical field
The present invention relates to a kind of electrical energy changer, especially a kind of high power factor DCM Buck-FlybackPFC becomes Parallel operation.
Background technique
PFC (Power Factor Correction, PFC) converter can reduce Harmonics of Input, Input power factor is improved, is widely used.Pfc converter is divided into active and passive two ways, relative to passive side For formula, active mode has many advantages, such as that input power factor is high, small in size, at low cost.
Traditional DCM Buck pfc converter is widely applied since it is with high efficiency, low output voltage, low surge electricity Stream, low cost, short-circuit protection ability are strong, long service life, control is simple, inductance is small, diode does not have reverse-recovery problems etc. Advantage should be used in AC/DC converter extensively, but there are intrinsic dead zone when BuckPFC converter is due to its work, Keep the distortion of converter input current waveform serious, reduces the PF value of converter, increase the THD value of converter, so that its nothing Method meets requirement of the country to power quality, while inductive current peak is big, EMI differential-mode characteristic is poor, switching tube conduction loss is big, Efficiency cannot optimize.
Summary of the invention
The purpose of the present invention is to provide a kind of high power factor DCM Buck-Flyback pfc converters.
Realize the technical solution of the object of the invention are as follows: a kind of high power factor DCM Buck-Flyback pfc converter, Including main power circuit and control circuit, the main power circuit includes input voltage source vin, diode rectifier circuit RB, LC filter Wave device, Buck circuit and Flyback circuit common transformer T, transformer T primary coil inductance Lp, transformer T secondary coil electricity Feel Ls, Buck circuit switch pipe Qb, diode Db, sustained diodefw, Flyback circuit switch pipe Qf, output capacitance Co, it is negative Carry RLd；Input voltage source vinIt is connect with the input port of RB rectification circuit, output port and the LC filter of RB rectification circuit Input port connection, the output negative pole of LC filter are reference potential zero point, and the output cathode of LC filter is electric with Buck respectively Way switch pipe QbOne end and transformer T primary coil LpSame Name of Ends connection, transformer T primary coil LpThe other end with Flyback circuit switch pipe QfOne end connection, switching tube QfThe other end be reference potential zero point, switching tube QbThe other end With diode DbOne end be connected, diode DbThe other end respectively with transformer T secondary coil LsSame Name of Ends and afterflow two Pole pipe DfwOne end be connected, transformer T secondary coil LsThe other end simultaneously with output capacitance CoWith load RLdOne end connection, Output capacitance CoWith load RLdThe other end be reference potential zero point.
Further, control circuit includes that output voltage sampling circuit, output voltage feedback control circuit, sawtooth wave compare And switch tube driving circuit, input voltage comparison circuit, logic switching circuit；Sampling resistor R in output voltage sampling circuit1With R2After series connection with the output voltage V of main power circuitoIt is connected in parallel, the sampled output and output electricity of output voltage sampling circuit Press the input terminal connection of feedback control circuit, the positive input and reference voltage V of output voltage feedback control circuitrefIt is connected, Sawtooth wave compare and the positive input of switch tube driving circuit and reverse input end respectively with output voltage feedback control circuit Output end connected with triangular wave, the positive input of input voltage comparison circuit is filtered through the LC of divider resistance and main power circuit The connection of wave device forward direction output end, the reverse input end and critical voltage V of input voltage comparison circuitboundaryConnection, logic switch Two of circuit are with door input terminal is compared with sawtooth wave and the output end of switch tube driving circuit connects, in logic switching circuit Second and door ANDgate2The output end of another input terminal and input voltage comparison circuit connected after sign-changing amplifier, Two and door ANDgate2Output signal V of the output end as control circuitd_fAnd with the Flyback circuit in main power circuit Switching tube QfGate pole be connected and driving switch pipe QfIt works, first in logic switching circuit and door ANDgate1It is another A input terminal is connect with the output end of input voltage comparison circuit, first and door ANDgate1Output end as control circuit Output signal Vd_b, switching tube Q with the Buck circuit in main power circuitbGate pole be connected and driving switch pipe QbWork.
