CN105871235B - PFC pfc circuit and its inductance discrimination method and device - Google Patents
PFC pfc circuit and its inductance discrimination method and device Download PDFInfo
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- CN105871235B CN105871235B CN201610370380.7A CN201610370380A CN105871235B CN 105871235 B CN105871235 B CN 105871235B CN 201610370380 A CN201610370380 A CN 201610370380A CN 105871235 B CN105871235 B CN 105871235B
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- power switch
- switch tube
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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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal 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
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal 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
- H02M7/219—Conversion of ac power input into dc power output without possibility of reversal 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 in a bridge configuration
-
- 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
-
- 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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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
Abstract
The invention discloses a kind of PFC pfc circuit and its inductance discrimination methods and device, the described method comprises the following steps：To inductance injected pulse test voltage；The input voltage of pfc circuit is detected, and detects the input current of pfc circuit；According to the voltage at input voltage calculating power switch tube inductance both ends when in the conduction state；And according to power switch tube when in the conduction state the variable quantity of the Flux consumption of the voltage at inductance both ends and input current inductance is recognized to obtain the inductance value of inductance.This method calculates the inductance value of inductance by injected pulse test voltage, and according to the variable quantity of the Flux consumption of pulse test voltage effect and input current, to judge whether the inductance is damaged according to inductance value.
Description
Technical field
The present invention relates to power factor correction technology field, more particularly to a kind of PFC (Power Factor
Correction, PFC) circuit and its inductance discrimination method and device.
Background technology
Most household electrical appliance use following circuit topology：Direct current of the single phase alternating current power supply Jing Guo uncontrollable rectification output ripple
Voltage adjusts output steady dc voltage using power factor corrector, is then connected to the electrolytic capacitor of large capacity, finally
Internal switch power supply and basic load is given to power again.Wherein, power factor corrector often uses Boost type pfc circuit, i.e., by electricity
Sense, power switch tube and diode composition.
During household electrical appliance production and transport, the inductance of pfc circuit easy tos produce magnetic core fracture or fragmentation so that electricity
The sensibility reciprocal of sense seriously becomes smaller, to cause power factor emendation function abnormal.If household electrical appliance long-term work is in power factor
In the state of calibration function exception, then the service life of household electrical appliance will be influenced, and local power net can be polluted, even result in house
Electrical appliance can not work normally.
For this purpose, being highly desirable to carry out the inductance self-test of product before product export, prevent defective product from coming into the market.Together
When, the sensibility reciprocal of inductance has positive effect to optimization PFC control parameters.
Invention content
The present invention is directed to solve at least some of the technical problems in related technologies.For this purpose, the present invention
First purpose be to propose a kind of inductance discrimination method of pfc circuit, this method by injected pulse test voltage, and according to
The Flux consumption of pulse test voltage effect and the variable quantity of input current calculate the inductance value of inductance, to be sentenced according to inductance value
Whether the disconnected inductance is damaged.
Second object of the present invention is to propose a kind of inductance device for identifying of pfc circuit.
Third object of the present invention is to propose a kind of pfc circuit.
To achieve the above object, first aspect present invention embodiment proposes a kind of inductance discrimination method of pfc circuit, institute
It includes inductance, power switch tube and diode to state pfc circuit, be the described method comprises the following steps：To the inductance injected pulse
Test voltage；The input voltage of the pfc circuit is detected, and detects the input current of the pfc circuit；According to input electricity
The voltage at pressure calculating power switch tube inductance both ends when in the conduction state；And according to the power switch tube at
The Flux consumption of the voltage at the inductance both ends and the variable quantity of the input current distinguish the inductance when conducting state
Know to obtain the inductance value of the inductance.
The inductance discrimination method of pfc circuit according to the ... of the embodiment of the present invention, by inductance injected pulse test voltage, so
Afterwards by detecting inductive current, and inductance is calculated according to the variable quantity of the Flux consumption of pulse test voltage effect and inductive current
Inductance value replaced in time if damage, with judging whether the inductance is damaged according to inductance value to effectively avoiding
The problem of pfc circuit power factor emendation function exception caused by inductance damages, and then ensure the related production with pfc circuit
Product can work normally, and ensure the reliability of product, improve user experience.
According to one embodiment of present invention, it is obtained by the following formula the inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VindThe inductance two when in the conduction state for the power switch tube
The voltage at end, t1And t2Quarter and finish time at the beginning of the respectively described pulse test voltage injection, Iind(t1) and Iind(t2)
The input current and the pulse test voltage of the respectively described pulse test voltage injection start time injects finish time
Input current.
According to one embodiment of present invention, it is calculated by the following formula power switch tube when institute in the conduction state
State the voltage at inductance both ends：
Vind=Vbd-VIGBT,
Wherein, VindFor the voltage at power switch tube inductance both ends when in the conduction state, VbdFor the input
Voltage, VIGBTFor the conduction voltage drop of the power switch tube.
According to one embodiment of present invention, it when the input current is zero, is injected to the inductance and presets duty ratio
Pulse voltage so that the input current rises, and it is pre- to inductance injection again when the input current drops to zero
If the pulse voltage of duty ratio, so that the pfc circuit is operated in discontinuous current state.
According to one embodiment of present invention, it when injecting n times pulse voltage to the inductance, is obtained by the following formula
The inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VbdFor the input voltage, VIGBTFor the conducting of the power switch tube
Pressure drop, Duty (k) are the duty ratio of the pulse voltage of kth time injection, TPWMFor the work period of the power switch tube, Iind
(k) variable quantity of input current when being injected for kth subpulse voltage, N and k are positive integer.
According to one embodiment of present invention, the default duty ratio meets following formula：
Wherein, Duty is the default duty ratio, L0For the inductance value under the inductance normal condition, IthFor the power
The maximum current value that switching tube allows, VbdFor the input voltage, TPWMFor the work period of the power switch tube.
To achieve the above object, second aspect of the present invention embodiment proposes a kind of inductance device for identifying of pfc circuit, institute
It includes inductance, power switch tube and diode to state pfc circuit, and described device includes：Injection module, the injection module be used for
The inductance injected pulse test voltage；Voltage detection module, the voltage detection module is for detecting the defeated of the pfc circuit
Enter voltage；Current detection module, the current detection module are used to detect the input current of the pfc circuit；Recognize module, institute
It states identification module to be respectively connected with the injection module, the voltage detection module and the current detection module, the identification
Module be used for according to the input voltage calculate the power switch tube it is in the conduction state when the inductance both ends voltage, and
According to the change of power switch tube Flux consumption and the input current of the voltage at the inductance both ends when in the conduction state
Change amount recognizes the inductance to obtain the inductance value of the inductance.
The inductance device for identifying of pfc circuit according to the ... of the embodiment of the present invention, by inductance injected pulse test voltage, so
Afterwards by detecting inductive current, and inductance is calculated according to the variable quantity of the Flux consumption of pulse test voltage effect and inductive current
Inductance value replaced in time if damage, with judging whether the inductance is damaged according to inductance value to effectively avoiding
The problem of pfc circuit power factor emendation function exception caused by inductance damages, and then ensure the related production with pfc circuit
Product can work normally, and ensure the reliability of product, improve user experience.
According to one embodiment of present invention, the identification module is obtained by the following formula the inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VindThe inductance two when in the conduction state for the power switch tube
The voltage at end, t1And t2Quarter and finish time at the beginning of the respectively described pulse test voltage injection, Iind(t1) and Iind(t2)
The input current and the pulse test voltage of the respectively described pulse test voltage injection start time injects finish time
Input current.
According to one embodiment of present invention, the identification module is calculated by the following formula the power switch tube and is in
The voltage at inductance both ends when conducting state：
Vind=Vbd-VIGBT,
Wherein, VindFor the voltage at power switch tube inductance both ends when in the conduction state, VbdFor the input
Voltage, VIGBTFor the conduction voltage drop of the power switch tube.
According to one embodiment of present invention, when the input current is zero, the injection module is noted to the inductance
Enter the pulse voltage of default duty ratio so that the input current rises, and when the input current drops to zero again to institute
The pulse voltage that duty ratio is preset in inductance injection is stated, so that the pfc circuit is operated in discontinuous current state.
According to one embodiment of present invention, described when the injection module injects n times pulse voltage to the inductance
Identification module is obtained by the following formula the inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VbdFor the input voltage, VIGBTFor the conducting of the power switch tube
Pressure drop, Duty (k) are the duty ratio of the pulse voltage of kth time injection, TPWMFor the work period of the power switch tube, Iind
(k) variable quantity of input current when being injected for kth subpulse voltage, N and k are positive integer.
