Embodiment
In the power-supply controller of electric that one embodiment of the invention are illustrated, a compensating signal V
cOMPonly have and determine an opening time T
oN.This power-supply controller of electric can go detection one assist winding AUX one discharge time T
dIS, then utilize current detection signal V
cSand discharge time T
dIS, go to extrapolate a load representation signal V
l-EST.This load representation signal V
l-ESTroughly can represent power supply unit instantly, to the output current I that a load provides
oUT.This power-supply controller of electric is according to this load representation signal V
l-ESTdecide one and cover time T
bLOCK.Time T is covered at this
bLOCKafter past, this power-supply controller of electric just allows end period time T
cYC.
Briefly, in one embodiment of this invention, opening time T
oNby compensating signal V
cOMPdetermined, and covered time T
bLOCKby representing this output current I
oUTthis load representation signal V
l-ESTdetermined.
Under such design, as long as under the constant limit of this load, this output current I
oUTbe a fixing constant, and this of correspondence cover time T
bLOCKit will be approximately a definite value.Now, this compensating signal V
cOMPcan be adjusted automatically, and be produced appropriate opening time T
oN.Result is exactly that the power switch of this power supply unit can carry out trough switching at a fixing signal trough, no longer has trough in known technology and switches unstable problem and occur.So possibility can stress release treatment.
In one embodiment of this invention, switch the Electromagnetic Interference that may cause to eliminate fixing trough, therefore a power-supply controller of electric covers time T for this
bLOCKcarry out shaking (jittering).This covers time T
bLOCKshake result, certainly can have influence on compensating signal V
cOMP.But, in this embodiment, compensating signal V
cOMPcan't have influence on and cover time T
bLOCK, because this covers time T
bLOCKroughly only have by this output current I
oUTand this shake affected, and when measuring Electromagnetic Interference, this output current I
oUTfor definite value.Therefore, can determine that this covers time T
bLOCKshake result, roughly verily also effectively, this can be covered time T
bLOCKchange in necessarily among a small circle in, may can by switching frequency f
cYCchange in corresponding one among a small circle in, solve the problem of Electromagnetic Interference.
Fig. 3 shows the QR controller 80 implemented according to the present invention, in one embodiment, that replaces the QR controller 26 in Fig. 1.As shown in Figure 3, QR controller 80 include valley detection device 82, discharge time detector 84, output current estimation device 86, with door 88, cover time generator 90, frequency jitter device 92 and pulse-width modulator 94.Fig. 4 shows after QR controller 80 instead of the QR controller 26 of Fig. 1, some signal waveforms in circuit.The following description, referring to Fig. 1,3 and 4.
Discharge time, detector 84, by test side QRD and divider resistance 30 and 28, was coupled to auxiliary winding AUX.Discharge time, detector 84 was according to the cross-pressure V of auxiliary winding AUX
aUX, produce discharge time signal S
tDIS, its can indicate auxiliary winding AUX one discharge time T
dIS.For example, as the discharge time signal S in Fig. 4
tDISwaveform shown in, discharge time T
dISbe approximately at opening time T
oNafter end, cross-pressure V
aUXthe 1st rising edge (in time point t
1) between the 1st falling edge (in time point t
2) time.
Valley detection device 82, by test side QRD, detects at T discharge time
dISafter, cross-pressure V
aUXon the signal trough that occurs.Test side QRD has and detects voltage V
qRD.Valley detection device 82 can produce a trough index signal S
vD, it has multiple pulse, the time that each expression one respective signal trough occurs.For example, as cross-pressure V
aUXunder be reduced to a set time after 0V, trough index signal S
vDjust there is a pulse.As the cross-pressure V in Fig. 4
aUXwith trough index signal S
vDwaveform illustrate, cross-pressure V
aUXat shut-in time T
oFF0V (time point t is reduced under interior first time
3) after, represent signal trough VL
1occur, so cause at time point t
4, trough index signal S
vDthere is a pulse.Similar, signal trough VL
2a set time after occurring, trough index signal S
vDthere is another pulse.
