CN103780075A - Digital frequency conversion control method for power factor corrector - Google Patents
Digital frequency conversion control method for power factor corrector Download PDFInfo
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- CN103780075A CN103780075A CN201410010654.2A CN201410010654A CN103780075A CN 103780075 A CN103780075 A CN 103780075A CN 201410010654 A CN201410010654 A CN 201410010654A CN 103780075 A CN103780075 A CN 103780075A
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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
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- 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 invention discloses a digital frequency conversion control method for a power factor corrector. The method comprises the following links: (1) an A/D sampling conversion link: A/D conversion is carried out on ui, iL, uo and io of the power factor corrector through current and voltage sensors to convert the analog values into digital values uiD, iLD, uoD and ioD, which are used as input values of other links; a voltage control link: digital control is carried out on an error value obtained from comparison between the digital value uoD of output voltage and a preset reference voltage value Uref to keep the output voltage stable; a current control link: digital control is carried out on an error value obtained from comparison between the reference current iref provided by the voltage control link and the digital value iLD of inductive current to carry out power factor correction to enable the inductive current to track the input voltage phase; a feedforward link; and a pulse frequency modulation link. The invention aims to provide a digital frequency conversion control method which is capable of reducing the number of peripheral circuits of a controller to the greatest extent under the condition of load change and designed for a power factor corrector.
Description
Technical field
The present invention relates to field of switch power, relate in particular to a kind of digital frequency conversion control method for power factor corrector.
Background technology
The research of power factor correction technology is mainly divided into two aspects: topological structure and control strategy.Topological structure is the main circuit structure of realizing power factor correction (PFC, Power Factor Correction) function, according to got access to grid multi-form two types of the single-phase and three-phases that are divided into.According to the difference of application scenario, can the different PFC topological structure of design and use, and no matter adopt which kind of PFC structure, all need suitable control and implementation, from current present Research, mainly contain analog-and digital-two kinds of implementations.
The analog control system that traditional circuit of power factor correction adopts is through years of researches, and technology is very ripe.But analogue system has its fixing defect: need a large amount of discrete component and circuit board, number of devices is many, device cost is high, and problem of aging and the temperature of analog element are floated, and are subject to environmental interference (electromagnetic noise, temperature), can affect like this long-time stability of system.Special simulation control chip has greatly reduced the trouble of control system, wherein take UC3854 as representative, the control that it is some circuit provides convenience, but in control network, still need the analog elements such as a large amount of resistance capacitances, the problems such as the error of these elements directly affects the performance of system, and while original paper is aging still exist.And, be analog control method due to what adopt, the therefore control underaction of chip, is difficult to realize complicated, advanced control algolithm.The system that simultaneously adopts simulation to control for each will be passed through special design.Upgrade for product renewal each time, all will redesign their control system, transplantability and versatility are poor.Therefore, limitation and the inferior position of traditional simulation power ratio control factor corrector are further obvious.
The current Power Factor Correction Control method in high-power applications occasion, main Average Current Control, peak current control, the duty ratio PREDICTIVE CONTROL of using, its operating frequency is fixed, duty ratio changes according to curent change, but use under the occasion of load variations, switching device loss is larger, affects delivery efficiency simultaneously.
The switching device loss and the raising delivery efficiency that under the occasion of load variations, use in order to reduce power factor corrector, the Chinese invention patent that number of patent application is 2011110009039 provides " a kind of charging device that power factor is carried out to variable ratio frequency changer control ".This equipment is used for the charging process of battery of electric vehicle, the cell load state of exporting by battery management system, and the power factor controller being made up of pulse width modulator and pulse frequency modulator changes the frequency of pulse signal and carries out switch control.While the switching device of circuit of power factor correction being carried out to switch control when the pulsewidth by modulated pulse signal, carry out switch control by the frequency that changes pulse signal.Heavy duty is lower to using the switching device of pulse-width modulation high-frequency drive circuit of power factor correction, and under underload, use the switching device of pulse-width modulation low frequency driving circuit of power factor correction, even thereby under light-load state, reduce the switching loss under low frequency, also can holding power factor.But still there is following drawback in the method that this patent is recorded: 1. power factor corrector is made up of pulse-width modulator and pulse frequency modulator, adopt analog control method, device is subject to external disturbance, can not guarantee stability, the height of controlling cost, control precision is low simultaneously; 2. in load variations occasion, as battery charging, power output constantly changes, provide load condition then to carry out the mode of switch control by power factor controller by battery management system, simple feedback is larger to the dependence of load state information, once larger fluctuation appears in load, can not guarantee higher power factor.
Summary of the invention
For above deficiency of the prior art, the object of the present invention is to provide a kind of switching device loss that reduces in load variations situation, improve controller response and stability, improve control precision, the digital frequency conversion control method of guarantee power factor.Technical scheme of the present invention is as follows:
A kind of digital frequency conversion control method for power factor corrector, described power factor corrector comprises A/D sample conversion link, voltage control link, Current Control link, feedforward link, pulse frequency modulated link, it is characterized in that, described digital frequency conversion control method comprises the following steps:
101, the analog current, the analog voltage information that gather power factor corrector by current sensor and voltage sensor, comprise input voltage u
i, inductive current i
l, output voltage u
oand output current i
o;
102, by the input voltage u collecting in step 101
i, inductive current i
l, output voltage u
oand output current i
oconvert input voltage digital quantity u to by A/D sample conversion link
iD, output voltage numeral amount u
oD, inductive current digital quantity i
lDand output current numeral amount i
oD;
103, by the output voltage numeral amount u in step 102
oDbe input to voltage control link, voltage control link comprises voltage comparator, controller I and multiplier, and first comparator is by output voltage numeral amount u
oDthe reference voltage U preset with voltage comparator
refrelatively, obtain voltage deviation signal △ u=u
oD-U
refthen input control device I is processed and output signal u
1,
wherein K
pfor proportion adjustable coefficient, T
ifor adjustable integration time constant.Described voltage control link output u
1with the input voltage digital quantity u in step 103
iDinput multiplier multiplies each other and obtains the reference value i of Current Control link
ref;
104, by the reference value i of the Current Control link obtaining in step 103
refwith the inductive current digital quantity i obtaining in step 102
lDinput current controlling unit, Current Control link comprises current comparator, controller II and adder, first current comparator obtains current deviation signal △ i=i
lD-i
ref, described current deviation signal △ i input control device II is processed and output signal u
2,
wherein K
pfor proportion adjustable coefficient, T
ifor adjustable integration time constant.Feed-forward voltage value u with feedforward link controller
fFinput summer, stack obtains frequency conversion reference voltage u
pFM=u
fF+ u
2;
105, by the frequency conversion reference voltage u obtaining in step 104
pFMand the output voltage obtaining in step 102 numeral amount u
oD, output current numeral amount i
oD, input pulse frequency modulator, produce duty ratio constant pulse frequency modulated signal, the switching device that pulse frequency modulated signal constant described duty ratio is transferred to Switching Power Supply is realized digital frequency conversion control.
Further, feedover in the step 104 feed-forward voltage output valve of link
Further, in step 105, the frequency of pulse frequency modulated signal is
wherein L is input inductance, and D is that duty ratio is definite value, P
ofor power output.
Further, the duty ratio of described pulse frequency modulated signal
wherein u
iD (min)for minimum input voltage.
Advantage of the present invention and beneficial effect are as follows:
The inventive method is the dicyclo control mode that adopts voltage control link and Current Control link under load variations application scenario, simultaneously by load variations is followed the tracks of, integrated load information and dicyclo output reference, pulse frequency modulated link is exported frequency conversion digital signal accurately switching device is controlled, and has guaranteed the power factor in stable Voltage-output and varying load situation.This digital frequency conversion control method has greatly reduced Control peripheral circuit device on the one hand, has reduced on the other hand the switching device loss in load variations situation, has guaranteed efficiency and power factor.By the method that realizes at power factor corrector, can effectively reduce cost, improve control precision and the power factor of power factor corrector in varying load situation.
Accompanying drawing explanation
Fig. 1 is the digital frequency conversion control method flow chart of the specific embodiment of the invention;
Fig. 2 is the power factor corrector digitial controller block diagram of one embodiment of the present invention;
Fig. 3 is power factor corrector digitial controller method for controlling frequency conversion block diagram of the present invention;
Fig. 4 is the oscillogram that the present invention follows the tracks of inductive current under digital frequency conversion control mode.
Embodiment
The invention will be further elaborated to provide the embodiment of an indefiniteness below in conjunction with accompanying drawing.
Shown in Fig. 1-4, the digital frequency conversion control method flow chart of one embodiment of the invention, specifically comprises step as follows:
First define following parameter amount:
P
o-power output, f
s-switching frequency, D-duty ratio, L-inputs boost inductance, u
i-input voltage analog quantity, u
o-output voltage analog quantity, i
l-inductive current analog quantity, i
o-output current analog quantity, u
iD-input voltage digital quantity, u
iD (min)-minimum input voltage digital quantity, u
oD-output voltage numeral amount, i
lD-inductive current digital quantity, i
oD-output current numeral amount, △ u-voltage link deviation signal, △ i-electric current link deviation signal, K
p-proportion adjustable coefficient, T
i-adjustable integration time constant.
Step 101: gather the current-voltage information of power factor corrector by transducer, comprise input voltage u
i, inductive current i
l, output voltage u
o, output current i
o.
Step 102: the analog quantity that sensor sample is obtained, input voltage u
i, inductive current i
l, output voltage u
o, output current i
oby AD sample conversion link, analog quantity is converted to digital quantity u
iD, u
oD, i
lD, i
oD.
Step 103: by output voltage numeral amount u
oDas the input variable of voltage control link, u
oDthe reference voltage U preset with voltage comparator
refrelatively, obtain voltage deviation signal △ u=u
oD-U
ref, deviation signal △ u is input in controller, and controller regulates output voltage by voltage deviation signal △ u, the output voltage of firm power factor corrector.When deviation signal △ u ∈ [0, ± 10%u
o] time, switching frequency f
sdo not do to change, keep output; As deviation signal △ u>10%u
otime, controller output u
1reduce u
1reduce Current Control link with reference to i
refreduce, current deviation amount △ i increases, and reaches △ i>5%i
lDwhen condition, switching frequency f
sincrease, due to duty ratio, D is constant, reduces switching device ON time, makes inductive current i
lreduce, thereby suitably reduce output voltage; As departure △ u<-10%u
o, controller output u
1increase u
1increase Current Control link with reference to i
refincrease, current deviation amount △ i increases, and reaches △ i<-5%i
lDwhen condition, reduce switching frequency f
s, make inductive current i
lincrease, thereby suitably improve output voltage.
Step 104: voltage control link controller is output as
wherein K
pfor proportion adjustable coefficient, T
ifor adjustable integration time constant.U
1with input voltage digital quantity u
iDinput multiplier, multiplies each other and obtains the reference value i of Current Control link
ref, i
refbe the output of voltage control link, as power factor correction current reference in Current Control link, carry out next link.
Step 105: by inductive current digital quantity i
lDas the input variable of Current Control link, i
lDwith the current reference value i in input current comparator
refrelatively, obtain current deviation signal △ i=i
lD-i
ref, current deviation signal △ i is input in controller, and controller carries out phasing by current deviation signal △ i to inductive current, makes inductive current waveform tracking current reference, guarantee power factor.When deviation signal △ i ∈ [0, ± 5%i
lD] time, switching frequency f
sdo not do to change, inductive current is constant; As deviation signal △ i>5%i
lDtime, increase switching frequency f
s, reduce switching device ON time, make inductive current i
lreduce; As departure △ i<-5%i
lDtime, reduce switching frequency f
s, increase switching device ON time, make inductive current i
lincrease.
