CN106908665B - A kind of one-phase AC-system dq decomposition impedance measurement method - Google Patents
A kind of one-phase AC-system dq decomposition impedance measurement method Download PDFInfo
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Abstract
The invention discloses a kind of one-phase AC-system dq to decompose impedance measurement method, by injecting two independent disturbances into circuit, measuresαThe response voltage and current of axis, it is then rightαThe response voltage and current of axis carries out Hilbert transformation, generates its phaseπ/ 2 lag, obtainsβThe voltage and current of axis；When forcing frequency is greater than fundamental frequency, need to correct correspondingβThe voltage and current of axis；Park transformation is recycled, it willαβVoltage and current under coordinate system is converted to the voltage and current under dq coordinate system, obtains corresponding numerical value under its frequency domain using FFT transform；Finally by under dq axis voltage matrix and current matrix calculating acquire impedance matrix.The present invention is suitable for measuring the impedance of all monophase systems, compensates for the failure conditions that frequency sweep in the measurement method based on Hilbert transformation is greater than fundamental frequency.
Description
Technical field
The present invention relates to the impedance measurement technique field of monophase system, specially a kind of one-phase AC-system dq decomposes impedance
Measurement method.
Background technique
As to energy production, the requirements at the higher level transmitted and utilized, more Power electronic converters are due to its high efficiency
It comes into operation in current electric system with flexibly controlling.In view of the complex control of each converter, it is based on impedance
Method for analyzing stability be widely adopted.The stability of whole system can pass through each subsystem of analysis cascade or parallel connection
External impedance or admittance analyze.Therefore, the precision impedance for measuring each subsystem is of great significance.
Currently, the Power electronic converter used in AC electric power systems generallys use the control decomposed based on dq, because
It in terms of the independent control of effective power and reactive power is excellent in DC level for it.If impedance can be in dq coordinate
It is measured under system, then it is more convenient to carry out stability analysis with it, because it is closely related with dq decomposition control.G.Francis etc.
People realizes dq impedance measurement method and is applied to three-phase system, and S.Lissandron et al. describes the RI coordinate system of monophase system
In impedance measurement method, and the dq impedance measurement method of monophase system is still in research.
Summary of the invention
For these reasons, the impedance that the purpose of the present invention is to provide a kind of suitable for measuring all monophase systems, and
The one-phase AC-system dq that the failure conditions that frequency sweep in the measurement method based on Hilbert transformation is greater than fundamental frequency can be made up decomposes resistance
Anti- measurement method, technical solution are as follows:
A kind of one-phase AC-system dq decomposition impedance measurement method, comprising the following steps:
Step 1: injection disturbance measures the response voltage and current of α axis:
Select a frequencies omegap, inject two independent current disturbing ipα1And ipα2:
ipα1=cos (ω1-ωp)t
ipα2=cos (ω1+ωp)t
Wherein ωpFor forcing frequency, ω1For fundamental frequency；Then the response voltage u of circuit α axis is measuredα1、uα2And response
Electric current iα1、iα2；
Step 2: it is converted by Hilbert, obtains the voltage and current of β axis:
To the response voltage u of α axisα1、uα2With response current iα1、iα2Hilbert transformation is carried out, its phase is made to generate pi/2
Lag, obtains the voltage u of β axisβ1、uβ2With electric current iβ1、iβ2:
Wherein, H indicates Hilbert transformation,
Step 3: it is converted by Park, the data under α β coordinate system is converted to the data under dq coordinate system:
Wherein, x indicates variable u or i, PθFor Park transformation matrix；
Step 4: the voltage and current under corresponding frequencies is obtained using FFT method:
Wherein, x indicates that variable u or i, N are the quantity of sampled point；
Step 5: calculate the impedance matrix under dq coordinate:
In formula, ud1、id1、uq1、iq1Respectively d axle response voltage, d axle response electric current, q axis are rung after first disturbance of injection
Answer voltage, q axle response electric current；ud2、id2、uq2、iq2Respectively inject second disturbance after d axle response voltage, d axle response electric current,
Q axle response voltage, q axle response electric current.
Further, work as ω1<ωpWhen, inject a new disturbance-cos (ω1-ωp) t, obtain the new response electricity of α axis
Press u'α1With response current i'α1, to u'α1And i'α1Hilbert transformation is carried out, the voltage u of new β axis is obtainedβ1_desAnd electric current
iβ1_desResulting u was calculated originally with replacementβ1And iβ1, and uα1And iα1It remains unchanged.
