CN110112939A - Based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU - Google Patents
Based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU Download PDFInfo
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- CN110112939A CN110112939A CN201910407226.6A CN201910407226A CN110112939A CN 110112939 A CN110112939 A CN 110112939A CN 201910407226 A CN201910407226 A CN 201910407226A CN 110112939 A CN110112939 A CN 110112939A
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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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
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- Electric Propulsion And Braking For Vehicles (AREA)
Abstract
Based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU, including, the d-q transformation of three-phase rectifier is introduced into monophase system the single-phase three-level NPC rectifier mathematical model derived based on d-q coordinate system；Enhance the robustness of locomotive traction system by the outer voltage control strategy based on sliding formwork control；Inhibit the buffeting occurred in first-order system using supercoil；Design supercoil inner ring current control.Control method of the invention is strong using sliding formwork control invariance, responds the advantages that fast, anti-interference design voltage outer ring controller, improves the response speed of system, reduces the fluctuation of DC voltage, enhancing system adapts to the ability of load sudden change；Using the current inner loop controller of the supercoil control algorithm design in High-Order Sliding Mode, it ensure that traditional sliding formwork advantage, efficiently solve the problems, such as the buffeting of system, the ability of enhancing input current tracking net side voltage-phase eliminates the problems such as chattering phenomenon in input current.
Description
Technical field
The present invention relates to the control methods of the single-phase three-level NPC rectifier of EMU, and in particular to one kind is based on supercoil
The single-phase three-level NPC rectifier control method of the EMU of sliding formwork.
Background technique
Three-level PWM rectifier is the important component of high-speed railway motor train unit traction system, is become to enhance traction
The ability that device adapts to load sudden change is flowed, the fluctuation of DC voltage is reduced and ensures to exchange the quality of side input current, traction
The selection of system rectifier control mode is most important.In the development of high-speed railway, although in serial motor train unit traction system
Structure be not quite similar, but if analyzed from the angle of equivalent circuit, the structure of net side substantially can it is equivalent at
Multiple PWM rectifiers are connected in parallel according to the principle of multiplex, finally start traction electric machine.Maximum difference is: different
It is that the tuple of rectifier is different used by serial EMU, the number of rectifier is also different, and topological structure slightly becomes
Change, in DC link, whether there is or not take LC secondary filtering etc..By taking CRH2 series EMU as an example, in trailer system, using two
A three-level pwm voltage-type single-phase rectifier, is combined with doubleization technology, and reduces the secondary filtering of DC side
Structure enormously simplifies the internal structure of motor train unit converter, but complexity greatly increases, the selection pair of rectifier control mode
It is most important for whole system.However EMU is in high-speed cruising state at any time, running environment complexity in addition it is various it is non-linear because
Influence of the element to system, traction current fluctuation acutely, are easy to produce resonance phenomena.Therefore, scholar rectifies traction generator
Device control mode has carried out a large amount of research, such as Instantaneous Comparison Method, hysteretic loop current control.And conventional rectifier PI controlling party
Method because the limitation of its own is difficult to meet the needs of actual control system, there are control efficiencies it is low, stability is poor the problems such as.Cause
This controls rectifier, and for it there are nonlinear feature, scholars propose self adaptive control, fuzzy control, sliding formwork
The nonlinear control methods such as control.
Sliding formwork control has stronger robustness, still can be with the stabilization of maintenance system after controling parameter is interfered
Property, it is widely used in electric electronic current change technology.When the DC lateral load of trailer system rectifying part mutation, the side DC voltage
Also it will fluctuate, it will the control performance for directly affecting current inner loop such as cannot be effective in the operational process of high-speed EMUs
The stability for controlling converter system, can bring huge security risk.Sliding formwork control can when load changes have compared with
Fast response speed, the stabilization of maintenance voltage reduce the influence to current inner loop control.Control amount is placed in high-order by High-Order Sliding Mode
Sliding-mode surface on, efficiently solve the problems, such as the buffeting of traditional sliding formwork, be applied in current inner loop control, can guarantee control
The stability of current inner loop is safeguarded under the premise of precision processed.
Summary of the invention
The purpose of the present invention is to provide a kind of control methods of new railway power, using the supercoil in High-Order Sliding Mode
Control algorithm design current inner loop controller, ensure that traditional sliding formwork advantage, efficiently solves the problems, such as the buffeting of system, increase
The ability of strong input current tracking net side voltage-phase eliminates the problems such as chattering phenomenon in input current.
For achieving the above object, technical solution of the present invention is specific as follows:
Based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU, comprising:
S1: the d-q transformation of three-phase rectifier is introduced into monophase system single-phase three level derived based on d-q coordinate system
NPC rectifier mathematical model:
S2: enhance the robustness of locomotive traction system by the outer voltage control strategy based on sliding formwork control.
S3: inhibit the buffeting occurred in first-order system using supercoil.
S4: design supercoil inner ring current control specifically includes:
(1) determine that sliding-mode surface switching function s (x) and Variable Structure Control rule u (x), current inner loop sliding-mode surface may be designed as:
Wherein:For outer voltage output valve；For given value；
(2) design control law are as follows:
As
Control algolithm are as follows:
Further, the step S2 is specifically included:
It enablesSliding-mode surface can then be designed are as follows:
S=x1+αx2 (5)
Wherein: α is related with DC voltage filtering link.
It can be obtained according to formula (4) and (5):
When system, which is in, to be stablized:And udcFor constant；UqAnd IqIt is zero；Have for line voltage
Valid value obtainsCalculation formula are as follows:
Further, the step S3 is specifically included: control amount being placed in the sliding-mode surface of higher order, to guarantee control amount
Continuity, eliminate buffet；
U (t)=u1(t)+u2(t) (8)
Guarantee Finite-time convergence is in the adequate condition of sliding-mode surface origin:
In formula: W, ρ, λ and S0It is normal number；When system and control law u degree of correlation r >=1, controller be can simplify
Are as follows:
By formula (12) it is found that when designing controller, not needing to carry out sliding-mode surface differential, control using super-twisting algorithm
Measurer has continuity；To make second order sliding mode reach an exponentially stable state, then the value of ρ is 1；It can to maximum
It is able to achieve second order sliding mode, then the value of ρ is 0.5.
Further, further include step S5 after the step S4: being calculated according to Lyapunov stability principle access control
The convergence of method constructs positive definite integral form
Formula (17) derivation is obtained:
By formula sd(18) are brought into obtain:
Proving by the same methodsTherefore super-twisting algorithm is convergent in finite time, meets the stabilization of system
Property require.
Compared with prior art, beneficial effects of the present invention:
Control method of the invention, according to design voltage outer ring control the advantages that sliding formwork control fast response time, strong robustness
Device processed, using super-twisting algorithm High-Order Sliding Mode Theoretical Design current inner loop device is based on, in Matlab/Simulink environment Imitating
EMU starting operating condition and the increased operating condition of tractive load, and emulation has been carried out to traditional PI and supercoil sliding-mode control and has been ground
Study carefully, the results showed that compared to traditional PI double-closed-loop control, it is defeated that control method of the invention reduces EMU rectifier DC side
The fluctuation of voltage out, the robustness of output voltage when enhancing load variation are buffeted exchange side input current and are controlled, and
And the harmonic content of input current can be reduced effectively under two kinds of operating conditions, guarantee the quality of input current, maintained and be
The stabilization of system.
Detailed description of the invention
Fig. 1 is single-phase three-level NPC rectifier main circuit diagram；
Fig. 2 is the waveform diagram for passing PI the starting stage and controlling lower voltage and current；
Fig. 3 is the waveform diagram under the control of starting stage supercoil；
Fig. 4 is that starting stage PI controls lower alternating current circuit frequency analysis figure；
Fig. 5 is that supercoil controls lower alternating current frequency analysis figure；
Fig. 6 is that PI controls lower DC voltage waveform figure；
Fig. 7 is DC voltage enlarged drawing under PI；
Fig. 8 is that supercoil controls lower DC voltage waveform figure；
Fig. 9 is that supercoil controls lower DC voltage enlarged drawing；
Figure 10 is that PI controls lower voltage current waveform；
Figure 11 is that PI controls lower net side current harmonics analysis chart；
Figure 12 is voltage and current waveform under supercoil sliding formwork control；
Figure 13 is that supercoil controls lower net side current harmonics analysis；
Figure 14 is DC voltage waveform when PI is controlled；
Figure 15 is DC voltage waveform diagram under supercoil sliding formwork control.
Specific embodiment:
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that the described embodiment is only a part of the embodiment of the present invention, instead of all the embodiments.Based on this
Embodiment in invention, every other reality obtained by those of ordinary skill in the art without making creative efforts
Example is applied, shall fall within the protection scope of the present invention.
Embodiment 1
The topological structure of trailer system rectifier is as shown in Figure 1.usRectifier net side electricity by mobile transformer output
Pressure；R and L is the equivalent resistance and inductance of on-board traction transformer respectively；DC bus capacitor such as figure is C1And C2；RLIt is that system is negative
The equivalent resistance of load；For the ease of analysis, defining the switch in rectifier first is perfect switch, are as follows:
Wherein i=a, b.
According to formula (1), 9 kinds of switching modes of the main circuit and corresponding voltage value are represented by shown in table 1
The operating mode of 1 NPC rectifier of table
By being analyzed using Kirchhoff's law the main circuit in Fig. 1, the mathematical model of available circuit:
The d-q transformation idea of three-phase rectifier, which is introduced into monophase system, can then derive the list based on d-q coordinate system
Phase three-level NPC rectifier mathematical model:
In traction power supply system for emu, DC side will lead to when the number of locomotives run in system increases or decreases
Voltage loses stabilization.For such problem, have fast response time, strong robustness etc. excellent according to conventional first order sliding mode control algorithm
Point proposes the outer voltage control strategy based on sliding formwork control, the robustness of Lai Zengqiang locomotive traction system.
Firstly, enablingSliding-mode surface can then be designed are as follows:
S=x1+αx2 (5)
Wherein: α is related with DC voltage filtering link.
It can be obtained according to formula (4) and (5):
When system, which is in, to be stablized:And udcFor constant；UqAnd IqIt is zero；Have for line voltage
Valid value.Therefore it can obtainCalculation formula are as follows:
The effect principal security rectifier of current inner loop can be realized unity power factor control, when control exchange side due to
Comprising harmonic wave, making current waveform, there are apparent chattering phenomenons, and single order sliding formwork control is placed on item is switched in control amount, and is controlled
Amount processed does not have continuity, and therefore, system inevitably has certain chattering phenomenon, has unfavorable shadow to current inner loop control
It rings.In view of the problem, propose using supercoil without inhibiting the chattering phenomenon occurred in first-order system the advantages of buffet,
Principle is that control amount is placed in the sliding-mode surface of higher order, to guarantee the continuity of control amount, to eliminate buffeting problem.Except this
Except, the advantages that supercoil still maintains first-order system design simple, strong robustness.
U (t)=u1(t)+u2(t) (8)
Guarantee Finite-time convergence is in the adequate condition of sliding-mode surface origin:
In formula: W, ρ, λ and S0It is normal number.When system and control law u degree of correlation r >=1, controller be can simplify
Are as follows:
By formula (12) it is found that when designing controller, not needing to carry out sliding-mode surface differential, control using super-twisting algorithm
Measurer has continuity.To make second order sliding mode reach an exponentially stable state, then the value of ρ is 1；It can to maximum
It is able to achieve second order sliding mode, then the value of ρ is 0.5.
When designing supercoil inner ring current control, it is first determined sliding-mode surface switching function s (x) and Variable Structure Control are restrained
u(x)。
Current inner loop sliding-mode surface may be designed as:
Wherein:For outer voltage output valve；For given value.
Design control law are as follows:
As
So control algolithm are as follows:
The convergence of control algolithm is proved according to Lyapunov stability principle[13], construct positive definite integral form
Formula (17) derivation is obtained:
By formula sd(18) are brought into obtain:
Proving by the same methodsTherefore super-twisting algorithm is convergent in finite time, meets the stabilization of system
Property require.
Embodiment 2
In order to verify design control algolithm feasibility, simulate system traction starting and tractive load variation when
Two kinds of operating conditions, to the stabilization of DC side output voltage, the robustness of DC voltage and exchange side Harmonics of Input characteristic into
Row simulation analysis.It is as shown in table 2 to emulate parameter setting used.
2 simulation parameter of table
Traction working condition refers to that system loads to this state of constant-speed operation in access, by comparing two kinds of different control modes
Lower system reaches the data such as the time of stable state, net side Harmonics of Input content and voltage fluctuation, final to verify institute's controlling party
The superiority of method.
R=7 Ω is loaded in starting stage system access, as seen from the figure in 0.4s, it is dynamic that system is in stabilization sub stage simulation
Vehicle group constant-speed operation, under Fig. 2,3 two kinds of control modes, the waveform diagram of voltage on line side electric current.By Fig. 2 and Fig. 3 it is found that working as system
When access load, under two kinds of control strategies, rectifier can quickly reach to be run under limit, but the electric current under PI control
There are certain phase difference, sliding formwork control effects to control better than PI for voltage, and the alternating current of input is also more stable, can be better
Guarantee the performance of current tracking voltage, and power factor is approximately one.Harmonic wave for alternating current under two kinds of strategies of analysis is special
Property Fig. 4,5 pairs of alternating currents carry out Fourier analyses.From Fig. 4 and Fig. 5: what rectifier alternating current was primarily present is low order
Harmonic wave, the Harmonics of Input content of system is less under supercoil control, hence it is evident that is better than Traditional control, can effectively reduce dynamic
Harmonic pollution of the vehicle group to power grid.
Fig. 6 to Fig. 9 provides the waveform diagram of DC voltage under two kinds of control modes, from the lower rectification of Fig. 6-9: PI control
Device output voltage can reach near the given reference value of system by 0.2s seconds or so, and direct current under supercoil sliding formwork control
Voltage reaches stable state in 0.05s or so.
The actual operating status of EMU is more complicated, for convenience of studying, considers to load unexpected increase under traction state
The case where adding, does emulation to two kinds of control strategies and compares, and for rectifier in 0.5s, load increases to 12 Ω, Figure 10 by 7 Ω suddenly
The analogous diagram of current on line side voltage is provided with Figure 11.What Figure 12 was provided is voltage and current waveform under supercoil sliding formwork control, figure
13 provide is that supercoil controls lower net side current harmonics analysis.From Figure 10-13: when the load increases, because of DC side
Voltage is kept approximately constant, so DC load current will be reduced, ac-side current can also become smaller to a certain extent, and two kinds
Circuit under control method will eventually be reduced to 700V or so.The percent harmonic distortion variation of electric current is little, but than constant speed shape
State slightly increases, and the alternating current under sliding formwork control reaches stable state in 0.2s or so, and response speed is significantly better than PI control
0.4s。
Figure 14,15 be given at load variation when DC voltage waveform, thus it can also be seen that, DC voltage overshoot,
PI reaches 600V or so when control, and response speed is slower than sliding formwork control.
Claims (4)
1. being based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU characterized by comprising
S1: the d-q transformation of three-phase rectifier is introduced into monophase system the single-phase three level NPC derived based on d-q coordinate system
Rectifier mathematical model:
S2: enhance the robustness of locomotive traction system by the outer voltage control strategy based on sliding formwork control.
S3: inhibit the buffeting occurred in first-order system using supercoil.
S4: design supercoil inner ring current control specifically includes:
(1) determine that sliding-mode surface switching function s (x) and Variable Structure Control rule u (x), current inner loop sliding-mode surface may be designed as:
Wherein:For outer voltage output valve；For given value；
(2) design control law are as follows:
As
Control algolithm are as follows:
。
2. according to claim 1 be based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU, spy
Sign is that the step S2 is specifically included:
It enablesSliding-mode surface can then be designed are as follows:
S=x1+αx2 (5)
Wherein: α is related with DC voltage filtering link.
It can be obtained according to formula (4) and (5):
When system, which is in, to be stablized:And udcFor constant；UqAnd IqIt is zero；For line voltage virtual value,
?Calculation formula are as follows:
3. according to claim 1 be based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU, spy
Sign is that the step S3 is specifically included: control amount is placed in the sliding-mode surface of higher order, to guarantee the continuity of control amount,
It eliminates and buffets；
U (t)=u1(t)+u2(t) (8)
Guarantee Finite-time convergence is in the adequate condition of sliding-mode surface origin:
In formula: W, ρ, λ and S0It is normal number；When system and control law u degree of correlation r >=1, controller be can simplify are as follows:
By formula (12) it is found that when designing controller, not needing to carry out differential to sliding-mode surface using super-twisting algorithm, measurer is controlled
There is continuity；To make second order sliding mode reach an exponentially stable state, then the value of ρ is 1；To maximum possible reality
Existing second order sliding mode, then the value of ρ is 0.5.
4. according to claim 1 be based on the single-phase three-level NPC rectifier control method of supercoil sliding formwork EMU, spy
Sign is, further includes step S5 after the step S4: according to Lyapunov stability principle access control convergence,
Construct positive definite integral form
Formula (17) derivation is obtained:
By formula sd(18) are brought into obtain:
Proving by the same methodsTherefore super-twisting algorithm is convergent in finite time, and the stability for meeting system is wanted
It asks.
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2019
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| CN106549399A (en) * | 2016-12-10 | 2017-03-29 | 三峡大学 | A kind of APF DC side voltage control methods in parallel based on sliding formwork PI complex control algorithms |
| CN106712552A (en) * | 2017-02-10 | 2017-05-24 | 南京航空航天大学 | Control method for VIENNA rectifier of aviation multi-electric engine |
| CN107565832A (en) * | 2017-07-25 | 2018-01-09 | 西南交通大学 | A kind of high ferro low-frequency oscillation suppression method based on sliding formwork control |
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Application publication date: 20190809 |