CN106526424A - Power transmission line single-phase ground fault parameter recognition method - Google Patents

Power transmission line single-phase ground fault parameter recognition method Download PDF

Info

Publication number
CN106526424A
CN106526424A CN201611040399.1A CN201611040399A CN106526424A CN 106526424 A CN106526424 A CN 106526424A CN 201611040399 A CN201611040399 A CN 201611040399A CN 106526424 A CN106526424 A CN 106526424A
Authority
CN
China
Prior art keywords
value
phasor
measurement
power transmission
transmission line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN201611040399.1A
Other languages
Chinese (zh)
Other versions
CN106526424B (en
Inventor
沈鑫
闫永梅
周年荣
刘柱揆
马红升
张林山
王科
李月梅
常亚东
张文斌
唐立军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Electric Power Research Institute of Yunnan Power System Ltd
Original Assignee
Electric Power Research Institute of Yunnan Power System Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Electric Power Research Institute of Yunnan Power System Ltd filed Critical Electric Power Research Institute of Yunnan Power System Ltd
Priority to CN201611040399.1A priority Critical patent/CN106526424B/en
Publication of CN106526424A publication Critical patent/CN106526424A/en
Application granted granted Critical
Publication of CN106526424B publication Critical patent/CN106526424B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/088—Aspects of digital computing
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
    • 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
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Theoretical Computer Science (AREA)
  • Locating Faults (AREA)

Abstract

The invention provides a power transmission line single-phase ground fault parameter recognition method. In the power transmission line single-phase ground fault parameter recognition method, when a single-phase ground fault occurs, line data is measured by phasor measurement devices arranged on two lines of a hybrid power transmission line, the least square method is improved by using uncertainty estimation to obtain new uncertainty estimation, and the new uncertainty estimation can eliminate the influence of measurement errors and even gross errors, thus improving the reliability and accuracy of the parameter recognition result. The power transmission line single-phase ground fault parameter recognition method can accurately position the fault line, and thus has a good application prospect.