As shown in Figure 3, output current estimation device 86 received current detection signal V
cSand discharge time signal S
tDIS, produce load representation signal V according to this
l-EST.Current detection signal V
cSbe positioned at current detecting end CS, it represents the electric current I flowing through resistance 36
cS, it is also the electric current I flowing through armature winding PRM
pRM.Although load representation signal V
l-ESTbe a result estimated, but it roughly can represent the output current I being supplied to load 24
oUT.Citing is described in detail output current estimation device 86 after a while.
Cover time generator 90, according to load representation signal V
l-EST, produce a mask signal S
bLOCK, cover time T to provide
bLOCK.For example, as load representation signal V
l-ESTtime larger, cover time T
bLOCKlarger.As the mask signal S of Fig. 4
bLOCKwaveform illustrated, cover time T
bLOCKwith T cycle time
cYCroughly synchronously start (in time point t
sTR), and cover time T
bLOCKend at time point t
rELEASE.
Frequency jitter device 92, is connected to and covers time generator 90, provides a dither control signal S
jITTER, cover time T in order to a little change
bLOCK.For example, under the stable state that load 24 is constant, dither control signal S
jITTERbe a cyclical signal, its change frequency is 400Hz, and dither control signal S
jITTERcan make to cover time T
bLOCKchange between 1/ (27.5kHz) ~ 1/ (25kHz), so switching frequency f
cYCmay approximately change between 25kHz ~ 27.5kHz.In other words, now, dither control signal S
jITTERperiod of change (=1/400), much larger than T cycle time
cYC(between 1/ (27.5kHz) and 1/ (25kHz)).
Input to be connected to respectively cover time generator 90 and valley detection device 82 with two of door 88.Only covering time T
bLOCKafter end, just can transmit trough index signal S with door 88
vD, and trough index signal S
vDin pulse (set) pulse-width modulator 94 could be set.As the trough index signal S of Fig. 4
vDwith mask signal S
bLOCKwaveform illustrate, covering time T
bLOCKterminate (t
rELEASE) after time point t
eND, trough index signal S
vDoccurred a pulse, and this pulse is provided with pulse-width modulator 94, makes pwm signal V
gATEbe set to " 1 " in logic.T cycle time is made with door 88
cYCend to cover time T
bLOCKafter first signal trough (time point t when occurring
eND).The time point t of this switch periods
eND, equal the time point t of next switch periods
sTR.
As the time point t in Fig. 4
sTRwith t
eNDillustrated, as pwm signal V
gATEone when being set to " 1 " in logic, and power switch 34 is unlocked, start one cycle time T
cYCand an opening time T
oN.Pulse-width modulator 94 is according to compensating signal V
cOMPwith current detection signal V
cS, determine opening time T
oNlength.For example, display one proportional compensation signal V is had in Fig. 4
cOMP-SCALED, it is roughly ratio in compensating signal V
cOMP.As the current detection signal VCS in Fig. 4 waveform shown in, as current detection signal V
cSexceed proportional compensation signal V
cOMP-SCALEDtime (time point t
1), pwm signal V
gATEbe changed to " 0 " in logic, opening time T
oNterminate, shut-in time T
oFFstart.
Fig. 5 illustrates output current estimation device 86, and it has transducer 190, electric potential transducer (levelshifter) 192, refresh circuit 196, collects electric capacity 198, one switch 104, Voltage-controlled Current Source (voltage-controlledcurrentsource) 102 and a CS peak voltage detector 100.
