CN107612335B - A kind of crisscross parallel control method of three-level LLC resonance inverter - Google Patents
A kind of crisscross parallel control method of three-level LLC resonance inverter Download PDFInfo
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- CN107612335B CN107612335B CN201710851061.2A CN201710851061A CN107612335B CN 107612335 B CN107612335 B CN 107612335B CN 201710851061 A CN201710851061 A CN 201710851061A CN 107612335 B CN107612335 B CN 107612335B
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Abstract
The invention discloses a kind of crisscross parallel control methods of three-level LLC resonance inverter, include at least: to each phase LLC resonant converter output drive signal；The electric current of each phase LLC resonant converter is compared；Based on comparative result by incremental time be added to the biggish each phase LLC resonant converter of electric current driving signal the second dead time on.The electric current of each phase LLC resonant converter is first compared by the present invention, again based on comparative result by incremental time be added to the biggish each phase LLC resonant converter of electric current driving signal the second dead time on, make the second dead time T of the driving signal of these phase LLC resonant convertersd2Become larger, to reduce the time that input voltage acts on resonant cavity, reduces the resonance current of the LLC resonant converter of the phase, thus the power-balance of the road Shi Ge LLC resonant converter, and then improve the efficiency and reliability of power supply.
Description
Technical field
The present invention relates to a kind of controls of the crisscross parallel of power technique fields more particularly to three-level LLC resonance inverter
Method.
Background technique
LLC resonant converter, since its structure is simple, high-efficient and energy full-load range realizes zero voltage switch (Zero
Voltage Switch, abbreviation ZVS) the advantages that, it is widely used in the design of current power supply.By three level
(Three-Level) structure is applied in LLC resonant converter, and the input voltage of converter can be improved, and is applicable in converter
In high voltage applications.Meanwhile LLC converter is in parallel with the mode of staggeredly (interleaving), power supply not only can be improved
Output electric current, but also can reduce the filter capacitor of input and output.
But when LLC resonant converter crisscross parallel, the deviation in resonant element parameter lower than 5% will be caused very
Big unbalanced power compromises the efficiency and reliability of entire power supply.
Summary of the invention
The present invention solves existing skill by providing a kind of crisscross parallel control method of three-level LLC resonance inverter
In art the technical issues of unbalanced power, the technical effect for improving the efficiency and reliability of power supply is realized.
The present invention provides a kind of crisscross parallel control methods of three-level LLC resonance inverter, include at least:
To each phase LLC resonant converter output drive signal；
The electric current of each phase LLC resonant converter is compared；
Based on comparative result by incremental time be added to the biggish each phase LLC resonant converter of electric current driving signal
In two dead times.
Further, described to each phase LLC resonant converter output drive signal, it includes at least:
The driving signal for being 360 °/N to each phase LLC resonant converter phase difference output φ；Wherein, N is the LLC
The number of controlled resonant converter.
Further, the electric current by each phase LLC resonant converter is compared, and is included at least:
The input current of each phase LLC resonant converter or output electric current are compared.
Further, described that incremental time is added to the biggish each phase LLC resonant converter of electric current based on comparative result
Driving signal the second dead time on, include at least:
The minimum current in each phase LLC resonant converter is determined based on comparative result；
The electric current of each phase LLC resonant converter and the minimum current are asked poor；
The incremental time of each phase LLC resonant converter is obtained based on current differential；
Each incremental time is added in the second dead time of the driving signal of each LLC resonant converter.
Further, described that the incremental time of each phase LLC resonant converter is obtained based on current differential, at least wrap
It includes:
By each current differential by proportional-plus-integral controller, the incremental time of each phase LLC resonant converter is obtained.
Further, described by each current differential by also including at least after proportional-plus-integral controller:
By each current differential by limiter, the incremental time of each phase LLC resonant converter is obtained.
One or more technical solution provided in the present invention, has at least the following technical effects or advantages:
First the electric current of each phase LLC resonant converter is compared, then incremental time is added to electricity based on comparative result
In the second dead time for flowing the driving signal of biggish each phase LLC resonant converter, make the drive of these phase LLC resonant converters
Second dead time T of dynamic signald2Become larger, to reduce the time that input voltage acts on resonant cavity, makes the LLC of the phase
The resonance current of controlled resonant converter reduces, thus the power-balance of the road Shi Ge LLC resonant converter, and then improve the effect of power supply
Rate and reliability.
Detailed description of the invention
Fig. 1 is the circuit diagram of three-level LLC resonance inverter；
Fig. 2 is the waveform diagram of the driving signal of single three-level LLC resonance inverter；
Fig. 3 is the circuit diagram of three-level LLC resonance inverter crisscross parallel；
Fig. 4 is the flow chart of the crisscross parallel control method of three-level LLC resonance inverter provided in an embodiment of the present invention；
Fig. 5 is the phase schematic diagram of the road three-level LLC resonance inverter crisscross parallel Shi Ge driving signal；
Fig. 6 is step in the crisscross parallel control method of three-level LLC resonance inverter provided in an embodiment of the present invention
The flow chart of first part in S130；
Fig. 7 is step in the crisscross parallel control method of three-level LLC resonance inverter provided in an embodiment of the present invention
The flow chart of second part in S130；
The waveform diagram of output power Fig. 8 does not apply balance control when being three-level LLC resonance inverter crisscross parallel when；
Fig. 9 is applied with the waveform diagram of output power after balance control when being three-level LLC resonance inverter crisscross parallel.
Specific embodiment
The embodiment of the present invention is solved by providing a kind of crisscross parallel control method of three-level LLC resonance inverter
In the prior art the technical issues of unbalanced power, the technical effect for improving the efficiency and reliability of power supply is realized.
Technical solution in the embodiment of the present invention is to solve the above problems, general thought is as follows:
First the electric current of each phase LLC resonant converter is compared, then incremental time is added to electricity based on comparative result
In the second dead time for flowing the driving signal of biggish each phase LLC resonant converter, make the drive of these phase LLC resonant converters
Second dead time T of dynamic signald2Become larger, to reduce the time that input voltage acts on resonant cavity, makes the LLC of the phase
The resonance current of controlled resonant converter reduces, thus the power-balance of the road Shi Ge LLC resonant converter, and then improve the effect of power supply
Rate and reliability.
Above-mentioned technical proposal in order to better understand, in conjunction with appended figures and specific embodiments to upper
Technical solution is stated to be described in detail.
It is illustrated in the crisscross parallel control method to three-level LLC resonance inverter provided in an embodiment of the present invention
Before, need the first control method to the circuit structure of three-level LLC resonance inverter, three-level LLC resonance inverter and three electricity
The circuit structure of flat LLC resonant converter crisscross parallel is illustrated.Firstly, to the circuit knot of three-level LLC resonance inverter
Structure is illustrated:
Referring to Fig. 1, the circuit structure of three-level LLC resonance inverter is by transformer XFR1, primary side resonance circuit and two
Secondary side rectification circuit composition.Wherein, the primary side of transformer XFR1 uses a winding.Primary side resonance circuit, including four opened
Close pipe S1, S2, S3, S4, two diodes D1, D2, and the resonant cavity being made of resonant inductance Lr and resonant capacitance Cr；It is secondary
Side rectification circuit, including two diodes D3, D4.Four switching tube S1-S4 of primary side are sequentially connected in series.Two Diode series
It is in parallel with switching tube S2, S3 afterwards.After the first winding three series connection of resonant inductance Lr, resonant capacitance Cr and transformer XFR1, one
End is connected to the junction (end s of S2) of S2 and S3, another junction for being connected to diode D1, D2.The positive Vin+ of input
It is connected to the end d of switching tube S1, the cathode Vin- of input is connected to the end s of switching tube S4, and the midpoint N of input is connected to diode D1, D2
Junction.Transformer XFR1 secondary side winding and diode form rectification circuit.One terminal p2 of the first winding and two poles
The anode of pipe D3 is connected, and the different name end p3 of another terminal m2 and the second winding is connected, and is connected to the cathode Vout- of output.The
Another terminal m3 of two windings is connected with the anode of diode D4.Diode D3 is connected with the cathode of D4, and is connected to output
Positive Vout+.Driving signal g1, g2, g3, g4 produed by the controller respectively control switch pipe S1, S2, S3, S4 open and
Shutdown.When driving signal is high level, corresponding switching tube is opened；When driving signal is low level, corresponding switching tube is turned off.
Referring to fig. 2, if not considering dead time, driving signal g1, g2, g3, g4 are the same frequency side that duty ratio is 0.5
Wave, frequency fsw.Wherein, g1 is identical as g2 phase, and g3 is identical as g4 phase；G1, g2 and g3, g4 reverse phase, i.e. phase difference
180°.The frequency f that controller passes through change driving signalsw, to control the output voltage of LLC converter.
In order to avoid switching tube leads directly to and realize ZVS, the first dead time T is added between driving signal g1, g2, g3, g4d1
With the second dead time Td2.Specifically, postpone a period of time T after driving signal g1 is lowerd2, then driving signal g2 is made to be lower；
G2 postpones a period of time T after being lowerd1, then get higher driving signal g3, g4.Similarly, postpone one section after driving signal g4 is lower
Time Td2, then driving signal g3 is made to be lower；G3 postpones a period of time T after being lowerd1, then get higher driving signal g3, g4.
Referring to Fig. 3, the circuit structure of three-level LLC resonance inverter crisscross parallel is by n three-level LLC resonance inverter
It forms, wherein n >=2.The anode of input and two connect and one end of equal capacitor C1, the C2 of capacitance is connected, the cathode of input
It is connected with the other end of two concatenated capacitor C1, C2.The anode of input the anode Vin+ and input of all LLC resonant converters
It is connected；The input cathode Vin- of all LLC resonant converters is connected with the cathode of input；The midpoint N of all LLC resonant converters
It is connected with the tie point of capacitor C1, C2.The output cathode Vout+ of all LLC resonant converters is connected with the anode of output, institute
There is the output negative pole Vout- of LLC resonant converter to be all connected with the cathode of output.The indirect capacitor C3 of the positive and negative anodes of output.
Referring to fig. 4, the crisscross parallel control method of three-level LLC resonance inverter provided in an embodiment of the present invention, at least
Include:
Step S110: to each phase LLC resonant converter output drive signal；
This step is illustrated:
The driving signal for being 360 °/N to each phase LLC resonant converter phase difference output φ；Wherein, N is LLC resonant transformation
The number of device.Since the fundamental wave of input current is switching frequency, and the switching frequency that the fundamental wave for exporting electric current is 2 times, therefore this
Sample can not only be such that output ripple electric current reduces, but also can eliminate the ripple of the switching frequency of input current.Simultaneously with three tunnels
For connection, as shown in figure 5, the phase difference of each road driving signal is 120 °, achieve the purpose that while reducing to output and input ripple.
Step S120: the electric current of each phase LLC resonant converter is compared；
This step is illustrated:
The input current of each phase LLC resonant converter or output electric current are compared.
What needs to be explained here is that due to compare input current and compare output electric current be it is of equal value, be not different, because
This can both compare input current under any circumstance, can also compare output electric current.
Step S130: incremental time is added to the drive of the biggish each phase LLC resonant converter of electric current based on comparative result
In second dead time of dynamic signal, make the second dead time T of these phase LLC resonant convertersd2Become larger.
This step is illustrated:
The minimum current in each phase LLC resonant converter is determined based on comparative result；
The electric current of each phase LLC resonant converter and minimum current are asked poor；
What needs to be explained here is that minimum current is minimum input if comparison result is the comparison result of input current
Electric current；The input current of each phase LLC resonant converter and minimum input current are asked poor；If comparison result is the ratio for exporting electric current
Compared with as a result, then minimum current is minimum output current；The output electric current of each phase LLC resonant converter is asked with minimum output current
Difference.
The incremental time of each phase LLC resonant converter is obtained based on current differential；
In second dead time of the driving signal of each LLC resonant converter that each incremental time is added to.
Wherein, the incremental time of each phase LLC resonant converter is obtained based on current differential, included at least:
By each current differential by proportional-plus-integral controller, the incremental time of each phase LLC resonant converter is obtained.
Specifically, it after each current differential is passed through proportional-plus-integral controller, also includes at least:
By each current differential by limiter, the incremental time of each phase LLC resonant converter is obtained.
More specifically, step S130 is completed by two parts, as shown in Figure 6 and Figure 7.First part selects a phase LLC to become
Parallel operation is as benchmark phase.It specifically includes: converter (the namely Δ T of the second dead time will be had not been changedd=0 converter) make
For alternative objects, their output electric current is compared, selects the smallest phase of electric current (assuming that being m phase) as benchmark
Phase.And using the electric current of benchmark phase as current reference.Second part respectively mutually generates respective second dead time increment Delta Td。
Specifically include: if this is mutually benchmark phase (i.e. m=i), dead zone increment is set as zero (i.e. Δ Td=0).If the phase is not
Benchmark phase (i.e. m ≠ i) then the output electric current of output electric current and benchmark phase to the phase asks poor, and is controlled by proportional, integral
Device and limiter generate dead time increment Delta Td.Wherein, the effect of limiter is that incremental time is made to be more than or equal to zero,
If the dead time increment Delta T that proportional-plus-integral controller generatesdLess than zero, then limiter will make Δ Td=0.It is each mutually to generate
Dead time increment Delta TdBe added to the second original dead time Td2On, increasing by the second dead time is Td2+ΔTd。
What needs to be explained here is that each dead time increment mutually generated sends first part back to, as generation benchmark phase
Foundation.
When figure shows using crisscross parallel but does not apply balance control, the effect in parallel of three tunnel LLC resonant converters.It hands over
Wrong 120 ° of driving signal mutual deviation of the road mode Shi Ge in parallel.Since difference is mutually staggered, ripple becomes smaller the peak value of electric current.But due to
Inconsistent (there are 5% deviations) of resonant parameter, when not applying balance control, the unbalanced power of each road output.
The crisscross parallel effect after applying balance control is shown in figure.The driving of the balance control road Shi Ge LLC converter
Second dead time of signal is different, so that the output power of the road Shi Ge converter reaches unanimity.
1, first the electric current of each phase LLC resonant converter is compared, then incremental time is added to based on comparative result
In second dead time of the driving signal of the biggish each phase LLC resonant converter of electric current, make these phase LLC resonant converters
Second dead time T of driving signald2Become larger, to reduce the time that input voltage acts on resonant cavity, makes the phase
The resonance current of LLC resonant converter reduces, thus the power-balance of the road Shi Ge LLC resonant converter, and then improve power supply
Efficiency and reliability.
2, the driving signal for being 360 °/N to each phase LLC resonant converter phase difference output φ, due to the base of input current
Wave is switching frequency, and the fundamental wave for exporting electric current is 2 times of switching frequency, therefore output ripple electric current not only can be made to subtract
It is small, but also the ripple of the switching frequency of input current can be eliminated.
The embodiment of the present invention can not only reduce the ripple current of input and output, can especially reduce the input of switching frequency
Current ripples, and multiple LLC resonant converters can also be overcome in crisscross parallel, the unbalanced power phenomenon of appearance, thus
The power density of converter is improved, and keeps its operation safer, reliable, efficient.
Although preferred embodiments of the present invention have been described, it is created once a person skilled in the art knows basic
Property concept, then additional changes and modifications may be made to these embodiments.So it includes excellent that the following claims are intended to be interpreted as
It selects embodiment and falls into all change and modification of the scope of the invention.
Obviously, various changes and modifications can be made to the invention without departing from essence of the invention by those skilled in the art
Mind and range.In this way, if these modifications and changes of the present invention belongs to the range of the claims in the present invention and its equivalent technologies
Within, then the present invention is also intended to include these modifications and variations.
Claims (5)
1. a kind of crisscross parallel control method of three-level LLC resonance inverter, which is characterized in that include at least:
To each phase LLC resonant converter output drive signal；
The electric current of each phase LLC resonant converter is compared；
Based on comparative result by incremental time be added to the biggish each phase LLC resonant converter of electric current driving signal it is second dead
On area's time；
It is described based on comparative result by incremental time be added to the biggish each phase LLC resonant converter of electric current driving signal
In two dead times, include at least:
The minimum current in each phase LLC resonant converter is determined based on comparative result；
The electric current of each phase LLC resonant converter and the minimum current are asked poor；
The incremental time of each phase LLC resonant converter is obtained based on current differential；
Each incremental time is added in the second dead time of the driving signal of each LLC resonant converter；
Wherein, the second dead time be driving signal g1 be lower with driving signal g2 be lower between delay time, and the drive
Dynamic signal g1 is identical as the phase of the driving signal g2.
2. the method as described in claim 1, which is characterized in that it is described to each phase LLC resonant converter output drive signal, until
Include: less
The driving signal for being 360 °/N to each phase LLC resonant converter phase difference output φ；Wherein, N is the LLC resonance
The number of converter.
3. the method as described in claim 1, which is characterized in that the electric current by each phase LLC resonant converter carries out
Compare, include at least:
The input current of each phase LLC resonant converter or output electric current are compared.
4. the method as described in claim 1, which is characterized in that described to obtain each phase LLC resonance change based on current differential
The incremental time of parallel operation, includes at least:
By each current differential by proportional-plus-integral controller, the incremental time of each phase LLC resonant converter is obtained.
5. method as claimed in claim 4, which is characterized in that each current differential is passed through proportional-plus-integral controller described
Later, it also includes at least:
By each current differential by limiter, the incremental time of each phase LLC resonant converter is obtained.
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| CN110572040B (en) * | 2019-09-24 | 2021-04-02 | 西北工业大学 | Half-bridge LLC resonant converter interleaved parallel circuit and current-sharing control method thereof |
| CN113098278B (en) * | 2021-04-01 | 2023-03-03 | 武汉麦格米特电气有限公司 | Current-sharing adjusting method and circuit for interleaved LLC circuit in parallel and resonant converter |
| CN116073643B (en) * | 2023-02-02 | 2023-10-10 | 中山大学 | Method for controlling interleaving of parallel DC-DC converters in decentralization mode |
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| CN101674016A (en) * | 2009-10-01 | 2010-03-17 | 旭丽电子(广州)有限公司 | Power supply device and current sharing control method |
| CN102545596A (en) * | 2010-12-17 | 2012-07-04 | 世系动力公司 | Interleaved llc converter employing active balancing |
| CN102545638A (en) * | 2012-01-20 | 2012-07-04 | 华为技术有限公司 | Interleaving three-level DC/DC converter and AC/DC converter |
| CN102684464A (en) * | 2011-03-15 | 2012-09-19 | 雅达电子国际有限公司 | Resonant converter device and use method therefor |
| CN103532393A (en) * | 2012-07-04 | 2014-01-22 | Det国际控股有限公司 | LLC balancing |
| CN103780081A (en) * | 2012-10-22 | 2014-05-07 | 伊顿公司 | Interleaved LLC current-sharing converter |
| CN105897000A (en) * | 2016-04-25 | 2016-08-24 | 陕西科技大学 | Phase shift compensation interleaved three-level LLC resonant converter |
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- 2017-09-20 CN CN201710851061.2A patent/CN107612335B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101674016A (en) * | 2009-10-01 | 2010-03-17 | 旭丽电子(广州)有限公司 | Power supply device and current sharing control method |
| CN102545596A (en) * | 2010-12-17 | 2012-07-04 | 世系动力公司 | Interleaved llc converter employing active balancing |
| CN102684464A (en) * | 2011-03-15 | 2012-09-19 | 雅达电子国际有限公司 | Resonant converter device and use method therefor |
| CN102545638A (en) * | 2012-01-20 | 2012-07-04 | 华为技术有限公司 | Interleaving three-level DC/DC converter and AC/DC converter |
| CN103532393A (en) * | 2012-07-04 | 2014-01-22 | Det国际控股有限公司 | LLC balancing |
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| CN105897000A (en) * | 2016-04-25 | 2016-08-24 | 陕西科技大学 | Phase shift compensation interleaved three-level LLC resonant converter |
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Application publication date: 20180119 Assignee: Wuhan Financial Leasing Co.,Ltd. Assignor: WUHAN NANHUA INDUSTRIAL EQUIPMENT ENGINEERING Co.,Ltd. Contract record no.: X2023420000146 Denomination of invention: A interleaved parallel control method for three-level LLC resonant converters Granted publication date: 20191025 License type: Exclusive License Record date: 20230607 |
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