CN107408890B - Synchronous rectification formula switch converters - Google Patents
Synchronous rectification formula switch converters Download PDFInfo
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- CN107408890B CN107408890B CN201580078312.7A CN201580078312A CN107408890B CN 107408890 B CN107408890 B CN 107408890B CN 201580078312 A CN201580078312 A CN 201580078312A CN 107408890 B CN107408890 B CN 107408890B
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- 230000001360 synchronised effect Effects 0.000 title claims abstract description 51
- 230000000903 blocking effect Effects 0.000 claims abstract description 36
- 238000001514 detection method Methods 0.000 claims abstract description 32
- 238000012937 correction Methods 0.000 claims abstract description 24
- 238000005070 sampling Methods 0.000 claims abstract description 23
- 238000010992 reflux Methods 0.000 claims description 13
- 239000003990 capacitor Substances 0.000 claims description 12
- 230000033228 biological regulation Effects 0.000 claims description 2
- 230000005611 electricity Effects 0.000 description 7
- 230000008859 change Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 230000006378 damage Effects 0.000 description 3
- 206010020751 Hypersensitivity Diseases 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 208000026935 allergic disease Diseases 0.000 description 2
- 230000007815 allergy Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000000518 rheometry Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
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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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
-
- 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
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0009—Devices or circuits for detecting current in a converter
-
- 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
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
- Rectifiers (AREA)
Abstract
Synchronous rectification formula switch converters have the control circuit in the circuit of synchronous rectification of the secondary side connection of transformer and according to each sampling timing to primary side switching circuit and circuit of synchronous rectification progress on-off control.The control circuit has：Grid blocking unit compares the detected value of reactor current detection sensor with defined threshold value, grid blocking signal of the output for stopping the work of the synchronous rectification element when the detected value is the threshold value or less；And correction unit, when being reduced to fixed above of the reactor current is detected in the detected value based on the detection sensor, and either one or two of they are corrected with reference to the resume of the detected value of the detection sensor when the detected value of this time sampling of the detection sensor is compared with the defined threshold value by the grid blocking unit.
Description
Technical field
The present invention relates to the synchronous rectification formula switch change-overs for having used FET as rectifier cell in Circuit Fault on Secondary Transformer
Device, more particularly to its control circuit.
Background technology
The primary side of transformer be connected with switching circuit and secondary side be connected with rectification circuit switch converters it
In, there are the switch converters for the circuit of synchronous rectification formula that FET is used as to rectification circuit.In the switch change-over of the synchronous rectification formula
In device, the conducting resistance of FET is relatively low compared with the conducting resistance of diode, accordingly, there exist heat loss tail off and efficiency improve
Advantage.
Fig. 1 is the schematic circuit diagram of the synchronous rectification formula switch converters.
It is connected with the switching circuit comprising FET element Q1, Q2 in the primary side of transformer Tr（Such as 2 pipe positive energizing switch electricity
Road（2-transistor forward switching circuit））, 2 FET elements Q3, Q4 are connected in secondary side.The
One FET element Q3 is the FET element of rectification side, and the second FET element Q4 is the FET element of reflux side.First, second FET members
Part Q3, Q4 are connected, are ended instead of previous diode, are supplied electric power as a result, to load-side（power）.In these FET
The load-side of element Q3, Q4 are connected with by reactor（reactor）L, the smooth circuit that capacitor C is constituted, reactor current inspection
It surveys sensor SH and reactor L to be connected in series with, the output of current detection sensor SH is fed back to control unit.About above-mentioned defeated
Go out, in order to constant current control and be used for determine FET element Q1, Q2 turn-on deadline timing, in addition, for synchronous rectification and
It is used to determine the turn-on deadline timing of FET element Q3, Q4.
Fig. 2 shows the portion of time figures of above-mentioned converter.
V（Q3）For the both end voltage of FET element Q3, V（Q4）For the both end voltage of FET element Q4, I is in reactor L
The reactor current of flowing.
