CN106410813B - A method of analysis low-frequency modulation signal is in HXD type locomotive rectifier propagation law - Google Patents
A method of analysis low-frequency modulation signal is in HXD type locomotive rectifier propagation law Download PDFInfo
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- 230000003137 locomotive effect Effects 0.000 title claims abstract description 18
- 238000004458 analytical method Methods 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 claims abstract description 14
- 238000013178 mathematical model Methods 0.000 claims abstract description 6
- 238000012544 monitoring process Methods 0.000 claims abstract description 5
- 230000005540 biological transmission Effects 0.000 claims abstract description 4
- 239000011159 matrix material Substances 0.000 abstract description 6
- 238000009412 basement excavation Methods 0.000 abstract 1
- 230000005764 inhibitory process Effects 0.000 abstract 1
- 230000010355 oscillation Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 5
- 239000004020 conductor Substances 0.000 description 4
- 238000013016 damping Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 2
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
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Abstract
The invention discloses a kind of low-frequency modulation signals of analyzing in the method for HXD type locomotive rectifier propagation law, it include: the implicit information of deep excavation Traction networks, locomotive intermediate DC link actual monitoring data, quantify the relationship of the two, and and low-frequency modulation signal propagation law in rectifier compare verifying, specifically: using method of the DFT transform in conjunction with TLS-ESPRIT, the unstable electrical quantity mode composition of the Traction networks of analysis；Construct the voltage signal u (n) when more vehicle access tractive power supply systems, Hankel matrix X, recycle constructed mathematical model, derive its mechanism of transmission under SPWM algorithm, it is extracted the mode composition for leading to voltage fluctuation, the propagation characteristic of unstable constant voltage is analyzed by modulation theory.The present invention specifies the mathematical relationship of the harmonic propagation at rectifier both ends, has established theoretical basis for effective inhibition of voltage fluctuation.
Description
Technical field
The invention belongs to high-speed railway traction power supply power quality analysis fields, and in particular to a kind of analysis low frequency modulations letter
Number HXD type locomotive rectifier propagation law method.
Background technique
HXD, EMUs are typical nonlinear-loads, preferably overcome power factor after using " cross-straight-intersection " mode
Lower disadvantage.However when largely electric locomotive rising bows take stream to reorganize and outfit, so that Traction networks network pressure larger fluctuation, leads to locomotive relay protection
Device action, IGBT appearance is self-locking, or even causes transport paralysis.Scene inhibits this by the gradual rising bow mode of power train
Problem, but can not tackle the problem at its root.
For the phenomenon, study from low-frequency oscillation angle research Traction networks electrical quantity instability problem.In electric system
Low-frequency oscillation problem is characterized primarily by mutually waving between disturbing lower generator amature, the caused lasting vibration when lacking damping
It swings.Currently, mainly having for low-frequency oscillation mechanism of production: negative damping mechanism, forced oscillation mechanism and chaology.In addition, existing
There is technology to be investigated the distribution of power grid chain type, interregional unbalanced power etc. and damping effect point is carried out to low-frequency oscillation of electric power system
Analysis.Consider the particularity, the randomness of load and non-linear, object, production with theory analysis of tractive power supply system topological structure
Raw process and mathematical modeling have differences, thus cannot simply be attributed to low-frequency oscillation problem, need to deeply excavate traction
The implicit information of net actual monitoring data.
Summary of the invention
Technical problem to be solved by the invention is to provide a kind of analysis low-frequency modulation signals to pass in HXD type locomotive rectifier
The feature of supply conductor voltage fluctuation is accurately positioned in the method for broadcasting rule；It is steady to the safety of maintenance high-speed railway tractive power supply system
Fixed operation has very important engineering significance.
In order to solve the above technical problems, the technical solution adopted by the present invention is that:
A method of analysis low-frequency modulation signal is in HXD type locomotive rectifier propagation law, comprising the following steps:
Step 1: practical to Traction networks, locomotive intermediate DC link using method of the DFT transform in conjunction with TLS-ESPRIT
The implicit information of monitoring data is excavated, and determines that net side, intermediate dc side cause the specific mode of fluctuation, network pressure frequency signal
With the relationship of rectifier middle dc voltage radio-frequency component are as follows:
In formula, uabFor locomotive rectifier input terminal voltage；UkrIndicate the amplitude of rectifier output modulated signal voltage, k=
1,2,3…；b1And b59It is the 1st time, the 59th subharmonic energy coefficient respectively；UdcFor the DC voltage in rectifier output voltage point
Amount；N indicates harmonic wave total degree；
Step 2: the mathematical model of Traction networks net voltage fluctuation signal of the building under mode shown in step 1:
In formula, miAnd fiIndicate the relative magnitude and frequency of i-th of amplitude-modulated wave；f0WithRespectively indicate fundamental frequency and just
Beginning phase；mhj、fhjWithRespectively indicate the relative magnitude, frequency and phase of j-th of harmonic wave；The total degree of M expression amplitude-modulated wave；N
Indicate harmonic wave total degree；
Step 3: the mathematical model constructed in recycle step 2 derives its mechanism of transmission under SPWM algorithm are as follows:
In formula, S (t) indicates rectifier switch function；N indicates harmonic wave total degree；bnIndicate harmonic energy coefficient；N is indicated
Odd harmonic number；ωmIndicate modulated signal angular frequency；Indicate the phase of nth harmonic；UkrWithIt is defeated to respectively indicate rectifier
The amplitude and phase of modulated signal voltage out, k=1,2,3 ...；ωkFor k subharmonic angular frequency；UdcFor in rectifier output voltage
DC voltage component.
Compared with prior art, the beneficial effects of the present invention are:
1. for the electrical quantity instability problem that more vehicles access tractive power supply system causes, the present invention uses DFT and TLS-
The method that ESPRIT is combined has determined that Traction networks electrical quantity wild effect is not low-frequency oscillation problem, but power quality is electric
Press fluctuation problem；And accurate recognition result is provided to its dominant mode；
It is voltage fluctuation 2. specifying the mathematical relationship of the harmonic propagation at rectifier both ends from the angle of mathematical derivation
Effectively inhibit to have established theoretical basis.
Detailed description of the invention
Fig. 1 is the single-phase two level pulses rectifier main circuit of HXD type electric locomotive.
Fig. 2 is net side traction convertor switch function figure.
Specific embodiment
The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.The analysis of the method for the present invention
Object is that more vehicles access Traction networks initiation supply conductor voltage wave phenomenon, mainly realizes step are as follows: deeply excavate Traction networks, locomotive
The implicit information of intermediate DC link actual monitoring data quantifies the relationship of the two, and passes in rectifier with low-frequency modulation signal
It broadcasts rule and compares verifying, key step includes the following aspects:
1, the method using DFT transform in conjunction with TLS-ESPRIT, the unstable electrical quantity mode composition of the Traction networks of analysis；
Construct the voltage signal u (n), Hankel matrix X when more vehicle access tractive power supply systems
In formula, αi、ωi、Ai、θiThe attenuation coefficient, angular frequency of respectively the i-th mode, oscillation amplitude and initial phase；TsFor letter
Number sampling period；P be signal order, twice of generally practical sinusoidal component number；W (n) is white noise；The referred to as pole of the signal；N is the data amount check of u, M=N/2, L=N-M+1.
Singular value decomposition X=U Σ V is carried out to XT, and determine signal subspace order p, structural matrix [V1V2], it seeks total
Body least square solution is
Seek matrix ΨTlsEigenvalue λi(i=1,2 ... ..., p) calculates the frequency and damping ratio of mode
The amplitude and initial phase that mode is then calculated by structural matrix, fitting coefficient, carry out dominant pattern screening；Using
The mode that frequency compares, determines the mode composition of signal.Similarly, rectifier middle dc voltage is handled.As a result network pressure
There are following relationships with rectifier middle dc voltage radio-frequency component for frequency signal:
In formula, uabFor locomotive rectifier input terminal voltage；UkrIndicate the amplitude of rectifier output modulated signal voltage, k=
1,2,3…；b1、b59And b60It is the 1st time, the 59th time and the 60th subharmonic energy coefficient respectively；UdcFor in rectifier output voltage
DC voltage component；N indicates harmonic wave total degree；
2, consider that being constructed voltage fluctuation signal by modulation phenomenon and being expressed as also occur in higher hamonic wave composition in the phenomenon
In formula, miAnd fiIndicate the relative magnitude and frequency of i-th of amplitude-modulated wave；f0WithRespectively indicate fundamental frequency and just
Beginning phase；mhj、fhjWithRespectively indicate the relative magnitude, frequency and phase of j-th of harmonic wave；The total degree of M expression amplitude-modulated wave；N
Indicate harmonic wave total degree；
3, the mathematical model of combined structure, locomotive rectifier circuit is as shown in Figure 1, for convenient for analysis, defining ideal switch
Function SaAnd SbAnd ignore tractive winding resistance, and since upper bridge arm does not allow to lead directly to lower bridge arm, then in every phase bridge arm, upper bridge
The switching signal of arm must be reciprocal with the switching signal of lower bridge arm.Using bipolar SPWM algorithm, switch function as shown in Fig. 2,
Input terminal voltage uabValue have Ud、0、-UdThree kinds of level, effective switch combination have 22=4 kinds, i.e. Sab=00,01,10,
11 4 kinds of logics.When modulating wave voltage greater than carrier voltage, SAIt is 1, is otherwise 0.B phase is identical as a phase modulation system, but b
Phase modulating wave modulates wave phase with a phase and differs 180 °.The traction convertor switch function that the present invention analyzes are as follows:
In formula, JnIt (x) is Bessel function；ωmFor modulated signal angular frequency；ωcFor carrier signal angular frequency；P is modulation
Wave and carrier frequency proportionality coefficient (inverse of carrier wave ratio)；ε is downsampling factor, and value is generally 0~1；M is the index of modulation,
Value range is 0~1.
Ignore influencing each other between harmonic wave, then formula (5) can be simplified as:
After arrangement
In formula, S (t) indicates rectifier switch function；N indicates harmonic wave total degree；bnIndicate harmonic energy coefficient；N is indicated
Odd harmonic number；ωmIndicate modulated signal angular frequency；Indicate the phase of nth harmonic；UkrWithIt is defeated to respectively indicate rectifier
The amplitude and phase of modulated signal voltage out, k=1,2,3 ...；ωkFor k subharmonic angular frequency；UdcFor in rectifier output voltage
DC voltage component；
Formula (7) is the expression formula of tractive power supply system side modulation voltage, which can accurately reflect traction power supply
The spectrum signature that system side voltage is modulated.Obviously, in formula (7) first item be the sum of fundamental wave and series of features harmonic wave,
It is rectifier switch function to DC voltage component U in rectifier output voltagedcModulation result, the frequency of characteristic harmonics meets 2v
± 1 relationship.Wherein, v=1,2 ..., ∞.The 2nd in formula (7), 3 ... item is the sum of a series of voltage modulating wave, for rectification
Switch function exports the modulation result of modulation wave voltage to rectifier.
In addition, formula (7) shows to be f for frequencykDC voltage fluctuation component, can be attached in fundamental wave and each characteristic harmonics
The radio-frequency component for closely causing constant amplitude pairs of, i.e. nfm±fk.With the variation of characteristic harmonics number, amplitude, modulation wave amplitude will
Change therewith, consider supply conductor voltage based on power frequency, thus, it is leading on the modulated signal of power frequency effect to influence network pressure amplitude not
Stablize.Contrast (3), (7) can find that two formulas have high degree of uniformity, and formula (3) is only a special case of formula (7), demonstrate this
The practicability of method.
The method of the present invention is illustrated in more detail below.
1) it, is distributed using each period dominant frequency energy magnitude of DFT transform analysis Traction networks network pressure, as shown in table 1.
The distribution of each period dominant frequency energy magnitude of table 1
2) amplitude and initial phase of mode, are calculated by TLS-ESPRIT structural matrix, fitting coefficient, and carry out leading mould
Formula screening.Then by the way of frequency comparison, the mode composition of signal is determined, as shown in table 2.
The supply conductor voltage mode of table 2TLS-ESPRIT algorithm analysis
| Decay factor/(1/s) | Frequency/Hz | Amplitude/kV | Phase/° |
| 0.100 | 50.0 | 36.75 | 3.0 |
| -0.200 | 2950 | 0.581 | 95.2 |
| -0.270 | 3050 | 0.509 | 180 |
| 0.100 | 52.1 | 0.471 | 117.2 |
| 0.100 | 48.0 | 0.450 | 67.7 |
| -5.300 | 2952 | 0.380 | 94.0 |
| -368.2 | 2948 | 0.269 | 115.6 |
3), there are mathematical relationships for description network pressure frequency signal and rectifier middle dc voltage radio-frequency component, such as formula (3) institute
Show.
4), consider that higher hamonic wave composition also occurs voltage fluctuation signal being constructed, such as formula (4) by modulation phenomenon in the phenomenon
It is shown.
5) modulated signal mechanism of transmission in HXD type power train rectifier, is analyzed in conjunction with modulation theory, what this was derived
Formula is able to reflect the leading influence network pressure amplitude wild effect of modulated signal of power frequency effect.
6), again in the case where uncompensated device, the electrical quantity fluctuation pattern that more vehicle access Traction networks cause is analyzed, verifying is originally
The practicability of invention.
Claims (1)
1. a kind of analysis low-frequency modulation signal is in the method for HXD type locomotive rectifier propagation law, which is characterized in that including following
Step:
Step 1: using method of the DFT transform in conjunction with TLS-ESPRIT to Traction networks, locomotive intermediate DC link actual monitoring
The implicit information of data is excavated, determine net side, intermediate dc side cause fluctuation specific mode, network pressure frequency signal with it is whole
Flow the relationship of device middle dc voltage radio-frequency component are as follows:
In formula, uabFor locomotive rectifier input terminal voltage；UkrThe amplitude of expression rectifier output modulated signal voltage, k=1,2,
3…；b1And b59It is not the 1st time, the 59th subharmonic energy coefficient；UdcFor the DC voltage component in rectifier output voltage；N table
Show harmonic wave total degree；
Step 2: the mathematical model of Traction networks net voltage fluctuation signal of the building under mode shown in step 1:
In formula, miAnd fiIndicate the relative magnitude and frequency of i-th of amplitude-modulated wave；f0WithRespectively indicate fundamental frequency and initial phase
Position；mhj、fhjWithRespectively indicate the relative magnitude, frequency and phase of j-th of harmonic wave；The total degree of M expression amplitude-modulated wave；N is indicated
Harmonic wave total degree；
Step 3: the mathematical model constructed in recycle step 2 derives its mechanism of transmission under SPWM algorithm are as follows:
In formula, S (t) indicates rectifier switch function；N indicates harmonic wave total degree；bnIndicate harmonic energy coefficient；N indicates that odd times are humorous
Wave number；ωmIndicate modulated signal angular frequency；Indicate the phase of nth harmonic；UkrWithRectifier output is respectively indicated to adjust
The amplitude and phase of signal voltage processed, k=1,2,3 ...；ωkFor k subharmonic angular frequency；UdcIt is straight in rectifier output voltage
Flow component of voltage.
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