Description

Method for identifying single-phase earth fault parameters of power transmission line
Technical Field
The invention relates to the technical field of fault identification, in particular to a method for identifying single-phase earth fault parameters of a power transmission line.
Background
With the high-speed development of modern towns, urban space is increasingly tense, and for power transmission lines, an overhead line corridor not only needs to occupy a large amount of space resources, but also is not attractive in aerial criss-cross, so that most urban areas adopt buried cables to replace overhead lines for transmitting power. The large number of laid cables not only beautifies city appearance and optimizes city layout, but also has much larger capacitance than overhead lines, thereby improving power factor and increasing line transmission capacity. Because of the high cost of cabling, overhead lines are generally still used in regions far from urban areas, and thus the transmission lines form an overhead line-cable hybrid line.
The fault location method of the overhead line-cable hybrid line is generally a traveling wave location method, a fault analysis method and a traveling wave method. The traveling wave distance measurement mainly comprises a wave velocity normalization method and a traveling wave time difference method, wherein the wave velocity normalization method is used for normalizing the wave velocity and the wave length of a cable or an overhead line, a mixed line needs to be simplified into a single line for distance measurement during normalization, and the fault distance is calculated so as to be converted into the length of an actual line; however, this method requires repeated conversion, and the traveling wave velocity fluctuates to some extent due to the influence of the line parameters and the surrounding environment, and therefore, the calculation error is large. The traveling wave time difference method firstly determines the fault line section according to the time difference of the fault traveling wave reaching two ends and carries out accurate positioning according to the single-end or double-end traveling wave method. The fault analysis method is only suitable for a mixed line with a simple structure and only two or three sections, and for a multi-section mixed line with alternately appearing power cables and overhead lines, the fault analysis method has complex criterion, and errors can be increased along with the increase of the connecting points of the cables and the overhead lines, so that the ranging precision is reduced. Due to the difference of the cable and the overhead line in the aspects of physical structure, electrical characteristics and the like, the traditional traveling wave distance measurement and fault analysis method cannot be completely applied to fault distance measurement of the hybrid line, and the traveling wave rule is widely applied in recent years due to the fact that the distance measurement is simple and is not affected by transition resistance and fault types.
According to the fault location method of the overhead line-cable hybrid line, line fault parameters are generally required to be identified and measured so as to determine the line with the fault, and therefore, whether the line fault parameters are measured accurately directly relates to the determination of the line with the fault. For a mixed circuit with phasor measuring devices arranged on two sides, the existing method for measuring the circuit fault parameters needs manual on-off control of the circuit or addition of a zero sequence power supply, which not only consumes manpower and material resources, but also influences the stable operation of a power grid. In line fault parameter identification, most measurement errors obey normal distribution, so a Least square method (LS) for processing the measurement is commonly used for fault parameter identification, but when a large error occurs in measurement data, the identification result based on the LS often deviates from an actual value, so that line identification of a mixed line with a fault is inaccurate.
Disclosure of Invention
The invention provides a single-phase earth fault parameter identification method for a power transmission line, which aims to solve the problem that the identification result deviation of the existing fault parameter identification method is large when a large error occurs in measured data.
The invention provides a method for identifying single-phase earth fault parameters of a power transmission line, which comprises the following steps:
setting initial weight P of each phasor measurement unit measurement point in power transmission linei (0)；
Calculating an initial value of the phasor measurement unit measurement value from the LS
According to the initial valueCalculating a residual v of the phasor measurement device measurement values(0)；
According to the residual error v(0)Calculating equivalent weight values of the measurement points of the phasor measurement unit according to the uncertainty
According to the equivalent weight valueIteratively calculating new parameter result values for the phasor measurement device measurement valuesAnd a new residual v(k)Wherein
judgment ofWhether or not less than or equal to 0.01;
if it is as describedIf the number of the recognition results is less than or equal to the number of the recognition results, outputting the recognition result
If it is as describedIf yes, recalculating equivalent weight value of measurement point of phasor measurement deviceUp to saidIs less than or equal to.
Preferably, the initial weight P of each phasor measurement device measurement point in the power transmission line is seti (0)The method comprises the following steps:
acquiring zero sequence voltage and current phasors at measurement points of each phasor measurement device in the single-phase earth fault process;
and forming a phasor beta, a line parameter phasor alpha to be identified and a matrix A by the zero sequence voltage and the current phasor.
Preferably, the initial weight P of each phasor measurement device measurement point in the power transmission line is seti (0)The method comprises the following steps:
acquiring the number N of the measuring points of the phasor measuring device;
setting the initial weight P of each phasor measurement device measurement point according to the number Ni (0)Is 1/N.
Preferably, the difference v is(0)Calculating equivalent weight values of the measurement points of the phasor measurement unit according to the uncertaintyThe method comprises the following steps:
according to the residual error v(0)And calculating uncertainty value rho (v) by using control coefficient ci)；
Judging the uncertainty value rho (v)i) Whether greater than 0.5;
if the uncertainty value rho (v)i) If the phasor measurement value is more than 0.5, deleting the phasor measurement device measurement value;
if the uncertainty value rho (v)i) Less than or equal to 0.5, retaining the phasor measurement device measurement value;
judging the residual v(0)The absolute value and the magnitude of the control coefficient c;
if the residual error v(0)The absolute value is less than or equal to the control coefficient c, the equivalent weight value
If the residual error v(0)If the absolute value is greater than the control coefficient c, the equivalent weight value
Preferably, said recalculating equivalent weight values for said phasor measurement device measurement pointsThe method comprises the following steps:
judging the residual v(k)The absolute value and the magnitude of the control coefficient c;
if the residual error v(k)The absolute value is less than or equal to the control coefficient c, the equivalent weight value
If the residual error v(k)If the absolute value is greater than the control coefficient c, the equivalent weight value
Preferably, the value range of the control coefficient c is 1.0-2.0.
Preferably, the value of the control coefficient c is 1.7.
The technical scheme provided by the embodiment of the invention can have the following beneficial effects:
the invention provides a method for identifying single-phase earth fault parameters of a power transmission line, which comprises the following steps: setting initial weight P of each phasor measurement unit measurement point in power transmission linei (0)(ii) a Calculating an initial value of the phasor measurement unit measurement value from the LSAccording to the initial valueCalculating a residual v of the phasor measurement device measurement values(0)(ii) a According to the residual error v(0)And c, calculating equivalent weight value of measuring point of the phasor measuring device by using control coefficient cAccording to the equivalent weight valueIteratively calculating new parameter values for the phasor measurement device measurementsAnd a new residual v(k)Whereinjudgment ofWhether or not less than or equal to 0.01; if it is as describedIf the number of the recognition results is less than or equal to the number of the recognition results, outputting the recognition resultIf it is as describedIf yes, recalculating equivalent weight value of measurement point of phasor measurement deviceUp to saidIs less than or equal to. In the method for identifying the single-phase earth fault parameters of the power transmission line, when the single-phase earth fault occurs, the phasor measurement devices arranged on two sides of the hybrid power transmission line measure line data, and the LS is improved by using the uncertainty estimation to obtain a new uncertainty estimation, so that the new uncertainty estimation can eliminate the influence caused by measurement errors and even gross errors, and further the reliability and the accuracy of the parameter identification result are improved. The method for identifying the single-phase earth fault parameters of the power transmission line can accurately position the faulted line, thereby having good application prospect.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
Fig. 1 is a flowchart of a method for identifying a single-phase earth fault parameter of a power transmission line according to an embodiment of the present invention;
FIG. 2 is a pi-type equivalent circuit diagram according to an embodiment of the present invention;
fig. 3 is a voltage amplitude diagram of two phases b and c in the measured online data test provided by the embodiment of the invention.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.
Referring to fig. 1, fig. 1 is a flowchart illustrating a method for identifying a single-phase ground fault parameter of a power transmission line according to an embodiment of the present invention, where the following description of the fault parameter identification method is based on fig. 1.
The method for identifying the single-phase earth fault parameters of the power transmission line provided by the embodiment of the invention comprises the following steps:
s01: setting initial weight P of each phasor measurement unit measurement point in power transmission linei (0)；
S02: calculating an initial value of the phasor measurement unit measurement value from the LS
S03: according to the initial valueCalculating a residual v of the phasor measurement device measurement values(0)；
S04: according to the residual error v(0)Calculating equivalent weight values of the measuring points of the phasor measuring device by using the control coefficient c and the uncertainty
S05: according to the equivalent weight valueIteratively calculating new parameter values for the phasor measurement device measurementsAnd a new residual v(k)Wherein
s06: judgment ofWhether or not less than or equal to 0.01;
s07: if it is as describedIf the number of the recognition results is less than or equal to the number of the recognition results, outputting the recognition result
S08: if it is as describedIf yes, recalculating equivalent weight value of measurement point of phasor measurement deviceThat is, the step S04 is repeated until the aboveIs less than or equal to.
The specific method comprises the following steps:
s01: setting initial weight P of each phasor measurement unit measurement point in power transmission linei (0)；
For a line with phasor measurement devices arranged on both sides of an overhead line-cable mixed line, when a single-phase earth fault occurs, each phasor measurement device records three-phase voltage and current phasors from the time after the single-phase tripping of a circuit breaker to the time before reclosing, and corresponding zero-sequence voltage and current phasors can be obtained through calculation. According to the pi-type equivalent circuit diagram shown in fig. 2, zero sequence voltage and current phasors can be listed as a line equation, and the line equation is as follows:
wherein,respectively representing a zero-sequence voltage component and a zero-sequence current component of an m end of the line;respectively representing a zero-sequence voltage component and a zero-sequence current component of the n end of the line; z0＝R0+jX0Representing zero sequence impedance, Y0＝jB0And representing the zero sequence susceptance to ground.
Further, the line equation is simplified into two real part equations and two imaginary part equations, and the real part equation and the imaginary part equation form a matrix as follows:
wherein, Im0R，Im0I，In0R，In0IRepresenting the real part and the imaginary part of zero sequence current phasor of the m end and the n end; u shapem0，θm0，Un0，θn0Representing the amplitude and phase angle of zero sequence voltage phasor of the m end and the n end; g0、b0Represents 1/Z0The real and imaginary parts of (c); y isC0Represents Y0The imaginary part of/2.
Constant terms consisting of real parts and imaginary parts of zero-sequence current phasors in the matrix are replaced by the phasor β, the matrix A replaces a coefficient matrix consisting of real parts and imaginary parts of zero-sequence voltage phasors at two ends of m and n of the line in the matrix, and α ═ g0b0yC0]TReplacing the line parameter phasor to be identified, and adding a measurement residual phasor v formed by the measurement error of the phasor measurement device to form a parameter identification equation, wherein the parameter identification equation is β -A α + v;
the parameter identification target function can be obtained by LS and a parameter identification equation, and is as follows:
wherein N is the number of data points, i.e. phasor measurement in a hybrid transmission lineThe number of points; v. ofiResidual phasor of the ith data point is obtained; piAnd if the weight of the ith data point is obtained, the parameter identification result corresponding to the parameter identification target function is as follows:wherein P is a diagonal element of PiThe weight matrix of (2).
Setting initial weight P of each phasor measurement device measurement point according to the number N of data pointsi (0)Is 1/N, i.e. the initial weight of the ith data point is 1/N.
S02: calculating an initial value of a phasor measurement device measurement value from LSThe initial value
S03: according to the initial valueAnd calculating the residual v of the measured value of the phasor measuring device by using the parameter identification equation β (A α + v)(0)；
S04: according to the residual error v(0)Control coefficient c and uncertainty calculation phasor measurement device measurement point equivalent weight value
Using a function rho with slower growth to replace a parameter to identify a sum of squares function in an objective function, and according to the residual v(0)And calculating uncertainty value rho (v) by using control coefficient ci) Wherein the uncertainty value ρ (v)i) The calculation formula of (2) is as follows:
wherein,the value range of the control coefficient c is generally 1.0-2.0, and in the embodiment of the invention, the value of the control coefficient c is preferably 1.7 in order to optimize uncertainty and improve other accuracy of parameters;
judging the calculated uncertainty value rho (v)i) Whether greater than 0.5;
if the uncertainty value ρ (v)i) If the measured value is more than 0.5, deleting the measured value measured by the measuring point of the phase measuring device;
if the uncertainty value ρ (v)i) If the phasor measurement value is less than or equal to 0.5, the measurement value measured by the measurement point of the phasor measurement device is reserved;
from the uncertainty value ρ (v)i) Determining its equivalence weight function asThe equivalent weight functionThe calculation formula of (2) is as follows:
determining residual v(0)The absolute value and the magnitude of the control coefficient c;
if the residual v(0)If the absolute value is less than or equal to the control coefficient c, the initial weight value is retained, i.e. the equivalent weight value of the initial weight value is
If the residual v, (0) If the absolute value is greater than the control coefficient c, the weight of the initial weight value is reduced, that is, the equivalent weight value of the initial weight value is
S05: equivalent weight value according to initial weight valueIterative computation of new parameter result values for phasor measurement device measurementsAnd a new residual v(k)Wherein
since the function ρ with a slower growth has been used instead of the sum of squares function in the parameter identification objective function, i.e., the parameter identification objective function has changed, the parameter identification result corresponding to the changed parameter identification objective function is:the residual error is calculated asThe parameter identification result is a least squares iterative function based on uncertainty estimation.
S06: judgment ofWhether or not less than or equal to 0.01;
s07: if it isIf the number of the recognition results is less than or equal to the number of the recognition results, outputting the recognition result
S08: if it isIf so, repeating steps S04-S06 untilLess than or equal to, thereby outputting a parameter recognition result
According to the method for identifying the single-phase earth fault parameters of the power transmission line, provided by the embodiment of the invention, different weights are given to different measurement data, and a least square (RLS) iteration function based on uncertainty estimation can remove a numerical value with larger uncertainty and can reduce the weight of bad data, so that the influence of the bad data is eliminated, and the accuracy and the reliability of an identification result are improved.
In order to verify that the method for identifying the single-phase earth fault parameters of the Power transmission line provided by the embodiment of the invention has higher accuracy and reliability in identifying the fault parameters, the embodiment of the invention also verifies the BPA (Bonneville Power administration) simulation data test and the actual measurement online data, and the specific contents of the verification are as follows:
1. BPA simulation data testing
