CN110854828A - Single-ended adaptive traveling wave ultra-high speed protection system and method for dealing with high-resistance fault - Google Patents

Single-ended adaptive traveling wave ultra-high speed protection system and method for dealing with high-resistance fault Download PDF

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CN110854828A
CN110854828A CN201911221690.2A CN201911221690A CN110854828A CN 110854828 A CN110854828 A CN 110854828A CN 201911221690 A CN201911221690 A CN 201911221690A CN 110854828 A CN110854828 A CN 110854828A
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fault
current
zero
protection
mode
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CN110854828B (en
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宋国兵
张晨浩
王婷
赵乐
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Xian Jiaotong University
State Grid Shanghai Electric Power Co Ltd
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Xian Jiaotong University
State Grid Shanghai Electric Power Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/265—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured making use of travelling wave theory
    • 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
    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
    • 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

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

Abstract

The invention discloses a single-ended adaptive traveling wave ultra-high speed protection system and a single-ended adaptive traveling wave ultra-high speed protection method for dealing with high resistance faults, wherein the current and the voltage at the protection installation position of a direct current transmission line are measured, the initial traveling wave of the zero mode fault current is calculated, and an absolute value is taken; carrying out wavelet transform modulus maximum detection on the absolute value of the first wave of the zero-mode fault current, and adaptively changing the length of a data window for protection calculation; constructing a basic fitting function to fit the absolute value of the zero-mode fault current first traveling wave according to the expression form of the zero-mode fault current first traveling wave to obtain a fitting coefficient; forming a fault data set containing different fault distances and transition resistance faults, and obtaining (b) according to the fitted fault zero-mode current first-wave when the actual fault occursf,af) Obtaining a transition resistance estimation interval of a fault at a position in a fault data set; root of herbaceous plantAccording to the obtained estimation interval of the transition resistance, the setting value of the traveling wave protection is changed in a self-adaptive manner, and high-sensitivity judgment of faults inside and outside the area is realized.

Description

Single-ended adaptive traveling wave ultra-high speed protection system and method for dealing with high-resistance fault
Technical Field
The invention belongs to the technical field of relay protection of power systems, and particularly relates to a single-ended adaptive traveling wave ultra-high speed protection method for dealing with high-resistance faults.
Background
The flexible direct-current power transmission system is small in damping and low in inertia, current rises rapidly after a direct-current line fails, and the fault development process is fast. The flexible dc transmission system requires that the protection system must respond quickly in a short time (a few milliseconds). The main protection of the direct current transmission line which is actually put into operation comprises traveling wave protection and differential undervoltage protection, wherein the traveling wave protection mainly adopts the single-ended traveling wave protection principle of two companies, namely ABB and SIEMENS, the action time is several milliseconds, and the requirement of quick action is met. However, these two protection principles are essential to construct protection using an abrupt change in the electrical quantity, and the full-band information of the fault traveling wave is not sufficiently used, so that there is a problem that the protection sensitivity is low at the time of a high-transition-resistance fault.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a single-ended adaptive traveling wave ultra-high speed protection method for dealing with high-resistance faults aiming at the defects in the prior art, wherein parameters reflecting fault distance and transition resistance information are obtained by fitting a fault first traveling wave at the head end of a line, and an estimation interval of the fault transition resistance is given by combining a fault data set; and realizing the self-adaptive traveling wave protection method by using the obtained fault transition resistance estimation interval. The invention improves the performance of the existing traveling wave protection and meets the requirement of the flexible direct current transmission line on relay protection.
The invention adopts the following technical scheme:
a single-ended adaptive traveling wave ultra-high speed protection method for dealing with high-resistance faults comprises the following steps:
s1, measuring the current and voltage of the protection installation position of the direct current transmission line, calculating the first wave of the zero-mode fault current and taking an absolute value;
s2, carrying out wavelet transformation modulus maximum detection on the zero-modulus fault current first traveling wave, and changing the length of a data window for protection calculation;
s3, constructing a basic fitting function to fit the zero-mode fault current primary traveling wave according to the expression form of the zero-mode fault current primary traveling wave to obtain a fitting coefficient b reflecting the fault position and a fitting coefficient a reflecting the transition resistance;
s4, forming a fault data set containing different fault distances and transition resistance faults according to the obtained fitting coefficient b reflecting the fault position and the fitting coefficient a reflecting the transition resistance, and obtaining (b) according to the fitting fault zero-mode current first-going wave when the faults actually occurf,af) Obtaining a transition resistance estimation interval of a fault at a position in a fault data set;
and S5, changing the setting value of the traveling wave protection according to the obtained estimated interval of the transition resistance, and judging the high sensitivity of the faults inside and outside the area to realize the single-ended self-adaptive traveling wave ultra-high speed protection.
Specifically, in step S1, the zero-mode fault current first wave i0fComprises the following steps:
Figure BDA0002301041200000021
wherein Z isc0Taking the absolute value i of the first wave of the zero-mode fault current for the zero-mode wave impedance of the transmission line0Is zero mode current, u0Is a zero mode voltage.
Further, zero mode current i0And zero mode voltage u0Comprises the following steps:
Figure BDA0002301041200000022
Figure BDA0002301041200000023
wherein ip、in、up、unThe current and the voltage of the anode and the cathode which are measured at the protection installation position are respectively, and the current direction is that the bus points to the circuit.
Specifically, in step S2, when W is equal to Wmax≥WsetProtecting and starting; wherein, WmaxA threshold W as a result of the modulus maximum of zero-mode currentset0.02kA was taken.
Further, the action time of the starting element is recorded as t0Sampling the next 1 millisecond data, and detecting the singular value of the sampled 1 millisecond data by using a wavelet transform mode maximum value method;
if W2max≥W2setIf, | is satisfied, the reflected wave is proved to arrive at the protection installation position within 1 millisecond after the protection is started, and the time t at the moment is recorded1The data window of the guard computation now becomes Tn＝t1-t0(ii) a If within 1 millisecond | W2max≥W2setIf | is not satisfied, the data window is Tn＝1ms，W2maxA threshold value W as a result of the modulus maximum of the zero-mode current at the time of the second discrimination2set0.001kA was taken.