According to one embodiment of present invention, the default duty ratio meets following formula：
Wherein, Duty is the default duty ratio, L0For the inductance value under the inductance normal condition, IthFor the power
The maximum current value that switching tube allows, VbdFor the input voltage, TPWMFor the work period of the power switch tube.
To achieve the above object, third aspect present invention embodiment proposes a kind of pfc circuit comprising above-mentioned inductance
Device for identifying.
The pfc circuit of the embodiment of the present invention can effectively judge whether inductance is sent out by above-mentioned inductance device for identifying
Raw damage, is replaced in time if damaging, to effectively avoid the power factor emendation function exception caused by inductance damages
Problem, and then ensure that Related product can work normally, ensure the reliability of product, improves user experience.
Description of the drawings
Fig. 1 is the topological diagram of pfc circuit according to an embodiment of the invention；
Fig. 2 is the flow chart of the inductance discrimination method of pfc circuit according to the ... of the embodiment of the present invention；
Fig. 3 is the schematic diagram of pulse voltage injection according to an embodiment of the invention；And
Fig. 4 is the block diagram of the inductance device for identifying of pfc circuit according to the ... of the embodiment of the present invention.
Specific implementation mode
The embodiment of the present invention is described below in detail, examples of the embodiments are shown in the accompanying drawings, wherein from beginning to end
Same or similar label indicates same or similar element or element with the same or similar functions.Below with reference to attached
The embodiment of figure description is exemplary, it is intended to for explaining the present invention, and is not considered as limiting the invention.
The pfc circuit proposed according to embodiments of the present invention and its inductance discrimination method and dress described with reference to the accompanying drawings
It sets.
In an embodiment of the present invention, as shown in Figure 1, the circuit of power factor correction of single phase ac input includes control core
Piece, main circuit and detection circuit, main circuit include rectifier bridge, filter capacitor, pfc circuit and big capacity electrolyte capacitor and bear
It carries, pfc circuit includes inductance, power switch tube and diode, wherein power switch tube can be IGBT (Insulated
Gate Bipolar Transistor, insulated gate bipolar transistor) and MOSFET (Metal-Oxide-Semiconductor
Field-Effect Transistor, Metal-Oxide Semiconductor field-effect transistor), diode can be two poles of fast recovery
Pipe.
When power switch tube is opened, input voltage VbdIt is applied on inductance and power switch tube, electric current is from rectifier bridge
Anode exports, and flows through inductance, power switch tube and sampling resistor, returns to the negative terminal of rectifier bridge.Inductive current linearly rises,
Variation relation meets：
Wherein, VbdFor input voltage, L is the inductance value of inductance, IindFor input current, VIGBTFor leading for power switch tube
Logical pressure drop.
When power switch tube turns off, input voltage VbdIt is applied on inductance and diode, anode of the electric current from rectifier bridge
Output, flows through inductance, diode enters electrolytic capacitor and load, and the negative terminal of rectifier bridge is returned to using sampling resistor.It is inputting
Voltage VbdHigher than output voltage VdcWhen, inductive current continues to rise, otherwise electric current declines, and curent change relationship meets：
Wherein, VFRDFor the conduction voltage drop of diode, VdcFor output voltage.
It controls chip and passes through DC voltage (the i.e. input voltage V of pfc circuit after detecting rectifier bridge rectificationbd), inductance electricity
Flow (the i.e. input current I of pfc circuitind) and DC bus-bar voltage (i.e. the voltage namely pfc circuit at electrolytic capacitor both ends is defeated
Go out voltage Vdc) carry out pfc circuit control and inductance identification.Wherein, input current IindResistance sampling method or logical can be used
Cross Hall current sensor detection, input voltage VbdWith output voltage VdcThe detection of electric resistance partial pressure method can be used.
As shown in Fig. 2, the inductance discrimination method of the pfc circuit includes the following steps：
S1, to inductance injected pulse test voltage.
Specifically, when needing the inductance to pfc circuit to recognize, survey can be injected to inductance by controlling chip
Try voltage, wherein test voltage can be pulse test voltage.
S2, detects the input voltage of pfc circuit, and detects the input current of pfc circuit.
S3, according to the voltage at input voltage calculating power switch tube inductance both ends when in the conduction state.
S4, according to the variation of power switch tube Flux consumption and input current of the voltage at inductance both ends when in the conduction state
Amount recognizes inductance to obtain the inductance value of inductance.
Specifically, when being recognized to inductance, control chip injects test voltage to inductance, while passing through sampling resistor
The methods of detection pfc circuit input current Iind, then according to the Flux consumption and input current I of injection test voltage effectind
Variable quantity inductance is recognized, to obtain Flux consumption/input electricity of inductance value=injection test voltage effect of inductance
Flow IindVariable quantity, that is, pass through following formula (3) obtain inductance inductance value：
Wherein, t1And t2Quarter and finish time, I respectively at the beginning of test voltage injectionind(t1) and Iind(t2) respectively
The input current of the input current and test voltage injection finish time of start time, V are injected for test voltageindFor inductance two
The voltage (also referred to as with the counter electromotive force of voltage or inductance generation on inductance) at end, in an embodiment of the present invention, can
The voltage at inductance both ends is calculated by following formula (4)：
Further, when control chip is to inductance injected pulse test voltage, and shape is on according to power switch tube
The variable quantity of the Flux consumption of the voltage at inductance both ends and input current recognizes inductance to obtain the inductance value of inductance when state
When, the V in above-mentioned formula (3)indFor the voltage at power switch tube inductance both ends when in the conduction state, t1And t2Respectively pulse
Test voltage is carved at the beginning of injecting and finish time, Iind(t1) and Iind(t2) be respectively pulse test voltage injection start when
The input current of input current and pulse test voltage the injection finish time at quarter, can be obtained inductance by above-mentioned formula (3)
Inductance value.
Therefore, the inductance discrimination method of the pfc circuit of the embodiment of the present invention, by inductance injected pulse test voltage,
Then by detecting inductive current, and electricity is calculated according to the variable quantity of the Flux consumption of pulse test voltage effect and inductive current
The inductance value of sense is replaced with judging whether the inductance is damaged according to inductance value if damage in time, to effectively keep away
Exempt from the problem of the pfc circuit power factor emendation function exception caused by inductance damages, and then ensures the correlation with pfc circuit
Product can work normally, and ensure the reliability of product, improve user experience.
Further, when control chip by inductance injected pulse test voltage come when being recognized to inductance, at this
In one embodiment of invention, the pulse voltage for presetting duty ratio can be injected so that defeated to inductance when input current is zero
Enter electric current rising, and inject the pulse voltage for presetting duty ratio to inductance again when input current drops to zero, so that PFC is electric
Road is operated in discontinuous current state.
Specifically, as shown in figure 3, control chip injects n times pulse voltage to inductance, if the injection of kth subpulse voltage
Duty ratio is Duty (k), input current IindStart from scratch and rises to Iind(k), it is then shut off pulse voltage output, until input
Electric current IindThe injection for re-starting next pulse voltage after zero again is fallen to, so that input current IindIt is operated in interrupted shape
State.Wherein, the duty ratio for the pulse voltage injected every time may be the same or different.
Then, according in n times pulse voltage injection length, under power switch tube is in the conduction state, injected pulse voltage
The accumulation amount of the Flux consumption of effect and the accumulation amount of input current variable quantity calculate the inductance value of inductance, that is, are noted when to inductance
When entering n times pulse voltage, the inductance value of inductance can be obtained by following formula (5)：
Wherein, Duty (k) is the duty ratio of the pulse voltage of kth time injection, TPWMFor the work period of power switch tube,
Iind(k) variable quantity of input current when being injected for kth subpulse voltage, N and k are positive integer.
Therefore, the inductance discrimination method of pfc circuit of the invention can carry out inductance identification under discontinuous conduct mode,
When each pulse voltage injection, electric current is all rising of starting from scratch, and identification result is closer to the inductance value under zero current condition.
It should be noted that in the above-described embodiments, setting and the input voltage V of duty ratiobd, output voltage Vdc, inductance
Inductance value it is related with default first inductive current, wherein default first inductive current is less than the maximum that power switch tube allows
Current value.
If duty ratio is excessive, in input voltage VbdWhen larger, in pulse voltage injection period, input current I can be madeind
More than default first inductive current so that the saturated characteristic of inductance shows, and inductance identification result is caused to be less than under zero current
Inductance value, or even input current I can be madeindMore than the rotection thresholds of power switch tube, power switch tube overcurrent is caused.For this purpose,
Default duty ratio meets：
That is, under conditions of ignoring the conduction voltage drop of power switch tube, default duty ratio meets following formula (7)：
Wherein, Duty is default duty ratio, L0For the inductance value under inductance normal condition, IthAllow for power switch tube
Maximum current value.
And if duty ratio is too small, it will cause input current IindVariable quantity (ascending amount) it is too small, influence detection essence
Degree extends detection time.Therefore, it is necessary to select suitable duty ratio to ensure input current IindWith input current IindVariation
Amount is in the reasonable scope.
It should be noted that the inductance discrimination method of the embodiment is less than especially suitable for inductance valueInductance
Identification.In addition, in identification process, need to use input voltage VbdWith input current Iind, wherein to detect input current Iind
Input current I in a pulse voltage of power switch tubeindVariable quantity, therefore adopted before and after at least each pulse voltage
Sample input current I twiceind, i.e., in each pulse voltage injection start time and injection finish time sampling input current Iind。
In the embodiment of invention, PWM frequency, the detection frequency of electric current and voltage are improved as far as possible, helps to improve electricity
Feel the precision of identification.
In conclusion the inductance discrimination method of the pfc circuit of the embodiment of the present invention, by testing electricity to inductance injected pulse
Pressure, and the inductance value of inductance is calculated according to the variable quantity of the Flux consumption of pulse test voltage effect and inductive current, with basis
Inductance value judges whether the inductance is damaged, and is replaced in time if damage, to effectively avoid causing because of inductance damage
Pfc circuit power factor emendation function exception problem, and then ensureing can normal work with the Related product of pfc circuit
Make, ensure the reliability of product, improves user experience.
Fig. 4 is the block diagram of the inductance device for identifying of pfc circuit according to the ... of the embodiment of the present invention.
In an embodiment of the present invention, as shown in Figure 1, pfc circuit includes inductance L1, power switch tube Q and diode
FRD, particular circuit configurations and operation principle are already described above, and which is not described herein again.
As shown in figure 4, the inductance device for identifying of the pfc circuit includes：Injection module 10, voltage detection module 20, electric current
Detection module 30 and identification module 40.
Wherein, injection module 10 is used for inductance L1 injected pulse test voltages.Voltage detection module 20 is for detecting PFC
The input voltage V of circuitbd.Current detection module 30 is used to detect the input current I of pfc circuitind.Recognize module 40 respectively with
Injection module 10, voltage detection module 20 are connected with current detection module 30, and identification module 40 is used for according to input voltage VbdMeter
Calculate power switch tube Q it is in the conduction state when the both ends inductance L1 voltage, and it is in the conduction state according to power switch tube Q when electricity
Feel the Flux consumption and input current I of the voltage at the both ends L1indVariable quantity inductance L1 is recognized to obtain the inductance of inductance
Value.
Specifically, injection module 10 and identification module 40 can integrate in control chip in Fig. 1.When needing to PFC
When the inductance L1 of circuit is recognized, test voltage can be injected to inductance L1, wherein test voltage can by injection module 10
Think pulse test voltage, identification module 40 is according to the Flux consumption and input current I for injecting test voltage effectindVariable quantity
Inductance L1 is recognized, to obtain Flux consumption/input current I of inductance value=injection test voltage effect of inductance L1ind
Variable quantity, that is, pass through the inductance value that above-mentioned formula (3) obtains inductance L1.
Therefore, the inductance device for identifying of the pfc circuit of the embodiment of the present invention, by inductance injected pulse test voltage,
Then by detecting inductive current, and electricity is calculated according to the variable quantity of the Flux consumption of pulse test voltage effect and inductive current
The inductance value of sense is replaced with judging whether the inductance is damaged according to inductance value if damage in time, to effectively keep away
Exempt from the problem of the pfc circuit power factor emendation function exception caused by inductance damages, and then ensures the correlation with pfc circuit
Product can work normally, and ensure the reliability of product, improve user experience.
Further, when identification module 40 by injection module 10 to inductance L1 injected pulses test voltage come to inductance L1
When being recognized, in one embodiment of the invention, when input current is zero, injection module 10 is default to inductance L1 injections
The pulse voltage of duty ratio is so that input current rises, and is injected again to inductance when input current drops to zero and preset duty
The pulse voltage of ratio, so that pfc circuit is operated in discontinuous current state.
Specifically, as shown in figure 3, injection module 10 injects n times pulse voltage to inductance L1, if kth subpulse voltage is noted
The duty ratio entered is Duty (k), input current IindStart from scratch and rises to Iind(k), it is then shut off pulse voltage output, until
Input current IindThe injection for re-starting next pulse voltage after zero again is fallen to, so that input current IindIt is operated in discontinuously
State.Wherein, the duty ratio for the pulse voltage injected every time may be the same or different.Then, identification module 40 is according to N
In subpulse voltage injection length, under power switch tube Q is in the conduction state, the Flux consumption of injected pulse voltage effect adds up
The accumulation amount of amount and input current variable quantity calculates the inductance value of inductance L1, that is, when injecting n times pulse voltages to inductance L1
When, the inductance value of inductance L1 can be obtained by above-mentioned formula (5).
Therefore, the inductance device for identifying of pfc circuit of the invention can carry out inductance identification under discontinuous conduct mode,
When each pulse voltage injection, electric current is all rising of starting from scratch, and identification result is closer to the inductance value under zero current condition.
It should be noted that in the above-described embodiments, setting and the input voltage V of duty ratiobd, output voltage Vdc, inductance
The inductance value of L1 is related with default first inductive current, wherein default first inductive current is less than power switch tube Q and allows most
High current value.
If duty ratio is excessive, in input voltage VbdWhen larger, in pulse voltage injection period, input current I can be madeind
More than default first inductive current so that the saturated characteristic of inductance L1 shows, and inductance identification result is caused to be less than zero current
Under inductance value, or even input current I can be madeindMore than the rotection thresholds of power switch tube Q, power switch tube Q overcurrents are caused.
For this purpose, default duty ratio meets above-mentioned formula (7).
And if duty ratio is too small, it will cause input current IindVariable quantity (ascending amount) it is too small, influence detection essence
Degree extends detection time.Therefore, it is necessary to select suitable duty ratio to ensure input current IindWith input current IindVariation
Amount is in the reasonable scope.
It should be noted that the inductance device for identifying of the embodiment is less than especially suitable for inductance valueInductance
Identification.In addition, in identification process, need to use input voltage VbdWith input current Iind, wherein current detection module 30 is wanted
Detect input current IindInput current I in a pulse voltage of power switch tube QindVariable quantity, therefore electric current examine
Survey the front and back sampling of at least each pulse voltage of module 30 input current I twiceind, i.e., inject start time in each pulse voltage
With injection finish time sampling input current Iind。
In an embodiment of the present invention, PWM frequency, the detection frequency of electric current and voltage are improved as far as possible, are helped to improve
The precision of inductance identification.
The inductance device for identifying of pfc circuit according to the ... of the embodiment of the present invention, by inductance injected pulse test voltage, so
Afterwards by detecting inductive current, and inductance is calculated according to the variable quantity of the Flux consumption of pulse test voltage effect and inductive current
Inductance value replaced in time if damage, with judging whether the inductance is damaged according to inductance value to effectively avoiding
The problem of pfc circuit power factor emendation function exception caused by inductance damages, and then ensure the related production with pfc circuit
Product can work normally, and ensure the reliability of product, improve user experience.
In addition, the embodiment of the present invention also proposed a kind of pfc circuit comprising above-mentioned inductance device for identifying.
The pfc circuit of the embodiment of the present invention can effectively judge whether inductance is sent out by above-mentioned inductance device for identifying
Raw damage, is replaced in time if damaging, to effectively avoid the power factor emendation function exception caused by inductance damages
Problem, and then ensure that Related product can work normally, ensure the reliability of product, improves user experience.
In the description of the present invention, it is to be understood that, term " first ", " second " are used for description purposes only, and cannot
It is interpreted as indicating or implies relative importance or implicitly indicate the quantity of indicated technical characteristic.Define as a result, " the
One ", the feature of " second " can explicitly or implicitly include at least one of the features.In the description of the present invention, " multiple "
It is meant that at least two, such as two, three etc., unless otherwise specifically defined.
In the present invention unless specifically defined or limited otherwise, term " installation ", " connected ", " connection ", " fixation " etc.
Term shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or integral；Can be that machinery connects
It connects, can also be electrical connection；It can be directly connected, can also can be indirectly connected through an intermediary in two elements
The interaction relationship of the connection in portion or two elements, unless otherwise restricted clearly.For those of ordinary skill in the art
For, the specific meanings of the above terms in the present invention can be understood according to specific conditions.
In the description of this specification, reference term " one embodiment ", " some embodiments ", " example ", " specifically show
The description of example " or " some examples " etc. means specific features, structure, material or spy described in conjunction with this embodiment or example
Point is included at least one embodiment or example of the invention.In the present specification, schematic expression of the above terms are not
It must be directed to identical embodiment or example.Moreover, particular features, structures, materials, or characteristics described can be in office
It can be combined in any suitable manner in one or more embodiments or example.In addition, without conflicting with each other, the skill of this field
Art personnel can tie the feature of different embodiments or examples described in this specification and different embodiments or examples
It closes and combines.
Although the embodiments of the present invention has been shown and described above, it is to be understood that above-described embodiment is example
Property, it is not considered as limiting the invention, those skilled in the art within the scope of the invention can be to above-mentioned
Embodiment is changed, changes, replacing and modification.
Claims (13)
1. a kind of inductance discrimination method of PFC pfc circuit, which is characterized in that the pfc circuit includes inductance, work(
Rate switching tube and diode, the described method comprises the following steps：
To the inductance injected pulse test voltage；
The input voltage of the pfc circuit is detected, and detects the input current of the pfc circuit；
According to the input voltage calculate the power switch tube it is in the conduction state when the inductance both ends voltage；And
According to the power switch tube Flux consumption of the voltage at the inductance both ends and input current when in the conduction state
Variable quantity the inductance is recognized to obtain the inductance value of the inductance, wherein when to the inductance inject n times pulse
Voltage and when the pfc circuit being made to be operated in discontinuous current state, according in n times pulse voltage injection length, power switch tube
Under in the conduction state, the accumulation amount of Flux consumption and the accumulation amount of input current variable quantity of the effect of injected pulse voltage calculate
The inductance value of inductance.
2. the inductance discrimination method of pfc circuit according to claim 1, which is characterized in that be obtained by the following formula institute
State the inductance value of inductance：
Wherein, L is the inductance value of the inductance, VindFor power switch tube inductance both ends when in the conduction state
Voltage, t1And t2Quarter and finish time at the beginning of the respectively described pulse test voltage injection, Iind(t1) and Iind(t2) respectively
The input of the input current and pulse test voltage injection finish time of start time is injected for the pulse test voltage
Electric current.
3. the inductance discrimination method of pfc circuit according to claim 2, which is characterized in that be calculated by the following formula institute
State power switch tube it is in the conduction state when the inductance both ends voltage：
Vind=Vbd-VIGBT,
Wherein, VindFor the voltage at power switch tube inductance both ends when in the conduction state, VbdFor input electricity
Pressure, VIGBTFor the conduction voltage drop of the power switch tube.
4. the inductance discrimination method of pfc circuit according to any one of claim 1-3, which is characterized in that described defeated
When to enter electric current be zero, the pulse voltage for presetting duty ratio is injected to the inductance so that the input current rises, and described
Input current injects the pulse voltage for presetting duty ratio to the inductance again when dropping to zero, so that the pfc circuit works
In discontinuous current state.
5. the inductance discrimination method of pfc circuit according to claim 4, which is characterized in that when to the inductance inject n times
When pulse voltage, it is obtained by the following formula the inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VbdFor the input voltage, VIGBTFor the conduction voltage drop of the power switch tube,
Duty (k) is the duty ratio of the pulse voltage of kth time injection, TPWMFor the work period of the power switch tube, Iind(k) it is the
The variable quantity of input current when k subpulse voltages inject, N and k are positive integer.
6. the inductance discrimination method of pfc circuit according to claim 4, which is characterized in that the default duty ratio meets
Following formula：
Wherein, Duty is the default duty ratio, L0For the inductance value under the inductance normal condition, IthFor the power switch
The maximum current value that pipe allows, VbdFor the input voltage, TPWMFor the work period of the power switch tube.
7. a kind of inductance device for identifying of PFC pfc circuit, which is characterized in that the pfc circuit includes inductance, work(
Rate switching tube and diode, described device include：
Injection module, the injection module are used for the inductance injected pulse test voltage；
Voltage detection module, the voltage detection module are used to detect the input voltage of the pfc circuit；
Current detection module, the current detection module are used to detect the input current of the pfc circuit；
Recognize module, the identification module respectively with the injection module, the voltage detection module and the current detecting mould
Block is connected, identification module electricity when being used in the conduction state according to the input voltage calculating power switch tube
Feel the voltage at both ends, and according to the power switch tube Flux consumption of the voltage at the inductance both ends and institute when in the conduction state
The variable quantity for stating input current recognizes the inductance to obtain the inductance value of the inductance, wherein when to the inductance
Injection n times pulse voltage and when the pfc circuit being made to be operated in discontinuous current state, according in n times pulse voltage injection length,
Under power switch tube is in the conduction state, the accumulation amount of the Flux consumption of injected pulse voltage effect and tiring out for input current variable quantity
Dosage calculates the inductance value of inductance.
8. the inductance device for identifying of pfc circuit according to claim 7, which is characterized in that the identification module by with
Lower formula obtains the inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VindFor power switch tube inductance both ends when in the conduction state
Voltage, t1And t2Quarter and finish time at the beginning of the respectively described pulse test voltage injection, Iind(t1) and Iind(t2) respectively
The input of the input current and pulse test voltage injection finish time of start time is injected for the pulse test voltage
Electric current.
9. the inductance device for identifying of pfc circuit according to claim 8, which is characterized in that the identification module by with
Lower formula calculate the power switch tube it is in the conduction state when the inductance both ends voltage：
Vind=Vbd-VIGBT,
Wherein, VindFor the voltage at power switch tube inductance both ends when in the conduction state, VbdFor input electricity
Pressure, VIGBTFor the conduction voltage drop of the power switch tube.
10. the inductance device for identifying of the pfc circuit according to any one of claim 7-9, which is characterized in that described defeated
When to enter electric current be zero, the injection module injects the pulse voltage for presetting duty ratio so that on the input current to the inductance
It rises, and injects the pulse voltage for presetting duty ratio to the inductance again when the input current drops to zero, so that described
Pfc circuit is operated in discontinuous current state.
11. the inductance device for identifying of pfc circuit according to claim 10, which is characterized in that when the injection module to
When the inductance injection n times pulse voltage, the identification module is obtained by the following formula the inductance value of the inductance：
Wherein, L is the inductance value of the inductance, VbdFor the input voltage, VIGBTFor the conduction voltage drop of the power switch tube,
Duty (k) is the duty ratio of the pulse voltage of kth time injection, TPWMFor the work period of the power switch tube, Iind(k) it is the
The variable quantity of input current when k subpulse voltages inject, N and k are positive integer.
12. the inductance device for identifying of pfc circuit according to claim 10, which is characterized in that the default duty ratio is full
Sufficient following formula：
Wherein, Duty is the default duty ratio, L0For the inductance value under the inductance normal condition, IthFor the power switch
The maximum current value that pipe allows, VbdFor the input voltage, TPWMFor the work period of the power switch tube.
13. a kind of PFC pfc circuit, which is characterized in that include according to described in any one of claim 7-12
Inductance device for identifying.
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| CN201610370380.7A CN105871235B (en) | 2016-05-27 | 2016-05-27 | PFC pfc circuit and its inductance discrimination method and device |
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| CN201610370380.7A CN105871235B (en) | 2016-05-27 | 2016-05-27 | PFC pfc circuit and its inductance discrimination method and device |
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| CN105871235B true CN105871235B (en) | 2018-09-11 |
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| US6847195B2 (en) * | 2002-08-07 | 2005-01-25 | Skynet Electronic Co., Ltd. | Auxiliary circuit for power factor corrector having self-power supplying and zero current detection mechanisms |
| CN102497700A (en) * | 2011-12-05 | 2012-06-13 | 北方工业大学 | Power factor correction method for LED (light-emitting diode) lighting |
| CN105242118B (en) * | 2015-10-26 | 2018-08-17 | 广东美的制冷设备有限公司 | The inductance detection method and device of PFC pfc circuit |
| CN105429451B (en) * | 2015-12-08 | 2018-05-01 | 广东美的制冷设备有限公司 | A kind of PFC inductance saturation suppression circuit, method and power-supply device |
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