CN107328996B - Robust electric transmission line positive sequence parameter identification method - Google Patents
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
Abstract
The invention discloses a kind of robust electric transmission line positive sequence parameter identification methods, comprising: obtains the three-phase current and voltage phasor at route both ends by the phasor measurement unit measurement that single back transmission line both ends are installed；According to single back transmission line three-phase Equivalent Model and the three-phase current and voltage phasor at combined circuit both ends, the accounting equation of line impedance parameter and admittance parameter is established；The objective function that there is the Huber estimation objective function of robustness to recognize as line impedance parameter and admittance parameter is constructed, obtains line impedance matrix and admittance matrix parameters to solve；Line impedance matrix and admittance matrix are decoupled using symmetrical component method, obtain positive sequence impedance and positive sequence admittance parameter.This method strong operability, it is easy to implement, and the positive sequence impedance parameters precision that identification obtains is high, has good robustness, identification result is more credible.
Description
Technical field
The present invention relates to technical field of power system operation control more particularly to a kind of robust electric transmission line positive sequence parameter to distinguish
Knowledge method.
Background technique
With the continuous development of electric system, transmission line of electricity is also more and more, and what system also just became becomes increasingly complex, therefore
Our requirements to the parameter accuracy of transmission line of electricity are also just relatively high.Accurate line parameter circuit value is correct progress Load flow calculation,
Accident analysis, relay protection setting, the basis of the various power system computations such as line losses management.When line parameter circuit value inaccuracy, to short
The calculating of road electric current, stability Calculation, the correctness of Load flow calculation influence very big.So the accuracy of transmission line parameter is also with regard to shadow
Ring the safety of electric system, stable and reliability service.
Transmission line of electricity can be divided into overhead transmission line and cable run, be the carrier of power Transmission, and voltage class is remote
Most of parameter higher than power distribution network, and major network be it is known, be very different with power distribution network.
Line parameter circuit value measurement method has very much, there is theoretical calculation, the offline measurement that has a power failure, online live line measurement.Traditional circuit
Theoretical calculation utilizes route geometric mean distance, the physical parameters such as material structure, in conjunction with temperature, geographical location based on Carson
Etc. being calculated from the formula reactance, resistance, susceptance.Or according to handbook formula, directly calculating route power frequency parameter, this method
Have ignored the influence of aerial earth wire.And theoretical calculation only considered full symmetric situation, not account for real time temperature, arc
The practical problems such as vertical, therefore there is very big difference in the result of this method and actual parameter.The offline measurement that has a power failure is will be by survey line
Road has a power failure, and is detached from power grid, using additional power source, track data is measured using the various meters such as voltmeter, ammeter, through artificial
It reads tabular value and calculates parameters in conjunction with corresponding formula.This method, which exists, to be needed to have a power failure test line, backhauls row more
Parallel circuit the problems such as being unable to measure mutual inductance.
Summary of the invention
It the object of the present invention is to provide a kind of robust electric transmission line positive sequence parameter identification method, calculates simply, and not by outer
Boundary's environment, payload influence, can be with accurate recognition line parameter circuit value, and practicability is good, have good robustness.
The purpose of the present invention is what is be achieved through the following technical solutions:
A kind of robust electric transmission line positive sequence parameter identification method, comprising:
The three-phase current and electricity at route both ends are obtained by the phasor measurement unit measurement that single back transmission line both ends are installed
Press phasor；
According to single back transmission line three-phase Equivalent Model and the three-phase current and voltage phasor at combined circuit both ends, line is established
The accounting equation of road impedance parameter and admittance parameter；
Construct the mesh that there is the Huber estimation objective function of robustness to recognize as line impedance parameter and admittance parameter
Scalar functions obtain line impedance matrix and admittance matrix parameters to solve；
Line impedance matrix and admittance matrix are decoupled using symmetrical component method, positive sequence resistance, reactance is obtained and leads over the ground
Receive parameter.
