CN106455278B - X-ray high-voltage generator, the control circuit of series resonant converter and method - Google Patents
X-ray high-voltage generator, the control circuit of series resonant converter and method Download PDFInfo
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- CN106455278B CN106455278B CN201611005443.5A CN201611005443A CN106455278B CN 106455278 B CN106455278 B CN 106455278B CN 201611005443 A CN201611005443 A CN 201611005443A CN 106455278 B CN106455278 B CN 106455278B
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05G—X-RAY TECHNIQUE
- H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
- H05G1/08—Electrical details
- H05G1/26—Measuring, controlling or protecting
- H05G1/30—Controlling
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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
- 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
- H02M3/33507—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 with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—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 with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
-
- 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
- H02M3/33569—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 having several active switching elements
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0054—Transistor switching losses
- H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- 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)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Inverter Devices (AREA)
Abstract
The invention provides a kind of X-ray high-voltage generator, the control circuit of series resonant converter and control method.The inverter circuit of series resonant converter includes leading-bridge and lagging leg, leading-bridge includes the first and second switching devices, lagging leg includes the third and fourth switching device, and control circuit includes drive circuit there is provided first to fourth drive signal to first to fourth switching device.First and second drive signals constitute bipolar modulation, the turn-on instant of third and fourth drive signal is identical with the turn-on instant of the second and first drive signal respectively, and the shut-off moment of the third and fourth drive signal is determined according to the cavity current of series resonant converter；Or first and the 3rd drive signal constitute bipolar modulation, second and fourth drive signal turn-on instant respectively with the 3rd and first drive signal turn-on instant it is identical, second and fourth drive signal the shut-off moment be according to the cavity current of series resonant converter determine.
Description
Technical field
Become the invention mainly relates to the series resonance of X-ray high-voltage generator, more particularly to a kind of X-ray high-voltage generator
The control circuit and control method of parallel operation.
Background technology
X-ray high-voltage generator is used for roentgenotherapia equipment, x-ray diagnostic equipment, X ray computer layer radiography and set
In the equipment such as standby (CT), Positron Emission Computed Tomography (PET-CT).In the inversion of high power x-ray high pressure generator
In circuit, in order to meet the requirement worked long hours, generally from insulated gate bipolar switching device (Insulated Gate
Bipolar Transistor, IGBT) it is used as switching device.This generally has claimed below to inverter circuit：1. inversion electricity is needed
There is higher load capacity on road, to adapt to the requirement of wide range output；2. the current peak for flowing through switching device is reduced as far as possible
Value is to reduce cost, while reducing the turn-off power loss of switching device；3. inductive current full-load range is kept to be in on-off state,
To realize the zero current turning-on of switching device；4. higher switching frequency is kept, to reduce high-tension transformer and rectification circuit
Volume；5. inverter circuit needs to adapt to the influence of high-tension transformer larger parasitic capacitance and stray inductance.
Inverter circuit constitutes series-resonant inverting circuit with series resonant circuit.Series-resonant inverting circuit further with change
The devices such as depressor, rectifier constitute series resonant converter.
A kind of main circuit of series resonant converter 10 is as shown in figure 1, the inverter circuit constituted including switching device Q1-Q4
11, inductance Ls and electric capacity Cs compositions series resonant circuit 12, high frequency high voltage transformer Tr and voltage-doubler rectifier 13.Series resonance
Converter 10 is output to X-ray tube 14.The control mode that series resonant converter 10 is used generally includes bipolar modulation, phase shift
Modulation and Frequency-variable Modulation.
Bipolar modulation mode as shown in Fig. 2 switching device Q1 and Q2 drive signal non-overlapping copies, switching device Q3 and
Q4 drive signal non-overlapping copies, and switching device Q1 and the Q4 same phase of drive signal.Due to switching device (such as Q1 of diagonally opposing corner
And Q4, Q2 and Q3) with opening with pass, all switching devices will bear larger turn-off power loss.
Phase shift modulation mode is and complementary as shown in figure 3, leading-bridge switching device Q1 and Q2 dutycycle are all 50%
Conducting, lagging leg switching device Q3 and Q4 dutycycle are also all 50%, and complementary conducting；By adjust leading-bridge and
The relative phase relation of lagging leg, to control output voltage switching device switching device switching device.By then passing through two
The mode of bridge arm voltage phase shift adjusts output voltage, and only leading-bridge has turn-off power loss, lagging leg is substantially without shut-off
Loss.But there is current oscillation, and transformer distribution capacity C during there is zero vector, afterflow due to bridge arm mid-point voltagewMore
Greatly, vibration is stronger, and switching device will be unable to realize that no-voltage is open-minded.As illustrated in figures 4 a and 4b, when consider transformer distribution
Electric capacity CwWhen, under severe duty and under light duty, it can all produce concussion.
During using Frequency-variable Modulation, the switching frequency of switching device needs wide variation, causes rectification circuit 11 and transformation
Device Tr needs larger volume.
Sum it up, this several technical scheme generally used be difficult to and meanwhile meet HF switch, wide range output, it is low into
The requirement of sheet, low-loss, and high-adaptability.
The content of the invention
The technical problem to be solved in the present invention is to provide a kind of control of the series resonant inverter of X-ray high-voltage generator
Circuit, the problem of overcoming the modulation system of existing series resonant converter.
In order to solve the above technical problems, the invention provides a kind of control circuit of series resonant converter, the series connection
Controlled resonant converter includes inverter circuit, and the inverter circuit includes leading-bridge and lagging leg, and the leading-bridge includes the
One switching device and second switch device, the lagging leg include the 3rd switching device and the 4th switching device, the control
Circuit includes：Drive circuit there is provided the first drive signal to the first switch device there is provided the second drive signal to described the
Two switching devices are switched to the 3rd switching device there is provided the 3rd drive signal there is provided fourth drive signal to the described 4th
Device；Wherein：First drive signal and second drive signal constitute bipolar modulation, and the 3rd drive signal drives
The turn-on instant for moving the 3rd switching device drives the turn-on instant of second switch device identical with second drive signal,
The fourth drive signal drives the turn-on instant of the 4th switching device and first drive signal to drive first switch
The turn-on instant of device is identical, and the 3rd drive signal and the fourth drive signal drive the 3rd switching device and the
The shut-off moment of four switching devices is determined according to the cavity current of the series resonant converter；Or first driving
Signal and the 3rd drive signal constitute bipolar modulation, and second drive signal drives leading for the second switch device
The logical moment drives the turn-on instant of the 3rd switching device identical with the 3rd drive signal, and the fourth drive signal is driven
The turn-on instant for moving the 4th switching device drives the turn-on instant of the first switch device with first drive signal
It is identical, the pass of second drive signal and the fourth drive signal driving second switch device and the 4th switching device
The disconnected moment is determined according to the cavity current of the series resonant converter.
In one embodiment of this invention, the shut-off moment of the 3rd drive signal driving the 3rd switching device is
At the time of the cavity current of the series resonant converter rises to zero, the fourth drive signal drives the 4th switching device
Shut-off moment at the time of drop to zero for the cavity current of the series resonant converter；Or second drive signal drives
At the time of the shut-off moment of the dynamic second switch device rises to zero for the cavity current of the series resonant converter, institute
State fourth drive signal and drive the cavity current that the shut-off moment of the 4th switching device is the series resonant converter
At the time of dropping to zero.
In one embodiment of this invention, the drive circuit is by the way that sawtooth waveforms and the adjustable threshold value of amplitude are compared,
To produce a pair of drive signals for constituting bipolar modulation.
In one embodiment of this invention, the drive circuit is electric by the resonator for judging the series resonant converter
Whether stream reaches threshold value to determine the shut-off moment.
In one embodiment of this invention, the drive circuit judges that the cavity current of the series resonant converter reaches
Postpone a scheduled time to after at the time of the threshold value as the shut-off moment.
In one embodiment of this invention, the dutycycle for constituting a pair of drive signals of bipolar modulation is respectively less than 50%.
The present invention also proposes a kind of X-ray high-voltage generator, including series resonant converter as described above, and the control
Circuit processed controls the resonator of the series resonant converter to be in discontinuous conduct mode.
The present invention proposes a kind of control method of series resonant converter, and the series resonant converter includes inversion electricity
Road, the inverter circuit includes leading-bridge and lagging leg, and the leading-bridge includes first switch device and second switch
Device, the lagging leg includes the 3rd switching device and the 4th switching device, and methods described includes：First drive signal is provided
Give described there is provided the 3rd drive signal to the second switch device there is provided the second drive signal to the first switch device
3rd switching device gives the 4th switching device there is provided fourth drive signal；Wherein described first drive signal and described
Two driving signal drives the leading-bridge to carry out bipolar modulation, and the 3rd drive signal drives the 3rd switching device
Turn-on instant and second drive signal drive the turn-on instant of the second switch device identical, the 4th driving letter
The turn-on instant of number driving the 4th switching device drives the conducting of the first switch device with first drive signal
Moment is identical, the 3rd drive signal and the fourth drive signal drive the 3rd switching device and the 4th derailing switch
The shut-off moment of part is determined according to the cavity current of the series resonant converter；Or first drive signal and institute
State the 3rd drive signal and constitute bipolar modulation, second drive signal drive the turn-on instant of the second switch device with
3rd drive signal drives the turn-on instant of the 3rd switching device identical, the fourth drive signal driving described the
The turn-on instant of four switching devices drives the turn-on instant of the first switch device identical with first drive signal, described
Second drive signal and the fourth drive signal drive the shut-off moment of the second switch device and the 4th switching device to be
Determined according to the cavity current of the series resonant converter.
In one embodiment of this invention, the shut-off moment of the 3rd drive signal driving the 3rd switching device is
At the time of the cavity current of the series resonant converter rises to zero, fourth drive signal driving the 4th switch
At the time of the shut-off moment of device drops to zero for the cavity current of the series resonant converter；Or the second driving letter
The shut-off moment of number driving second switch device be the series resonant converter cavity current rise to zero when
Carve, the resonator that it is the series resonant converter at the shut-off moment of the 4th switching device that the fourth drive signal, which drives,
At the time of electric current drops to zero.
In one embodiment of this invention, the above method also includes comparing sawtooth waveforms and the adjustable threshold value of amplitude, comes
Produce a pair of drive signals for constituting bipolar modulation.
In one embodiment of this invention, connect by judging whether the cavity current of the series resonant converter reaches
Nearly zero threshold value determines the shut-off moment.
In one embodiment of this invention, the dutycycle for constituting a pair of drive signals of bipolar modulation is respectively less than 50%.
In one embodiment of this invention, the cavity current is discontinuous conduct mode, and when the inverter circuit is deposited
In switching device in the conduction state, the cavity current is in non-zero status；When the derailing switch of the inverter circuit
Part is off state, and the cavity current is in nought state.
Compared with prior art, the present invention had both had bipolar modulation without Zero voltage vector, thus in the absence of continuous current circuit
Advantage, turn-off power loss is again as phase shift modulation, the only half of bipolar modulation；In addition, leading-bridge and lagging leg
There is larger dead time, reduce the possibility of bridge arm direct pass, improve the reliability of converter；On the other hand, pass through
Detect zero crossing to produce cut-off signals, inverter circuit can be made to always work in discontinuous conduct mode, reduce turn-on consumption, and
Keep to high-tension transformer stray inductance LlkWith parasitic capacitance CwThe adaptability of fluctuation.
Brief description of the drawings
Fig. 1 is the circuit diagram of the X-ray high-voltage generator based on series resonant converter.
Fig. 2 is the bipolar modulation oscillogram of series resonant inverter.
Fig. 3 is the phase shift modulation oscillogram of series resonant inverter.
Fig. 4 A and Fig. 4 B are the phase shift modulation oscillograms for considering transformer parasitic capacitance influence.
Fig. 5 is the X-ray high-voltage generator circuit diagram based on series resonant converter of one embodiment of the invention.
Fig. 6 is the modulation waveform figure of the series resonant inverter of first embodiment of the invention.
Fig. 7 is the modulation waveform figure of the change case of embodiment illustrated in fig. 6.
Fig. 8 is the modulation waveform figure of the series resonant inverter of second embodiment of the invention.
Embodiment
For the above objects, features and advantages of the present invention can be become apparent, below in conjunction with tool of the accompanying drawing to the present invention
Body embodiment elaborates.
Many details are elaborated in the following description to facilitate a thorough understanding of the present invention, still the present invention can be with
It is different from other manner described here using other and implements, therefore the present invention is not limited by following public specific embodiment
System.
Embodiments of the invention describe the series-resonant inverting circuit of X-ray high-voltage generator.X-ray high-voltage generator can
To apply in such as roentgenotherapia equipment, x-ray diagnostic equipment, X ray computer layer radiography equipment (CT), positive electron hair
Penetrate in the equipment such as computerized tomograph (PET-CT), but be not limited thereto.
Fig. 5 is that the series resonance of the X-ray high-voltage generator based on series resonant converter of one embodiment of the invention is inverse
Become the circuit diagram of device.With reference to shown in Fig. 5, the series resonant inverter of the X-ray high-voltage generator of the present embodiment includes inversion electricity
Road 51, series resonant circuit 52, transformer Tr and voltage doubling rectifing circuit 53.X-ray high-voltage generator includes being used to control series connection
The control circuit of controlled resonant converter.In the present embodiment, control circuit includes drive circuit 54.
Inverter circuit 51 includes first switch device Q1, second switch device Q2, the switches of the 3rd switching device Q3 and the 4th
Device Q4.First switch device Q1 and second switch device Q2 composition leading-bridges, bridge arm midpoint A is used as the of inverter circuit 51
One output end.3rd switching device Q3 and the 4th switching device Q4 composition lagging legs, bridge arm midpoint B is used as inverter circuit 51
Second output end.First switch device to the 4th switching device Q1-Q4 be, for example, insulated gate bipolar transistor (Insulated
Gate Bipolar Transistor,IGBT).First switch device Q1 colelctor electrode connection power supply Vin anode, emitter stage
Connect bridge arm midpoint A.Second switch device Q2 colelctor electrode connection bridge arm midpoint A, emitter stage connection power supply Vin negative terminal.The
Three switching device Q3 colelctor electrode connection power supply Vin anode, emitter stage connection bridge arm midpoint B.4th switching device Q4 collection
Electrode connects bridge arm midpoint A, emitter stage connection power supply Vin negative terminal.Each switching device Q1-Q4 has parasitic diode respectively
D1-D4。
Series resonant circuit 52 connects the first output terminals A of inverter circuit 51.1 series resonant circuit 52 is for example including inductance
Ls and electric capacity Cs.
Second output end B of transformer Tr connections series resonant circuit 52 and inverter circuit 51.Transformer Tr, which has, to be posted
Raw inductance LlkWith parasitic capacitance Cw。
Drive circuit 54 provides the first drive signal S1 and gives first switch device Q1, and the second drive signal S2 is to second switch
Device Q2, the 3rd drive signal S3 give the 3rd switching device Q3, fourth drive signal Q3 to give the 4th switching device Q4.
First embodiment
According to the present embodiment, the leading-bridge of inverter circuit 51 uses bipolar modulation, and lagging leg is opened and surpassed
Preceding bridge arm it is identical to pipe, cut-off signals are then by detecting realizing to zero-signal for series resonant circuit electric current.Fig. 6 is
The modulation waveform figure of the series resonant inverter of first embodiment of the invention.With reference to shown in Fig. 6, the first drive signal S1 and second
Drive signal S2 constitutes bipolar modulation；3rd drive signal S3 drives the 3rd switching device Q3 turn-on instant and the second driving
Signal S2 driving second switch devices Q2 turn-on instant is identical, and fourth drive signal S4 drives the 4th switching device Q4 conducting
Moment drives first switch device Q1 turn-on instant identical with the first drive signal S1.In addition, the 3rd drive signal S3 drives
3rd switching device Q3 shut-off moment and fourth drive signal S4 drive the 4th switching device Q4 shut-off moment to be according to institute
The cavity current for stating series resonant converter is determined.In order to make turn-off power loss smaller, it can select less in inverter current
Moment turns off.For example, a threshold value can be set, during by detecting that cavity current is less than this threshold value to determine to turn off
Carve.In order that turn-off power loss is minimum, it is humorous that the 3rd drive signal S3 drives the 3rd switching device Q3 shut-off moment to be preferably series connection
At the time of the electric current of converter of shaking rises to zero.Fourth drive signal S4 drives the 4th switching device Q4 turn-on instant and first
Drive signal S1 driving first switch devices Q1 turn-on instant is identical, and fourth drive signal S4 drives the 4th switching device Q4's
At the time of the electric current that the shut-off moment is preferably series resonant converter drops to zero.It should be noted that in above process, driving
The turn-on instant of dynamic Signal-controlled switch device is drive signal rising edge time, during the shut-off of drive signal controlling switch device
Carve as the drive signal trailing edge moment.
In the first half cycle of a switch periods：Switching device Q1, Q4 are simultaneously turned on, and switching device Q2, Q3 are off
State, input voltage vin, switching device Q1, resonator, switching device Q4 are composed in series loop, 2 points of A, B voltage VA,BFor
High level, the inverter current exported by inverter circuit 51 or flows through the electric current of resonator and gradually increases (the electric current side in resonator
To identical with scheduled current direction)；
Afterwards, only Q4 is turned on, and Q1, Q2, Q3 are off state, resonator, switching device Q4, the second diode D2 simultaneously
It is composed in series loop, 2 points of A, B voltage VA,BFor zero level, and resonator series inductance is discharged, flow through the electric current of resonator by
It is decrescence small；
Afterwards, Q1, Q2, Q3, Q4 are off only electric capacity Cs two ends in state, resonator simultaneously voltage, 2 points of A, B
Voltage VA,BFor electric capacity Cs both end voltages (high level), now there is not resonator to flow through electric current；
In the later half cycle of a switch periods：Q2, Q3 are simultaneously turned on, and Q1, Q4 are off state, input voltage vin,
Switching device Q3, resonator, switching device Q2 are composed in series loop, 2 points of A, B voltage VA,BIt is defeated by inverter for low level
The inverter current that goes out flows through the electric current of resonator and gradually increased (sense of current and scheduled current in resonator are in opposite direction)；
Afterwards, only Q3 is turned on, and Q1, Q2, Q4 are off state, switching device Q3, resonator, the first diode D1 simultaneously
It is composed in series loop, 2 points of A, B voltage VA,BFor zero level, and resonator series inductance is discharged, flow through the electric current of resonator by
It is decrescence small；
Afterwards, Q1, Q2, Q3, Q4 are off only electric capacity Cs two ends in state, resonator simultaneously voltage, 2 points of A, B
Voltage VA,BFor electric capacity Cs both end voltages (low level), now there is not electric current to flow through resonator；
Drive circuit 54 can be by by sawtooth signal VtriWith threshold value VmodCompare, bipolar modulation is constituted to produce
A pair of drive signals S1 and S2.Therefore, drive circuit 54 may include first comparator, one input input sawtooth signal
Vtri, another input input gate limit value Vmod.Threshold value VmodAmplitude can be adjustable, can so control drive signal
S1 and S2 dutycycle.The dutycycle for preferably constituting a pair of drive signals S1, S2 of bipolar modulation is respectively less than 50%.
Corresponding to minimum turn-off loss, drive circuit 54 is by judging the cavity current i of series resonant converterLs_meas
The threshold value whether reached close to zero determines the shut-off moment.
In the change case shown in Fig. 7, drive circuit 54 can also judge the cavity current of series resonant converter
iLs_measPostpone a scheduled time after reaching at the time of threshold value as the shut-off moment.
In the present embodiment, cavity current is discontinuous conduct mode, and when inverter circuit exist it is in the conduction state
During switching device, cavity current is in non-zero status；When the switching device of inverter circuit is off state, cavity current
In nought state.
In the present embodiment, by detecting cavity current iLs_measCome what is produced ensure that lagging leg exists to zero-signal
Electric current is turned off again after dropping to zero, so as to realize lagging leg (Q3 and Q4) zero-current switching.And now will be without no-voltage
Vector loop, in the absence of afterflow during series inductance and series capacitance the problem of vibrate, electric current will be always zero, Zhi Daoyou
Other switching devices are open-minded, thus it is also ensured that the zero current turning-on of switching device.Therefore, the present embodiment had both had bipolar
Property modulation be not present the advantage of continuous current circuit without Zero voltage vector, turn-off power loss is again as phase shift modulation, only bipolarity
The half of modulation；In addition, leading-bridge and lagging leg have larger dead time, the possibility of bridge arm direct pass is reduced,
Improve the reliability of inverter circuit；On the other hand, cut-off signals are produced by detecting zero crossing, inverter circuit can be made to begin
Discontinuous conduct mode is operated in eventually, reduces turn-on consumption, and keep to high-tension transformer stray inductance LlkWith parasitic capacitance CwRipple
Dynamic adaptability.
Second embodiment
According to the present embodiment, the switching device Q1 and Q3 of inverter circuit 51 use bipolar modulation, and switching device Q2 is with opening
The turn-on instant for closing device Q3 is identical, and switching device Q4 is identical with switching device Q1 turn-on instant, second switch device Q2 with
4th switching device Q4 cut-off signals be then by detect the cavity current of series resonant converter to zero-signal come reality
Existing.Fig. 8 is the modulation waveform figure of the series resonant converter of second embodiment of the invention.With reference to shown in Fig. 8, the first driving letter
Number S1 and the 3rd drive signal S3 constitutes bipolar modulation；Second drive signal S2 driving second switch devices Q2 turn-on instant
Identical with the turn-on instant that the 3rd drive signal S3 drives the 3rd switching device Q3, fourth drive signal S4 drives the 4th derailing switch
Part Q4 turn-on instant drives first switch device Q1 turn-on instant identical with the first drive signal S1.In addition, the second driving
When signal S2 driving second switch devices Q2 shut-off moment and fourth drive signal S4 drive the 4th switching device Q4 shut-off
Quarter is determined according to the cavity current of the series resonant converter.In order to make turn-off power loss smaller, it can select in inversion
The less moment shut-off of electric current.For example, a threshold value can be set, determined by detecting cavity current less than this threshold value
Surely the moment is turned off.In order that turn-off power loss is minimum, the second drive signal S2 driving second switch devices Q2 shut-off moment is preferable
At the time of rising to zero for the electric current of series resonant converter, when fourth drive signal S4 drives the 4th switching device Q4 shut-off
At the time of the electric current for carving preferably series resonant converter drops to zero.
In the first half cycle of a switch periods：Switching device Q1, Q4 are simultaneously turned on, and switching device Q2, Q3 are off
State, input voltage vin, switching device Q1, resonator, switching device Q4 are composed in series loop, 2 points of A, B voltage VA,BFor
High level, the inverter current exported by inverter circuit 51 or flows through the electric current of resonator and gradually increases (the electric current side in resonator
To identical with scheduled current direction)；
Afterwards, only switching device Q4 is turned on, and switching device Q1, Q2, Q3 are off state, resonator, derailing switch simultaneously
Part Q4, the second diode D2 are composed in series loop, 2 points of A, B voltage VA,BFor zero level, and resonator series inductance is discharged,
The electric current for flowing through resonator is gradually reduced；
Afterwards, switching device Q1, Q2, Q3, Q4 is off only electric capacity Cs two ends in state, resonator simultaneously electricity
Pressure, 2 points of A, B voltage VA,BFor electric capacity Cs both end voltages (high level), now there is not resonator to flow through electric current；
In the later half cycle of a switch periods：Switching device Q2, Q3 are simultaneously turned on, and switching device Q1, Q4 are off
State, input voltage vin, switching device Q3, resonator, switching device Q2 are composed in series loop, 2 points of A, B voltage VA,BFor
Low level, the inverter current exported by inverter or flow through resonator electric current gradually increase (sense of current in resonator with
Scheduled current is in opposite direction)；
Afterwards, only switching device Q2 is turned on, and switching device Q1, Q3, Q4 are off state simultaneously, switching device Q2, humorous
Shake chamber, the 4th diode D4 is composed in series loop, 2 points of A, B voltage VA,BFor zero level, and resonator series inductance is discharged,
The electric current for flowing through resonator is gradually reduced；
Afterwards, switching device Q1, Q2, Q3, Q4 is off only electric capacity Cs two ends in state, resonator simultaneously electricity
Pressure, 2 points of A, B voltage VA,BFor electric capacity Cs both end voltages (low level), now there is not electric current to flow through resonator.
Drive circuit 54 can be by by sawtooth signal VtriWith threshold value VmodCompare, bipolar modulation is constituted to produce
A pair of drive signal S1 and S3 are therefore, drive circuit 54 may include first comparator, one input input sawtooth signal
Vtri, another input input gate limit value Vmod.Threshold value VmodAmplitude can be adjustable, can so control drive signal
S1 and S3 dutycycle.The dutycycle for preferably constituting a pair of drive signals S1, S3 of bipolar modulation is respectively less than 50%.
Corresponding to minimum turn-off loss, drive circuit 54 is by judging the cavity current i of series resonant converterLs_meas
The threshold value whether reached close to zero determines the shut-off moment.
Drive circuit 54 can also judge the cavity current i of series resonant converterLs_measAt the time of reaching threshold value
After postpone a scheduled time as shut-off the moment.
In the present embodiment, cavity current is discontinuous conduct mode, and when inverter circuit exist it is in the conduction state
During switching device, cavity current is in non-zero status；When the switching device of inverter circuit is off state, cavity current
In nought state.
In the present embodiment, there is turn-off power loss during switching device Q1 and Q3 shut-offs, turn-off power loss is in lead-lag two
Bridge arm is evenly distributed, and this using half-bridge module for that, as the occasion of switching device, can be substantially reduced the temperature rise of switching device.
Be with previous embodiment identical, without Zero voltage vector loop in the present embodiment, in the absence of afterflow during series inductance with connecting
The problem of electric capacity vibrates, electric current will be always zero, until there is other switching devices open-minded, thus it is also ensured that switch
The zero current turning-on of device.Therefore, the present embodiment had both had bipolar modulation without Zero voltage vector in the absence of continuous current circuit
Advantage, turn-off power loss is again as phase shift modulation, the only half of bipolar modulation；In addition, leading-bridge and lagging leg are all
There is larger dead time, reduce the possibility of bridge arm direct pass, improve the reliability of inverter circuit；On the other hand, pass through
Detect zero crossing to produce cut-off signals, inverter circuit can be made to always work in discontinuous conduct mode, reduce turn-on consumption, and
Keep to high-tension transformer stray inductance LlkWith parasitic capacitance CwThe adaptability of fluctuation.
From another viewpoint, the present invention proposes a kind of control method of series resonant converter, the series resonance conversion
Device includes inverter circuit, and the inverter circuit includes leading-bridge and lagging leg, and the leading-bridge includes first switch device
Part and second switch device, the lagging leg include the 3rd switching device and the 4th switching device, and methods described includes：There is provided
There is provided the second drive signal, to the second switch device, there is provided the 3rd drive to the first switch device for first drive signal
Dynamic signal gives the 4th switching device to the 3rd switching device there is provided fourth drive signal；Wherein described first driving
Signal and second drive signal constitute bipolar modulation, the 3rd drive signal and fourth drive signal driving institute
The turn-on instant for stating the 3rd switching device and the 4th switching device is believed with second drive signal and first driving respectively
Number driving second switch device is identical with the turn-on instant of first switch device, the 3rd drive signal and the described 4th
Drive signal drives the shut-off moment of the 3rd switching device and the 4th switching device to be according to the series resonant converter
Cavity current determine；Or first drive signal and the 3rd drive signal constitute bipolar modulation, described the
Two driving signal and the fourth drive signal drive the turn-on instant difference of the second switch device and the 4th switching device
The conducting of the 3rd switching device and first switch device is driven with the 3rd drive signal and first drive signal
Moment is identical, and second drive signal and the fourth drive signal drive the second switch device and the 4th switching device
The shut-off moment be according to the cavity current of the series resonant converter determine.
In one embodiment of this invention, the shut-off moment of the 3rd drive signal driving the 3rd switching device is
At the time of the cavity current of the series resonant converter rises to zero, fourth drive signal driving the 4th switch
At the time of the shut-off moment of device drops to zero for the cavity current of the series resonant converter；Or the second driving letter
The shut-off moment of number driving second switch device be the series resonant converter cavity current rise to zero when
Carve, the resonator that it is the series resonant converter at the shut-off moment of the 4th switching device that the fourth drive signal, which drives,
At the time of electric current drops to zero.
In one embodiment of this invention, the above method also includes comparing sawtooth waveforms and the adjustable threshold value of amplitude, comes
Produce a pair of drive signals for constituting bipolar modulation.
In one embodiment of this invention, connect by judging whether the cavity current of the series resonant converter reaches
Nearly zero threshold value determines the shut-off moment.
In one embodiment of this invention, the dutycycle for constituting a pair of drive signals of bipolar modulation is respectively less than 50%.
Although the present invention is described with reference to current specific embodiment, those of ordinary skill in the art
It should be appreciated that the embodiment of the above is intended merely to the explanation present invention, it can also make in the case of without departing from spirit of the invention
Go out various equivalent change or replacement, therefore, as long as change, change in the spirit of the present invention to above-described embodiment
Type will all fall in the range of following claims.
Claims (10)
1. a kind of control circuit of series resonant converter, the series resonant converter includes inverter circuit, the inversion electricity
Road includes leading-bridge and lagging leg, and the leading-bridge includes first switch device and second switch device, described delayed
Bridge arm includes the 3rd switching device and the 4th switching device, and the control circuit includes：
Drive circuit is opened to the first switch device there is provided the first drive signal there is provided the second drive signal to described second
Pass device gives the 4th switching device to the 3rd switching device there is provided the 3rd drive signal there is provided fourth drive signal；
Wherein：First drive signal and second drive signal constitute bipolar modulation, and the 3rd drive signal drives
The turn-on instant for moving the 3rd switching device drives the turn-on instant of second switch device identical with second drive signal,
The fourth drive signal drives the turn-on instant of the 4th switching device and first drive signal to drive first switch
The turn-on instant of device is identical, and the 3rd drive signal and the fourth drive signal drive the 3rd switching device and the
The shut-off moment of four switching devices is determined according to the inverter current of the inverter circuit；
Or, first drive signal and the 3rd drive signal constitute bipolar modulation, and second drive signal drives
The turn-on instant for moving the second switch device drives the turn-on instant of the 3rd switching device with the 3rd drive signal
Identical, the fourth drive signal drives the turn-on instant of the 4th switching device and first drive signal driving described
The turn-on instant of first switch device is identical, and second drive signal and the fourth drive signal drive the second switch
The shut-off moment of device and the 4th switching device determines according to the cavity current of the series resonant converter.
2. the control circuit of series resonant converter as claimed in claim 1, it is characterised in that the 3rd drive signal drives
At the time of the shut-off moment of dynamic 3rd switching device rises to zero for the cavity current of the series resonant converter, institute
State fourth drive signal and drive the shut-off moment of the 4th switching device under the cavity current of the series resonant converter
At the time of dropping to zero；
Or, second drive signal drives the shut-off moment of the second switch device to be the series resonant converter
At the time of cavity current rises to zero, the fourth drive signal drives the shut-off moment of the 4th switching device to be described
At the time of the cavity current of series resonant converter drops to zero.
3. the control circuit of series resonant converter according to claim 1 or 2, it is characterised in that the drive circuit
By the way that sawtooth waveforms and the adjustable threshold value of amplitude are compared, to produce a pair of drive signals for constituting bipolar modulation.
4. the control circuit of series resonant converter according to claim 3, it is characterised in that constitute bipolar modulation
The dutycycle of a pair of drive signals is respectively less than 50%.
5. a kind of X-ray high-voltage generator, including series resonant converter, and the string as described in claim any one of 1-4
Join the control circuit of controlled resonant converter, and the control circuit controls the resonator of the series resonant converter disconnected in electric current
Discontinuous Conduction mode.
6. a kind of control method of series resonant converter, the series resonant converter includes inverter circuit, the inversion electricity
Road includes leading-bridge and lagging leg, and the leading-bridge includes first switch device and second switch device, described delayed
Bridge arm includes the 3rd switching device and the 4th switching device, and methods described includes：
There is provided the first drive signal to the first switch device there is provided the second drive signal to the second switch device, carry
For the 3rd drive signal the 4th switching device is given to the 3rd switching device there is provided fourth drive signal；
Wherein described first, second drive signal drives the leading-bridge to carry out bipolar modulation, the 3rd drive signal
When driving the conducting of turn-on instant and second drive signal driving second switch device of the 3rd switching device
Carve identical, the fourth drive signal drives the turn-on instant of the 4th switching device and first drive signal to drive institute
The turn-on instant for stating first switch device is identical, the described 3rd, fourth drive signal drive the three, the 4th switching device
The moment is turned off according to the determination of the inverter current of the inverter circuit；Or,
Described first, the 3rd drive signal constitutes bipolar modulation, and second drive signal drives the second switch device
Turn-on instant and the 3rd drive signal drive the turn-on instant of the 3rd switching device identical, the 4th driving letter
The turn-on instant of number driving the 4th switching device drives the conducting of the first switch device with first drive signal
Moment is identical, described second, fourth drive signal drive the shut-off moment of the second, the 4th switching device according to the string
The cavity current for joining controlled resonant converter is determined.
7. the control method of series resonant converter as claimed in claim 6, it is characterised in that the 3rd drive signal drives
At the time of the shut-off moment of dynamic 3rd switching device rises to zero for the cavity current of the series resonant converter, institute
State fourth drive signal and drive the shut-off moment of the 4th switching device under the cavity current of the series resonant converter
At the time of dropping to zero；
Or, second drive signal drives the shut-off moment of the second switch device to be the series resonant converter
At the time of cavity current rises to zero, the fourth drive signal drives the shut-off moment of the 4th switching device to be described
At the time of the cavity current of series resonant converter drops to zero.
8. the control method of series resonant converter as claimed in claim 7, it is characterised in that also including by sawtooth waveforms and width
Spend adjustable threshold value to compare, to produce a pair of drive signals for constituting bipolar modulation.
9. the control method of series resonant converter as claimed in claim 8, it is characterised in that by judging that the series connection is humorous
Whether the cavity current of converter of shaking reaches threshold value to determine the shut-off moment.
10. the control method of the series resonant converter as described in claim 6,7 or 9 any one, it is characterised in that described humorous
The cavity current that shakes is discontinuous conduct mode, and when the inverter circuit has switching device in the conduction state, the resonance
Cavity current is in non-zero status；When the switching device of the inverter circuit is off state, the cavity current is in zero
State.
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| CN107070234B (en) * | 2017-03-24 | 2019-02-01 | 上海联影医疗科技有限公司 | The control circuit and control method of series resonant converter |
| CN107809178B (en) | 2017-11-03 | 2021-06-11 | 上海联影医疗科技股份有限公司 | High-voltage generator and control method thereof |
| CN110739876B (en) * | 2018-07-20 | 2020-10-02 | 郑州宇通客车股份有限公司 | Inverter control method and device |
| CN110719031A (en) * | 2019-08-30 | 2020-01-21 | 上海瞻芯电子科技有限公司 | Constant frequency oscillation DC/DC power conversion device and power supply equipment |
| CN112821769A (en) * | 2020-12-31 | 2021-05-18 | 深圳市科华恒盛科技有限公司 | Control method of resonant circuit and terminal equipment |
| CN112994503B (en) * | 2021-04-30 | 2022-11-01 | 石家庄通合电子科技股份有限公司 | SPWM (sinusoidal pulse Width modulation) method and terminal equipment of single-phase full-bridge inverter |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101075784A (en) * | 2007-06-21 | 2007-11-21 | 艾默生网络能源有限公司 | Zero-voltage DC/DC switch circuit with phase-shift control |
| CN103078515A (en) * | 2011-10-25 | 2013-05-01 | 通用电气公司 | Resonant power supply, converter controller, magnetic resonance imaging system and control method |
| CN103259443A (en) * | 2013-05-23 | 2013-08-21 | 吕莹 | Limited dual-polarity-controlled full bridge inverter |
| CN103795257A (en) * | 2012-10-29 | 2014-05-14 | 三垦电气株式会社 | Synchronous rectifier circuit |
| CN103858330A (en) * | 2011-03-16 | 2014-06-11 | 菲艾姆股份有限公司 | Converter for an electric machine and method for controlling a power circuit breaker |
| CN104300811A (en) * | 2014-09-05 | 2015-01-21 | 西安理工大学 | Unipolar and bipolar hybrid modulation method for single-phase voltage type PWM rectifier |
| CN104821736A (en) * | 2015-05-15 | 2015-08-05 | 国家电网公司 | Modularized multi-level converter with function of DC side short circuit protection |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080025050A1 (en) * | 2006-07-25 | 2008-01-31 | Lv Power (2003) Ltd. | Wide Input Range Power Supply |
-
2016
- 2016-11-15 CN CN201611005443.5A patent/CN106455278B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101075784A (en) * | 2007-06-21 | 2007-11-21 | 艾默生网络能源有限公司 | Zero-voltage DC/DC switch circuit with phase-shift control |
| CN103858330A (en) * | 2011-03-16 | 2014-06-11 | 菲艾姆股份有限公司 | Converter for an electric machine and method for controlling a power circuit breaker |
| CN103078515A (en) * | 2011-10-25 | 2013-05-01 | 通用电气公司 | Resonant power supply, converter controller, magnetic resonance imaging system and control method |
| CN103795257A (en) * | 2012-10-29 | 2014-05-14 | 三垦电气株式会社 | Synchronous rectifier circuit |
| CN103259443A (en) * | 2013-05-23 | 2013-08-21 | 吕莹 | Limited dual-polarity-controlled full bridge inverter |
| CN104300811A (en) * | 2014-09-05 | 2015-01-21 | 西安理工大学 | Unipolar and bipolar hybrid modulation method for single-phase voltage type PWM rectifier |
| CN104821736A (en) * | 2015-05-15 | 2015-08-05 | 国家电网公司 | Modularized multi-level converter with function of DC side short circuit protection |
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Address after: 201807 2258 Chengbei Road, Jiading District, Shanghai Patentee after: Shanghai Lianying Medical Technology Co., Ltd Patentee after: SHANGHAI ADVANCED Research Institute CHINESE ACADEMY OF SCIENCES Address before: 201807 2258 Chengbei Road, Jiading District, Shanghai Patentee before: SHANGHAI UNITED IMAGING HEALTHCARE Co.,Ltd. Patentee before: SHANGHAI ADVANCED Research Institute CHINESE ACADEMY OF SCIENCES |