The beneficial effects of the present invention are: the present invention expands the dq axis impedance measurement in three-phase system in single phase ac system
System realizes the precise measurement of monophase system impedance by the method for fabricating β axis；And have modified by Hilbert convert in absolutely
It is worth the voltage and current of β axis caused by operation, solves and failed based on the measurement method that frequency sweep is greater than fundamental frequency in Hilbert transformation
Problem.
Detailed description of the invention
Fig. 1 a is that current disturbing of the invention injects schematic diagram.
Fig. 1 b is that voltage disturbance of the invention injects schematic diagram.
Fig. 2 is practical disturbance i of the inventionpαIt is injected into the schematic diagram of actual circuit.
Fig. 3 is RL series circuit artificial circuit figure of the invention.
Fig. 4 is algorithm flow chart of the invention.
Fig. 5 a does not correct measurement method for use and measures RL series circuit ZddThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 5 b does not correct measurement method for use and measures RL series circuit ZdqThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 5 c does not correct measurement method for use and measures RL series circuit ZqdThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 5 d does not correct measurement method for use and measures RL series circuit ZqqThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 6 a is to measure RL series circuit Z using measurement method after amendmentddThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 6 b is to measure RL series circuit Z using measurement method after amendmentdqThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 6 c is to measure RL series circuit Z using measurement method after amendmentqdThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Fig. 6 d is to measure RL series circuit Z using measurement method after amendmentqqThe Bode diagram (amplitude frequency diagram, phase frequency figure) of impedance.
Specific embodiment
It elaborates with reference to the accompanying drawing with example to the embodiment of the present invention.
The present embodiment is implemented under the premise of the technical scheme of the present invention, gives detailed implementation process, with note
Enter and is analyzed for current disturbing.It is disturbed including injection, measures the response voltage and current of α axis；It is converted by Hilbert,
Obtain the voltage and current of β axis；It is converted by Park, the data under α β coordinate system is converted to the data under dq coordinate system；Benefit
The voltage and current under corresponding frequencies is obtained with FFT method；The impedance matrix under dq coordinate is obtained by calculation.
Step 1: injection disturbance measures the response voltage and current of α axis.
In order to measure subsystem external impedance value, need to inject disturbance, as illustrated in figs. 1A and ib.There are two types of types
Disturbance, voltage disturbance and current disturbing are related to the type in source.In monophase system, practical disturbance can be injected only in
I in actual circuit, i.e. in Fig. 1 apα.It is above-mentioned, idAnd iqOn two pairs of disturbances need to be independent, therefore ipαOn
Disturbance is not arbitrary.In order to generate the disturbance of our needs, the practical disturbance of injection is obtained using Park inverse transformation, is such as schemed
Shown in 2.Expectation disturbance in dq coordinate system is designed to:
I in formulap1And ip2It is independent, ωpIt is the frequency of disturbance.
By Park inverse transformation, the disturbance in α axis can be obtained are as follows:
[ipα1 ipα2]=[cos (ω1-ωp)t cos(ω1+ωp)t]
Wherein ω1It is the frequency of power supply fundamental wave.
By injecting above-mentioned two independent current disturbing ipα1And ipα2, the response voltage u of circuit α axis can be measuredα1、uα2
With response current iα1、iα2。
Step 2: being converted by Hilbert, obtain the voltage and current of β axis.
By the way that the disturbance in step 1 to be injected into monophase system, response voltage and current can be measured.In order to realize
Park transformation, needs to generate imaginary β component by delayed phase α component pi/2.To the response voltage u for obtaining α axisα1、uα2
With response current iα1、iα2Carry out Hilbert transformation, it may be assumed that
Wherein H indicates Hilbert transformation:
It converts to obtain the voltage and current of β axis by Hilbert, is denoted as uβ1、uβ2、iβ1、iβ2；
Work as ω1<ωpWhen, inject a new disturbance-cos (ω1-ωp) t, obtain the new response voltage u' of α axisα1And sound
Answer electric current i'α1, to u'α1And i'α1Hilbert transformation is carried out, the voltage and current of modified β axis is obtained, is denoted as uβ1_des、
iβ1_des.Use uβ1_des、iβ1_desSubstitute original uβ1、iβ1。
Step 3: being converted by Park, the data under α β coordinate system are converted to the data under dq coordinate system.
In monophase system, alternating voltage and electric current can be converted by Park and be broken down into ud, uqAnd id, iq:
X indicates variable u or i, ω in formula1For fundamental frequency, PθIt is defined as Park transformation matrix.PθIn-pi/2 phase shift is
In order to ensure working as xαWhen being ideal sine wave, d axis component value is equal to the amplitude of fundamental wave, and q axis component value is equal to zero.
To the impedance Z under dq coordinate systemdqIt can be expressed as follows with voltage and current:
4) voltage and current under corresponding frequencies, is obtained using FFT method；
WhereinX indicates that variable u or i, N are the quantity of sampled point.
By to the u in step 3d, uqAnd id, iqMake FFT transform, the ω can be obtainedpLower corresponding frequency-region signal, for step
Impedance matrix in rapid 5 provides basis.
Step 5: calculate the impedance matrix under dq coordinate:
U in formulad1、id1、uq1、iq1D axle response voltage, d axle response electric current, q axle response respectively after first disturbance of injection
Voltage, q axle response electric current；ud2、id2、uq2、iq2D axle response voltage, d axle response electric current, q respectively after second disturbance of injection
Axle response voltage, q axle response electric current.
A simple model, i.e. RL series circuit are built in Matlab/Simulink, as shown in figure 3, to verify the party
The validity and correctness of method.The circuit has used voltage source, so the perturbation scheme of selection Fig. 1 b.
By deriving, the impedance of RL series circuit in dq coordinate system are as follows:
Wherein R and L is the value of the resistance and inductance in Fig. 3 respectively.
Parameter value in simulation model is as shown in table 1.
1 simulation parameter of table
According to described previously, the detail flowchart that the impedance of RL series circuit is measured in dq coordinate system is devised, such as Fig. 4 institute
Show.Colored closed area is represented in ω1<ωpWhen, for correcting the measure of β shaft voltage and electric current.
Frequency of use scan method, in logarithm section [100,103] ten frequencies are equably selected in Hz.Reference Fig. 4,
Impedance measurement algorithm is realized in Matlab.By emulating and calculating, respectively with do not correct and modified method measure RL series electrical
The dq impedance on road compares, and is as a result plotted on the Bode diagram of Fig. 5 and Fig. 6.Measured impedance is compared with theoretical value
Compared with circle indicates measurement result, lines representation theory value.In Fig. 5 a-5d, X, Y are solid dot coordinate, and open circles are not correct
Method measured value, solid line are theoretical value, and fundamental frequency 50Hz does not correct measurement method and theory when frequency is greater than fundamental wave 50Hz
There are deviations for value.In Fig. 6 a-6d, X, Y are solid dot coordinate, and open circles are method measured value after amendment, and solid line is theoretical value,
When frequency is greater than fundamental wave 50Hz, measurement method is consistent with theoretical value after amendment.It was found that working as ω1<ωpWhen, uncorrected method is not
Correct impedance can be obtained, and the measurement result of modification method is correctly corresponding with theoretical value.
Claims (2)
1. a kind of one-phase AC-system dq decomposes impedance measurement method, which comprises the following steps:
Step 1: injection disturbance measures the response voltage and current of α axis:
Select a frequencies omegap, inject two independent current disturbing ipα1And ipα2:
ipα1=cos (ω1-ωp)t
ipα2=cos (ω1+ωp)t
Wherein ωpFor forcing frequency, ω1For fundamental frequency；Then the response voltage u of circuit α axis is measuredα1、uα2And response current
iα1、iα2；
Step 2: it is converted by Hilbert, obtains the voltage and current of β axis:
To the response voltage u of α axisα1、uα2With response current iα1、iα2Hilbert transformation is carried out, its phase is made to generate the stagnant of pi/2
Afterwards, the voltage u of β axis is obtainedβ1、uβ2With electric current iβ1、iβ2:
Wherein, H indicates Hilbert transformation,
Step 3: it is converted by Park, the data under α β coordinate system is converted to the data under dq coordinate system:
Wherein, x indicates variable u or i, PθFor Park transformation matrix；
Step 4: the voltage and current under corresponding frequencies is obtained using FFT method:
Wherein, x indicates that variable u or i, N are the quantity of sampled point；
Step 5: calculate the impedance matrix under dq coordinate:
In formula, ud1、id1、uq1、iq1D axle response voltage, d axle response electric current, q axle response electricity respectively after first disturbance of injection
Pressure, q axle response electric current；ud2、id2、uq2、iq2D axle response voltage, d axle response electric current, q axis respectively after second disturbance of injection
Respond voltage, q axle response electric current.
2. one-phase AC-system dq according to claim 1 decomposes impedance measurement method, which is characterized in that work as ω1<ωp
When, inject a new disturbance-cos (ω1-ωp) t, obtain the new response voltage u' of α axisα1With response current i'α1, to u'α1With
i'α1Hilbert transformation is carried out, the voltage u of new β axis is obtainedβ1_desWith electric current iβ1_desResulting u was calculated originally with replacementβ1With
iβ1, and uα1And iα1It remains unchanged.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108051682A (en) * | 2017-12-22 | 2018-05-18 | 西南交通大学 | A kind of verification method of single-phase rectifier system impedance model |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108680792B (en) * | 2018-05-28 | 2020-06-05 | 国网内蒙古东部电力有限公司 | Dynamic admittance measuring method for new energy grid-connected system with power electronic device |
| CN109507482B (en) * | 2018-12-29 | 2021-08-24 | 西北工业大学 | Three-phase alternating current circuit impedance test system and method |
| CN110763918B (en) * | 2019-09-26 | 2020-09-11 | 西南交通大学 | Method for measuring input impedance of traction pulse rectifier and output impedance of traction network |
| CN110780118A (en) * | 2019-10-15 | 2020-02-11 | 西南交通大学 | Multi-frequency dq impedance measurement calculation method applied to vehicle network system |
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| CN111308207B (en) * | 2020-03-06 | 2021-06-25 | 西南交通大学 | Dq impedance measuring method for single-phase alternating current system |
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| CN116718837B (en) * | 2023-08-11 | 2023-11-07 | 四川大学 | Active broadband-based multidimensional impedance measurement method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103376363A (en) * | 2013-07-04 | 2013-10-30 | 西安交通大学 | Impedance measurement method of three-phase alternating current system |
| CN103630748A (en) * | 2013-11-11 | 2014-03-12 | 西安交通大学 | Device and method for harmonic impedance measurement of micro-grid |
| CN105606900A (en) * | 2016-03-18 | 2016-05-25 | 华南理工大学 | Single-phase harmonic impedance measuring method based on square wave signals |
| CN105717360A (en) * | 2016-01-26 | 2016-06-29 | 云南电网有限责任公司电力科学研究院 | Low-voltage single-phase harmonic impedance measuring method and device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010008146A (en) * | 2008-06-25 | 2010-01-14 | Chino Corp | Internal impedance measuring device |
-
2017
- 2017-02-10 CN CN201710072749.0A patent/CN106908665B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103376363A (en) * | 2013-07-04 | 2013-10-30 | 西安交通大学 | Impedance measurement method of three-phase alternating current system |
| CN103630748A (en) * | 2013-11-11 | 2014-03-12 | 西安交通大学 | Device and method for harmonic impedance measurement of micro-grid |
| CN105717360A (en) * | 2016-01-26 | 2016-06-29 | 云南电网有限责任公司电力科学研究院 | Low-voltage single-phase harmonic impedance measuring method and device |
| CN105606900A (en) * | 2016-03-18 | 2016-05-25 | 华南理工大学 | Single-phase harmonic impedance measuring method based on square wave signals |
Non-Patent Citations (2)
| Title |
|---|
| "三相电力变压器零序阻抗分析计算";董爽丽等;《变压器》;20160630;第53卷(第6期);全文 |
| "新型换流变压器及其滤波系统的换相电抗的分析计算";许加柱等;《电工技术学报》;20071031;第22卷(第10期);全文 |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108051682A (en) * | 2017-12-22 | 2018-05-18 | 西南交通大学 | A kind of verification method of single-phase rectifier system impedance model |
| CN108051682B (en) * | 2017-12-22 | 2019-12-20 | 西南交通大学 | Verification method of single-phase rectifier system impedance model |
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