Specifically, in step S3, the basic fitting function is:
p(t)＝-ae(-bt)+c
wherein e is a natural exponential function, a, b and c are fitting parameters, and t is time.
Specifically, in step S4, it is determined that the fault zero-mode current is first wave-fitted (b)f,af) The method for extracting the fault transition resistance information at the position in the fault data set specifically comprises the following steps:
first, it is judged (b)f,af) Whether it belongs to a failure data set, for (b) belonging to a failure data setf,af) Directly giving out a fault distance and a transition resistance value; if not, traversing the fault data set S (i, j), and judging (b)f,af) Whether the data set is in a quadrangle formed by four adjacent points S (i, j), S (i, j +1), S (i +1, j +1) and S (i +1, j) as end points (i is less than or equal to m-1, and j is less than or equal to n-1) is judged; when there is one (i, j) such that | s (i, j) | ssum(i, j), then determine that the fault distance is (L)j,Lj+1]Has a transition resistance of (R)f,i,Rf,i+1]In the meantime.
Specifically, in step S5, the transition resistance is determined to be (R)f,i,Rf,i+1]The protection criterion is as follows:
wherein, max [ (di/dt)Rf,i+1]The transition resistance at the outlet outside the zone is Rf,i+1Maximum value of the pole current derivative measured at the head end of the line at fault; delta1,Rf,i+1Is that the line has a transition resistance of RfSetting value of i +1 protection at fault, krelFor reliability reasons, if there is no (i, j) satisfied, the protection setting is set as the maximum value of the derivative of the pole current max [ (di/dt) measured at the head end of the line in the event of a metallic fault at the exit of the protection circuit outside the zone0]Is set to delta1,0。
Further, krelIs 1.2.
The other technical scheme of the invention is that a single-end adaptive traveling wave ultra-high speed protection system for dealing with high-resistance faults utilizes the single-end adaptive traveling wave ultra-high speed protection method for dealing with the high-resistance faults, and comprises the following steps:
the current sampling processing module is used for measuring the current and the voltage at the protection installation position of the direct-current transmission line and determining the absolute value of the first wave of the zero-mode fault current;
a calibration module for calibrating the arrival time t of zero-mode fault current0；
Judgment module for TnJudging whether the reflected wave arrives within time, and fitting the absolute value of the first wave of the zero-mode fault current to obtain a fitting coefficient b reflecting the fault position and a fitting coefficient a reflecting the transition resistance; taking the fitting coefficients a and b as protection judgment bases, and sending information whether to protect to a protection module;
and the protection module determines whether to perform protection action according to the judgment result of the judgment module.
Compared with the prior art, the invention has at least the following beneficial effects:
the invention relates to a single-end self-adaptive traveling wave ultra-high speed protection method for high-resistance faults, which utilizes fault information contained in a fault first traveling wave, obtains a fault data set by fitting a zero-mode fault current first traveling wave, gives an estimation interval of fault transition resistance by combining the fault data set, and realizes the self-adaptive selection of a traveling wave protection setting value. Simulation verification shows that the protection method has high speed and reliability, and effectively improves the sensitivity of traveling wave protection.
Further, the absolute value of the first wave of the zero-mode fault current at the protection installation position is extracted, and preparation is made for the protection calculation of the steps S2-S5.
Further, when the modulus maximum value of the zero-mode current is larger than or equal to the threshold value WsetThe guard is initiated and the window length of data used for the fitting in step S3 is determined.
Furthermore, the extraction of the fault distance and the transition resistance information is realized through a basic fitting function, wherein the parameter b reflects the fault distance, and the parameter a reflects the transition resistance.
Further, by forming a fault data set in step S4, an estimation of fault transition resistance is achieved.
Further, for the protection criterion, the transition resistance estimation interval obtained in the step S4 is used to adaptively change the setting value of the protection, thereby significantly improving the sensitivity of the protection.
In conclusion, the invention has high speed and high reliability, and effectively improves the sensitivity of traveling wave protection.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
Fig. 1 is a schematic diagram of a ± 400kV flexible dc transmission system;
FIG. 2 is a fitting result of a zero-mode fault current first-order wave;
FIG. 3 is a fault data set;
fig. 4 shows the results of protection calculations for different fault conditions.
Detailed Description
The invention relates to a single-ended adaptive traveling wave ultra-high speed protection method for dealing with high-resistance faults, which comprises the following steps of:
s1, measuring the current and voltage of the protection installation position of the direct current transmission line, calculating the first wave of the zero-mode fault current and taking an absolute value;
measuring the current and the voltage of the line protection installation position of the direct current transmission line, and calculating the zero-mode current and the zero-mode voltage according to the following formula:
Figure BDA0002301041200000061
wherein ip、in、up、unThe current and the voltage of the anode and the cathode which are measured at the protection installation position are respectively, and the current direction is that the bus points to the circuit. And calculating the zero-mode fault current first traveling wave according to the following formula:
Figure BDA0002301041200000062
wherein Z isc0And taking the absolute value of the first wave of the zero-mode fault current for the zero-mode wave impedance of the power transmission line.
S2, carrying out wavelet transformation module maximum detection on the absolute value of the first wave of the zero-module fault current, and adaptively changing the length of a data window for protection calculation;
the method of wavelet transform modulus maximum is adopted to carry out singularity detection on zero-modulus current at the protection installation position, the result of secondary spline wavelet scale five is utilized to carry out identification of the arrival time of the first-row wave, and when:
Wmax≥Wset(3)
starting protection; wherein, WmaxA threshold W as a result of the modulus maximum of zero-mode currentset0.02kA was taken.
Recording the action time of the starting element as t0To next TsSampling data in time window, and using wavelet transform modulus maximum value method to sample TsAnd carrying out singular value detection on the data in the time window.
If W2max≥W2setIf, | is satisfied, it proves that the reflected wave is T after the protection is startedsThe inner part reaches the protection installation position, and the time t at the moment is recorded1The length of the data window of the guard calculation now becomes Tn＝t1-t0(ii) a If TsWithin a time window | W2max≥W2setIf | is not satisfied, thenThe data window length is Tn＝Ts。
Wherein, W2maxA threshold value W as a result of the modulus maximum of the zero-mode current at the time of the second discrimination2set0.001kA was taken.
S3, constructing a basic fitting function p (t) ═ ae according to the expression form of the zero-mode fault current first traveling wave(-bt)+ c, fitting the absolute value of the first traveling wave of the zero-mode fault current to obtain fitting coefficients a and b;
the zero-mode fault current first traveling wave expression at the protection installation position of the head end of the line is y ═ ae(-bx)Form + c. The parameter b becomes smaller as the failure distance increases, and the fitting coefficient a becomes smaller as the transition resistance increases. From this, a basic fitting function p (t) ═ ae is constructed(-bt)+ c measured T at protection installation position of line head end after protection startingnAnd fitting the zero-mode fault current initial wave in the length of the data window to obtain a fitting coefficient b reflecting the fault position and a fitting coefficient a reflecting the transition resistance. The fitting uses a least squares algorithm.
And S4, forming a fault data set containing different fault distances and transition resistance faults. When the actual fault occurs, (b) obtained by fitting the first wave of the fault zero-mode currentf,af) Obtaining a transition resistance estimation interval of a fault at a position in a fault data set;
fault data sets are formed containing different fault distances and transition resistance faults. For a DC line, select L1,L2…LnTotal n fault distances (L)1<L2<…<Ln<L) and Rf,1<Rf,2<…<Rf,mTotal m transition resistances (0 ═ R)f,1<Rf,2<…<Rf,m) A failure data set S (i, j) is formed as a sample, the sample capacity of which is m × n. Any one element in the failure data set can be represented as (b)i,j,ai,j) Wherein b isi,j、ai,jAnd the fitting parameters are respectively the fault zero-mode current first-wave fitting parameters in the fault under the conditions of the j fault distance and the i transition resistance.
When the actual fault occurs, the zero-mode electricity of the fault is judgedFitted with the first wave of the flow (b)f,af) And extracting fault transition resistance information at the position in the fault data set. The specific implementation mode is as follows:
first, it is judged (b)f,af) Whether it belongs to a failure data set, for (b) belonging to a failure data setf,af) And directly giving the fault distance and the transition resistance value. If not, traversing the fault data set S (i, j), and judging (b)f,af) Whether the data set is in a quadrangle formed by four adjacent points S (i, j), S (i, j +1), S (i +1, j +1) and S (i +1, j) as end points (i is less than or equal to m-1, and j is less than or equal to n-1) is judged. Defining:
Figure BDA0002301041200000071
Figure BDA0002301041200000072
Figure BDA0002301041200000073
Figure BDA0002301041200000081
Figure BDA0002301041200000082
ssum(i,j)＝|s1(i,j)|+|s2(i,j)|+|s3(i,j)|+|s4(i,j)| (9)
when there is one (i, j) such that:
|s(i,j)|＝ssum(i,j) (10)
then the fault distance is determined to be (L)j,Lj+1]Has a transition resistance of (R)f,i,Rf,i+1]In the meantime.
And S5, changing the setting value of the traveling wave protection in a self-adaptive manner according to the obtained estimated interval of the transition resistance, and realizing high-sensitivity judgment of faults inside and outside the area.
For the determination of transition resistance in (R)f,i,Rf,i+1]The protection criterion is as follows:
Figure BDA0002301041200000083
wherein max [ (di/dt)Rf,i+1]The transition resistance at the outlet outside the zone is Rf,i+1Maximum value of the pole current derivative measured at the head end of the line at fault; delta1,Rf,i+1Is that the line has a transition resistance of RfSetting value of i +1 protection at fault, krelFor the reliability factor, the invention takes 1.2.
If there is no (i, j) satisfying equation (10), the protection setting in equation (11) is determined as the maximum value of the derivative of pole current max [ (di/dt) measured at the head end of the line when a metallic fault occurs at the exit avoiding the outside of the zone0]Is set to delta1,0。
A single-end adaptive traveling wave ultra-high speed protection system for dealing with high-resistance faults utilizes the single-end adaptive traveling wave ultra-high speed protection method for dealing with the high-resistance faults, and comprises the following steps:
the current sampling processing module is used for measuring the current and the voltage at the protection installation position of the direct-current transmission line and determining the absolute value of the first wave of the zero-mode fault current;
a calibration module for calibrating the arrival time t of zero-mode fault current0；
Judgment module for TnJudging whether the reflected wave arrives within time, and fitting the absolute value of the first wave of the zero-mode fault current to obtain a fitting coefficient b reflecting the fault position and a fitting coefficient a reflecting the transition resistance; taking the fitting coefficients a and b as protection judgment bases, and sending information whether to protect to a protection module;
and the protection module determines whether to perform protection action according to the judgment result of the judgment module.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1 and fig. 2, fig. 1 is a model of a ± 400kV flexible direct-current transmission system built on a PSCAD; fig. 2 is a fitting result of the first wave of the zero-mode fault current, and it can be seen that:
the basic fitting function and the zero-mode fault current first traveling wave have high coincidence degree, the fitting result has high fitting goodness, and the fitting coefficient can effectively reflect fault information.
Fig. 3 is the resulting fault data set, and fig. 4 is the protection calculation results for different fault conditions, as can be seen:
1) the protection criterion can effectively judge the faults inside and outside the area within 1 millisecond, the faults inside the area can correctly act, and the faults outside the area can reliably not act;
2) for the fault of 300 omega transition resistance of a 500km direct current transmission line, the protection can still quickly and reliably protect the whole length of the line;
3) by self-adaptively selecting a setting value, the protection method can still correctly act when the direct current transmission line has a high-resistance fault, and the action rejection condition does not exist.
Simulation verification:
a +/-400 kV true bipolar connection flexible direct current transmission system as shown in figure 1 is built on a PSCAD, a converter station is a full-bridge MMC, a direct current line adopts a frequency-variable parameter model, the length of the line is 500km, and two end smoothing reactors of the line are 200 mH. In simulation verification, the sampling frequency is 50 kHz.
For the simulation verification model of the invention, 150km, 200km, 250km and 300km are takenAnd five fault distances of 350km, and four transition resistances of 0 omega, 100 omega, 200 omega and 300 omega are used as samples to form a fault data set S (i, j), wherein i is less than or equal to 4, and j is less than or equal to 5. Element (b) in fault data seti,j,ai,j) Plotted on a planar coordinate system, resulting in the failure data set plane shown in fig. 3.
The maximum value of the pole current derivative measured by the protection of the head end of the line when the single-pole ground fault with the transition resistances of 0 omega, 100 omega, 200 omega and 300 omega occurs at the outlet of the converter side of the current-limiting reactor of the direct-current transmission line is utilized to obtain the setting values of the protection method under different transition resistances, as shown in table 1.
TABLE 1 protection setting values
Figure BDA0002301041200000101
When a 190 omega transition resistance fault occurs on the DC transmission line at 275km from the head end, the fitting result of the fault zero-mode current is as follows: a is1＝0.3019，b1＝12660.67。
Calculating (12660.67,0.3019) the location in the fault data set as:
Figure BDA0002301041200000111
Figure BDA0002301041200000112
|s(2,3)|＝ssum(2,3)
the estimated fault distance is (250km,300 km), and the transition resistance range is (100 omega, 200 omega), as shown in fig. 3.
At this time, max (di/dt) is 0.2904p.u./0.15ms, and the setting value of the protection is set to Δ according to the obtained transition resistance interval1,200Correct action is protected 0.2301p.u./0.15 ms.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.

Claims (10)

1. The single-ended adaptive traveling wave ultra-high speed protection method for dealing with the high-resistance fault is characterized by comprising the following steps of:
s1, measuring the current and voltage of the protection installation position of the direct current transmission line, calculating the first wave of the zero-mode fault current and taking an absolute value;
s2, carrying out wavelet transformation modulus maximum detection on the absolute value of the first wave of the zero-modulus fault current, and changing the length of a data window for protection calculation;
s3, constructing a basic fitting function to fit the absolute value of the zero-mode fault current first traveling wave in the length of the data window according to the expression form of the zero-mode fault current first traveling wave, and obtaining a fitting coefficient b reflecting the fault position and a fitting coefficient a reflecting the transition resistance;
s4, forming a fault data set containing different fault distances and transition resistance faults according to the obtained fitting coefficient b reflecting the fault position and the fitting coefficient a reflecting the transition resistance, and obtaining (b) according to the fitting fault zero-mode current first-going wave when the faults actually occurf,af) Obtaining a transition resistance estimation interval of a fault at a position in a fault data set;
and S5, changing the setting value of the traveling wave protection according to the obtained estimated interval of the transition resistance, and judging the high sensitivity of the faults inside and outside the area to realize the single-ended self-adaptive traveling wave ultra-high speed protection.
2. The single-ended adaptive traveling-wave ultra-high speed protection method for high-resistance faults according to claim 1, wherein in step S1, the first traveling wave i of zero-mode fault current0fComprises the following steps:
Figure FDA0002301041190000011
wherein Z isc0Taking the absolute value i of the first wave of the zero-mode fault current for the zero-mode wave impedance of the transmission line0Is zero mode current, u0Is a zero mode voltage.
3. The method of claim 2, wherein the zero-mode current i is zero mode current0And zero mode voltage u0Comprises the following steps:
Figure FDA0002301041190000021
Figure FDA0002301041190000022
wherein ip、in、up、unThe current and the voltage of the anode and the cathode which are measured at the protection installation position are respectively, and the current direction is that the bus points to the circuit.
4. The method for single-ended adaptive traveling-wave ultra-high speed protection against high-resistance faults according to claim 1, wherein in step S2, when W is greater than Wmax≥WsetProtecting and starting; wherein, WmaxA threshold W as a result of the modulus maximum of zero-mode currentset0.02kA was taken.
5. The method according to claim 4, wherein the actuation time of the startup element is t0To next TsSampling data in time window, and using wavelet transform modulus maximum value method to sample TsCarrying out singular value detection on data in the time window;
if W2max≥W2setIf, | is satisfied, it proves that the reflected wave is T after the protection is startedsThe inner part reaches the protection installation position, and the time t at the moment is recorded1Protecting the calculated data window lengthChange to Tn＝t1-t0(ii) a If TsWithin a time window | W2max≥W2setIf | is not satisfied, the data window length Tn＝Ts，W2maxA threshold value W as a result of the modulus maximum of the zero-mode current at the time of the second discrimination2set0.001kA was taken.
6. The method for single-ended adaptive traveling-wave ultra-high speed protection against high-resistance faults according to claim 1, wherein in step S3, T after protection is started is determined by using a basic fitting functionnFitting the zero-mode current sampling data in the length of the data window to obtain fitting parameters corresponding to the fault, wherein the basic fitting function is as follows:
p(t)＝-ae(-bt)+c
wherein e is a natural exponential function, a, b and c are fitting parameters, and t is time.
7. The single-ended adaptive traveling-wave ultra-high speed protection method for high-resistance faults according to claim 1, wherein in step S4, the fault zero-mode current initial wave-fitting is judged (b)f,af) The method for extracting the fault transition resistance information at the position in the fault data set specifically comprises the following steps:
first, it is judged (b)f,af) Whether it belongs to a failure data set, for (b) belonging to a failure data setf,af) Directly giving out a fault distance and a transition resistance value; if not, traversing the fault data set S (i, j), and judging (b)f,af) Whether the data set is in a quadrangle formed by four adjacent points S (i, j), S (i, j +1), S (i +1, j +1) and S (i +1, j) as end points (i is less than or equal to m-1, and j is less than or equal to n-1) is judged; when there is one (i, j) such that | s (i, j) | ssum(i, j), then determine that the fault distance is (L)j,Lj+1]Has a transition resistance of (R)f,i,Rf,i+1]In the meantime.
8. The method for single-ended adaptive traveling-wave ultra-high speed protection against high-resistance faults according to claim 1, wherein in step S5, the method comprisesIn determining that the transition resistance is in (R)f,i,Rf,i+1]The protection criterion is as follows:
Figure FDA0002301041190000031
wherein, max [ (di/dt)Rf,i+1]The transition resistance at the outlet outside the zone is Rf,i+1Maximum value of the pole current derivative measured at the head end of the line at fault; delta1,Rf,i+1Is that the line has a transition resistance of RfSetting value of i +1 protection at fault, krelFor reliability reasons, if there is no (i, j) satisfied, the protection setting is set as the maximum value of the derivative of the pole current max [ (di/dt) measured at the head end of the line in the event of a metallic fault at the exit of the protection circuit outside the zone0]Is set to delta1,0。
9. The method according to claim 8, wherein k is krelIs 1.2.
10. A single-ended adaptive traveling wave ultra-high speed protection system for dealing with high-resistance faults, which is characterized in that the single-ended adaptive traveling wave ultra-high speed protection method for dealing with high-resistance faults, according to any one of claims 1 to 9, is used, and comprises the following steps:
the current sampling processing module is used for measuring the current and the voltage at the protection installation position of the direct-current transmission line and determining the absolute value of the first wave of the zero-mode fault current;
a calibration module for calibrating the arrival time t of zero-mode fault current0；
Judgment module for TnJudging whether the reflected wave arrives within time, and fitting the absolute value of the first wave of the zero-mode fault current to obtain a fitting coefficient b reflecting the fault position and a fitting coefficient a reflecting the transition resistance; taking the fitting coefficients a and b as protection judgment bases, and sending information whether to protect to a protection module;
and the protection module determines whether to perform protection action according to the judgment result of the judgment module, so that single-ended self-adaptive traveling wave ultrahigh-speed protection is realized.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111478273A (en) * 2020-04-02 2020-07-31 合肥凯高电气设备有限公司 Bus relay protection method for fault transient component with specific wavelength
CN118380980A (en) * 2024-06-21 2024-07-23 南京国电南自电网自动化有限公司 Active power distribution network self-adaptive protection method and system based on fault traveling wave

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102279309A (en) * 2011-03-29 2011-12-14 昆明理工大学 Criterion method for protection startup of extra-high voltage direct-current circuit
US20170117701A1 (en) * 2014-03-17 2017-04-27 Abb Schweiz Ag Method and apparatus for sensing a fault in a power system
CN108896874A (en) * 2018-07-10 2018-11-27 中国矿业大学 A kind of fault positioning method for transmission line of end connection short-term road
CN109119977A (en) * 2018-09-20 2019-01-01 山东大学 Multiterminal flexible direct current power grid DC line fast protection method and system based on single ended voltage
CN109193578A (en) * 2018-08-13 2019-01-11 西安交通大学 DC power transmission line fast protection method based on wavefront Generalized Logistic Function Fitting

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102279309A (en) * 2011-03-29 2011-12-14 昆明理工大学 Criterion method for protection startup of extra-high voltage direct-current circuit
US20170117701A1 (en) * 2014-03-17 2017-04-27 Abb Schweiz Ag Method and apparatus for sensing a fault in a power system
CN108896874A (en) * 2018-07-10 2018-11-27 中国矿业大学 A kind of fault positioning method for transmission line of end connection short-term road
CN109193578A (en) * 2018-08-13 2019-01-11 西安交通大学 DC power transmission line fast protection method based on wavefront Generalized Logistic Function Fitting
CN109119977A (en) * 2018-09-20 2019-01-01 山东大学 Multiterminal flexible direct current power grid DC line fast protection method and system based on single ended voltage

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
张帆等: "基于模量行波传输时间差的线路接地故障测距与保护", 《中国电机工程学报》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111478273A (en) * 2020-04-02 2020-07-31 合肥凯高电气设备有限公司 Bus relay protection method for fault transient component with specific wavelength
CN118380980A (en) * 2024-06-21 2024-07-23 南京国电南自电网自动化有限公司 Active power distribution network self-adaptive protection method and system based on fault traveling wave

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