A single-loop overhead transmission line with a line length of 200km and a voltage class of 220kV and a zero-sequence resistor R are set up in BPA power system simulation software027.8456 Ω, zero sequence reactance X099.8648 omega, zero sequence earth susceptance B0＝2.1876×10- 4And S. Assuming that the line has single-phase reclosing after single-phase earth fault, acquiring phasor measurement data of two ends of the line of 0.5s in the time period from single-phase tripping to reclosing completion, wherein the sampling period is 0.01s, simultaneously performing line parameter identification by using an RLS method and an LS method, adding random noise in a test environment, and recording a parameter identification result of bad data.
1.1 noise immunity test
Simultaneously, Gaussian noise is superposed in the three-phase voltage amplitude measurement and the three-phase current amplitude measurement, and parameter identification results of two algorithms in the absence of noise and in the presence of noise are recorded, and the identification results refer to table 1.
Table 1: identification results of RLS method and LS method under noisy and non-noisy conditions
As can be seen from table 1, when there is no noise in the measurement, the RLS method preserves the weight of all data, which is the same as the LS method, and the results obtained by the two methods after the RLS method performs equal weight estimation are both consistent with the design values; in the case of random noise with the standard deviation of 0.5% in the measurement, the RLS method carries out weight reduction on data with slightly large partial residual errors, and the obtained identification result is superior to that of the LS method.
Secondly, random noises with standard deviations of 0.5%, 1% and 2% are superposed in the three-phase voltage amplitude measurement and the three-phase current amplitude measurement, and parameter identification results of two algorithms when different noises occur are recorded, wherein the identification results refer to table 2.
Table 2: recognition results of RLS method and LS method under different noise conditions
As can be seen from table 2, the data amount in which a large residual exists increases with the increase of the standard deviation of random noise, resulting in an increase in error of the recognition result obtained by the LS method; the RLS method can effectively eliminate the influence of large residual data, and can obtain high-precision identification results under various noise intensities.
The results can show that when the noise in the measured data is large, the identification result of the LS method deviates from the actual value, and the RLS method still keeps high identification precision, so that the method for identifying the single-phase earth fault parameters of the power transmission line provided by the embodiment of the invention has good anti-noise capability.
1.2 resistance to gross errors test
In this test, three cases containing bad data are designed, the gross error resisting capabilities of the RLS method and the LS method are compared according to the three cases, and the parameter identification results are recorded, which is shown in table 3. The three cases of design are: case 1-there is a 10% deviation in the amplitude data of several consecutive a-phase currents on one side; case 2-there is a 1 ° deviation in phase angle data of a number of continuous a-phase currents on one side; case 3-packet loss occurs in the data uploading process, and a plurality of continuous three-phase voltage and current data on one side are all 0.
Table 3: recognition results of gross error resistance of RLS method and LS method
From table 3, it can be known that, no matter what kind of bad data exists in the measurement, the RLS method can eliminate the effect of the gross error and obtain a more accurate recognition result; in some cases, the identification results of all parameters of the LS method even deviate from the true values seriously.
The above results show that in all three cases, RLS gives a relatively accurate recognition result with a strong resistance against failure, while LS gives a recognition result that deviates from the actual value to a different extent and does not have a resistance against failure. Therefore, the influence of various bad data can be effectively resisted by adopting the least square method based on uncertainty estimation, and the engineering application value is higher.
2. Measured on-line data testing
In the actual measurement on-line data test, the adopted data is a 220kV power grid single-circuit transmission line, wherein the offline measured value of the parameter is as follows: zero sequence resistance R012.56 Ω, zero sequence reactance X027.88 omega, zero sequence earth susceptance B0＝7.86544×10-5And S. In thatIn the actual measurement on-line data test, the non-full-phase operation steady-state data of the phasor measurement device at two sides of the phasor measurement device after a phase a has a single-phase earth fault and before the circuit breaker is reclosed is recorded, the LS method and the RLS method are respectively adopted for line parameter identification, the parameter identification result is recorded in the table 4, and meanwhile, the voltage amplitudes of the phase b and the phase c are recorded in the attached drawing 3, wherein the sampling period is 10ms, and the length of the selected data is 500 ms.
Table 4: parameter identification result of actually measured online data by RLS method and LS method
As can be known from table 4 and fig. 3, compared with the LS method, the identification error of the RLS method is lower, so that the method for identifying the single-phase earth fault parameters of the power transmission line provided by the embodiment of the invention also has accurate identification on the online data, and the identification precision is higher.
The identification results of the BPA simulation data test and the actual measurement online data test show that the power transmission line single-phase earth fault parameter identification method provided by the embodiment of the invention improves LS by using uncertainty estimation to obtain new uncertainty estimation, and forms a least square method of uncertainty estimation. The method for identifying the single-phase earth fault parameters of the power transmission line can accurately position the faulted line, thereby having good application prospect.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (7)