Further, switch pipe driving chip can select the integrated IC circuit of UC3843, UC3844 or UC3525 model, The sawtooth wave compares and the sawtooth wave comparison circuit output end of switch tube driving circuit is through rest-set flip-flop and switching tube driving core Piece connection, switch pipe driving chip the 14th and be with pin respectively through the 8th diode D8With the 7th diode D7As saw Tooth Bobbi compared with and switch tube driving circuit output signal；Amplifier IC1-IC6 used in output voltage feedback control circuit Select the operational amplifier of TL074, TL072, LM358, LM324 one of which model；Sawtooth wave compares and switching tube driving electricity Voltage comparator in road and input voltage comparison circuit selects LM324, LM358, UA741, TL081, LM339, LM393 wherein A kind of voltage comparator of model；Sawtooth wave compare and switch tube driving circuit in rest-set flip-flop select 74LS71, The rest-set flip-flop of 74LS279,74HC279,74279 one of models；In logic switching circuit with door select 7408, 7409, the integrated AND gate circuit of 7411,7415 one of models.
A kind of high power factor DCM Buck-Flyback pfc converter proposed by the present invention is integrated due to use Buck-Flyback topology can improve PF value to close to 1 in entire 90~264VAC wide input voltage range, hence it is evident that Has many advantages, such as input power factor height, output voltage ripple is small, Harmonics of Input content is small.
The invention will be further described with reference to the accompanying drawings of the specification.
Detailed description of the invention
Fig. 1 is DCM Buck pfc converter main circuit schematic diagram.
Fig. 2 is DCM Buck pfc converter inductive current, switching tube current waveform figure.
Fig. 3 is that DCM Buck pfc converter corresponds to input current waveform figure (v under different output voltagesin= 110VAC)。
Fig. 4 is curve of the DCM Buck pfc converter in wide input voltage range internal power factor PF.
Fig. 5 is DCM Buck-Flyback pfc converter main circuit schematic diagram.
Fig. 6 is the transformer primary secondary inductor current of DCM Buck-Flyback pfc converter, switching tube current waveform.
Fig. 7 be in wide input voltage range under different output voltages DCM Buck-FlybackPFC transformer turn ratio n with The relation curve schematic diagram of power factor PF is (b) schematic diagram under 110VAC, (c) is wherein (a) is schematic diagram under 90VAC Schematic diagram under 220VAC is (d) schematic diagram under 264VAC.
Fig. 8 is the function relation figure of power factor PF and input voltage, and neutralizing (a) is Vo=70 play schematic diagrames, (b) are Vo=80 lower schematic diagrames, (c) are Vo=90, lower schematic diagram (d) is Vo=100 lower schematic diagrames.
Fig. 9 is the power factor PF curve under the optimal turn ratio is combined with output voltage in wide input voltage range.
Figure 10 is threshold inductance value curve synoptic diagram in wide input voltage range: (a) being Buck converter schematic diagram, (b) For Flyback converter schematic diagram.
Figure 11 is the transformer primary secondary inductance peak point current waveform diagram of DCM Buck-Flyback converter.
Figure 12 is transformer primary side inductive current virtual value curve in wide input voltage range.
Figure 13 is transformer secondary inductive current virtual value curve in wide input voltage range.
Figure 14 is the comparison of Buck Yu Buck-Flyback converter power factor PF.
Figure 15 is the comparison of 3,5,7 subharmonic contents in Buck and Buck-Flyback converter input current.
Figure 16 is the comparison of Buck Yu output voltage waveforms of the Buck-Flyback converter in half of power frequency period.
Figure 17 is the comparison of Buck Yu Buck-Flyback converter voltage ripple size in wide input voltage range.
Figure 18 is the threshold inductance value curve of Buck Yu Buck-Flyback converter.
Figure 19 is the inductive current peak curve of Buck Yu Buck-Flyback converter.
Figure 20 is the inductive current virtual value curve of Buck Yu Buck-Flyback converter.
Figure 21 is the electrical block diagram of high power factor DCM Buck-Flyback converter of the present invention.
Primary symbols title in above-mentioned figure: vin- supply voltage, iin- input current, RB-rectifier bridge, vg- rectification Output voltage afterwards, iLb- inductive current, Lb- inductance, Qb- switching tube, Qf- switching tube, Db- diode, Dfw- bis- poles Pipe, T-transformer, Lp- primary transformer coil inductance, Ls- secondary transformer inductance, Co- output filter capacitor, Io- output electric current, RLd- load, Vo- output voltage, VrefThe reference voltage of-output voltage feedback control, vEA- output electricity Press the error voltage signal output of feedback control, Vboundary- critical voltage, t-time, ω-input voltage angular frequency, Vm— Input voltage peak value, vd_f- switching tube QfDriving voltage, vd_b- switching tube QbDriving voltage, D-duty ratio, fs- become Parallel operation switching frequency, PF-power factor.
Specific embodiment
Fig. 1 is BuckPFC inverter main circuit.Make the following assumptions: (1) all devices are ideal element；(2) output electricity Emboss wave very little compared with its DC quantity；(3) switching frequency is much higher than input voltage frequency.
Fig. 2 gives DCM BuckPFC converter, inductive current and switching tube current waveform in a switch periods Figure.Work as QbWhen conducting, DfwCut-off, inductance LsThe voltage at both ends is vg- Vo, electric current iLsWith (v by zerog- Vo)/LsIt is oblique Rate linear rise, vgTo load and storage capacitor CoPower supply.Work as QbWhen shutdown, iLsPass through DfwAfterflow, at this time LsThe voltage at both ends For-Vo, iLsWith Vo/LsSlope decline, and iLsZero can be dropped to before a new period starts.
Without loss of generality, input ac voltage v is definedinExpression formula are as follows:
vin=Vm sinθ (1)
Wherein VmIt is respectively amplitude and the phase angle of input ac voltage with θ.
In half of power cycle [0, π], rectified input voltage vgIt is identical with input voltage, i.e.,
vg=vin=Vm sinθ (2)
In a switch periods, inductance LsCurrent peak iLs_pkFor
Wherein DQbFor switching tube QbDuty ratio, fsFor switching frequency.
In each switch periods, LsThe volt-seconds area at both ends balances, i.e.,
Wherein VoFor output voltage, DDfwbFor inductive current drop to zero corresponding to duty ratio.
It can be obtained by formula (2) and formula (4):
According to formula (3) and formula (5), switching tube Q is flowed through in an available switch periodsbAverage value are as follows:
Then in [θ0,(-θ0] in, the input current average value of Buck converter are as follows:
Since Buck converter is only in input voltage vinIt just works when higher than critical voltage value, therefore, input current iin Are as follows:
Convolution (1) and formula (8) can find out input power are as follows:
Assuming that transducer effciency is 100%, then input power is equal to output power, i.e. Pin=Po, available duty Compare DQbExpression formula:
Place's input power factor can be calculated according to formula (1) and formula (8) are as follows:
V can be made according to formula (8)-(11)inWhen=110VAC, DCM Buck pfc converter corresponds to different output voltages Under input current waveform figure and wide input voltage range internal power factor PF curve graph, it is as shown in Figure 3 and Figure 4 respectively.From It can be obtained in figure, there are dead zones for input current waveform, cause power factor lower, it is therefore desirable to which new method eliminates input current Dead zone, increase power factor value.
Fig. 5 is DCM Buck-Flyback pfc converter main circuit.Make the following assumptions: (1) all devices are ideal Element；(2) output voltage ripple very little compared with its DC quantity；(3) switching frequency is much higher than input voltage frequency.
Switch tube current and transformer primary secondary inductor current waveform when Fig. 6 gives DCM in one switch periods.When When the instantaneous value of input voltage is less than critical voltage value, QfConducting, QbShutdown, D cut-off, DfwCut-off, primary transformer coil electricity Feel LpThe voltage at both ends is vg- Vo, electric current iLpWith (v by zerog- Vo)/LpSlope linear rise, vgTo load and storage It can capacitor CoPower supply.Work as QfWhen shutdown, iLsPass through DfwAfterflow, at this time secondary transformer inductance LsThe voltage at both ends is-Vo, iLsWith Vo/LsSlope decline, and iLsZero can be dropped to before a new period starts.When the instantaneous value of input voltage is big When critical voltage value, QbConducting, QfShutdown, D conducting, DfwCut-off, secondary transformer inductance LsThe voltage at both ends is vg? Vo, electric current iLsWith (v by zerog- Vo)/LsSlope linear rise, vgTo load and storage capacitor CoPower supply.Work as QbIt closes When disconnected, iLsPass through DfwAfterflow, at this time secondary transformer inductance LsThe voltage at both ends is-Vo, iLsWith Vo/LsSlope under Drop, and iLsZero can be dropped to before a new period starts.
When the instantaneous value of input voltage is less than critical voltage value, converter works under Flyback state, opens at one It closes in the period, transformer primary end inductive current peak iLp_pkFor
Wherein DQbfFor switching tube QfDuty ratio, fsFor switching frequency.
In each switch periods, primary transformer coil LpThe volt-seconds area at both ends balances, i.e.,
Wherein VoFor output voltage, DDfwfFor transformer pair end inductive current drop to zero corresponding to duty ratio.
It can be obtained by formula (2) and formula (13):
According to formula (12) and formula (14), switching tube Q is flowed through in an available switch periodsfAverage value are as follows:
Then [0, θ0] and [(- θ0, (] in, the input current average value of converter are as follows:
When the instantaneous value of input voltage is greater than critical voltage value, converter works under Buck state, and analysis conclusion is shown in First segment.
Therefore, input current iinAre as follows:
Wherein
The average value P of converter input power in half period can be found out by formula (1) and formula (13)inAre as follows:
Assuming that transducer effciency is 100%, then input power is equal to output power.Duty ratio D can be obtained by formula (14)Qbf:
It can be in the hope of the expression formula of PF value by formula (17) and formula (18) are as follows:
Wherein Irms_bfFor input current virtual value.
In conjunction with the parameter of (20) and converter, can make in wide input voltage range, under different output voltages, the turn ratio The function curve of n and PF value, as shown in Fig. 7 (a-d).From in figure can from obtain 90VAC, 110VAC, 220VAC, 264VAC Input voltage and 70VDC, 80VDC, 90VDC, corresponding optimal turn ratio n under 100VDC output voltage.
In order to more obviously observe in wide input voltage range, under different output voltages, influence of the turn ratio to power factor, We draw out the function relation figure of Fig. 8 power factor PF and input voltage.In view of 110VAC and 220VAC are nominally to input Voltage, therefore we select blue curve as the foundation for determining the optimal turn ratio, thus n=1.42, n=1.52, n from Fig. 8 =1.65 and n=1.80 is chosen as optimal turn ratio when Vo=70, Vo=80, Vo=90 and Vo=100V, corresponds to circle herein Under number ratio, converter can obtain maximum power factor value.
According to the above analysis, we can be made in Fig. 9 wide input voltage range, and the optimal turn ratio combines down with output voltage Power factor curve.As can be seen that under the combination of the optimal turn ratio and output voltage, DCMBuck-Flyback PFC transformation The power factor of device can all guarantee 0.956 or more, and as the increased wattage factor of input voltage is close to 1.
In order to make converter work under DCM state, it is necessary to so that inductive current is reduced to 0 before the pipe that opens the light is opened, then For Buck converter, duty ratio needs to meet following formula:
Formula (5) are substituted into formula (21) and are obtained:
Formula (19) are substituted into formula (22), the threshold inductance value of transformer secondary winding can be obtained are as follows:
Threshold inductance value curve in Buck converter wide input voltage range is made according to formula (23), as shown in Figure 10 (a).
For Flyback converter, in order to make converter work under DCM state, duty ratio needs to meet following formula:
Formula (14) are substituted into formula (24) and are obtained:
Formula (19) are substituted into formula (25), the threshold inductance value of transformer secondary winding can be obtained are as follows:
Transformer secondary winding threshold inductance in Flyback converter wide input voltage range can be made according to formula (26) It is worth curve, as shown in Figure 10 (b).
In order to which converter can be worked normally, the transformer secondary winding to work under Buck and Flyback state is most Low value needs to be ensured of identical.
According to formula (3), formula (12) and formula (19), DCM Buck-Flyback converter inductance peak point current wave can be made Shape, as shown in figure 11.It can be found that peak point current reduces with the increase of output voltage from figure.
When the pipe that opens the light is in the conductive state, it can calculate and flow through switching tube QbWith switching tube QfThe virtual value of electric current:
When the pipe that opens the light is in an off state, it can calculate and flow through sustained diodefwVirtual value:
As the pipe Q that opens the lightfWhen in the conductive state, the virtual value for flowing through transformer primary end-coil inductance can be calculated:
As the pipe Q that opens the lightfIt is in an off state, QbWhen being on off state, it can calculate and flow through transformer pair end The virtual value of coil inductance:
Transformer primary pair end winding current virtual value waveform, i.e. Figure 12 and figure can be made respectively according to (27)~(32) formula 13。
Traditional DCM Buck converter can be compared according to formula (1), formula (11) and formula (20) and DCMBuck-Flyback becomes The power factor PF of parallel operation, as shown in figure 14.It can be seen from the figure that relative to traditional DCM Buck converter, DCM Buck- The power factor of Flyback converter is greatly improved, and PF value is close to 1 especially under high input voltage.
Fourier analysis is carried out to the input current waveform of DCM Buck-Flyback converter, can be obtained
As can be seen from Figure 15,3 times, 5 times and 7 subharmonic contents whole satisfactions of DCM Buck-Flyback converter Requirements of the national standard, and 3 times, 5 times of tradition DCM Buck converter and 7 subharmonic contents are unsatisfactory for requirements of the national standard, it is special Not at a low input voltages, 3 times, 5 times and 7 subharmonic contents are very high.
The instantaneous output voltage value expression formula of output capacitor is
The output voltage ripple of DCM Buck converter and DCM Buck-Flyback converter can all calculate according to the following formula
WhenWhen, output capacitance charging, whenWhen, output capacitance electric discharge, θ1,θ2,θ3,andθ4It is tradition respectively DCM Buck converter and DCM Buck-Flyback converter existPhase angle when 1.Half can be drawn according to formula (34) The output voltage waveforms of two kinds of converters in a power frequency period, as shown in figure 16.Wide input voltage can be drawn according to formula (35) The curve of two kinds of converter output voltage ripple sizes in range, as shown in figure 17.It can be seen from the figure that DCM Buck- The output voltage ripple of Flyback converter has substantial degradation compared to tradition Buck converter.
According to formula (21) and convolution (5) and (10), then the threshold inductance formula of DCM Buck converter is as follows:
Figure 18, the threshold inductance value song of DCM Buck converter and DCM Buck-Flyback converter can be obtained by formula (36) Line.In the case where considering allowance, DCM Buck converter threshold inductance value is that 33uH ratio DCM Buck-Flyback converter faces Boundary inductance value 40uH wants small, it is seen that converter proposed by the invention can make threshold inductance value have certain promotion.
According to formula (3) and formula (10), in conjunction with Figure 11, can make under input voltage 110VAC DCMBuck converter with The inductive current peak curve of DCM Buck-Flyback converter, as shown in figure 19.It can be seen from the figure that DCM Buck- The inductive current peak of Flyback converter has substantial degradation compared to traditional DCMBuck converter, and whole peak envelope Closer to sine, therefore the power factor of DCM Buck-Flyback converter improves a lot.
The inductive current virtual value expression formula of Buck converter are as follows:
Formula (3), formula (5) and formula (10) are updated in formula (37), in conjunction with Figure 13, two kinds of converters of Figure 20 can be made Inductive current virtual value curve.The current effective value of DCM Buck-Flyback converter is smaller.Therefore, in DCM Buck- In Flyback converter, the loss ratio Buck converter of main components is much smaller.