CS peak voltage detector 100 produces voltage V
cS-PEAK, which represent current detection signal V
cSa peak value.For example, publication number is the example that Figure 10 in the U.S. Patent application of US20100321956A1 just provides CS peak voltage detector 100.In certain embodiments, the average current detection device of illustrating in Figure 17 or Figure 18 of CS peak voltage detector 100 U.S. Patent application that can be US20100321956A1 with publication number is replaced.Voltage-controlled Current Source 102 is by voltage V
cS-PEAKconvert discharging current I to
dIS, it only has at discharge time signal S
tDISduring for " 1 " in logic, collecting terminal ACC is discharged.In other words, discharging current I
dISto the discharge time of collecting terminal ACC, equivalence approximates greatly T discharge time
dIS.In certain embodiments, the switch 104 in Fig. 5 can omit, instead, and discharge time signal S
tDISbe used for starting (activate) or closing (deactivate) Voltage-controlled Current Source 102.Voltage V on electric capacity 199
m, after being changed by displacement, become load representation signal V
l-EST, give transducer 190, be used for a predetermined reference voltage V
rEFrelatively.Transducer 190, according to comparative result, exports charging current I
cHARGE, collecting terminal ACC is charged constantly.Refresh circuit 196 is by update signal S
uPDATEtriggered, to the feedback voltage V on collecting terminal ACC
aCCsampling, upgrades voltage V
m, can each cycle time T
cYCupgrade once.Update signal S
uPDATEand unnecessary each cycle time T
cYCjust make refresh circuit 196 perform upgrade once, for example, also can every two cycle time T
cYCperform and upgrade once.In one embodiment, update signal S
uPDATEpulse width modulating signal V can be equal to
gATE, mean that the action of renewal is at shut-in time T
oFFbe performed time at the beginning.Voltage V
mbe all remain on a definite value at ordinary times, until refresh circuit 196 is to after its renewal, just can become another definite value.Can find, as voltage V from above explanation
mtime constant, charging current I
cHARGEalso can remain unchanged.
One cycle time T
cYCin, collect electric capacity 198 and note down and have collected charging current I
cHARGEin T cycle time
cYCa charge integrate result and discharging current I
dISin T discharge time
dISthe difference of electric discharge integral result two integral results.
Analyze in the U.S. Patent application that similar publication number is US20100321956A1, as charging current I
cHARGEbe a definite value, and feedback voltage V
aCCvalue when sampled, equal last sampled time value, that charging current I
cHARGEwill be the output current I with outputting to load 24
oUTproportional.In order to make charging current I
cHARGEwith output current I
oUTproportional, so feedback voltage V
aCCeach sampled time value, must be the same or stable.Refresh circuit 196, electric potential transducer 192 and transducer 190 together form the primary Ioops with negative loop gain (negativeloopgain), and this loop finally can make feedback voltage V
aCCeach sampled time value, be stabilized in a value.For example, if charging current I
cHARGEbe greater than with output current I
oUTa proportional desired value, that feedback voltage V
aCCwhen the sampling of next time, will become large, cause the voltage V after renewal
malso along with change is large, therefore, charging current I
cHARGEwill diminish.Vice versa.So, when the stable state that load 24 is constant, voltage V
mone can be stopped to be relatively fixed value, and charging current I
cHARGEwhat finally can become approximately follows output current I
oUTproportional.
Fig. 6 shows in one embodiment, load representation signal V
l-ESTwith output current I
oUTrelation.As shown in Figure 6, load representation signal V
l-ESTwith output current I
oUTbe roughly man-to-man relation, so load representation signal V
l-ESTcan roughly represent output current I
oUT.
Load representation signal V
l-ESTroughly determine that one covers time T
bLOCK, so output current I
oUTroughly determine and cover time T
bLOCK, namely maximum switching frequency f
cYC-MAX(=1/T
bLOCK).Fig. 7 shows in one embodiment, output current I
oUTwith a maximum switching frequency f
cYC-MAX(=1/T
bLOCK) between relation.As output current I
oUTbigger than normal, for example, be greater than predetermined current I
h, represent that load 24 is a high capacity, maximum switching frequency f
cYC-MAXwith dither control signal S
jITTERchange frequency, modulating frequency changes between 60kHz ~ 66kHz.As output current I
oUTtime less than normal, for example, predetermined current I is less than
l, represent that load 24 is a low load, maximum switching frequency f
cYC-MAXwith dither control signal S
jITTERchange frequency, modulating frequency changes between 25kHz ~ 27.5kHz.
Can find from Fig. 3 and Fig. 4, opening time T
oNby compensating signal V
cOMPdetermined, and covered time T
bLOCKby representing output current I
oUTload representation signal V
l-ESTdetermined.
As previously described, under such design, as long as under the constant limit of load 24, output current I
oUTa fixing constant, and time of the covering T of correspondence
bLOCKapproximately just a definite value, can not along with compensating signal V
cOMPchange and be changed.Result is exactly that the power switch 34 of this power supply unit can carry out trough switching at a fixing signal trough, no longer has trough in known technology and switches unstable problem and occur.So possibility can stress release treatment.
And, illustrate as Fig. 3 and Fig. 7, cover time T
bLOCKroughly only be output electric current I
oUTand dither control signal S
jITTERaffected, and when measuring Electromagnetic Interference, this output current I
oUTfor definite value.Therefore, dither control signal S can be determined
jITTERroughly verily also effectively, can will cover time T
bLOCKchange in necessarily among a small circle in, namely switching frequency f
cYCto change in corresponding one among a small circle in.So, the problem of Electromagnetic Interference can may be solved.
That more than illustrates is QR switch type power supplying device, but the present invention is not limited to this.Fig. 8 shows the power-supply controller of electric 200 implemented according to the present invention.Power-supply controller of electric 200 does not operate in QR pattern, but in one embodiment, can replace the QR controller 26 in Fig. 1.Power-supply controller of electric 200 shown in Fig. 8 do not have valley detection device in Fig. 3 82 with door 88, and mask signal S
bLOCKthe setting end of pulse-width modulator 94 is directly connected to oppositely.When covering time T
bLOCKat the end of, pulse-width modulator 94 is just set at once, and gets started T cycle time in next switch periods
cYCand opening time T
oN.In other words, under the control of power-supply controller of electric 200, cycle time T
cYCapproximate greatly and cover time T
bLOCK.
In another embodiment of the present invention, the power supply unit most of the time operates in trough to switch, just, in the process that the trough from the trough switch transition of a signal trough to another signal trough switches, some switch periods not operates in trough and switches.For example, this power supply unit is that the trough operating in the 3rd signal trough switches at the beginning, then may because load becomes large or other possible reason, the past previous signal trough (namely the 2nd signal trough) that the switching time of switch periods is afterwards gradual is close, after several switch periods, the trough that just can operate in the 2nd signal trough switches.Such transfer process, referred to herein as the soft conversion (softtransitionforvalleyswitching) that trough switches, it represents that two operate between the switch periods that switches at the trough of unlike signal trough, can admit of at least one or the switch periods of multiple non-trough switching.
Fig. 9 display can implement the QR controller 300 changed of walking around, and can replace the QR controller 26 in Fig. 1, as one embodiment of the invention.The place that QR controller 300 in Fig. 9 is similar or the same each other with the QR controller 80 in Fig. 3 can be learnt by prior teachings, is not repeated at this.QR controller 300 with shut-in time controller 302 instead of in QR controller 80 with door 88.Shut-in time controller 302 can make a power supply unit cover time T
bLOCKwhen first signal trough after end occurs, terminate a shut-in time T
oFF, carry out trough switching.But in some conditions, shut-in time controller 302 also can not carry out trough switching, will describe in detail after a while.
Figure 10 shows after QR controller 300 instead of the QR controller 26 of Fig. 1, some signal waveforms in circuit.The identical part of Figure 10 and Fig. 4 can reference diagram 4 bright and learn, be not repeated.