When load is fixed size, when the secondary side of transformer Tr generates positive voltage, electric current is along the secondary of Tr
The secondary side of side → reactor L → capacitor C → FET element Q3 → Tr flows.In addition, when the secondary side in transformer Tr generates
When negative voltage, back flow current is along reactor L → capacitor C → FET element Q4 → reactor L flowings.It is followed with above-mentioned electric current
Ring synchronously carries out ON-OFF control to FET element Q3, Q4.When FET element Q3, Q4 is connected, conducting resistance with
Diode current flow resistance is compared to smaller, and therefore, loss becomes smaller, and result efficiency improves.
Reactor current is that the waveform as shown in Figure 2 for including the ripple as caused by switching still such as is shown by the P of Fig. 2
Go out like that, when load for light load or no-load condition and reactor current gradually decreases when becoming zero nearby, reactor current
For the changed discontinuous electric current of polarity of positive direction or negative direction.At this point, when being that negative timing is in reactor current
When in reactor L → FET element Q4 → capacitor C → reactor L the timing FET element Q4 of streaming current is ended, by
Excessive surge voltage is generated at the both ends of FET element Q4 in the energy accumulation of reactor L（surge voltage）Vs has
When reach the destruction of FET element Q4.
Accordingly, with respect to previous synchronous rectification formula switch converters, it is proposed that will not reactor L → FET element with electric current
The mode flowed to Q4 → capacitor C → reactor L diode is connect with the paths in series after switch converters（Patent text
Offer 1）.As long as being the circuit, then since electric current will not flow to reactor L → FET element Q4 → capacitor C → reactor L, institute
To eliminate above-mentioned problem.
Existing technical literature
Patent document
Patent document 1：Japanese Unexamined Patent Publication 11-146650 bulletins.
Invention content
The subject that the invention solves
But as above-mentioned existing example, will not be via reflux side FET element to phase negative side with reactor current
In the circuit for connecting diode to the mode of flowing, the loss in diode cannot ignore and offset due to the use of FET element Q3,
For putting forward efficient benefit caused by Q4.
It is light the purpose of the present invention is to provide a kind of maintenance high efficiency and in the case of load change generation drastically
The synchronous rectification formula switch converters of surge voltage will not be generated when load or non-loaded in FET element.
Solution for solving the problem
The synchronous rectification formula switch converters of the present invention are that a kind of synchronous rectification formula switch converters have：Transformer；
Switching circuit switchs the DC power supply of the primary side connection in the transformer；Circuit of synchronous rectification, including synchronous rectification
Element, the synchronous rectification element is by the rectification side FET element that is connected in series in the secondary side of the transformer and is connected in parallel
Reflux side FET element constitute；Smooth circuit, by the reactor and capacitor structure of the outlet side connection in the circuit of synchronous rectification
At；
The detection sensor of the reactor current；And control circuit, the detected value based on the detection sensor come
The switching circuit and the rectification side FET element with reflux side FET element connect according to each sampling timing disconnected
Control is opened,
The synchronous rectification formula switch converters are characterized in that,
The control circuit in the present invention has：
Grid blocking unit compares the detected value of the detection sensor with defined threshold value, in the detected value
Grid blocking signal of the output for stopping the work of synchronous rectification element when for below the threshold value；And
Unit is corrected, detects that the reactor current is reduced to fix in the detected value based on the detection sensor
When above, by the grid blocking unit by detected value and the defined threshold of this time sampling of the detection sensor
Either one or two of they are corrected with reference to the resume of the detected value of the detection sensor when value compares.
In the case where correction unit is corrected the detected value of aforementioned detection sensor, aforementioned grid blocking unit will
Detected value after being corrected by aforementioned corrected unit is compared with aforesaid threshold values.In addition, being carried out to defined threshold value in correction unit
In the case of correction, aforementioned grid blocking unit will be by the detection of threshold value and aforementioned this time sampling after the correction of aforementioned corrected unit
Value compares.
Grid blocking signal is to carry out forcibly stopping the effect of the work of synchronous rectification element and detect
Detected value after surveying the detected value of sensor or being corrected by correction unit is less than the letter exported at once in the case of defined threshold value
Number.Becoming gently loading or when no-load condition, to be used to prevent reactor current i.e. reactor → reflux side round about
FET element（FET element Q4）The signal of the direction flowing of → capacitor → reactor, from control unit to the grid of synchronous rectification element
Pole exports.When reactor current will flow round about at once, grid blocking signal is sent out by synchronous rectification element
Work forcibly stop, preventing reflux side FET element from reaching destruction due to excessive surge voltage.
In the present invention, above-mentioned control unit is controlled according to each sampling timing of digital processing, still, aforementioned corrected
Unit is corrected with reference to the resume of the detected value comprising previous sampling come the detected value of this time sampling to reactor current.Or
Person is corrected threshold value.This is corrected to the correction of the first-order lag for ensureing the reponse system for including detection sensor, makes
This time closely actual value of differential of sample detecting value and threshold value（Difference）.Therefore, in the reduction drastically of reactor current, correction
Detected value afterwards is more than threshold value in timing earlier, the case where with without correcting compared with, grid blocking signal occurs earlier.
Grid blocking signal occurs earlier, and the work of synchronous rectification element as a result, stops periodically also shifting to an earlier date, therefore, it is possible to
Stop the work of synchronous rectification element before reactor current is gradually decreased and become zero nearby.As a result, without reactance
The case where device electric current flows round about via reflux side FET element can prevent to reflux side FET element（FET element
Q4）Apply excessive surge voltage Vs.Further more, replacing correcting the detected value this time sampled and corrected threshold also may be used.
Further more, threshold value is fixed as high value and generates grid blocking signal earlier, can also prevent to reflux side FET members
Part（FET element Q4）Apply excessive surge voltage Vs, still, when doing like this, no matter electricity when reactor current is reduced
The inclination of rheology is all same control can synchronize accordingly, with respect to the full output current scope of switch converters
The output current scope of rectification becomes smaller, and cannot say it is preferred from the viewpoint of raising efficiency is such.In the present invention, it deposits
The advantages of can prevent the generation of excessive surge voltage Vs not setting the threshold to high value.
Invention effect
In the present invention, it can realize that the destruction of the high efficiency and reflux side FET element of converter prevents.
Description of the drawings
Fig. 1 is the circuit diagram of previous synchronous rectification formula switch converters.
Fig. 2 is the portion of time figure of above-mentioned converter.
Fig. 3 is the circuit diagram of the synchronous rectification formula switch converters of embodiments of the present invention.
Fig. 4 is the grid signal of above-mentioned converter（gate signal）The on-off timing of G1 ~ G4.
Fig. 5 is the portion of time figure of above-mentioned converter.
Specific implementation mode
Fig. 3 is the circuit diagram of the synchronous rectification formula switch converters as embodiments of the present invention.
The 2 pipe normal shock switching circuits 2 comprising FET element Q1, Q2 are connected in the primary side of transformer Tr, are connected in secondary side
It is connected to the circuit of synchronous rectification 3 being made of 2 FET elements Q3, Q4.First FET element Q3 of circuit of synchronous rectification 3 is rectification side
FET element, the second FET element Q4 be reflux side FET element.First, second FET element Q3, Q4 replaces previous two
Pole pipe is connected, is ended, and supplies the electric power after rectification to load-side as a result,.In the load-side of these FET elements Q3, Q4
It is connected with the smooth circuit being made of reactor L, capacitor C, the current detection sensor SH and reactor L of reactor current go here and there
Connection connection, the output of current detection sensor SH are fed back to control unit 1.The output of current detection sensor SH be used to determine
The turn-on deadline timing for determining FET element Q1 ~ Q4, to carry out constant current control and synchronous rectification.
Control unit 1 has：The reactor current detection circuit that size and current direction to reactor current are detected
10, to comprising FET element Q1, Q2 switching circuit 2 supply gate driving pulse G1, G2 primary side gate driving circuit 11,
The synchronous rectification gate driving electricity of gate driving pulse G3, G4 is supplied to the circuit of synchronous rectification 3 being made of FET element Q3, Q4
Road 12 and based on reactor current detected value come carry out converter constant current control it is synchronous with circuit of synchronous rectification 3
Rectification controls or work stops the CPU13 of control.In addition, exporting gate driving pulse G3, G4 via grid circuit 14, work as generation
Aftermentioned grid blocking signal（gate block signal）When GB, by the grid circuit 14 by gate driving pulse G3, G4
It disconnects.
Fig. 4 shows the connection of grid signal G1 ~ G4 of FET element Q1 ~ Q4 of above-mentioned converter, grid blocking signal GB
Disconnect timing.In addition, Fig. 5 shows the portion of time figure of above-mentioned converter.V（Q3）For the both end voltage of FET element Q3, V
（Q4）For the both end voltage of FET element Q4, in fixed sampling period to the reactor electricity that is flowed in reactor L according to D
Stream be detected after detected value with straight line to the detected value of each sampling into the track after row interpolation（Reactor current itself
Including ripple as shown in Figure 2）.In addition, S is to the grid blocking signal GB for making the work of FET element Q3, Q4 stop
Threshold value when being exported.
Using gate drive signal G1, G2 from primary side gate driving circuit 11 same timing to FET element Q1,
Q2 carries out turn-on deadline driving.CPU13 monitors reactor current detected value the gate driving that output is controlled by PWM is believed
Number G1, G2, so that reactor current is constant current.In addition, with gate drive signal G1, G2 synchronously by gate drive signal
G3, G4 are supplied respectively to FET element Q3, Q4.
Then work is illustrated.
When load for fixed size when primary side switch element FET element Q1, Q2 be connected and in transformation
When the secondary side of device Tr generates positive voltage, electric current is with the secondary side of Tr → reactor L → capacitor C → FET element Q3 → Tr
Secondary side path flowing.CPU13 is to during in positive voltage, reactor current flows in the direction（The rectified current phase
Between）Judged, gate drive signal G3 is connected.In addition, when the secondary side of transformer Tr generates negative voltage, it is based on
The energy accumulation of reactor L, back flow current is along reactor L → capacitor C（C1,C2）The path of → FET element Q4 → reactor L
Flowing.During CPU13 flows the back flow current（During back flow current）Judged, gate drive signal G4 is connected.
The cycle is repeated on one side, controls the turn-on deadline of FET element Q1, Q2 on one side so as to be constant current, also, control FET element
The turn-on deadline of Q3, Q4 are so as to synchronize rectification, by the energy efficient rate inputted from transformer Tr primary sides to load confession
It gives.
In above circuit, conducting resistance when FET element Q3, Q4 is connected is smaller than diode current flow resistance, because
This, compared with replacing FET element Q3, Q4 and being only connected to the diode rectifier circuit of diode, loss becomes smaller, result efficiency
It improves.
Further more, in each gate drive signal G1（G2）, be provided with dead time as shown in Figure 4 between G3, G4 signal
（dead time）Dt prevents each FET element from being simultaneously turned on.
In addition, the detection signal exported from reactor current detection sensor SH is detected by CPU.Therefore, when being detected
Value is set as this detected value a（n）, previous detected value a（n-1）When, calculate the deviation δ of the detected value of these each samplings.
For a（n）<a（n-1）In the case of（When reactor current is reduced）, judge to indicate that this sample detecting value is adopted with previous
The deviation δ of the difference of sample detected value（Absolute value）Whether it is fixed value or less.Situation smaller than fixed value deviation δ is the flat of reactor
The case where equal electric current is slowly reduced, in this case, by this sample detecting value a（n）Directly compared with threshold value S, herein
Secondary detected value a（n）For threshold value S or less when, FET element Q4 is ended using grid blocking signal GB.It does like this, Neng Gou
Reactor current becomes making synchronous rectification element stop before discontinuous negative back flow current flowing.Like this, for slow
Reactor current reduction, by this sample detecting value a as newest detected value（n）Directly relatively come with threshold value S
Judge grid blocking signal output could, therefore, stop to allergy the circuit of synchronous rectification of the secondary side of transformer Tr, will not
Efficiency is interfered to improve.Further more, threshold value S is set to the amplitude of the ripple component of reactor current shown in figure 2 or more
Value is common.
Then, it sharp lightens to load or work when as no-load condition illustrates.
As shown in Figure 5, when load change is light load or no-load condition, reactor current detected value such as D1 institutes
Show and promptly move closer to zero like that, still, at this point, control circuit integrally carries out movement below.
In Figure 5, D2 indicates that the actual variation of reactor current detected value, D1 indicate the reactance detected by CPU13
The variation of the detected value of device electric current.That is, in reactor current detection sensor SH or reactor current detection circuit 10
The first-order lag of middle presence signal processing, therefore, D1 are to prolong in time compared with D2 using the lag as main cause
Slow characteristic.Due to the lag, CPU13 carries out the on-off control of gate drive signal G3, G4 based on D1.Reactor electricity
The detection of stream is carried out according to each of the sampling period of regulation, still, gradually happens variation in load and reactor is electric
In the case that stream is slowly reduced, since the variation is smaller, so the detected value D of reactor current can be detected roughly correctly
Go out the average value of reactor current.
In such a case, as being enumerated as problem in the job description of the previous converter in Fig. 2, when
When being controlled based on D1 to carry out the on-off of gate drive signal G3, G4 when reactor current I is dramatically reduced as shown,
Grid blocking signal GB is exported in the timing t 1 of the sample detecting value a4 according to CPU13.Then, due to the lag of detection in t1
Negative reactor current is flowed（Flow the back flow current of opposite direction）, therefore, when in this state utilize grid blocking
When signal GB ends FET element Q4, the both ends in FET element Q4 can not be avoided to generate excessive surge voltage Vs.This be because
For control when relative to load change is caused by reactor current detection sensor SH or reactor current detection circuit 10
Control system first-order lag it is big to the degree that cannot ignore.
Further more, Fig. 5 is be demonstrated by time shaft figure with expanding, reactor current above-mentioned slowly reduces and becomes threshold value
The situation of S or less and the situation of Fig. 5 are significantly different.That is, using on the threshold value S of Fig. 5 as with its less parallel
Line change and gradually less than threshold value S and again under threshold value S with the changed side of the approximately parallel lines of threshold value S
Formula indicates detected value D in this case.That is, when wanting to show slow variation above-mentioned in Figure 5, detected value D
It is expressed as Chong Die with threshold value S, the time shaft of variation is different.Therefore, in the feelings of slow reactor current reduction
Under condition, as long as in sample detecting value a（n）Timing less than threshold value S makes FETQ3 and Q4 end, and can avoid becoming reactance
The operating mode for the problem of device electric current is as negative back flow current flowing.
In the converter of present embodiment, when detecting that reactor current is sharp reduced, electricity is set in CPU13
The correction unit of the detected value of anti-device electric current.The correction is carried out by the operation of CPU13.
That is, in Figure 5, in the case where the sample detecting value of this sampling timing is set as a3, when for a2>The feelings of a3
Under condition（When reactor current is reduced）And and previous sample detecting value a2 deviation δ be some fixed value more than when, carry out to this
Secondary sample detecting is worth corrected calculation process.Detected value after by correction is set as b（n）When, by b（n）=a（n）- δ tables
Show, uses the detected value b after the correction（n）To carry out the comparison with threshold value.Therefore, detected value b after correction（n）For threshold value
When S or less, grid blocking signal is exported.As described above, the operation of deviation δ is carried out according to each sampling period, when this is inclined
When poor δ is that fixed value or more detects that the reduction amplitude of reactor current is the variation of some fixed value or more, it is used for
Export the correction calculation of grid blocking signal.
In Figure 5, to carrying out operation as the deviation δ of a3 and the difference of a2, whether judgement deviation δ is fixed value or more.?
When deviation δ is fixed value or more, a3 is corrected to b3（=a3-δ）, by the detected value b3 after correction compared with threshold value S.Then, when
When it is below threshold value, grid blocking signal GB is generated to make FETQ3 and Q4 end.Therefore, start in negative reactor current
Before the time t1 of flowing, grid blocking signal GB is exported in the sampling timing t2 of sample detecting value a3, it can be in transformer Tr
The negative back flow current of secondary side flowing before so that the work of FET element Q3 and Q4 is stopped.
When detected value D1 is more anxious high inclination, due to deviation δ biggers, so the generation timing of grid blocking signal GB
Earlier.
In the above example, for the corrected value of operation a3 and by and previous sample detecting value deviation δ be used as subtract
It goes to be worth, however, it is also possible to be multiplied by coefficient to deviation, such as makes deviation δ × 2.As long as doing like this, then grid blocking can be made to believe
Earlier, response improves for the generation timing of number GB.In addition it is also possible to by the inclined of the average value with past multiple sample detecting values
Difference can also change according to the inclination of D1 for carrying out average past number of samples as value is subtracted.Furthermore it is possible into
The various resume references of row.Further more, needing grid blocking signal GB being output to FET element Q3, Q4 both sides which to make all stop
Only work.Carrying out what kind of correction should be determined by testing, so as to which excessive wave will not be generated at the both ends of FET element Q4
It gushes voltage Vs and Corrective control will not become allergy.
In turn, alternatively, correction unit can also be based on deviation δ come corrected threshold S.Shown in Fig. 5
In example, threshold value S is corrected to S+ δ instead of carrying out the correction of a3- δ.It like this, also being capable of dynamically corrected threshold S.
When load reverts to common load from light load or no-load condition, reactor current starts to flow, therefore,
Its size is more than threshold value S, still, at this point, due to also disconnecting grid blocking signal GB, FET members is utilized so re-starting again
The rectification of part Q3, Q4 work.
Further more, by the way that the value of threshold value S is set as high fixed value, to can also make when load condition carries out the sudden turn of events
The generation timing of grid blocking signal GB is early（Such as from t1 to t2）, still, when threshold value S is set as high fixed value, electricity
The generation timing of grid blocking signal GB when variation when anti-device electric current is reduced is slow is excessively early.As a result, as a whole
It shortens during rectification can be synchronized, efficiency reduces.On the other hand, in the present embodiment, grid blocking signal GB
The emergency of variation when the timing of generation is reduced according to reactor current dynamically changes, therefore, as a whole can be into
The region of row synchronous rectification or range will not become smaller.
The explanation of reference numeral
1- control units
2-2 pipe normal shock switching circuits
3- circuit of synchronous rectification.
Claims (4)
1. a kind of synchronous rectification formula switch converters, have：
Transformer；
Switching circuit connect with the primary side of the transformer and is switched to DC power supply；
Circuit of synchronous rectification, including synchronous rectification element, the synchronous rectification element with the secondary side of the transformer by connecting
The rectification side FET element of connection and the reflux side FET element being connected in parallel are constituted；
Smooth circuit, the reactor and capacitor being connect by the outlet side with the circuit of synchronous rectification are constituted；
The detection sensor of the reactor current；And
Control circuit, based on the detected value of the detection sensor come according to each sampling timing to the switching circuit and institute
It states rectification side FET element and reflux side FET element carries out on-off control,
The synchronous rectification formula switch converters are characterized in that,
The control circuit has：
Grid blocking unit compares the detected value of the detection sensor with defined threshold value, is institute in the detected value
Grid blocking signal of the output for stopping the work of synchronous rectification element when stating threshold value or less；And
Correct unit, the detected value based on the detection sensor detect the reactor current be reduced to fixed value with
When upper, by the grid blocking unit by detected value and the defined threshold value of this time sampling of the detection sensor
Either one or two of they are corrected with reference to the resume of the detected value of the detection sensor when comparing.
2. synchronous rectification formula switch converters according to claim 1, wherein the correction unit is this time sampled described
Detected value and previous sampling detected value deviation be fixed value more than when, using the deviation to this detected value
It is corrected, the grid blocking unit is by the detected value of this time sampling after the correction compared with the defined threshold value
Compared with.
3. synchronous rectification formula switch converters according to claim 1, wherein the correction unit is this time sampled described
Detected value and previous sampling detected value deviation be fixed value more than when, carry out changing the regulation using the deviation
Threshold value correction, the grid blocking unit compares threshold value of the detected value after the correction of this time sampling.
4. synchronous rectification formula switch converters according to claim 2 or 3, wherein the correction unit make it is described this time
The deviation of the detected value of sampling and the detected value of the previous sampling is that the value after fixed coefficient is multiplied by the deviation.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015-064363 | 2015-03-26 | ||
| JP2015064363 | 2015-03-26 | ||
| PCT/JP2015/082823 WO2016151943A1 (en) | 2015-03-26 | 2015-11-24 | Synchronous rectification switching-converter |
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| Publication Number | Publication Date |
|---|---|
| CN107408890A CN107408890A (en) | 2017-11-28 |
| CN107408890B true CN107408890B (en) | 2018-11-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201580078312.7A Active CN107408890B (en) | 2015-03-26 | 2015-11-24 | Synchronous rectification formula switch converters |
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| Country | Link |
|---|---|
| JP (1) | JP6193529B2 (en) |
| KR (1) | KR101843793B1 (en) |
| CN (1) | CN107408890B (en) |
| SG (1) | SG11201706950UA (en) |
| TW (1) | TWI590576B (en) |
| WO (1) | WO2016151943A1 (en) |
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|---|---|---|---|---|
| JP4270820B2 (en) * | 2002-08-19 | 2009-06-03 | 富士通テレコムネットワークス株式会社 | Multi-output DC-DC converter |
| JP2008099395A (en) * | 2006-10-10 | 2008-04-24 | Toyota Industries Corp | Dc-dc converter |
| JP5454993B2 (en) * | 2008-03-17 | 2014-03-26 | 株式会社安川電機 | Matrix converter protection device |
| JP5115317B2 (en) * | 2008-05-12 | 2013-01-09 | ミツミ電機株式会社 | Switching power supply |
| JP5353119B2 (en) * | 2008-08-26 | 2013-11-27 | サンケン電気株式会社 | Switching power supply |
| JP6076839B2 (en) * | 2013-06-03 | 2017-02-08 | 株式会社デンソー | Power converter |
-
2015
- 2015-11-24 SG SG11201706950UA patent/SG11201706950UA/en unknown
- 2015-11-24 WO PCT/JP2015/082823 patent/WO2016151943A1/en active Application Filing
- 2015-11-24 KR KR1020177023602A patent/KR101843793B1/en active IP Right Grant
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- 2015-11-24 JP JP2017507334A patent/JP6193529B2/en active Active
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| SG11201706950UA (en) | 2017-10-30 |
| JPWO2016151943A1 (en) | 2017-09-21 |
| JP6193529B2 (en) | 2017-09-06 |
| KR101843793B1 (en) | 2018-03-30 |
| KR20170101316A (en) | 2017-09-05 |
| CN107408890A (en) | 2017-11-28 |
| TWI590576B (en) | 2017-07-01 |
| WO2016151943A1 (en) | 2016-09-29 |
| TW201637341A (en) | 2016-10-16 |
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