Step 106: the output of Current Control link controller
wherein K
pfor proportion adjustable coefficient, T
ifor adjustable integration time constant.U
2with the feed-forward voltage value that obtains of feedforward link
input summer adds up to the reference that pulse modulation link provides frequency to adjust, i.e. u
pFM=u
fF+ u
2, output voltage u simultaneously
oDwith output current i
oDas far as possible little at △ t(△ t) the external loading change information P that provides in the time
o1, P
o2..., P
on... for pulse modulation link provides the reference of frequency conversion scope.
Step 107:u
pFMas the power factor correction tracking signal of pulse frequency modulated link, make inductive current carry out phasing, guarantee power factor to current reference value in frequency conversion and duty ratio constant in the situation that.First by output voltage numeral amount u
oDwith output current numeral amount i
oDdetermine external loading change information P
o1, P
o2..., P
on... for pulse modulation link provides the reference of frequency conversion scope, obtain switching frequency f
s1, f
s2..., f
sn...Then u
pFMas the power factor correction tracking signal of pulse frequency modulated link, to switch frequency f
s1, f
s2..., f
sn... adjust, make inductive current carry out phasing to current reference value, guarantee power factor and regulated output voltage in frequency conversion and duty ratio constant in the situation that.
Switching frequency scope f
s1, f
s2..., f
sn... determine (as formula 1) according to switching frequency and load relationship.
Wherein, for definite circuit of power factor correction, in the situation of boost inductance L assurance input power maximum and input voltage minimum, do not reach capacity, its size is definite value, duty ratio D provides according to input and output voltage relation, guarantees the duty ratio (suc as formula 2) in the time that peak-peak appears in inductive current.
The present invention is by load, i.e. power output discretization, carries out switching frequency calculating for different loading conditions, and switching frequency changes according to the variation of outside power output, reduces switching loss.Because duty ratio is constant, by the variation of frequency, input inductive current is followed the tracks of, complete power factor correction.
The present invention is directed to the impact of discrete device on circuit working and the control of cost in simulation control in the past, adopt digital method for controlling frequency conversion, control precision is high, and control stability is strong, can effectively reduce the cost of manufacture of power factor correction controller.Feedforward simultaneously can effectively reduce the dependence of control system to load information with the dicyclo control mode of feedback combination, further improves the stability of system.
The present invention is applicable to use any digit chip to carry out power factor correction, such as DSP, FPGA etc.
These embodiment are interpreted as being only not used in and limiting the scope of the invention for the present invention is described above.After having read the content of record of the present invention, technical staff can make various changes or modifications the present invention, and these equivalences change and modification falls into the inventive method claim limited range equally.
Claims (4)
1. the digital frequency conversion control method for power factor corrector, described power factor corrector comprises A/D sample conversion link, voltage control link, Current Control link, feedforward link, pulse frequency modulated link, it is characterized in that, described digital frequency conversion control method comprises the following steps:
101, the analog current, the analog voltage information that gather power factor corrector by current sensor and voltage sensor, comprise input voltage u
i, inductive current i
l, output voltage u
oand output current i
o;
102, by the input voltage u collecting in step 101
i, inductive current i
l, output voltage u
oand output current i
oconvert input voltage digital quantity u to by A/D sample conversion link
iD, output voltage numeral amount u
oD, inductive current digital quantity i
lDand output current numeral amount i
oD;
103, by the output voltage numeral amount u in step 102
oDbe input to voltage control link, voltage control link comprises voltage comparator, controller I and multiplier, and first comparator is by output voltage numeral amount u
oDthe reference voltage U preset with voltage comparator
refrelatively, obtain voltage deviation signal △ u=u
oD-U
refthen input control device I is processed and output signal u
1,
wherein K
pfor proportion adjustable coefficient, T
ifor adjustable integration time constant, described voltage control link output u
1with the input voltage digital quantity u in step 103
iDinput multiplier multiplies each other and obtains the reference value i of Current Control link
ref;
104, by the reference value i of the Current Control link obtaining in step 103
refwith the inductive current digital quantity i obtaining in step 102
lDinput current controlling unit, Current Control link comprises current comparator, controller II and adder, first current comparator obtains current deviation signal △ i=i
lD-i
ref, described current deviation signal △ i input control device II is processed and output signal u
2,
wherein K
pfor proportion adjustable coefficient, T
ifor adjustable integration time constant, with the feed-forward voltage value u of feedforward link controller
fFinput summer, stack obtains frequency conversion reference voltage u
pFM=u
fF+ u
2;
105, by the frequency conversion reference voltage u obtaining in step 104
pFMand the output voltage obtaining in step 102 numeral amount u
oD, output current numeral amount i
oD, input pulse frequency modulator, produce duty ratio constant pulse frequency modulated signal, the switching device that pulse frequency modulated signal constant described duty ratio is transferred to Switching Power Supply is realized digital frequency conversion control.
2. the digital frequency conversion control method for power factor corrector according to claim 1, is characterized in that: the feed-forward voltage output valve of the link that feedovers in step 104
3. according to the digital frequency conversion control method for power factor corrector of claim 1, it is characterized in that: in step 105, the frequency of pulse frequency modulated signal is
wherein L is input inductance, and D is that duty ratio is definite value, P
ofor power output.
4. according to the digital frequency conversion control method for power factor corrector of claim 3, it is characterized in that: the duty ratio of described pulse frequency modulated signal
wherein u
iD (min)for minimum input voltage.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105337262A (en) * | 2015-09-08 | 2016-02-17 | 广东美的制冷设备有限公司 | Variable frequency air conditioner and over-current protective circuit of power factor correction (PFC) circuit |
| CN110784102A (en) * | 2019-11-29 | 2020-02-11 | 广东美的制冷设备有限公司 | Control method, control device, household appliance and computer readable storage medium |
| CN110871539A (en) * | 2018-08-31 | 2020-03-10 | 财团法人精密机械研究发展中心 | Load scanning device, use method thereof and plastic molding machine |
| CN111211668A (en) * | 2020-01-13 | 2020-05-29 | 深圳市高斯宝电气技术有限公司 | Constant power regulation method for digital switching power supply output |
| CN113932396A (en) * | 2020-07-13 | 2022-01-14 | 海信（山东）空调有限公司 | Air conditioner and control method |
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| CN101185044A (en) * | 2005-04-28 | 2008-05-21 | 国际整流器公司 | Digital implementation of power factor correction |
| US20130127358A1 (en) * | 2011-11-17 | 2013-05-23 | Gang Yao | Led power source with over-voltage protection |
-
2014
- 2014-01-09 CN CN201410010654.2A patent/CN103780075A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101185044A (en) * | 2005-04-28 | 2008-05-21 | 国际整流器公司 | Digital implementation of power factor correction |
| US20130127358A1 (en) * | 2011-11-17 | 2013-05-23 | Gang Yao | Led power source with over-voltage protection |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105337262A (en) * | 2015-09-08 | 2016-02-17 | 广东美的制冷设备有限公司 | Variable frequency air conditioner and over-current protective circuit of power factor correction (PFC) circuit |
| CN105337262B (en) * | 2015-09-08 | 2019-01-22 | 广东美的制冷设备有限公司 | The current foldback circuit of convertible frequency air-conditioner and PFC pfc circuit |
| CN110871539A (en) * | 2018-08-31 | 2020-03-10 | 财团法人精密机械研究发展中心 | Load scanning device, use method thereof and plastic molding machine |
| CN110784102A (en) * | 2019-11-29 | 2020-02-11 | 广东美的制冷设备有限公司 | Control method, control device, household appliance and computer readable storage medium |
| CN111211668A (en) * | 2020-01-13 | 2020-05-29 | 深圳市高斯宝电气技术有限公司 | Constant power regulation method for digital switching power supply output |
| CN113932396A (en) * | 2020-07-13 | 2022-01-14 | 海信（山东）空调有限公司 | Air conditioner and control method |
| CN113932396B (en) * | 2020-07-13 | 2023-08-04 | 海信空调有限公司 | Air conditioner and control method |
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Application publication date: 20140507 |
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