In conjunction with Figure 21, high power factor DCM Buck-Flyback converter of the invention comprising main power circuit (1) And control circuit, the main power circuit (1) includes input voltage source vin, diode rectifier circuit RB, LC filter, Buck electricity Road and Flyback circuit common transformer T, transformer T primary coil inductance Lp, transformer T secondary coil inductance Ls, Buck electricity Way switch pipe Qb, diode Db, sustained diodefw, Flyback circuit switch pipe Qf, output capacitance Co, load RLd, wherein defeated Enter voltage source vinIt is connect with the input port of RB rectification circuit, the output port of RB rectification circuit and the input port of LC filter Connection, the output negative pole of LC filter are reference potential zero point, the output cathode of LC filter simultaneously with Buck circuit switch pipe QbOne end and transformer T primary coil LpSame Name of Ends connection, transformer T primary coil LpThe other end and Flyback circuit Switching tube QfOne end connection, switching tube QfThe other end be reference potential zero point, switching tube QbThe other end and diode Db's One end is connected, diode DbThe other end simultaneously with transformer T secondary coil LsSame Name of Ends and sustained diodefwOne End is connected, transformer T secondary coil LsThe other end simultaneously with output capacitance CoWith load RLdOne end connection, output capacitance Co With load RLdThe other end be reference potential zero point Buck inductance LbThe other end simultaneously with output capacitance CoWith load RLdOne End connection, output capacitance CoWith load RLdThe other end be reference potential zero point.
High power factor DCM Buck-FlybackPFC converter of the invention, it is characterised in that control circuit includes defeated Out voltage sampling circuit (2), output voltage feedback control circuit (3), sawtooth wave compares and switch tube driving circuit (4), input Voltage comparator circuit (5), logic switching circuit (6), sampling resistor R in the output voltage sampling circuit (2)1And R2After series connection With the output voltage V of main power circuit (1)oIt is connected in parallel, the sampled output F and output electricity of output voltage sampling circuit (2) Press the end the A connection of feedback control circuit (3)；The positive input and reference voltage V of output voltage feedback control circuit (3)refPhase Even；Sawtooth wave compares and the positive input of switch tube driving circuit (4) and reverse input end feed back with output voltage control respectively The output end B of circuit processed is connected with triangular wave；The positive input of input voltage comparison circuit (5) is through divider resistance and main power The LC filter forward direction output end of circuit (1) connects, reverse input end and critical voltage VboundaryConnection；Logic switching circuit (6) two and door input terminal are compared with sawtooth wave and the output end Q connection of switch tube driving circuit (4), wherein with door ANDgate2The output end E of another input terminal and input voltage comparison circuit (5) connected after sign-changing amplifier, with door ANDgate2Output signal V of the output end as control circuitd_f, with the Flyback circuit in main power circuit (1) Switching tube QfGate pole be connected and driving switch pipe QfWork, with door ANDgate1Another input terminal compared with input voltage The output end E connection of circuit (5), with door ANDgate1Output signal V of the output end as control circuitd_b, with main power The switching tube Q of Buck circuit in circuit (1)bGate pole be connected and driving switch pipe QbWork.
The sawtooth wave compares and the sawtooth wave comparison circuit output end C of switch tube driving circuit (4) through rest-set flip-flop with Pipe driving chip connection is switched, the output end 14 and output end 11 for switching pipe driving chip are respectively through diode D8With diode D7 Compare as sawtooth wave and the output signal of switch tube driving circuit (4), switch pipe driving chip can select UC3843, The integrated IC circuit of the models such as UC3844 or UC3525, amplifier IC1-used in output voltage feedback control circuit (3) IC6 selects the operational amplifier of the models such as TL074, TL072, LM358, LM324, and sawtooth wave compares and switch tube driving circuit (4) and the voltage comparator in input voltage comparison circuit (5) can select LM324, LM358, UA741, TL081, LM339, The voltage comparator of the models such as LM393, sawtooth wave compares and switch tube driving circuit (4) in rest-set flip-flop can select The rest-set flip-flop of the models such as 74LS71,74LS279,74HC279,74279, can be selected with door in logic switching circuit (6) 7408, the integrated AND gate circuit of the models such as 7409,7411,7415.
In conclusion high power factor DCM Buck-Flyback converter of the invention by Buck topological structure and Flyback topological structure combines, so that converter Flyback circuit when input voltage is lower than critical voltage value works, Buck circuit works when input voltage is higher than critical voltage value, to eliminate the dead of Buck circuit input current in dcm mode Area makes input current be close to the sine wave with input voltage same-phase, at the same time key design of the present invention Buck- The optimal turn ratio and output voltage of Flyback, thus in entire 90~264VAC wide input voltage range by PF value improve to Close to 1.In addition, with it is traditional containing only Buck circuit determine duty ratio control converter compared with, the Buck- that is proposed Flyback circuit topology also have output voltage ripple is small, switching tube conduction loss is small, required diode stress reduce etc. it is excellent Point.

Claims (3)

1. a kind of high power factor DCM Buck-Flyback pfc converter, which is characterized in that including main power circuit (1) and Control circuit, the main power circuit (1) includes input voltage source vin, diode rectifier circuit RB, LC filter, Buck circuit With Flyback circuit common transformer T, transformer T primary coil inductance Lp, transformer T secondary coil inductance Ls, Buck circuit Switching tube Qb, diode Db, sustained diodefw, Flyback circuit switch pipe Qf, output capacitance Co, load RLd；Wherein
Input voltage source vinIt is connect with the input port of RB rectification circuit,
The output port of RB rectification circuit is connect with the input port of LC filter,
The output negative pole of LC filter is reference potential zero point,
The output cathode of LC filter respectively with Buck circuit switch pipe QbOne end and transformer T primary coil LpSame Name of Ends Connection,
Transformer T primary coil LpThe other end and Flyback circuit switch pipe QfOne end connection,
Switching tube QfThe other end be reference potential zero point,
Switching tube QbThe other end and diode DbOne end be connected,
Diode DbThe other end respectively with transformer T secondary coil LsSame Name of Ends and sustained diodefwOne end be connected,
Transformer T secondary coil LsThe other end simultaneously with output capacitance CoWith load RLdOne end connection,
Output capacitance CoWith load RLdThe other end be reference potential zero point.
2. converter according to claim 1, which is characterized in that control circuit includes output voltage sampling circuit (2), defeated Out Voltage Feedback control circuit (3), sawtooth wave compares and switch tube driving circuit (4), input voltage comparison circuit (5), logic Switching circuit (6)；
Sampling resistor R in output voltage sampling circuit (2)1And R2After series connection with the output voltage V of main power circuit (1)oParallel connection is even It connects,
The sampled output of output voltage sampling circuit (2) is connect with the input terminal of output voltage feedback control circuit (3),
The positive input and reference voltage V of output voltage feedback control circuit (3)refIt is connected,
Sawtooth wave compares and the positive input of switch tube driving circuit (4) and reverse input end feed back with output voltage control respectively The output end of circuit (3) processed is connected with triangular wave,
LC filter forward direction of the positive input of input voltage comparison circuit (5) through divider resistance and main power circuit (1) is defeated Outlet connection,
The reverse input end and critical voltage V of input voltage comparison circuit (5)boundaryConnection,
Two of logic switching circuit (6) and door input terminal are compared with sawtooth wave and the output end of switch tube driving circuit (4) connects It connects,
Second in logic switching circuit (6) and door ANDgate2Another input terminal and input voltage comparison circuit (5) it is defeated Outlet connects after sign-changing amplifier,
Second and door ANDgate2Output signal V of the output end as control circuitd_fAnd in main power circuit (1) The switching tube Q of Flyback circuitfGate pole be connected and driving switch pipe QfWork,
First in logic switching circuit (6) and door ANDgate1Another input terminal and input voltage comparison circuit (5) it is defeated Outlet connection,
First and door ANDgate1Output signal V of the output end as control circuitd_b, in main power circuit (1) The switching tube Q of Buck circuitbGate pole be connected and driving switch pipe QbWork.
3. converter according to claim 2, which is characterized in that switch pipe driving chip can select UC3843, The integrated IC circuit of UC3844 or UC3525 model, the sawtooth wave compares and the sawtooth wave of switch tube driving circuit (4) compares Circuit output end connect through rest-set flip-flop with switch pipe driving chip, switch the 14th of pipe driving chip be to be distinguished with pin Through the 8th diode D8With the 7th diode D7Compare as sawtooth wave and the output signal of switch tube driving circuit (4)；
Amplifier IC1-IC6 used in output voltage feedback control circuit (3) selects TL074, TL072, LM358, LM324 The operational amplifier of one of model；
Sawtooth wave compares and switch tube driving circuit (4) and input voltage comparison circuit (5) in voltage comparator select The voltage comparator of LM324, LM358, UA741, TL081, LM339, LM393 one of which model；
Sawtooth wave compares and switch tube driving circuit (4) in rest-set flip-flop select 74LS71,74LS279,74HC279,74279 The rest-set flip-flop of one of model；
The integrated AND gate circuit that 7408,7409,7411,7415 one of models are selected with door in logic switching circuit (6).
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11561249B2 (en) 2020-12-17 2023-01-24 Cypress Semiconductor Corporation Inductive sensing methods, devices and systems
CN116191862A (en) * 2023-03-09 2023-05-30 西南交通大学 Bridgeless buck PFC converter based on buck and flyback conversion unit

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5416387A (en) * 1993-11-24 1995-05-16 California Institute Of Technology Single stage, high power factor, gas discharge lamp ballast
US20040085788A1 (en) * 2002-11-05 2004-05-06 Weng Da Feng Quasi active power factor correction circuit for switching power supply
US7538534B2 (en) * 2004-11-29 2009-05-26 Supentex, Inc. Method and apparatus for controlling output current of a cascaded DC/DC converter
US8183797B2 (en) * 2009-09-18 2012-05-22 Boca Flasher, Inc 90-260Vac dimmable MR16 LED lamp
CN103683952A (en) * 2013-11-22 2014-03-26 西南交通大学 Parallel integrated Buck-Flyback power factor correction (PFC) converter topology
US20140293657A1 (en) * 2013-04-02 2014-10-02 Phihong Technology Co., Ltd. Integrated converter with single-ended control, power factor correction, and low output ripple
WO2016169022A1 (en) * 2015-04-23 2016-10-27 The University Of Hong Kong Ac-dc single-inductor multiple-output led drivers
US20160359421A1 (en) * 2014-12-07 2016-12-08 Alpha And Omega Semiconductor (Cayman) Ltd. Power supply device
CN107800312A (en) * 2017-11-13 2018-03-13 四川大学 A kind of output ripple and low pfc converter

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5416387A (en) * 1993-11-24 1995-05-16 California Institute Of Technology Single stage, high power factor, gas discharge lamp ballast
US20040085788A1 (en) * 2002-11-05 2004-05-06 Weng Da Feng Quasi active power factor correction circuit for switching power supply
US7538534B2 (en) * 2004-11-29 2009-05-26 Supentex, Inc. Method and apparatus for controlling output current of a cascaded DC/DC converter
US8183797B2 (en) * 2009-09-18 2012-05-22 Boca Flasher, Inc 90-260Vac dimmable MR16 LED lamp
US20140293657A1 (en) * 2013-04-02 2014-10-02 Phihong Technology Co., Ltd. Integrated converter with single-ended control, power factor correction, and low output ripple
CN103683952A (en) * 2013-11-22 2014-03-26 西南交通大学 Parallel integrated Buck-Flyback power factor correction (PFC) converter topology
US20160359421A1 (en) * 2014-12-07 2016-12-08 Alpha And Omega Semiconductor (Cayman) Ltd. Power supply device
WO2016169022A1 (en) * 2015-04-23 2016-10-27 The University Of Hong Kong Ac-dc single-inductor multiple-output led drivers
CN107800312A (en) * 2017-11-13 2018-03-13 四川大学 A kind of output ripple and low pfc converter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
KENTARO FUKUSHIMA, ET AL: "Steady-State Characteristics of a Novel PFC Converter Operating in DCM", 《2006 12TH INTERNATIONAL POWER ELECTRONICS AND MOTION CONTROL CONFERENCE》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11561249B2 (en) 2020-12-17 2023-01-24 Cypress Semiconductor Corporation Inductive sensing methods, devices and systems
CN116191862A (en) * 2023-03-09 2023-05-30 西南交通大学 Bridgeless buck PFC converter based on buck and flyback conversion unit
CN116191862B (en) * 2023-03-09 2023-09-01 西南交通大学 Bridgeless buck PFC converter based on buck and flyback conversion unit

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