1. A method for identifying single-phase earth fault parameters of a power transmission line is characterized by comprising the following steps:
setting initial weight P of each phasor measurement unit measurement point in power transmission linei (0)；
Calculating an initial value of the phasor measurement unit measurement value according to a least square method
According to the initial valueCalculating a residual v of the phasor measurement device measurement values(0)；
According to the residual error v(0)Calculating equivalent weight values of the measurement points of the phasor measurement unit according to the uncertainty
According to the equivalent weight valueIteratively calculating new parameter result values for the phasor measurement device measurement valuesAnd a new residual v(k)Wherein
judgment ofWhether or not less than or equal to 0.01;
if it is as describedIf the number of the recognition results is less than or equal to the number of the recognition results, outputting the recognition result
If it is as describedIf yes, recalculating equivalent weight value of measurement point of phasor measurement deviceUp to saidIs less than or equal to.
2. The method for identifying the parameters of the single-phase earth fault of the power transmission line according to claim 1, wherein the initial weight P of each measurement point of the phasor measurement unit in the power transmission line is seti (0)The method comprises the following steps:
acquiring zero sequence voltage and current phasors at measurement points of each phasor measurement device in the single-phase earth fault process;
and forming a phasor beta, a line parameter phasor alpha to be identified and a matrix A by the zero sequence voltage and the current phasor.
3. The method for identifying the parameters of the single-phase earth fault of the power transmission line according to claim 1, wherein the initial weight P of each measurement point of the phasor measurement unit in the power transmission line is seti (0)The method comprises the following steps:
acquiring the number N of the measuring points of the phasor measuring device;
setting the initial weight P of each phasor measurement device measurement point according to the number Ni (0)Is 1/N.
4. The method for identifying the single-phase earth fault parameters of the power transmission line according to claim 1, wherein the parameter is determined according to the residual error v(0)Calculating equivalent weight values of the measurement points of the phasor measurement unit according to the uncertaintyThe method comprises the following steps:
according to the residual error v(0)And calculating uncertainty value rho (v) by using control coefficient ci)；
Judging the uncertainty value rho (v)i) Whether greater than 0.5;
if the uncertainty value rho (v)i) If the phasor measurement value is more than 0.5, deleting the phasor measurement device measurement value;
if the uncertainty value rho (v)i) Less than or equal to 0.5, retaining the phasor measurement device measurement value;
judging the residual v(0)The absolute value and the magnitude of the control coefficient c;
if the residual error v(0)The absolute value is less than or equal to the control coefficient c, the equivalent weight value
If the residual error v(0)If the absolute value is greater than the control coefficient c, the equivalent weight value
5. The method according to claim 1, wherein the recalculating the equivalent weight values of the phasor measurement device measurement pointsThe method comprises the following steps:
determining the residual v: (k) The absolute value and the magnitude of the control coefficient c;
if the residual error v(k)The absolute value is less than or equal to the control coefficient c, the equivalent weight value
If the residual error v(k)If the absolute value is greater than the control coefficient c, the equivalent weight value
6. The method for identifying the single-phase earth fault parameters of the power transmission line according to claim 4 or 5, wherein the value range of the control coefficient c is 1.0-2.0.
7. The method for identifying the single-phase earth fault parameters of the power transmission line according to claim 6, wherein the value of the control coefficient c is 1.7.
CN201611040399.1A 2016-11-21 2016-11-21 A kind of transmission line one-phase earth fault parameter identification method Active CN106526424B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201611040399.1A CN106526424B (en) 2016-11-21 2016-11-21 A kind of transmission line one-phase earth fault parameter identification method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201611040399.1A CN106526424B (en) 2016-11-21 2016-11-21 A kind of transmission line one-phase earth fault parameter identification method