It is described according to single back transmission line three-phase Equivalent Model and the three-phase current and voltage phasor at combined circuit both ends, build
The accounting equation of vertical line impedance parameter and admittance parameter includes:
The three-phase current and voltage at single back transmission line both ends meet following equation:
Wherein,
Respectively a, b, c three-phase electricity at the end M and N-terminal
Flow phasor；
Respectively a, b, c three-phase electricity at the end M and N-terminal
Press phasor；Z,YcLine impedance parameter respectively to be identified, admittance parameter；
Above-mentioned equation is converted into following forms:
In above formula,
Then current time, parameter x to be identified are as follows:
X=[x11 x12...x19 x21 x22...x29]T；
Meet following linear equation:
Ax=B+v；
Wherein, A is the coefficient matrix that current time three-phase voltage and electric current phasor are constituted, and B is current time both end voltage
The constant term of phasor composition drops, and v is equation residual error phasor；
It include 18 unknown quantitys in the parameter x of identification, then the number of equation is greater than equal to 18, takes multiple groups different moments
Data solve, wherein the dimension of A is 6n × 18, and the dimension of n >=3, B are 6n × 1, and objectives equation is as follows:
There is the Huber estimation objective function of robustness to recognize as line impedance parameter and admittance parameter for the building
Objective function, obtain line impedance matrix and admittance matrix includes: to solve
Huber robust estimation theory assumes that actual observation data obey Huber distribution, and Huber distribution is pollution distribution
One kind, main body is normal distribution, and interference sections obey Laplace distribution；
The probability density of Huber distribution are as follows:
Wherein, ε is pollution rate, it indicates the data of pollution part ratio shared in entire data；λ is observation；
The Maximum-likelihood estimation of Huber distribution is Huber estimation, objective function are as follows:
Wherein, k is robust threshold adjustment coefficient, related with pollution rate ε；viFor measurement residuals, vi=(yci-ymi)/s, yci
And ymiRespectively indicate the calculated value and measured value of output vector；S exists | viThe section |≤k, takes the standard deviation sigma of error in measurementi, s exists |
vi| the section > k takes Kmad, Kmad=med | yci-ymi|；According to objective function, when | vi| when > k, reducing large deviation and measuring influences；
The Huber estimation objective function to be established is the function of equation residual error, be may be defined as:
PiFor the weight of i-th of measurement, weight is 1/ σi 2, ρ (vi) it is the corresponding objective function of Huber method, viTo measure
Residual error；
Consider that PMU error in measurement is consistent, establish Huber estimation objective function are as follows:
Specifically, this estimation objective function can further indicate that according to linear equation Ax=B+v are as follows:
Wherein, Aixi-BiIt indicates residual error when sampling instant is i, is finally to seek meeting this objective function being minimum
When phasor x；N is sampling sum；The Huber estimation objective function as least square method when observation error is less than threshold value
Objective function, observation error be greater than threshold value when, its adverse effect to objective function, automatic rejection major network phase can be weakened
Bad data in amount measurement device data；
Recycle Optimization Method that can obtain line impedance matrix and admittance matrix.
Line impedance matrix and admittance matrix are decoupled using symmetrical component method, positive sequence resistance, reactance is obtained and leads over the ground
Parameter of receiving includes:
Structural matrix T:
The matrix T constructed herein is a kind of symmetrical component transformation, and effect is a, b, and the phase component conversion of c three-phase is positive
Sequence, negative phase-sequence and zero-sequence component；Wherein, a is twiddle factor,
The matrix equation of three-phase electricity pressure drop Yu three-phase current relationship is established using route phase component model:
In above formula,Indicate three-phase electricity pressure drop,
Indicate three-phase current；
Three-phase electricity pressure drop and three-phase current are replaced with into order components, obtained:
It further indicates that are as follows:
ZpThe as impedance matrix of order components, it may be assumed that
Z therein(1)For route positive sequence impedance, Z(2)Indicate route negative sequence impedance, Z(0)Indicate route zero sequence impedance；
Similarly, same to release for admittance matrix:
Y thereinc(1)For the admittance over the ground of route positive sequence, Yc(2)Indicate the admittance over the ground of route negative phase-sequence, Yc(0)Indicate route zero sequence
Admittance over the ground.
As seen from the above technical solution provided by the invention, it is only necessary to acquire three-phase current, the voltage phase at route both ends
Information is measured, strong operability is easy to implement, and the positive sequence impedance parameters precision that identification obtains is high, has good robustness,
Identification result is more credible.
Detailed description of the invention
In order to illustrate the technical solution of the embodiments of the present invention more clearly, required use in being described below to embodiment
Attached drawing be briefly described, it should be apparent that, drawings in the following description are only some embodiments of the invention, for this
For the those of ordinary skill in field, without creative efforts, it can also be obtained according to these attached drawings other
Attached drawing.
Fig. 1 is a kind of flow chart of robust electric transmission line positive sequence parameter identification method provided in an embodiment of the present invention；
Fig. 2 is the triphase flow schematic diagram of single back transmission line provided in an embodiment of the present invention；
Fig. 3 is 500kV analogue system schematic diagram provided in an embodiment of the present invention.
Specific embodiment
With reference to the attached drawing in the embodiment of the present invention, technical solution in the embodiment of the present invention carries out clear, complete
Ground description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Based on this
The embodiment of invention, every other implementation obtained by those of ordinary skill in the art without making creative efforts
Example, belongs to protection scope of the present invention.
The embodiment of the present invention provides a kind of robust electric transmission line positive sequence parameter identification method, and this method belongs to on-line identification side
Method.On-line identification method can not have to measurement line outage, can be to two end datas, such as voltage, electric current, the progress such as phase angle
Synchronous acquisition, thus realize the identification of online line parameter circuit value, and its precision, it is more efficient.As shown in Figure 1, real for the present invention
The flow chart for applying a kind of robust electric transmission line positive sequence parameter identification method of example offer, mainly includes the following steps:
Step 11 obtains the three-phase electricity at route both ends by the phasor measurement unit measurement that single back transmission line both ends are installed
Stream and voltage phasor.
In the embodiment of the present invention, transmission line of electricity Phasor Measurements are installed at single back transmission line both ends of required measurement in advance
Device measures three-phase voltage, the electric current phasor at single back transmission line both ends.
Illustratively, the triphase flow of single back transmission line may refer to Fig. 2, and the meaning of parameters will be rear in Fig. 2
Text is illustrated one by one.
Step 12, according to single back transmission line three-phase Equivalent Model and the three-phase current and voltage phase at combined circuit both ends
Amount, establishes the accounting equation of line impedance parameter and admittance parameter.
In the embodiment of the present invention, the three-phase current and voltage at single back transmission line both ends meet following equation:
Wherein,
Respectively a, b, c three-phase electricity at the end M and N-terminal
Flow phasor；Respectively a, b, c three-phase electricity at the end M and N-terminal
Press phasor；Z,YcLine impedance parameter respectively to be identified, admittance parameter；
Specifically:
In formula, Zkk=Rkk+jXkk, ZkkFor the route self-impedance of k (k=a, b, c) phase, correspondingly, RkkIndicate the line of k phase
Road series resistance, XkkIndicate that the route series reactance of k phase, j indicate imaginary unit；Zmn=Rmn+jXmn, Zmn(Rmn, Xmn), it is m (m
=a, b, c) the mutually mutual impedance (mutual resistance, mutual reactance) (m ≠ n) between n (n=a, b, c) phase, correspondingly, RmnIndicate m phase and
Mutual resistance between n phase, XmnIndicate the mutual reactance between m phase and n phase；YkkFor the line-to-ground admittance of k (k=a, b, c) phase,
YmnFor m (m=a, b, c) the mutually transadmittance between n (n=a, b, c) phase.Zmm(Rmm, Xmm), it is hindering certainly for m (m=a, b, c) phase
Anti- (self-resistance, from reactance).
Above-mentioned equation is converted into following forms:
In above formula,
Then current time, parameter x to be identified are as follows:
X=[x11 x12...x19 x21 x22...x29]T (7)
Meet following linear equation:
Ax=B+v (8)；
Wherein, A is the coefficient matrix that current time three-phase voltage and electric current phasor are constituted, and B is current time both end voltage
The constant term of phasor composition drops, and v is equation residual error phasor；
It include 18 unknown quantitys in the parameter x of identification, then the number of equation is greater than equal to 18.Therefore, multiple groups are taken not
Data in the same time solve, wherein the dimension of A is 6n × 18, and the dimension of n >=3, B are 6n × 1, and objectives equation is as follows:
Above-mentioned matrix equation (9) is measured by single back transmission line three-phase Equivalent Model of formula (4) according to route two sides multiple groups
What phasor obtained.It can be calculated by formula (9) and obtain each phase resistance, reactance, susceptance, i.e. Z and YcUnknown parameter in two matrixes.
Two parameter matrixs (3 × 3) to be identified have been written as the form of a linear vector x (18 × 1) by formula (9), from
And facilitate solution.
Further, then by symmetrical component method, convert order parameter for phase parameter, just obtained route positive sequence resistance,
Reactance and over the ground susceptance.It combines the robust method of Huber estimation to form objective function hereinafter need during robust identification
Above-mentioned matrix equation is used, and in instances, applies to the Huber estimation robust identification algorithm in conjunction with above-mentioned matrix equation
Come the positive sequence resistance of identification circuit, reactance and susceptance parameter.
Step 13, building have the Huber estimation objective function of robustness as line impedance parameter and admittance parameter
The objective function of identification obtains line impedance matrix and admittance matrix parameters to solve.
In the method for traditional least square (LS), that waits power treats each group of data, when occur individual data deviation compared with
When big situation, final identification result will significantly deviate true value, so that the robustness of algorithm is poor.
To make identification result that there is robustness, the Huber estimation objective function with robustness, Huber can be introduced
Robust estimation theory assumes that actual observation data obey Huber distribution, and Huber distribution is one kind of pollution distribution, main body
It is normal distribution, interference sections obey Laplace distribution；
The probability density of Huber distribution are as follows:
Wherein, ε is pollution rate, it indicates the data of pollution part ratio shared in entire data；λ is observation.
The Maximum-likelihood estimation of Huber distribution is Huber estimation, objective function are as follows:
Wherein, k is robust threshold adjustment coefficient, related with pollution rate ε；viFor measurement residuals, vi=(yci-ymi)/s, yci
And ymiRespectively indicate the calculated value and measured value of output vector；S exists | viThe section |≤k, takes the standard deviation sigma of error in measurementi, s exists |
vi| the section > k takes Kmad, Kmad=med | yci-ymi|；According to objective function, when | vi| when > k, reducing large deviation and measuring influences.
The Huber estimation objective function to be established is the function of equation residual error, be may be defined as:
PiFor the weight of i-th of measurement, weight is 1/ σi 2, ρ (vi) it is the corresponding objective function of Huber method, viTo measure
Residual error.
Consider that PMU error in measurement is consistent, establish Huber estimation objective function are as follows:
Specifically, this estimation objective function can further indicate that according to linear equation Ax=B+v are as follows:
Aixi-BiResidual error when sampling instant is i is indicated, when finally to seek meeting this objective function be minimum
Phasor x.N is sampling sum；The Huber estimation objective function as least square method when observation error is less than threshold value
Objective function, observation error be greater than threshold value when, its adverse effect to objective function, automatic rejection major network phase can be weakened
Bad data in amount measurement device data；
It recycles Optimization Method that can obtain line impedance matrix and admittance matrix, illustratively, can be calculated by heredity
Method is calculated line impedance matrix and admittance matrix.
Step 14 is decoupled line impedance matrix and admittance matrix using symmetrical component method, obtain positive sequence resistance, reactance and
Admittance parameter over the ground.
After the impedance matrix and admittance matrix that obtain by genetic algorithm, it can decouple to obtain positive-sequence component；Detailed process
It is as follows:
Structural matrix T:
The matrix T constructed herein is a kind of symmetrical component transformation, and effect is a, b, and the phase component conversion of c three-phase is positive
Sequence, negative phase-sequence and zero-sequence component.Wherein, a is twiddle factor,
This formula is the three-phase electricity pressure drop established by route phase component model and the matrix equation of three-phase current relationship.In formula,
Indicate three-phase electricity pressure drop,
Indicate three-phase current.
Three-phase electricity pressure drop and three-phase current are replaced with into order components, obtained:
It further indicates that are as follows:
ZpThe as impedance matrix of order components, it may be assumed that
Z therein(1)For route positive sequence impedance (that is, positive sequence resistance, reactance), Z(2)Indicate route negative sequence impedance, Z(0)It indicates
Route zero sequence impedance.
Similarly, same to release for admittance matrix:
Y thereinc(1)For the admittance over the ground of route positive sequence, Yc(2)Indicate the admittance over the ground of route negative phase-sequence, Yc(0)Indicate route zero sequence
Admittance over the ground.
Come below with specific example to robust electric transmission line positive sequence parameter identification method provided by the invention (following letter
Claim, the method for the present invention) it is proved:
This example builds 500kV analogue system using PSCAD, as shown in figure 3, to the positive order parameter of single time distribution line L1
It is recognized.500kV route L1 is single loop line, line length 200km；Positive sequence parameter design value are as follows: resistance R1=3.1524
Ω, reactance XL1=55.2061 Ω, susceptance B1=7.0564 × 10-4S.In Fig. 3, that mainly recognize is transmission line of electricity both ends (M, N)
Between positive sequence resistance, reactance and susceptance parameter over the ground, P+jQ indicates the load power of line end in figure, and P is having for load
Function, Q are the idle of load.
Assuming that phasor measurement unit has been installed at the both ends route L1, the three-phase at the both ends route L1 when operating normally has been measured not
(three-phase voltage, electric current phasor herein can be asymmetric, therefore this method is only needed using line for symmetrical voltage, electric current phasor
The road positive sequence that the metric data of the both ends asymmetrical three-phase at multiple stable state moment can be identified the route when operating normally is joined
Number), sampling interval 10ms.Sampling time is 10s, 900 after taking stable state group data and according to embodiment identification circuit L1
Positive sequence impedance, and following experiment is set, to show the validity of the method for the invention.
Experiment one: directly using emulation data, without processing；
Experiment two: being superimposed random Gaussian in ideal emulation data, simulates true transmission line of electricity Phasor Measurements dress
Set data；Wherein, the error in measurement standard deviation of voltage and current amplitude is 0.1%, and phase angle error is 0.1 °；
Experiment three: at random by 5 groups of Current magnitude measurement zero setting on the basis of testing one, with transmission line simulation phasor amount
It surveys device measurement and bad data occurs.
Under two kinds of experimental programs, the positive sequence parameter identification result that the method for the present invention obtains is as shown in table 1
1 positive sequence parameter identification result of table
Table 1 shows that identification result of the present invention is almost consistent with design value in the case where ideal emulates data, shows of the present invention
Method is basic feasible solution；In actual motion, when the data that power transmission line phasor measurement unit obtains are containing certain measurement noise, institute
It states method and is slightly better than least square method.If but in power transmission line phasor measurement unit metric data there are when bad data, the method
Be substantially better than least square method, identification result it is with a high credibility.
Comparative experiments strongly suggests that the method for the present invention is more suitable for containing the practical power transmission line for measuring noise or even bad data
Bad data can be effectively reduced to the adverse effect of positive sequence impedance parameter identification in the metric data of road phasor measurement unit, and gained is just
Sequence impedance parameter value is more credible.
Through the above description of the embodiments, those skilled in the art can be understood that above-described embodiment can
The mode of necessary general hardware platform can also be added to realize by software by software realization.Based on this understanding,
The technical solution of above-described embodiment can be embodied in the form of software products, which can store non-easy at one
In the property lost storage medium (can be CD-ROM, USB flash disk, mobile hard disk etc.), including some instructions are with so that a computer is set
Standby (can be personal computer, server or the network equipment etc.) executes method described in each embodiment of the present invention.
The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto,
Within the technical scope of the present disclosure, any changes or substitutions that can be easily thought of by anyone skilled in the art,
It should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with the protection model of claims
Subject to enclosing.
Claims (3)
1. a kind of robust electric transmission line positive sequence parameter identification method characterized by comprising
The three-phase current and voltage phase at route both ends are obtained by the phasor measurement unit measurement that single back transmission line both ends are installed
Amount；
According to single back transmission line three-phase Equivalent Model and the three-phase current and voltage phasor at combined circuit both ends, route resistance is established
The accounting equation of anti-parameter and admittance parameter；
Construct the target letter that there is the Huber estimation objective function of robustness to recognize as line impedance parameter and admittance parameter
Number obtains line impedance matrix and admittance matrix parameters to solve；
Line impedance matrix and admittance matrix are decoupled using symmetrical component method, obtain positive sequence resistance, reactance and over the ground admittance join
Number；
It is described according to single back transmission line three-phase Equivalent Model and the three-phase current and voltage phasor at combined circuit both ends, establish line
The accounting equation of road impedance parameter and admittance parameter includes:
The three-phase current and voltage at single back transmission line both ends meet following equation:
Wherein,
Respectively a, b, c three-phase current phase at the end M and N-terminal
Amount；
Respectively a, b, c three-phase voltage phase at the end M and N-terminal
Amount；Z,YcLine impedance parameter respectively to be identified, admittance parameter；
Above-mentioned equation is converted into following forms:
In above formula,
Then current time, parameter x to be identified are as follows:
X=[x11 x12 ...x19 x21 x22 ...x29]T；
Meet following linear equation:
Ax=B+v；
Wherein, A is the coefficient matrix that current time three-phase voltage and electric current phasor are constituted, and B is that phase drops in current time both end voltage
The constant term of composition is measured, v is equation residual error phasor；
It include 18 unknown quantitys in the parameter x of identification, then the number of equation is greater than equal to 18, takes the number of multiple groups different moments
According to solution, wherein the dimension of A is 6n × 18, and the dimension of n >=3, B are 6n × 1, and objectives equation is as follows:
2. a kind of robust electric transmission line positive sequence parameter identification method according to claim 1, which is characterized in that the building
The objective function that Huber estimation objective function with robustness is recognized as line impedance parameter and admittance parameter, thus
Solution obtains line impedance matrix and admittance matrix includes:
Huber robust estimation theory assumes that actual observation data obey Huber distribution, and Huber distribution is the one of pollution distribution
Kind, main body is normal distribution, and interference sections obey Laplace distribution；
The probability density of Huber distribution are as follows:
Wherein, ε is pollution rate, it indicates the data of pollution part ratio shared in entire data；λ is observation；
The Maximum-likelihood estimation of Huber distribution is Huber estimation, objective function are as follows:
Wherein, k is robust threshold adjustment coefficient, related with pollution rate ε；viFor measurement residuals, vi=(yci-ymi)/s, yciAnd ymi
Respectively indicate the calculated value and measured value of output vector；S exists | viThe section |≤k, takes the standard deviation sigma of error in measurementi, s exists | vi| >
The section k, takes Kmad, Kmad=med | yci-ymi|；According to objective function, when | vi| when > k, reducing large deviation and measuring influences；
The Huber estimation objective function to be established is the function of equation residual error, be may be defined as:
PiFor the weight of i-th of measurement, weight is 1/ σi 2, ρ (vi) it is the corresponding objective function of Huber method, viIt is residual to measure
Difference；
Consider that PMU error in measurement is consistent, establish Huber estimation objective function are as follows:
Specifically, this estimation objective function can further indicate that according to linear equation Ax=B+v are as follows:
Wherein, Aixi-BiResidual error when sampling instant is i is indicated, when finally to seek meeting this objective function be minimum
Phasor x；N is sampling sum；The mesh of the Huber estimation objective function as least square method when observation error is less than threshold value
Scalar functions can weaken its adverse effect to objective function, automatic rejection major network phasor amount when observation error is greater than threshold value
Survey the bad data in device data；
Recycle Optimization Method that can obtain line impedance matrix and admittance matrix.
3. a kind of robust electric transmission line positive sequence parameter identification method according to claim 1, which is characterized in that using symmetrical
Component method decouples line impedance matrix and admittance matrix, obtains positive sequence resistance, reactance and admittance parameter includes: over the ground
Structural matrix T:
The matrix T constructed herein is a kind of symmetrical component transformation, and effect is a, b, and the phase component of c three-phase is converted into positive sequence,
Negative phase-sequence and zero-sequence component；Wherein, a is twiddle factor,
The matrix equation of three-phase electricity pressure drop Yu three-phase current relationship is established using route phase component model:
In above formula,
Indicate three-phase electricity pressure drop,
Indicate three-phase current；
Three-phase electricity pressure drop and three-phase current are replaced with into order components, obtained:
It further indicates that are as follows:
ZpThe as impedance matrix of order components, it may be assumed that
Z therein(1)For route positive sequence impedance, Z(2)Indicate route negative sequence impedance, Z(0)Indicate route zero sequence impedance；
Similarly, same to release for admittance matrix:
Y thereinc(1)For the admittance over the ground of route positive sequence, Yc(2)Indicate the admittance over the ground of route negative phase-sequence, Yc(0)Indicate route zero sequence over the ground
Admittance.
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| CN108052725A (en) * | 2017-12-08 | 2018-05-18 | 华北电力大学 | A kind of robust distribution network line positive sequence parameter identification method based on exponential type object function |
| CN108089058A (en) * | 2017-12-13 | 2018-05-29 | 华北电力大学 | A kind of discrimination method of the positive order parameter of robust distribution network line |
| CN108226710A (en) * | 2017-12-29 | 2018-06-29 | 中国电力科学研究院有限公司 | A kind of transmission line parameter discrimination method and system |
| CN110414816B (en) * | 2019-07-19 | 2021-11-23 | 福建睿思特科技股份有限公司 | Least square-based power system state estimation method |
| CN112165115B (en) * | 2020-09-16 | 2022-08-02 | 上海交通大学 | Parameter identification method and device for ash box model of direct-drive wind turbine generator |
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