Duration of oscillation T
s-VLbe in a switch periods discharge time T
dISa regular time after end puts shut-in time T
oFFterminate (t
eND) between time span.In example in Fig. 10, duration of oscillation T
s-VLfrom time point t
2to t
eND.In another embodiment, it can be from time point t
3to t
eND, or from time point t
4to t
eND.In preferred example, duration of oscillation T
s-VLsart point in time must not be later than time point t
4, namely trough index signal S
vDat T discharge time
dISterminate the time that rear first pulse occurs.Duration of oscillation T
s-VLcross-pressure V can be considered as haply
aUXhow long vibrate, T cycle time instantly
cYCor shut-in time T
oFFjust terminate.
In some situations, front duration of oscillation PT
s-VLthen the duration of oscillation T in previous switch periods
s-VL.For example, the duration of oscillation T in switch periods instantly
s-VL, be exactly the front duration of oscillation PT in next switch periods
s-VL.In other some situations, front duration of oscillation PT
s-VLthe duration of oscillation T before multiple switch periods
s-VL.
Time window TW be between time point t
w-Swith t
w-Ebetween time, be according to front duration of oscillation PT
s-VLproduced.For example, time point t
w-Sbe positioned at front duration of oscillation PT
s-VLthe last scheduled time terminated, and time point t
w-Ebe positioned at front duration of oscillation PT
s-VLanother scheduled time after end.These two scheduled times can be the same or different.Time window TW length be preferably less than cross-pressure V
aUXone cycle of oscillation T
aUX-CYC.One cycle of oscillation T
aUX-CYCbe approximately the time between two signal wave valley portions, also approximate greatly cross-pressure V
aUXcontinuous two falling edges are lower than the time between 0V.
Time point t
aB-1STfor time point t
rELEASE(cover time T
bLOCKterminate) after, trough index signal S
vDthe time point that the first pulse produced occurs.In other words, be also exactly approximately cover time T
bLOCKafter end, the time point that first signal trough occurs.Time point t
aB-1STwith time point t
eNDinevitable as shown in Figure 10 while occur.Namely next switch periods must not start from time point t
aB-1ST.
Figure 11 is in an embodiment, the control method that shut-in time controller 302 adopts.Shut-in time controller 302 has a register, notes down and provides digital locking signal S
lOCK.As locking signal S
lOCKfor (differentiating in step 305) during " 1 " in logic, represent and want trough lock, mean trough switching to be locked in signal trough; Otherwise, locking signal S
lOCKfor " 0 " in logic, represent not trough locking, mean that the signal trough that trough switching occurs can change.
In shut-in time controller 302, record has a duration of oscillation record RT, and it can represent front duration of oscillation PT
s-VL.Step 306 is according to front duration of oscillation PT
s-VL, window TW when providing, namely determines time point t
w-Swith t
w-E.In other words, step 306, according to duration of oscillation record RT, determines time point t
w-Swith t
w-E.
When trough does not lock, step 308 makes time point t
eNDwhen can only occur in window TW, namely cannot early than time point t
w-S, time point t cannot be later than
w-E.As for definite time point t
eNDthen look time point t
aB-1STrelative position and determine.If time point t
aB-1STbefore form TW, namely time point t
aB-1STearly than time point t
w-Soccur, then time point t
eNDbe exactly time point t
w-S.If time point t
aB-1STcome across within form TW, then time point t
eNDbe exactly time point t
aB-1ST.If time point t
w-Eearly than time point t
aB-1ST, then cycle time T
cYCwith shut-in time T
oFFterminate at once, time point t
eNDequal time point t
w-E.At time point t
eND, pwm signal V
gATEhave a rising edge, carry out end period time T
cYCwith shut-in time T
oFF.Duration of oscillation record RT, at shut-in time T
oFFat the end of, can be updated, by the duration of oscillation T of this switch periods
s-VLinformation, take next switch periods to and go, become the front duration of oscillation PT in next cycle
s-VL.In this embodiment, shut-in time T
oFFthe time point terminated, depends on form TW and time point t
aB-1ST, and form TW notes down RT decision, time point t by duration of oscillation
aB-1STby covering time T
bLOCKwith trough index signal S
vDdetermined.
When trough locks, step 316 makes time point t
eNDbe exactly front duration of oscillation PT
s-VLat the end of.So instantly switch periods terminates shut-in time T
oFFtime place signal trough, shut-in time T can be terminated with previous switch periods
oFFtime place signal trough, the same, reach the object of trough locking.
Shut-in time controller 302 also has a counter, provides a count value, be used for haply calculate trough locking number of times, as shown in step 320.Counter also can be considered as a kind of timer, be used for calculate trough locking total time.Step 322 shows, when the number of times of trough locking reaches a preset value N, and locking signal S
lOCKmeeting " 1 " logically, becomes " 0 " in logic, removes trough locking.In other words, locking signal S
lOCKfor " 1 " continues there is N number of cycle time to I haven't seen you for ages.After trough latch-release, as time point t
aB-1STnot time window TW in time, represent it has not been that trough switches, so step 315 makes count value make zero.As time point t
aB-1STtime when entering again in window TW, expression should enter trough locking, so step 314 makes locking signal S
lOCKfor " 1 " in logic, make count value increase by 1, counter starts counting.
Please refer to Fig. 1, Fig. 9, Figure 11 and Figure 12.Figure 12 shows when turning low load by high capacity, the cross-pressure V in some continuous switch periods
aUX, and the sequential of some signals.
As the cross-pressure V in X switch periods in Figure 12
aUXshown in, assuming that before X switch periods, be in a stable state, what shut-in time controller 302 was stable make, and trough switches betides the 2nd signal trough when occurring.In X switch periods, time point t
aB-1STnamely time point t
eND(cycle time T
cYCend), duration of oscillation T
s-VLwill with front duration of oscillation PT
s-VLidentical, locking signal S
lOCKfor " 0 ", count value is N.In fig. 11, the shut-in time T in X switch periods
oFFbe follow step 304,305,306,308,310,312 and 324, such steps flow chart decides.
When X+1 switch periods in Figure 12 starts, possible because turning low load by high capacity, so time point t
rELEASEsuddenly delayed, caused then at the end of window TW, time point t
aB-1STstill do not occur.Shut-in time T in X+1 switch periods
oFFcan follow step 304,305,306,308,310,315 and 324, such steps flow chart decides.So, shown in Figure 12, the time point t of X+1 switch periods
eNDmeeting and time point t
w-Ethe while of about, locking signal S
lOCKfor " 0 ", count value is 0.Duration of oscillation T
s-VL, will than front duration of oscillation PT
s-VL, had more a scheduled time, shown in Figure 12.This scheduled time is cross-pressure V
aUXt cycle of oscillation
aUX-CYCa part, in fig. 12, this scheduled time is less than cross-pressure V
aUXt cycle of oscillation
aUX-CYC1/2nd.So obviously show as Figure 12, X+1 switch periods is not that trough switches.
In X+2 switch periods in Figure 12, then at the end of window TW, time point t
aB-1STstill do not occur.Therefore, the shut-in time T in X+2 switch periods
oFFstep 304,305,306,308,310,315 and 324 can be followed.The time point t of X+2 switch periods
eNDmeeting and time point t
w-Ethe while of about, locking signal S
lOCKfor " 0 ", count value is 0.X+2 switch periods also non-trough switches.
In X+3 switch periods in Figure 12, time point t
aB-1STtime window TW in occur.Therefore, the shut-in time T in X+3 switch periods
oFFstep 304,305,306,308,310,312 and 314 can be followed.Shown in Figure 12, the time point t of X+3 switch periods
eNDmeeting and time point t
aB-1STthe while of about, locking signal S
lOCKbecome " 1 ", count value is 1.X+3 switch periods is that trough switches.
In X+4 switch periods in Figure 12, because locking signal S
lOCKfor " 1 ", so time point t
eNDappear at front duration of oscillation PT
s-VLat the end of.Shut-in time T in X+4 switch periods
oFFstep 304,305,316,318 and 320 can be followed.Front duration of oscillation PT
s-VLcan not be updated, and duration of oscillation T
s-VLcan front duration of oscillation PT
s-VLthe same.Locking signal S
lOCKbe still " 1 ", count value becomes 2.X+4 switch periods is that trough switches.
From X switch periods to the process of X+4 switch periods, can find, duration of oscillation T
s-VLincrease along with switch periods.Duration of oscillation T
s-VLend time point, be from the 2nd signal trough occur time point, increase gradually, be finally parked in the 3rd signal trough occur time point, shown in Figure 12.Shut-in time controller 302 forced oscillation time T
s-VLwith front duration of oscillation PT
s-VLbetween difference, be less than cross-pressure V
aUXt cycle of oscillation
aUX-CYC.
After X+4 switch periods in Figure 12, front duration of oscillation PT
s-VLwith duration of oscillation T
s-VLremain unchanged always, also approximately equal, each shut-in time T
oFFthe step 304 in the 11st figure, 305,316,318 and 320 and determine can be followed.Shown in Figure 12, count value can increase by 1 along with each switch periods, until after count value becomes N, and locking signal S
lOCKjust can change to " 0 ", thus remove trough locking.
Please refer to Fig. 1, Fig. 9, Figure 11 and Figure 13.Figure 13 shows when turning high capacity by low load, the cross-pressure V in some continuous switch periods
aUX, and the sequential of some signals.
As the cross-pressure V in Y switch periods in Figure 13
aUXshown in, assuming that before Y switch periods, be in a stable state, what shut-in time controller 302 was stable makes trough switching betide the 3rd signal trough VL
3during appearance.In Y switch periods, time point t
aB-1STnamely time point t
eND(cycle time T
cYCend), duration of oscillation T
s-VLwill with front duration of oscillation PT
s-VLidentical, locking signal S
lOCKfor " 0 ", count value is N.In fig. 11, the shut-in time T in Y switch periods
oFFbe follow step 304,305,306,308,310,312 and 324, such steps flow chart decides.
In Y+1 switch periods in Figure 13, may because low load turns high capacity, so time point t
rELEASEsuddenly signal trough VL is arrived ahead of time
1near, cause time point t
aB-1STduring appearance, time window TW not yet do not occur.Shut-in time T in Y+1 switch periods
oFFcan follow step 304,305,306,308,310,315 and 324, such steps flow chart decides.So, the time point t of Y+1 switch periods
eNDmeeting and time point t
w-Sthe while of about, locking signal S
lOCKfor " 0 ", count value is 0.Duration of oscillation T
s-VL, will than front duration of oscillation PT
s-VL, lacked a scheduled time, shown in Figure 12.This scheduled time is cross-pressure V
aUXt cycle of oscillation
aUX-CYCa part, in fig. 13, this scheduled time is less than cross-pressure V
aUXt cycle of oscillation
aUX-CYC1/2nd.Figure 13 significantly shows, and Y+1 switch periods is not that trough switches.
In Y+2 switch periods in Figure 13, to time point t
aB-1STduring generation, time window TW terminate still not occur.Therefore, the shut-in time T in Y+2 switch periods
oFFstep 304,305,306,308,310,315 and 324 can be followed.The time point t of Y+2 switch periods
eNDmeeting and time point t
w-Sthe while of about, locking signal S
lOCKfor " 0 ", count value is 0.Y+2 switch periods also non-trough switches.
In Y+3 switch periods in Figure 13, time point t
aB-1STtime window TW in occur.Therefore, the shut-in time T in Y+3 switch periods
oFFstep 304,305,306,308,310,312 and 314 can be followed.The time point t of Y+3 switch periods
eNDmeeting and time point t
aB-1STthe while of about, locking signal S
lOCKbecome " 1 ", count value is 1.Y+3 switch periods is that trough switches.
In Y+4 switch periods in Figure 13, because locking signal S
lOCKfor " 1 ", so time point t
eNDappear at front duration of oscillation PT
s-VLat the end of.Shut-in time T in Y+4 switch periods
oFFstep 304,305,316,318 and 320 and determine can be followed.Front duration of oscillation PT
s-VLcan not be updated, and duration of oscillation T
s-VLcan front duration of oscillation PT
s-VLthe same.Locking signal S
lOCKbe still " 1 ", count value becomes 2.
From Y switch periods to the process of Y+4 switch periods, can find, duration of oscillation T
s-VLreduce along with switch periods.Duration of oscillation T
s-VLend time point, be from the 3rd signal trough occur time point, minimizing gradually, be finally parked in the 2nd signal trough occur time point.
After Y+4 switch periods in Figure 13, front duration of oscillation PT
s-VLwith duration of oscillation T
s-VLremain unchanged always, each shut-in time T
oFFthe step 304 in Figure 11,305,316,318 and 320 and determine can be followed.Shown in Figure 13, count value can increase by 1 along with each switch periods, until after count value becomes predetermined N, and locking signal S
lOCKjust can change to " 0 ", remove trough locking.
From Figure 11, Figure 12 and Figure 13, in one embodiment of this invention, once after entering the trough switching of a certain signal trough, trough locking will be there is.Namely the trough of this signal trough switches and will continue at least N number of switch periods, the trough of another signal trough just can be allowed to switch and occur.And also provide the soft conversion that trough switches in embodiment, between the switch periods of namely two switchings of the trough at unlike signal trough, having at least one is not the switch periods operating in trough switching.
Figure 14 shows in known technology, duration of oscillation T
s-VLone may change.The soft conversion that prior art does not have so-called trough to switch, therefore the duration of oscillation T of a switch periods
s-VL, with the duration of oscillation T of another switch periods
s-VL, must be cross-pressure V
aUXt cycle of oscillation
aUX-CYCintegral multiple, shown in Figure 14.Cycle of oscillation T
aUX-CYCit is exactly approximately the time difference occurred bottom two continuous signal troughs.Duration of oscillation T large like this
s-VLchange, easily causes the instability of whole system, also can cause output voltage V
oUTlarger shake (ripple).
And the power supply unit of prior art does not have so-called trough to lock yet.Therefore, may occur as situation shown in Figure 14, along with the advance of switch periods, trough switches in two signal troughs and jumps rapidly.
Figure 15 shows according in one embodiment of the invention, duration of oscillation T
s-VLone may change.Figure 15 shows soft conversion, so from the 4th signal trough VL
4trough switch, be transitted towards the 3rd signal trough VL
3the process that switches of trough in, experience the switch periods of three non-troughs switchings.Figure 15 also show the effect of trough locking, the 3rd signal trough VL
3trough switch must experienced by least 8 switch periods, just can arrive another signal trough trough switch advance.From Figure 14 and Figure 15 relatively, the duration of oscillation T in Figure 15
s-VLchange more smooth-going, compare the result that can not produce system instability.
QR controller 300 in Fig. 9 has 1 simultaneously) cover time T
bLOCKby load representation signal V
l-ESTdetermined; 2) the soft conversion of trough switching; And 3) trough locking, these three kinds of technical characterstics, but the present invention is not limited thereto.These three technical characterstics can independently be implemented separately, or two two combine enforcement mutually.For example, embodiments of the invention can implement 1) cover time T
bLOCKby load representation signal V
l-ESTdetermined; With 2) the soft conversion that switches of trough, these two technical characterstics, but do not implement trough locking.Another embodiment then implements soft conversion and the trough locking of trough switching, but covers time T
bLOCKby compensating signal V
cOMPdetermined, and unsupported representation signal V
l-EST.
The foregoing is only the preferred embodiments of the present invention, all equal changes of doing according to the claims in the present invention and modification, all should belong to protection scope of the present invention.