Publications (2)

Publication Number Publication Date
CN106526424A true CN106526424A (en) 2017-03-22
CN106526424B CN106526424B (en) 2019-02-15

Family

ID=58356809

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201611040399.1A Active CN106526424B (en) 2016-11-21 2016-11-21 A kind of transmission line one-phase earth fault parameter identification method

Country Status (1)

Country Link
CN (1) CN106526424B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109254225A (en) * 2018-08-13 2019-01-22 中国南方电网有限责任公司超高压输电公司南宁监控中心 A kind of detection of electric network fault and faulty line recognition methods
CN117148044A (en) * 2023-09-19 2023-12-01 山东华科信息技术有限公司 Power distribution network fault positioning method and device based on artificial intelligence
CN117890740A (en) * 2024-03-14 2024-04-16 云南电投绿能科技有限公司 Partial discharge positioning method, device and equipment for power station cable and storage medium

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0436668A (en) * 1990-05-31 1992-02-06 Kansai Electric Power Co Inc:The Fault point locating method for n-terminal parallel two-line transmission line
CN102163844A (en) * 2011-03-14 2011-08-24 国网技术学院 Method for detecting state of power system based on phasor measurement unit (PMU)
CN102175922A (en) * 2011-01-24 2011-09-07 重庆大学 Phasor measurement unit (PMU) measurement data-based power line parameter identification and estimation method
CN104297635A (en) * 2014-10-14 2015-01-21 河南理工大学 Fault line selection method for distribution network on basis of atom sparse decomposition and extreme learning machine
CN105588982A (en) * 2014-10-27 2016-05-18 国家电网公司 Measurement and calculation method of harmonic impedance of power system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0436668A (en) * 1990-05-31 1992-02-06 Kansai Electric Power Co Inc:The Fault point locating method for n-terminal parallel two-line transmission line
CN102175922A (en) * 2011-01-24 2011-09-07 重庆大学 Phasor measurement unit (PMU) measurement data-based power line parameter identification and estimation method
CN102163844A (en) * 2011-03-14 2011-08-24 国网技术学院 Method for detecting state of power system based on phasor measurement unit (PMU)
CN104297635A (en) * 2014-10-14 2015-01-21 河南理工大学 Fault line selection method for distribution network on basis of atom sparse decomposition and extreme learning machine
CN105588982A (en) * 2014-10-27 2016-05-18 国家电网公司 Measurement and calculation method of harmonic impedance of power system

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109254225A (en) * 2018-08-13 2019-01-22 中国南方电网有限责任公司超高压输电公司南宁监控中心 A kind of detection of electric network fault and faulty line recognition methods
CN117148044A (en) * 2023-09-19 2023-12-01 山东华科信息技术有限公司 Power distribution network fault positioning method and device based on artificial intelligence
CN117148044B (en) * 2023-09-19 2024-04-02 山东华科信息技术有限公司 Power distribution network fault positioning method and device based on artificial intelligence
CN117890740A (en) * 2024-03-14 2024-04-16 云南电投绿能科技有限公司 Partial discharge positioning method, device and equipment for power station cable and storage medium
CN117890740B (en) * 2024-03-14 2024-06-21 云南电投绿能科技有限公司 Partial discharge positioning method, device and equipment for power station cable and storage medium

Also Published As

Publication number Publication date
CN106526424B (en) 2019-02-15

Similar Documents

Publication Publication Date Title
Dobakhshari et al. A novel method for fault location of transmission lines by wide-area voltage measurements considering measurement errors
CN101344567B (en) Method for determining location of phase-to-earth fault
CN103954885B (en) The single-ended alignment system of double line down and localization method based on distributed constant
Xu et al. Fault location method based on single-end measurements for underground cables
CN107505538B (en) The asynchronous Fault Locating Method of half-wave power transmission circuit based on line mode voltage traveling wave amplitude attenuation characteristic
CN109523165B (en) Voltage sag state estimation method based on limited information
CN109633367B (en) Power transmission line fault positioning method based on voltage and current changes before and after fault
CN106526424B (en) A kind of transmission line one-phase earth fault parameter identification method
CN111141995B (en) Line double-end steady-state distance measuring method and system based on amplitude comparison principle
CN112415273B (en) Method for accurately measuring zero sequence parameters of double-circuit non-full-line parallel transmission line
CN115561580A (en) Zero-sequence component-based impedance method distribution network single-phase earth fault positioning method and system
Telló et al. Substation grounding grid diagnosis applying optimization techniques based on measurements and field tests
CN109299564B (en) Correction method for temperature factor influence in transformer bias current simulation calculation process
Lin et al. Fault location for three-ended ring-topology power system using minimum GPS-based measurements and CVT/CT sensing
CN108646134B (en) Method for positioning single-phase earth fault of generator stator winding based on phasor analysis
Patel et al. A new transmission line parameter estimation technique and its impact on fault localization
Daisy et al. Single phase fault location in power distribution network using combination of impedance based method and voltage sage matching algorithm
Goklani et al. Quantification of minimum unbalance required for accurate estimation of sequence parameters of transmission line using PMU data
Le et al. Earth fault location based on a Modified Takagi Method for MV distribution networks
CN104483577B (en) Electric power line parameter accuracy measurement method
CN114461982B (en) Power transmission line protection characteristic identification and voltage sag duration estimation method
CN106199192A (en) The positive sequence on-line testing method of parallel many back transmission lines Zero sequence parameter
KR20110059245A (en) Extraction method of fault point using mother wavelet transform in distribution system
Amin et al. Kalman filter estimation of impedance parameters for medium transmission line
CN112363009B (en) Single-ended fault location method and system for same-tower line ground fault

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant