CN105141135B - The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system - Google Patents
The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system Download PDFInfo
- Publication number
- CN105141135B CN105141135B CN201510547057.8A CN201510547057A CN105141135B CN 105141135 B CN105141135 B CN 105141135B CN 201510547057 A CN201510547057 A CN 201510547057A CN 105141135 B CN105141135 B CN 105141135B
- Authority
- CN
- China
- Prior art keywords
- llc
- bridge
- full
- way
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The present invention relates to a kind of control method of multi-channel parallel full-bridge LLC converters in cascading power source system, cascading power source system used by this method, including front stage converter, LLC, rear class converter are sequentially connected and form three-stage cascade structure；The energy storage device of front stage converter is located at the side of two-way DC DC converters, two-way DC DC converter opposite sides are parallel with multiple LLC, multiple LLC are connected in parallel on the three-phase inverter side of rear class converter, three-phase inverter opposite side connection wave filter, wave filter connection power network.In full-load range, the present invention proposes a whole set of complete voltage control and current share scheme, using this method LLC can be realized under unloaded and heavy duty operating mode and DC bus-bar voltage is controlled.
Description
Technical field
The invention belongs to cascading power source system regions, are related to multi-channel parallel full-bridge LLC in a kind of cascading power source system
The control method of converter.
Background technology
Cascading power source system, multiple power subsystems are connected in the form of cascade, multi-stage transformation is realized, exists in recent years
The field such as distributed power generation and electric automobile is widely applied.By taking the photovoltaic generating system of family as an example, prime uses Boost
Circuit carries out MPPT controls to photovoltaic, and rear class uses high-frequency isolation type DC-DC converter to provide electrical isolation for the system, and carries
DC bus-bar voltage is risen, realizes and is incorporated into the power networks eventually through inverter.It is well known that LLC mode of resonance high-frequency isolations DC-DC is converted
Device possesses high efficiency and power density, and broader gain ranging, in recent years in distributed generation system and electronic vapour
It is used widely in the fields such as car.But multi-channel parallel LLC is controlled in DC bus-bar voltage and also existed in terms of stream
Technical problem to be optimized.
First, it is larger in equivalent output resistance, i.e., under unloaded operating mode, influenceed by parasitic parameter, its gain curve holds
Easily upwarp, produce output voltage and raise, it is difficult to the phenomenon of control.It is affected by it, if controlling its prime bus with LLC,
In the case that rear class busbar voltage is constant, prime busbar voltage can be less than reference value.If following stage bus is controlled with LLC, preceding
In the case that level busbar voltage is constant, rear class busbar voltage can be higher than reference value.Can be under idle condition using fixed frequency to this
The mode of rate control, but the method can cause very high idling frequency, so as to cause LLC efficiency to decline.For raising efficiency,
Switching tube can also be controlled using burst patterns in stability at lower frequencies discontinuous operation.The method causes output voltage line
Ripple is excessive, can cause larger electromagnetic interference to direct current cascading power source system, be unfavorable for the operation steady in a long-term of system.
Second, being limited by narrower closed-loop bandwidth, LLC dynamic responding speed is relatively slow, especially in cascading power source
In system, when system produces disturbance, there is imbalance, larger impact may be caused to DC bus-bar voltage, makes direct current in power
Busbar voltage exceeds normal operation range, ultimately result in system current transformer can not normal work, trigger protection is moved when serious
Make, cause system crash.So control DC bus-bar voltage has vital effect for cascading power source system.
Third, in order to expand power grade, when LLC converters are carried out into parallel, the difference of each road parameter is limited by, respectively
Inductive current on LLC converters causes occur the problems such as circulation or heat distribution inequality in system there will be certain difference.
This is rather unfavorable to whole direct current cascading power source system.
According to above mentioned problem, in order to realize DC bus-bar voltage control and the target such as stream in full-load range, it is necessary to
The new type multipath parallel connection full-bridge LLC resonant type DC-DC converters DC bus-bar voltage control studied performance more preferably and be easy to implement
And current share scheme.
By retrieving, the disclosed patent document of following near field is found.
Power converter technical field (CN103633850A), more particularly to a kind of half-bridge LLCPFM frequency changer circuits and its control
Method, including on-off circuit, LLC resonance circuits and rectifying output circuit；On-off circuit is formed by two groups of half-bridge sub-module cascades,
Every group of half-bridge submodule includes 2 MOSFET and managed, and the voltage of the intermediate node connection LLC resonance circuits of two groups of half-bridge submodules is defeated
Enter side, the voltage output side connection rectifying output circuit of LLC resonance circuits.PWM is sent according to the current value of load or magnitude of voltage
Signal is to on-off circuit；On-off circuit generates drive signal according to pwm signal and is supplied to two groups of half-bridge submodules, soft to realize
Switch change-over.The present invention realizes ZVT using LLC resonant technologies, reduces the switching loss of circuit, realizes efficient
Half-bridge soft switch conversion, using electric asymmetric topology structure design, make circuit rapid reaction, improve circuit stability and subtract
The small volume and weight of circuit.
It is humorous based on the ultra-wide output voltage range charger and control method (CN104467443A) of LLC topologys, including LLC
Shake converter and control circuit, LLC resonant converter includes the switching network being made up of MOSFET full-bridge circuits, switchs net
The input of network is connected with power input, and output end is connected with the input of resonant network, the output end of resonant network and change
The leakage inductance of depressor is connected, and the secondary coil of transformer is connected with rectifying and wave-filtering network；Control circuit includes control unit, and control is single
Member controls the metal-oxide-semiconductor of MOSFET full-bridge circuits according to the input of the LLC resonant converter of reception and the signal of output end
Switch, enable LLC resonant converter realized in full voltage range primary side switch pipe no-voltage conducting, the pole of secondary rectification two
The zero-current switching of pipe.Output voltage of the present invention is wide, is not limited by charging object input voltage range, can be various new energy
Source electric car charges.
By contrast, there is relatively big difference in technical scheme and the present patent application of file disclosed above.
The content of the invention
It is an object of the invention in place of overcome the deficiencies in the prior art, there is provided provide a kind of new voltage control strategy
With equal Flow Policy, the full-bridge LLC resonant type DC-DC converter dc bus in parallel for the stability contorting in full-load range electricity
Pressure, ensure that parallel branch flows, do not change circuit hardware structure, also do not produce voltage ripple.
The present invention solves its technical problem and takes following technical scheme to realize：
The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system, it is characterised in that：This method institute
The cascading power source system of use, including front stage converter, LLC, rear class converter are sequentially connected and form three-stage cascade structure；
The energy storage device of front stage converter is located at the front side of bidirectional DC-DC converter, and bidirectional DC-DC converter opposite side is simultaneously
Multiple LLC are associated with, multiple LLC are connected in parallel on the three-phase inverter side of rear class converter, the connection filtering of three-phase inverter opposite side
Device, wave filter connection power network.
Moreover, LLC circuits include switching network, resonant network and the commutated network being sequentially connected,
Two bridge arms are parallel with the circuit of switching network, wherein a bridge arm is by the switching tube Q1 and switching tube Q2 that connect
Composition, another bridge arm are made up of switching tube Q3 and switching tube Q4；
Resonant network uses LLC type resonators, comprising resonant capacitance Cr, resonant inductance Lr and static exciter inductance Lm,
The resonant capacitance Cr, resonant inductance Lr and static exciter inductance Lm are sequentially connected in series, and the resonant network one end is connected to switch
On bridge arm between pipe Q1 and switching tube Q2, the resonant network other end is connected to the bridge arm between switching tube Q3 and switching tube Q4
On；
Rectification circuit realizes the transmission of electric energy using switch tube device or commutation diode.
Moreover, LLC half-bridge full-bridge mode switching method：
When LLC is in heavy condition, switching tube Q1, Q2, Q3 and Q4 use pulse frequency modulated control strategy, are formed
LLC full-bridge modes；
When LLC is in light condition, switching tube Q1 and Q2 control mode are constant, switching tube Q3 control signal resets
And by switching tube Q4 control signal sets, disconnect the upper switch pipe of the bridge arm, lower switch pipe closure, form LLC half-bridges
Pattern.
Moreover, concretely comprise the following steps：
(1) DC bus-bar voltage controls；In full-load range, it is U that two-way LLC, which controls prime DC bus-bar voltage,Front；
1. first, generate prime DC bus-bar voltage control half-bridge full-bridge switching mark symbol SIGNAL_FH_Front；
2. determination flag position SIGNAL_FH_Front state, to determine to enter unloaded regulation program or adjust journey with carrying
Sequence；
3. prime dc bus sharing control, in determination flag position while SIGNAL_FH_Front state, before progress
Level dc bus sharing control；
(2) rear class dc bus controls；Two-way LLC control rear class DC bus-bar voltages UBack；
1. first, introduce full-bridge half-bridge switching control flag bit SIGNAL_FH_Back；
2. determination flag position SIGNAL_FH_Back state, determine to enter unloaded regulation program or adjust program with carrying；
3. rear class dc bus sharing control, while determination flag position SIGNAL_FH_Back state, carry out rear class
Dc bus sharing control.
Moreover, the step (1) in 1. half-bridge full-bridge switching mark symbol SIGNAL_FH_Front product process be：
When LLC is transformed into Light Condition by heavy duty, SIGNAL_FH_Front is changed into " 0 " from " 1 ", and switching tube Q3 disconnects, and opens
Pipe Q4 closures are closed, LLC is transformed into half-bridge by full-bridge；
When LLC is transformed into heavy condition by zero load, SIGNAL_FH_Front is changed into " 1 " from " 0 ", and switching tube Q3, Q4 are normal
Work, LLC are transformed into full-bridge by half-bridge.
Moreover, the step (1) in 2. flag bit SIGNAL_FH_Front determine half-bridge full-bridge working condition
Flow is specially：
If SIGNAL_FH_Front is " 0 ", enter unloaded regulation program, set two-way LLC original frequency as
fh_Front, LLC working frequency is adjusted using Dead band controller and accumulator etc., the frequency is in fh_FrontInitial value on,
With Δ f1Step change, until output voltage is controlled in the absolute value of reference value error in Δ U1In the range of；
If SIGNAL_FH_Front is " 1 ", enters band and carry regulation program, set two-way LLC original frequency as
ff_Front, to being controlled with the full-bridge LLC converters carried under operating mode.The frequency is in ff_FrontInitial value on, with Δ f2Step-length
Change, until output voltage is controlled in the absolute value of reference value error in Δ U2In the range of；
If in the course of the work, detecting, SIGNAL_FH_Front signals are transformed into " 1 " by " 0 ", then adjust journey by zero load
Sequence jumps to band and carries regulation program operation；
When detecting that SIGNAL_FH_Front signals are transformed into " 0 " by " 1 ", then regulation programming jump is carried to unloaded by band
Adjust program operation.
Moreover, step (1) in 3. prime dc bus current-sharing control method be：
Detection is sorted successively from small to large per LLC resonant inductances current effective value all the way to it；
The minimum LLC all the way of current effective value frequency keeps constant；
When the absolute difference of the immediate two road LLC of current effective value current effective value is more than Δ IFrontWhen, electricity
The working frequency for flowing the larger LLC all the way of virtual value rises maximum Δ f3, and the less LLC all the way of current effective value work frequency
Rate is constant.When this absolute difference is less than or equal to Δ IFrontWhen, two-way LLC working frequencies keep constant；
Since the minimum two-way LLC of current effective value, the like, except the two-way LLC of virtual value minimum and maximum, often
Remaining LLC enters line frequency regulation respectively with virtual value and its immediate two-way LLC in individual controlling cycle, until all LLC
Inductive current virtual value be consistent, all immediate two-way LLC of size inductive current virtual value Error Absolute Value is small
In Δ IFront。
Moreover, step (2) in 1. half-bridge full-bridge switching mark symbol SIGNAL_FH_Back product process be：
As rear class converter power output PBackLess than PLWhen, now SIGNAL_FH_Back is changed into " 0 " from " 1 ", indicates
LLC is transformed into Light Condition by heavy duty, and now, switching tube Q3 disconnects, and switching tube Q4 closures, LLC is transformed into half-bridge by full-bridge；
As rear class converter power output PBackMore than PUWhen, now SIGNAL_FH_Back is changed into " 1 " from " 0 ", indicates
LLC is transformed into heavy condition by zero load, and now, switching tube Q3, Q4 normal work, LLC is transformed into full-bridge by half-bridge.
Moreover, step (1) in 2. flag bit SIGNAL_FH_Back determine that the flow of half-bridge full-bridge working condition is specific
For：
If SIGNAL_FH_Back is 0, enter unloaded regulation program, utilize the work frequency to LLC such as Dead band controller
Rate is adjusted；
If SIGNAL_FH_Back is 1, enters band and carry regulation program, to entering with the full-bridge LLC converters carried under operating mode
Row control；
If in the course of the work, detecting, SIGNAL_FH_Back signals are transformed into " 1 " by " 0 ", then adjust journey by zero load
Sequence jumps to band and carries regulation program, and LLC is converted into full-bridge by half-bridge and run；
When detecting that SIGNAL_FH_Back signals are transformed into " 0 " by " 1 ", then regulation programming jump is carried to unloaded tune by band
Program is saved, LLC is converted into half-bridge by full-bridge and run.
Moreover, step (1) in 3. rear class dc bus current-sharing control method be：
Detection is sorted successively from small to large per LLC resonant inductances current effective value all the way to it；
The minimum LLC all the way of current effective value frequency keeps constant；
When the absolute difference of the immediate two road LLC of current effective value current effective value is more than Δ IBackWhen, electricity
The working frequency for flowing the larger LLC all the way of virtual value rises maximum Δ f3, and the less LLC all the way of current effective value work frequency
Rate is constant；When this absolute difference is less than or equal to Δ IBackWhen, two-way LLC working frequencies keep constant；
Since the minimum two-way LLC of current effective value, the like；Except the two-way LLC of virtual value minimum and maximum, often
Remaining LLC is required for entering line frequency regulation respectively with virtual value and its immediate two-way LLC in individual controlling cycle, until all
LLC inductive current virtual value is consistent, and the immediate two-way LLC of size inductive current virtual value Error Absolute Value is less than
ΔIBack, this measure can reach the purpose that multichannel LLC reaches parallel current-sharing.
The advantages and positive effects of the present invention are：
1st, the working condition of the invention by changing switching tube, under the operating mode of LLC underloadings, full-bridge LLC is changed into half
Bridge LLC, the suppression that phenomenon is upwarped to LLC voltage gain curves is realized, LLC unloaded operation frequency is neither lifted, also will not
Produce excessive voltage ripple.
2nd, in full-load range, the present invention proposes a whole set of complete voltage control and current share scheme, using we
Method allows LLC to be realized to DC bus-bar voltage control under unloaded and heavy duty operating mode.
3rd, using this method, the setting of controlling dead error, it is ensured that for circuit in the case where disturbing, LLC will not frequency
It is numerous to switch under half-bridge and full-bridge two states.And when LLC switches under two kinds of operating modes, by rationally setting frequency initial
Value, voltage and current caused by can reducing in the transfer impact.And by introducing being averaged for two-way LLC inductive current absolute values
Value is simultaneously adjusted based on this to two-way LLC driving frequencies, it is possible to achieve LLC parallel current-sharings, the circulation in reduction system.
Brief description of the drawings
Fig. 1 is cascading power source system structure diagram；
Fig. 2 is that full-bridge LLC resonance DC-DCs converter half-bridge/full-bridge mode switches schematic diagram；
Fig. 2 (a) is LLC full-bridge mode schematic diagrames；
Fig. 2 (b) is LLC half-bridge mode schematic diagrames；
Fig. 3 is prime DC bus-bar voltage control and sharing control flow chart of the LLC based on Dead band controller；
Fig. 4 is that LLC primes DC bus-bar voltage controls half-bridge full-bridge (unloaded heavy duty) switching mark to accord with product process figure；
Fig. 5 is rear class DC bus-bar voltage control and sharing control flow chart of the LLC based on Dead band controller；
Fig. 6 is that LLC full-bridges half-bridge mode when rear class DC bus-bar voltage controls switches schematic diagram.
Embodiment
Below in conjunction with the accompanying drawings and the invention will be further described by specific embodiment, and following examples are descriptive
, it is not limited, it is impossible to which protection scope of the present invention is limited with this.
The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system, it is involved in the present embodiment
The structure of cascading power source system including front stage converter, LLC, rear class converter as shown in figure 1, be sequentially connected composition three-stage cascade
Structure, prime DC bus-bar voltage is transformed into rear class DC bus-bar voltage.
The concrete structure of front stage converter is bidirectional DC-DC converter side series connection accumulation device, bidirectional DC-DC converter
Opposite side is parallel with multiple LLC circuits；Two LLC circuits are parallel with cascading power source system shown in the present embodiment.
LLC circuits include switching network, resonant network and commutated network,
Switching network is specially：Two bridge arms are parallel with the circuit of switching network, wherein a bridge arm is opened by what is connected
Close pipe Q1 and switching tube Q2 compositions, another bridge arm be made up of switching tube Q3 and switching tube Q4, switching network using switching tube Q1,
Q2, Q3 and Q4, form the structure of the controllable inverter of single-phase full bridge；
Resonant network uses LLC type resonators, comprising resonant capacitance Cr, resonant inductance Lr and static exciter inductance Lm,
The resonant capacitance Cr, resonant inductance Lr and static exciter inductance Lm are sequentially connected in series, and the resonant network one end is connected to switch
On bridge arm between pipe Q1 and switching tube Q2, the resonant network other end is connected to the bridge arm between switching tube Q3 and switching tube Q4
On；
Rectification circuit realizes the transmission of electric energy using switch tube device or commutation diode.
Above-mentioned multiple LLC circuit in parallel are in the three-phase inverter side of rear class converter, the connection of three-phase inverter opposite side
Wave filter, wave filter connection power network.
The present embodiment uses the LLC converters of multi-channel parallel, realizes from prime DC bus-bar voltage to rear class dc bus
The conversion of voltage and electrical isolation, prime DC bus-bar voltage and rear class DC bus-bar voltage are controlled using LLC.
LLC half-bridges full-bridge mode switching schematic diagram is as shown in Figure 2.Shown in LLC full-bridge modes such as Fig. 2 (a), when LLC is in
During heavy condition, switching tube Q1, Q2, Q3 and Q4 use pulse frequency modulated control strategy；LLC half-bridge modes such as Fig. 2 (b) institutes
Show, and when LLC is in light condition, switching tube Q1 and Q2 control mode are constant, by switching tube Q3 control signals reset and
By switching tube Q4 control signal sets, disconnect the upper switch pipe of the bridge arm, lower switch pipe closure.Therefore in zero load, can
Full-bridge LLC is converted into half-bridge LLC, reaches the effect that output voltage is effectively controlled under idle condition.
The specific control method of the present embodiment is：
(1) DC bus-bar voltage controls；In full-load range, as two-way LLC control prime DC bus-bar voltages UFront
When, it is as shown in Figure 3 to the Tracing Controls of LLC input voltages, specific control flow chart to ensure；
1. prime DC bus-bar voltage control half-bridge full-bridge switching mark symbol first, is generated, as shown in Figure 4；As two-way LLC
When controlling prime DC bus-bar voltage, to ensure the Tracing Control to LLC input voltages, full-bridge half-bridge switching control mark is introduced
Position SIGNAL_FH_Front.
As front stage converter power output PFrontLess than PLWhen, now SIGNAL_FH_Front is changed into " 0 " from " 1 ", mark
LLC and Light Condition is transformed into by heavy duty.Switching tube Q3 disconnects, and switching tube Q4 closures, LLC is transformed into half-bridge by full-bridge.
As front stage converter power output PFrontMore than PUWhen, now SIGNAL_FH_Front is changed into " 1 " from " 0 ", mark
LLC and heavy condition is transformed into by zero load.Switching tube Q3, Q4 normal work, LLC are transformed into full-bridge by half-bridge.
2. determination flag position SIGNAL_FH_Front state, to determine to enter unloaded regulation program or adjust journey with carrying
Sequence, it is specially：
If SIGNAL_FH_Front is " 0 ", enter unloaded regulation program, set two-way LLC original frequency as
fh_Front, LLC working frequency (dutycycle is constant) is adjusted using Dead band controller and accumulator etc., the frequency exists
fh_FrontInitial value on, with Δ f1Step change, until output voltage is controlled in the absolute value of reference value error in Δ U1
In the range of；
If SIGNAL_FH_Front is " 1 ", enters band and carry regulation program, set two-way LLC original frequency as
ff_Front, to being controlled with the full-bridge LLC converters carried under operating mode.The frequency is in ff_FrontInitial value on, with Δ f2Step-length
Change, until output voltage is controlled in the absolute value of reference value error in Δ U2In the range of；
If in the course of the work, detecting, SIGNAL_FH_Front signals are transformed into " 1 " by " 0 ", then adjust journey by zero load
Sequence jumps to band and carries regulation program operation；
When detecting that SIGNAL_FH_Front signals are transformed into " 0 " by " 1 ", then regulation programming jump is carried to unloaded by band
Adjust program operation；
3. while determination flag position SIGNAL_FH_Front state, carry out prime dc bus sharing control；
Detection is sorted successively from small to large per LLC resonant inductances current effective value all the way to it；
The minimum LLC all the way of current effective value frequency keeps constant；
When the absolute difference of the immediate two road LLC of current effective value current effective value is more than Δ IFrontWhen, electricity
The working frequency for flowing the larger LLC all the way of virtual value rises maximum Δ f3, and the less LLC all the way of current effective value work frequency
Rate is constant.When this absolute difference is less than or equal to Δ IFrontWhen, two-way LLC working frequencies keep constant；
Since the minimum two-way LLC of current effective value, the like, except the two-way LLC of virtual value minimum and maximum, often
Remaining LLC in individual controlling cycle is required for progress twice frequency adjustment (to enter respectively with virtual value and its immediate two-way LLC
Line frequency is adjusted), until all LLC inductive current virtual value is consistent, the immediate two-way LLC of size inductive current
Virtual value Error Absolute Value is less than Δ IFront。
If the absolute value of two-way LLC inductive current virtual value errors is less than Δ IFront, two-way LLC frequencies do not become
Change.This measure can reach the purpose of parallel current-sharing.
(2) rear class dc bus controls；
As two-way LLC control rear class DC bus-bar voltages UBackWhen, ensure the Tracing Control to LLC input voltages, specifically
Control flow chart is as shown in Figure 5.
1. full-bridge half-bridge switching control flag bit SIGNAL_FH_Back first, is introduced, as shown in Figure 6；
As rear class converter power output PBackLess than PLWhen, now SIGNAL_FH_Back is changed into " 0 " from " 1 ", indicates
LLC is transformed into Light Condition by heavy duty, and now, switching tube Q3 disconnects, and switching tube Q4 closures, LLC is transformed into half-bridge by full-bridge；
As rear class converter power output PBackMore than PUWhen, now SIGNAL_FH_Back is changed into " 1 " from " 0 ", indicates
LLC is transformed into heavy condition by zero load, and now, switching tube Q3, Q4 normal work, LLC is transformed into full-bridge by half-bridge；
2. determination flag position SIGNAL_FH_Back state, determine to enter unloaded regulation program or adjust program with carrying；
If SIGNAL_FH_Back is 0, enter unloaded regulation program, utilize the work frequency to LLC such as Dead band controller
Rate (dutycycle is constant) is adjusted；
If SIGNAL_FH_Back is 1, enters band and carry regulation program, to entering with the full-bridge LLC converters carried under operating mode
Row control；
If in the course of the work, detecting, SIGNAL_FH_Back signals are transformed into " 1 " by " 0 ", then adjust journey by zero load
Sequence jumps to band and carries regulation program, and LLC is converted into full-bridge by half-bridge and run；
When detecting that SIGNAL_FH_Back signals are transformed into " 0 " by " 1 ", then regulation programming jump is carried to unloaded tune by band
Program is saved, LLC is converted into half-bridge by full-bridge and run；
3. rear class dc bus sharing control；
LC inductive current virtual value ILr1More than the average value I on the second tunnelLr2, and error exceedes Δ IBackWhen, the first via
LLC working frequency rises Δ f3, the second road LLC working frequency keeps constant；
As the second road LLC inductive current virtual value ILr2More than the average value I of the first viaLr1, and error exceedes Δ IBack
When, the second road LLC working frequency rises Δ f3, first via LLC working frequency keeps constant；
If the absolute value of two-way LLC inductive current virtual value errors is less than Δ IBack, frequency do not change.
Detection is sorted successively from small to large per LLC resonant inductances current effective value all the way to it；
The minimum LLC all the way of current effective value frequency keeps constant；
When the absolute difference of the immediate two road LLC of current effective value current effective value is more than Δ IBackWhen, electricity
The working frequency for flowing the larger LLC all the way of virtual value rises maximum Δ f3, and the less LLC all the way of current effective value work frequency
Rate is constant；When this absolute difference is less than or equal to Δ IBackWhen, two-way LLC working frequencies keep constant.
Since the minimum two-way LLC of current effective value, the like；Except the two-way LLC of virtual value minimum and maximum, often
Remaining LLC is required for progress twice frequency adjustment (to be carried out respectively with virtual value and its immediate two-way LLC in individual controlling cycle
Frequency is adjusted), until all LLC inductive current virtual value is consistent, the immediate two-way LLC of size inductive current has
Valid value Error Absolute Value is less than Δ IBack, this measure can reach the purpose that multichannel LLC reaches parallel current-sharing.
Although disclosing embodiments of the invention and accompanying drawing for the purpose of illustration, those skilled in the art can manage
Solution：Do not departing from the present invention and spirit and scope of the appended claims in, it is various replace, change and modifications all be it is possible,
Therefore, the scope of the present invention is not limited to embodiment and accompanying drawing disclosure of that.
Claims (8)
- A kind of 1. control method of multi-channel parallel full-bridge LLC converters in cascading power source system, it is characterised in that：This method is adopted Cascading power source system, including front stage converter, LLC, rear class converter are sequentially connected and form three-stage cascade structure；The energy storage device of front stage converter is located at the front side of bidirectional DC-DC converter, and bidirectional DC-DC converter opposite side is parallel with Multiple LLC, multiple LLC are connected in parallel on the three-phase inverter side of rear class converter, three-phase inverter opposite side connection wave filter, filter Ripple device connects power network；Concretely comprise the following steps：(1) DC bus-bar voltage controls；In full-load range, it is U that two-way LLC, which controls prime DC bus-bar voltage,Front；1. first, generate prime DC bus-bar voltage control half-bridge full-bridge switching mark symbol SIGNAL_FH_Front；2. determination flag position SIGNAL_FH_Front state, to determine to enter unloaded regulation program or adjust program with carrying；The flag bit SIGNAL_FH_Front flow for determining half-bridge full-bridge working condition is specially：If SIGNAL_FH_Front is " 0 ", enters unloaded regulation program, set two-way LLC original frequency as fh_Front, profit LLC working frequency is adjusted with Dead band controller and accumulator, the frequency is in fh_FrontInitial value on, with Δ f1Step Long change, until output voltage is controlled in the absolute value of reference value error in Δ U1In the range of；If SIGNAL_FH_Front is " 1 ", enters band and carry regulation program, set two-way LLC original frequency as ff_Front, it is right It is controlled with the full-bridge LLC converters carried under operating mode, the frequency is in ff_FrontInitial value on, with Δ f2Step change, until Output voltage is controlled in the absolute value of reference value error in Δ U2In the range of；If in the course of the work, detecting, SIGNAL_FH_Front signals are transformed into " 1 " by " 0 ", then are jumped by zero load regulation program Go to band and carry regulation program operation；When detecting that SIGNAL_FH_Front signals are transformed into " 0 " by " 1 ", then regulation programming jump is carried to unloaded regulation by band Program is run；3. prime dc bus sharing control, in determination flag position while SIGNAL_FH_Front state, it is straight to carry out prime Flow bus sharing control；(2) rear class dc bus controls；Two-way LLC control rear class DC bus-bar voltages UBack；1. first, introduce full-bridge half-bridge switching control flag bit SIGNAL_FH_Back；2. determination flag position SIGNAL_FH_Back state, determine to enter unloaded regulation program or adjust program with carrying；3. rear class dc bus sharing control, while determination flag position SIGNAL_FH_Back state, carry out rear class direct current Bus sharing control.
- 2. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 1 It is：LLC circuits include switching network, resonant network and the commutated network being sequentially connected,Two bridge arms are parallel with the circuit of switching network, wherein a bridge arm is by the switching tube Q1 and switching tube Q2 groups that connect Into another bridge arm is made up of switching tube Q3 and switching tube Q4；Resonant network uses LLC type resonators, and comprising resonant capacitance Cr, resonant inductance Lr and static exciter inductance Lm, this is humorous Shaken electric capacity Cr, and resonant inductance Lr and static exciter inductance Lm are sequentially connected in series, and the resonant network one end is connected to switching tube Q1 On bridge arm between switching tube Q2, the resonant network other end is connected on the bridge arm between switching tube Q3 and switching tube Q4；Rectification circuit realizes the transmission of electric energy using switch tube device or commutation diode.
- 3. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 2 It is：LLC half-bridge full-bridge mode switching method：When LLC is in heavy condition, switching tube Q1, Q2, Q3 and Q4 use pulse frequency modulated control strategy, and it is complete to form LLC Bridge mode；When LLC is in light condition, switching tube Q1 and Q2 control mode are constant, switching tube Q3 control signals reset and general Switching tube Q4 control signal sets, the upper switch pipe of the bridge arm is disconnected, lower switch pipe closure, form LLC half-bridge moulds Formula.
- 4. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 1 It is：The step (1) in 1. half-bridge full-bridge switching mark symbol SIGNAL_FH_Front product process be：When LLC is transformed into Light Condition by heavy duty, SIGNAL_FH_Front is changed into " 0 " from " 1 ", and switching tube Q3 disconnects, switching tube Q4 is closed, and LLC is transformed into half-bridge by full-bridge；When LLC is transformed into heavy condition by zero load, SIGNAL_FH_Front is changed into " 1 " from " 0 ", the normal work of switching tube Q3, Q4 Make, LLC is transformed into full-bridge by half-bridge.
- 5. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 1 It is：Step (1) in 3. prime dc bus current-sharing control method be：Detection is sorted successively from small to large per LLC resonant inductances current effective value all the way to it；The minimum LLC all the way of current effective value frequency keeps constant；When the absolute difference of the immediate two-way LLC of current effective value current effective value is more than Δ IFrontWhen, electric current is effective The working frequency for being worth larger LLC all the way rises maximum Δ f3, and the less LLC all the way of current effective value working frequency is not Become, when this absolute difference is less than or equal to Δ IFrontWhen, two-way LLC working frequencies keep constant；Since the minimum two-way LLC of current effective value, the like, except the two-way LLC of virtual value minimum and maximum, each control Remaining LLC enters line frequency regulation respectively with virtual value and its immediate two-way LLC in cycle processed, until all LLC electricity Inducing current virtual value is consistent, and all immediate two-way LLC of size inductive current virtual value Error Absolute Value is less than Δ IFront。
- 6. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 1 It is：Step (2) in 1. half-bridge full-bridge switching mark symbol SIGNAL_FH_Back product process be：As rear class converter power output PBackLess than PLWhen, now SIGNAL_FH_Back is changed into " 0 " from " 1 ", indicates LLC Light Condition is transformed into by heavy duty, now, switching tube Q3 disconnects, and switching tube Q4 closures, LLC is transformed into half-bridge by full-bridge；As rear class converter power output PBackMore than PUWhen, now SIGNAL_FH_Back is changed into " 1 " from " 0 ", indicates LLC Heavy condition is transformed into by zero load, now, switching tube Q3, Q4 normal work, LLC is transformed into full-bridge by half-bridge.
- 7. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 1 It is：Step (1) in 2. flag bit SIGNAL_FH_Back determine that the flow of half-bridge full-bridge working condition is specially：If SIGNAL_FH_Back is 0, enter unloaded regulation program, LLC working frequency is carried out using Dead band controller Regulation；If SIGNAL_FH_Back is 1, enters band and carry regulation program, to being controlled with the full-bridge LLC converters carried under operating mode System；If in the course of the work, detecting, SIGNAL_FH_Back signals are transformed into " 1 " by " 0 ", then are jumped by zero load regulation program Go to band and carry regulation program, LLC is converted into full-bridge by half-bridge and run；When detecting that SIGNAL_FH_Back signals are transformed into " 0 " by " 1 ", then regulation programming jump is carried to unloaded regulation journey by band Sequence, LLC are converted into half-bridge by full-bridge and run.
- 8. the control method of multi-channel parallel full-bridge LLC converters, its feature in cascading power source system according to claim 1 It is：Step (1) in 3. rear class dc bus current-sharing control method be：Detection is sorted successively from small to large per LLC resonant inductances current effective value all the way to it；The minimum LLC all the way of current effective value frequency keeps constant；When the absolute difference of the immediate two-way LLC of current effective value current effective value is more than Δ IBackWhen, current effective value Larger LLC all the way working frequency rises maximum Δ f3, and the less LLC all the way of current effective value working frequency is constant； When this absolute difference is less than or equal to Δ IBackWhen, two-way LLC working frequencies keep constant；Since the minimum two-way LLC of current effective value, the like；Except the two-way LLC of virtual value minimum and maximum, each control Remaining LLC is required for entering line frequency regulation respectively with virtual value and its immediate two-way LLC in cycle processed, until all LLC Inductive current virtual value be consistent, the immediate two-way LLC of size inductive current virtual value Error Absolute Value is less than Δ IBack, this measure can reach the purpose that multichannel LLC reaches parallel current-sharing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510547057.8A CN105141135B (en) | 2015-08-31 | 2015-08-31 | The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510547057.8A CN105141135B (en) | 2015-08-31 | 2015-08-31 | The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105141135A CN105141135A (en) | 2015-12-09 |
| CN105141135B true CN105141135B (en) | 2017-12-29 |
Family
ID=54726384
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510547057.8A Active CN105141135B (en) | 2015-08-31 | 2015-08-31 | The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105141135B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107659161A (en) * | 2016-07-25 | 2018-02-02 | 中兴通讯股份有限公司 | A kind of control method and device of three-phase half-bridge LLC controlled resonant converters |
| CN108964474B (en) * | 2018-08-13 | 2020-02-11 | 三峡大学 | Three-mode rectification topological structure based on LLC resonant converter |
| WO2021134288A1 (en) * | 2019-12-30 | 2021-07-08 | Oppo广东移动通信有限公司 | Power supply device and charging control method |
| CN111884607B (en) * | 2020-06-28 | 2024-06-18 | 季华实验室 | Full-bridge D-type amplifying circuit, cascade power module and high-power radio frequency power supply |
| CN113114041B (en) * | 2021-04-06 | 2022-09-06 | 上海科技大学 | LLC resonant converter with improved light-load performance |
| CN113992022B (en) * | 2021-10-20 | 2023-09-29 | 华中科技大学 | Multi-phase staggered parallel LLC converter optimal control method and device |
| CN114337287B (en) * | 2021-12-23 | 2023-08-15 | 阳光电源股份有限公司 | Power conversion system, isolated converter and operation control method thereof |
| CN115378276B (en) * | 2022-09-09 | 2024-07-23 | 山东大学 | Bidirectional power conversion topology, method and system for power battery test excitation power supply |
| CN117424458B (en) * | 2023-12-19 | 2024-02-23 | 深圳通业科技股份有限公司 | Control method, system and controller of power supply conversion circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1331723A2 (en) * | 2002-01-25 | 2003-07-30 | Appletec Ltd. | Low output voltage, high current, half-bridge, series-resonant, multiphase, DC-DC power supply |
| CN101247090A (en) * | 2008-03-07 | 2008-08-20 | 艾默生网络能源有限公司 | Multiphase DC-DC converter |
| CN101431296A (en) * | 2007-09-28 | 2009-05-13 | 雅达电子国际有限公司 | Variable output voltage power converter |
| CN103683955A (en) * | 2013-12-20 | 2014-03-26 | 华为技术有限公司 | Direct current converter and power supply system |
-
2015
- 2015-08-31 CN CN201510547057.8A patent/CN105141135B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1331723A2 (en) * | 2002-01-25 | 2003-07-30 | Appletec Ltd. | Low output voltage, high current, half-bridge, series-resonant, multiphase, DC-DC power supply |
| CN101431296A (en) * | 2007-09-28 | 2009-05-13 | 雅达电子国际有限公司 | Variable output voltage power converter |
| CN101247090A (en) * | 2008-03-07 | 2008-08-20 | 艾默生网络能源有限公司 | Multiphase DC-DC converter |
| CN103683955A (en) * | 2013-12-20 | 2014-03-26 | 华为技术有限公司 | Direct current converter and power supply system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105141135A (en) | 2015-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105141135B (en) | The control method of multi-channel parallel full-bridge LLC converters in a kind of cascading power source system | |
| Dao et al. | High-efficiency hybrid LLC resonant converter for on-board chargers of plug-in electric vehicles | |
| US11404965B2 (en) | DC-DC converter, on-board charger, and electric vehicle | |
| CN108879906B (en) | Modularized medium-voltage quick charger | |
| Li et al. | Family of enhanced ZCS single-stage single-phase isolated AC–DC converter for high-power high-voltage DC supply | |
| CN111064359A (en) | Wide-range bidirectional conversion circuit and control method | |
| CN108599583B (en) | General flexible energy management system based on modularized multi-level converter | |
| Higa et al. | Dual active bridge DC-DC converter using both full and half bridge topologies to achieve high efficiency for wide load | |
| US20150263646A1 (en) | Switching circuit, power converter, and control method | |
| CN104158400A (en) | Modularized high-pressure power supply circuit | |
| CN108377094A (en) | A kind of dead zone adjustment control method being suitable for double active bridge soft starts | |
| CN107294392A (en) | A kind of bidirectional DC/DC converter | |
| CN204334330U (en) | A kind of modularization high-voltage power supply circuit | |
| Ramakrishnan et al. | Power topology considerations for electric vehicle charging stations | |
| Chi et al. | A novel dual phase shift modulation for dual-active-bridge converter | |
| CN114257097B (en) | Wide-output direct-current converter with multi-mode switching and switching control thereof | |
| Wang et al. | Design and implementation of a bidirectional isolated dual-active-bridge-based DC/DC converter with dual-phase-shift control for electric vehicle battery | |
| CN111817566A (en) | LLCT resonant bidirectional DC converter | |
| CN110601525A (en) | Integrated vehicle-mounted charging conversion system of new energy automobile | |
| CN109004836B (en) | Frequency conversion optimization control method suitable for modular multilevel direct current transformer | |
| CN104779807B (en) | A kind of LLC resonant converter applied in distributed power source | |
| CN110061523B (en) | Multifunctional single-phase grid-connected inversion system and method with novel topological structure | |
| Zhang et al. | Soft-switching single-stage current-fed full-bridge isolated converter for high power AC/DC applications | |
| CN112054685A (en) | Electric energy router and control method thereof | |
| CN115189575B (en) | High-voltage direct-current converter and voltage regulating method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |