CN110456228B - Fault location method for power transmission line - Google Patents
Fault location method for power transmission line Download PDFInfo
- Publication number
- CN110456228B CN110456228B CN201910780586.0A CN201910780586A CN110456228B CN 110456228 B CN110456228 B CN 110456228B CN 201910780586 A CN201910780586 A CN 201910780586A CN 110456228 B CN110456228 B CN 110456228B
- Authority
- CN
- China
- Prior art keywords
- phase
- fault
- traveling wave
- line
- line mode
- 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.)
- Active
Links
Images
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
- G01R31/081—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
-
- 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
Abstract
The invention provides a fault location method of a power transmission line, which comprises the following steps: collecting a reclosing three-phase voltage traveling wave or a three-phase current traveling wave at a measuring point; constructing a line mode traveling wave containing a fault phase and a line mode traveling wave formed by a non-fault phase according to the three-phase voltage traveling wave or the three-phase current traveling wave; determining the superposition component of the reclosing line mode traveling wave at a fault point according to the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase; according to the superposition component of the reclosing line mode travelling wave at the fault point and the reclosing moment, the distance between the fault point and the measuring point is determined, so that the fault point is quickly and accurately positioned, the line patrol burden is reduced, acceleration of troubleshooting and power restoration are facilitated, the fault location result is not influenced by a line branch point, transition resistance, system operation mode change and load, meanwhile, the fault location device does not need to be additionally provided with injection equipment, the hardware investment is low, normal line reclosing wave recording data is not needed, and the practical performance and the economic performance are good.
Description
Technical Field
The invention relates to the technical field of power systems, in particular to a fault location method of a power transmission line.
Background
The high-voltage transmission line is an important component of an electric power system and is an important task of transmitting electric energy, meanwhile, the high-voltage transmission line is also a frequent part of a power grid fault, and in recent years, the proportion of the high-voltage transmission line fault in various electric equipment of the electric power system is increased. Due to the complex line corridor condition, the high-voltage transmission line needs to frequently pass through remote zones such as farmlands, forests, mountainous areas and the like, and the difficulty of manual line patrol and fault first-aid repair is high after a fault occurs. Therefore, when a fault occurs, the fault point is quickly and accurately positioned, the fault can be timely eliminated, the power failure time is shortened, the economic loss caused by power failure is effectively reduced, the line patrol burden can be reduced, manpower and material resources are saved, and the method has a very positive effect on the safe and economic operation of the whole power system.
The fault types of the high-voltage transmission line are divided into four types, namely a single-phase grounding short-circuit fault, a two-phase grounding short-circuit fault and a three-phase short-circuit fault. According to the operation experience and the statistics of the years, in various short-circuit faults of the power transmission line, the single-phase grounding short-circuit fault accounts for more than 80% of the total faults of the line, the two-phase short-circuit fault and the two-phase grounding short-circuit fault only account for 3% -5% of the total faults, and the proportion of the three-phase short-circuit fault is less than 1%. From the above statistics, it can be seen that the proportion of ground faults is the highest. At present, fault location is generally carried out by adopting a single-ended impedance method on site, but because the single-ended power frequency electric quantity is only utilized, the influence of transition resistance on a location result cannot be overcome in principle. The double-ended impedance rule can utilize double-ended electrical quantity, and although the problem that the single-ended impedance method is influenced by a transition resistor and a system operation mode is solved, the requirement on data synchronization is high, and the investment on hardware equipment is high.
In summary, after a single-phase connection fault occurs in a power transmission line, how to quickly and accurately locate the fault point without being affected by a branch point of the line, a transition resistor, a change in a system operation mode and a load, and meanwhile, avoiding high investment cost of hardware is a problem that needs to be solved at present.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art or the related art.
Therefore, the invention provides a fault location method of a power transmission line.
In view of this, a fault location method for a power transmission line is provided, which is suitable for a condition that a high-voltage power transmission line provided with a reclosing device has a single-phase ground fault, and includes: collecting a reclosing three-phase voltage traveling wave or a three-phase current traveling wave at a measuring point; constructing a line mode traveling wave containing a fault phase and a line mode traveling wave formed by a non-fault phase according to the three-phase voltage traveling wave or the three-phase current traveling wave; determining the superposition component of the reclosing line mode traveling wave at a fault point according to the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase; and determining the distance between the fault point and the measuring point according to the superimposed component of the reclosing line mode traveling wave at the fault point and the reclosing moment.
The fault location method of the power transmission line provided by the invention has the advantages that when the power transmission line has single-phase fault, the reclosing device can automatically execute reclosing operation, after the reclosing device completes reclosing, collecting reclosing three-phase voltage traveling waves or three-phase current traveling waves at a measuring point (a protection safety place), generating line mode traveling waves containing fault phases and line mode traveling waves consisting of non-fault phases according to the three-phase voltage traveling waves or the three-phase current traveling waves, determining the superposed components of the reclosing line mode traveling waves at fault points, determining the distance between the fault point and the measuring point according to the superposition component of the reclosing line mode travelling wave at the fault point and the reclosing time, the reclosing line mode traveling wave is a line mode traveling wave of the reclosing device, the line mode traveling wave containing a fault phase is a line mode traveling wave composed of phases containing the fault phase, and the line mode traveling wave composed of a non-fault phase is a line mode traveling wave composed of only the non-fault phase. By the fault location method, the single-phase earth fault distance of the power transmission line can be quickly and accurately obtained, the line inspection burden is reduced, manpower and material resources are saved, the acceleration of fault maintenance and the recovery of power supply are facilitated, the loss caused by power failure is reduced, the fault location result is not influenced by a line branch point, transition resistance, system operation mode change and load, and the position of a fault point can be accurately determined. Meanwhile, the fault location does not need to additionally install injection equipment, the hardware investment is low, the fault location method is suitable for both voltage traveling waves and current traveling waves, the application range is wide, normal line superposition wave recording data is not needed, the impact on a power grid is small, and the fault location method has good practical performance and economic performance.
In addition, according to the fault location method for the power transmission line in the above technical scheme provided by the present invention, the following additional technical features may also be provided:
in the above technical solution, preferably, the step of generating the line mode traveling wave including the faulty phase and the line mode traveling wave composed of the non-faulty phase according to the three-phase voltage traveling wave or the three-phase current traveling wave specifically includes: carrying out fault phase selection on the three-phase voltage traveling wave or the three-phase current traveling wave, and determining a fault phase and a non-fault phase of the power transmission line; and carrying out phase-mode conversion processing on the three-phase voltage traveling wave or the three-phase current traveling wave according to the fault phase selection result to obtain the line-mode traveling wave containing the fault phase and the line-mode traveling wave consisting of the non-fault phase.
In the technical scheme, the fault phase selection is carried out on the three-phase voltage traveling wave or the three-phase current traveling wave, the fault phase and the non-fault phase are determined, for example, the a-phase grounding fault is taken as the fault phase, the three-phase voltage traveling wave or the three-phase current traveling wave is subjected to phase-mode conversion processing according to the fault phase selection result, and the line-mode traveling wave containing the fault phase and the line-mode traveling wave formed by the non-fault phase are obtained, so that the superposition component of the reclosing line-mode traveling wave at the fault point is determined according to the line-mode traveling wave containing the fault phase and the line-mode traveling wave formed by the non-fault phase, the distance of the fault point is calculated, the line inspection burden is reduced, manpower and material resources are saved, the fault maintenance and the power supply recovery are facilitated, the loss caused by power failure is reduced.
In any of the above technical solutions, preferably, the three-phase voltage traveling wave or the three-phase current traveling wave is subjected to phase-mode conversion processing by the following formula, taking a phase-to-ground fault as an example:
Wherein, a phase is fault phase, b and c phases are non-fault phases, YαRepresenting line-mode travelling waves, Y, containing faulted phasesγLine mode travelling wave, U, representing the constitution of a non-faulted phaseaRepresenting a travelling wave, U, of the phase voltage ab、UcRepresents a traveling wave of the voltages of b and c phases, IaRepresents a traveling wave of a-phase current, Ib、IcThe b-phase current traveling wave and the c-phase current traveling wave are shown, respectively.
In the technical scheme, when a single-phase ground fault occurs in a power transmission line, taking an a-phase ground fault as an example, namely the a-phase is a fault phase, the b-phase and c-phase are non-fault phases, namely the a-phase voltage traveling wave is a fault phase voltage traveling wave, the b-phase voltage traveling wave and the c-phase voltage traveling wave are non-fault phase voltage traveling waves, the a-phase current traveling wave is a fault phase current traveling wave, and the b-phase and c-phase current traveling waves are non-fault phase current traveling waves.
Specifically, the Karenbauer (Kerenbel) transformation is used for phase-mode transformation, so that three-phase decoupling is realized.
In any of the above technical solutions, preferably, the step of determining the superimposed component of the reclosing line mode traveling wave at the fault point according to the line mode traveling wave including the fault phase and the line mode traveling wave composed of the non-fault phase specifically includes: respectively carrying out normalization processing on the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase; and determining the superposition component of the reclosing line mode traveling wave at the fault point according to the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave consisting of the non-fault phase.
In the technical scheme, the line mode traveling wave containing the fault phase and the line mode traveling wave composed of the non-fault phase are respectively subjected to normalization processing, and the superposition component of the reclosing line mode traveling wave at the fault point is calculated according to the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave composed of the non-fault phase. The propagation of the line mode travelling wave is influenced by the fault point because the line mode network containing the fault phase contains the fault branch, and the propagation of the line mode travelling wave is not influenced by the fault point because the line mode network consisting of the non-fault phase does not contain the fault branch. Therefore, according to the superposition principle, the superposition component of the reclosing line mode traveling wave only at the fault point can be constructed, normal line superposition wave recording data is not needed, data storage and data alignment are not needed, and the closing impact on a power grid is reduced.
In any of the above technical solutions, preferably, the line mode traveling wave including the fault phase and the line mode traveling wave including the non-fault phase are normalized by the following formulas:
wherein, YαRepresenting line-mode travelling waves, M, containing faulted phasesαRepresenting the first modal maximum of a line-mode travelling wave containing a faulted phase，YγLine mode travelling wave, M, representing the constitution of a non-faulted phaseγRepresenting the first modal maximum of the line-mode traveling wave formed by the non-faulted phase,
represents the normalized line mode traveling wave containing the fault phase,
and expressing the line mode travelling wave formed by the normalized non-fault phase.
According to the technical scheme, the line mode traveling wave containing the fault phase and the first modulus maximum value of the line mode traveling wave containing the fault phase are normalized, and the line mode traveling wave containing the non-fault phase are normalized, so that the superimposed component of the line mode traveling wave reflecting only fault point information at the fault point is calculated according to the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave containing the non-fault phase.
In any of the above technical solutions, preferably, the superimposed component of the reclosing line mode traveling wave at the fault point is determined by the following formula:
wherein the content of the first and second substances,
showing the superimposed components of the reclosing line mode travelling wave at the fault point,
represents the normalized line mode traveling wave containing the fault phase,
and expressing the line mode travelling wave formed by the normalized non-fault phase.
According to the technical scheme, according to the superposition principle, the superposition component of the reclosing line mode traveling wave only at the fault point is constructed through the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave consisting of the non-fault phase, so that in the process of ranging, normal line superposition recording data are not needed, data storage and data alignment are not needed, and the switching-on impact on a power grid is reduced.
In any of the above technical solutions, preferably, before the step of normalizing the line mode traveling wave including the faulty phase and the line mode traveling wave including the non-faulty phase, the method further includes: and respectively carrying out wavelet transformation on the line mode traveling wave containing the fault phase and the line mode traveling wave consisting of the non-fault phase to obtain a first modulus maximum value of the line mode traveling wave containing the fault phase and a first modulus maximum value of the line mode traveling wave consisting of the non-fault phase.
In the technical scheme, the amplitude of the line-mode traveling wave containing the fault phase and formed by the non-fault phase after the phase-mode transformation is different from that of the line-mode traveling wave formed by the non-fault phase, so that the line-mode traveling wave containing the fault phase and formed by the non-fault phase are respectively subjected to wavelet transformation to obtain a first mode maximum value after the wavelet transformation, namely the corresponding first hopping wave head, and then the line-mode traveling wave containing the fault phase and formed by the non-fault phase is subjected to normalization processing according to the first mode maximum value to obtain a superimposed component only reflecting fault point information, so that in the process of ranging, normal line coincident recording data is not needed, data storage and data alignment are not needed, and the switching-on impact on a power grid is reduced.
In any of the above technical solutions, preferably, the line mode traveling wave including the faulty phase and the line mode traveling wave including the non-faulty phase are respectively subjected to wavelet transformation by the following formulas:
wherein f (n) represents data points of the line mode traveling wave containing the fault phase or the line mode traveling wave consisting of the non-fault phase, n is a sampling point,
representing the approximation component of the j-th scale,
wavelet components of a j-th scale are represented, h (k), g (k) represent filter parameters, j is a scale degree, k is a data point, and eta is a construction coefficient.
In this technical scheme, carry out wavelet transform through above formula, can reduce the error of transmission line single-ended travelling wave range finding, guarantee the accuracy of fault point range finding to reduce the use of additionally installing injection device additional, the hardware investment is few, does not need normal circuit coincidence record ripples data moreover, and is little to the electric wire netting impact, has good practicality and economic performance.
In any of the above technical solutions, preferably, the modulus maximum after the wavelet transform is determined by the following formula:
wherein the content of the first and second substances,
modulus maximum, n, representing the wavelet transform of the j-th scalekRepresenting the kth point data in the current scale,
the wavelet component of the j-th scale representing the kth point data in the current scale.
In any of the above technical solutions, preferably, the distance between the fault point and the measurement point is determined by the following formula:
where x denotes the distance between the fault point and the measurement point, t1Indicating the reclosing time, t2Showing the corresponding time of the first module maximum value of the superposition component of the reclosing line mode travelling wave at the fault point, and v showsLinear mode wave velocity of three-phase voltage traveling waves or three-phase current traveling waves.
According to the technical scheme, the accurate distance between a fault point and a measuring point can be calculated according to the reclosing moment, the moment corresponding to the first mode maximum value of the superposition component of the reclosing line mode traveling wave at the fault point, namely the arrival moment of the first fault point reflected wave and the wave speed of the line mode traveling wave, so that the fault point is quickly and accurately positioned, the line patrol burden is reduced, the acceleration of fault maintenance and the recovery of power supply are facilitated, the loss caused by power failure is reduced, the fault location result is not influenced by a line branch point, a transition resistor, the change of a system operation mode and the load, meanwhile, the fault location does not need to additionally install injection equipment, the hardware investment is low, the fault location method is applicable to both voltage traveling waves and current traveling waves, the application range is wide, normal line superposition recording data is not needed, the impact on a power grid is low, and the practical performance.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 shows a schematic flow chart of a fault location method of a power transmission line according to an embodiment of the invention;
fig. 2 shows a schematic flow chart of a fault location method of a transmission line according to a further embodiment of the invention;
fig. 3 shows a schematic flow chart of a fault location method of a transmission line according to a further embodiment of the invention;
FIG. 4 shows a line mode network schematic with a failed phase according to one embodiment of the present invention;
FIG. 5 shows a line-mode network schematic of a non-faulted phase configuration of one embodiment of the present invention;
FIG. 6 illustrates a point of failure superimposed component network diagram of one embodiment of the present invention;
FIG. 7 is a diagram illustrating a T-connection power transmission line model according to an embodiment of the present invention;
FIG. 8 illustrates a reclosing three-phase voltage traveling wave schematic diagram of an embodiment of the invention;
FIG. 9 shows a line mode traveling wave with a failed phase and a line mode traveling wave with a non-failed phase according to an embodiment of the present invention;
FIG. 10 is a diagram illustrating superimposed components of a normalized line-mode traveling wave including a failed phase, a normalized line-mode traveling wave including a non-failed phase, and a reclosing line-mode traveling wave at a failure point according to an embodiment of the present invention;
FIG. 11 is a schematic diagram illustrating wavelet transforms and modulo maxima of a normalized line-mode traveling wave with a failed phase and a normalized line-mode traveling wave with a non-failed phase according to an embodiment of the present invention;
fig. 12 is a schematic diagram illustrating wavelet transformation and modulo maximum of the superimposed components of the reclosing line modal traveling wave at the fault point according to an embodiment of the present invention.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.
An embodiment of the present invention provides a fault location method for a power transmission line, which is suitable for a reclosing device to perform reclosing after a single-phase fault occurs in the power transmission line, and fig. 1 shows a schematic flow chart of the fault location method for the power transmission line according to an embodiment of the present invention. Wherein, the method comprises the following steps:
104, constructing a line mode traveling wave containing a fault phase and a line mode traveling wave consisting of a non-fault phase according to the three-phase voltage traveling wave or the three-phase current traveling wave;
106, determining the superposition component of the reclosing line mode traveling wave at the fault point according to the line mode traveling wave containing the fault phase and the line mode traveling wave consisting of the non-fault phase;
and 108, determining the distance between the fault point and the measuring point according to the superposition component of the reclosing line mode traveling wave at the fault point and the reclosing moment.
In the fault location method for the power transmission line provided by the embodiment, when the power transmission line has a single-phase fault, the reclosing device can automatically execute reclosing operation, after the reclosing device carries out reclosing, collecting a reclosing three-phase voltage traveling wave or a three-phase current traveling wave at a measuring point (a protection safety place), generating line mode traveling waves containing fault phases and line mode traveling waves consisting of non-fault phases according to the three-phase voltage traveling waves or the three-phase current traveling waves, determining the superposed component of the reclosing line mode travelling wave at the fault point, determining the distance between the fault point and the measuring point according to the superposed component of the reclosing line mode travelling wave at the fault point and the reclosing moment, the reclosing line mode traveling wave is a line mode traveling wave of the reclosing device, the line mode traveling wave containing a fault phase is a line mode traveling wave composed of phases containing the fault phase, and the line mode traveling wave composed of a non-fault phase is a line mode traveling wave composed of only the fault phase. By the fault location method, the single-phase earth fault distance of the power transmission line can be quickly and accurately obtained, the line inspection burden is reduced, manpower and material resources are saved, the acceleration of fault maintenance and the recovery of power supply are facilitated, the loss caused by power failure is reduced, the fault location result is not influenced by a line branch point, transition resistance, system operation mode change and load, and the position of a fault point can be accurately determined. Meanwhile, the fault location does not need to additionally install injection equipment, the hardware investment is low, the fault location method is suitable for both voltage traveling waves and current traveling waves, the application range is wide, normal line superposition wave recording data is not needed, the impact on a power grid is small, and the fault location method has good practical performance and economic performance.
Fig. 2 shows a schematic flow chart of a fault location method for a power transmission line according to a further embodiment of the present invention. Wherein, the method comprises the following steps:
208, determining the superposition component of the reclosing line mode traveling wave at the fault point according to the line mode traveling wave containing the fault phase and the line mode traveling wave consisting of the non-fault phase;
and 210, determining the distance between the fault point and the measuring point according to the superposition component of the reclosing line mode traveling wave at the fault point and the reclosing moment.
Preferably, the phase-mode conversion processing is performed on the three-phase voltage or current traveling wave by the following formula, taking the phase-to-ground fault as an example:
Wherein, a phase is fault phase, b and c phases are non-fault phases, YαRepresenting line-mode travelling waves, Y, containing faulted phasesγLine mode travelling wave, U, representing the constitution of a non-faulted phaseaRepresenting a travelling wave, U, of the phase voltage ab、UcRepresents a traveling wave of the voltages of b and c phases, IaRepresents a traveling wave of a-phase current, Ib、IcThe b-phase current traveling wave and the c-phase current traveling wave are shown, respectively.
In this embodiment, as shown in fig. 8 and 9, when a single-phase ground fault occurs in the power transmission line, a fault phase and a non-fault phase are determined by performing fault phase selection on a three-phase voltage traveling wave or a three-phase current traveling wave, taking an a-phase ground fault as an example, that is, the a-phase is a fault phase, and the b-phase and c-phase are non-fault phases, and performing phase-mode conversion processing on the three-phase voltage traveling wave or the three-phase current traveling wave according to a result of the fault phase selection to obtain a line-mode traveling wave including the fault phase and a line-mode traveling wave including the non-fault phase, so as to determine a superimposed component of the reclosing line-mode traveling wave at the fault point subsequently according to the line-mode traveling wave including the fault phase and the line-mode traveling wave including the non-fault phase, thereby calculating a distance of the fault point, reducing a burden of line patrol, saving manpower and material resources, facilitating acceleration of fault, the distance measurement method provided by the embodiment is applicable to both voltage traveling waves and current traveling waves, the traveling wave electrical quantity for fault distance measurement can be freely selected according to the installation condition of a field transformer and the engineering requirement, and the application range is wide, wherein a line mode network containing a fault phase is shown in fig. 4, and a line mode network consisting of a non-fault phase is shown in fig. 5.
In the specific embodiment, the phase-mode conversion is performed by using the Karenbauer (Kerenbel) conversion, so that three-phase decoupling is realized.
Fig. 3 shows a schematic flow chart of a fault location method for a power transmission line according to a further embodiment of the present invention. Wherein, the method comprises the following steps:
step 302, collecting a reclosing three-phase voltage traveling wave or a three-phase current traveling wave at a measuring point;
308, respectively carrying out normalization processing on the line mode traveling wave containing the fault phase and the line mode traveling wave consisting of the non-fault phase according to the first mode maximum value of the line mode traveling wave containing the fault phase and the first mode maximum value of the line mode traveling wave consisting of the non-fault phase;
and step 312, determining the distance between the fault point and the measuring point according to the superposition component of the reclosing line mode traveling wave at the fault point and the reclosing time.
Preferably, the line mode travelling wave containing the fault phase and the line mode travelling wave composed of the non-fault phase are respectively subjected to wavelet transformation by the following formula:
wherein f (n) represents data points of the line mode traveling wave containing the fault phase or the line mode traveling wave consisting of the non-fault phase, n is a sampling point,
representing the approximation component of the j-th scale,
wavelet components of a j-th scale are represented, h (k), g (k) represent filter parameters, j is a scale degree, k is a data point, and eta is a construction coefficient.
Preferably, the wavelet transformed modulus maxima are determined by the following formula:
wherein the content of the first and second substances,
modulus maximum, n, representing the wavelet transform of the j-th scalekRepresenting the kth point data in the current scale,
the wavelet component of the j-th scale representing the kth point data in the current scale.
Preferably, the line mode traveling wave including the fault phase and the line mode traveling wave including the non-fault phase are normalized by the following formula:
wherein, YαRepresenting line-mode travelling waves, M, containing faulted phasesαRepresenting the first modal maximum, Y, of a line-mode travelling wave containing a faulted phaseγLine mode travelling wave, M, representing the constitution of a non-faulted phaseγRepresenting the first modal maximum of the line-mode traveling wave formed by the non-faulted phase,
represents the normalized line mode traveling wave containing the fault phase,
and expressing the line mode travelling wave formed by the normalized non-fault phase.
And calculating the superposition component only reflecting the fault point information according to the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave consisting of the non-fault phase.
Preferably, the superimposed component of the reclosing line mode travelling wave at the fault point is determined by the following formula:
wherein the content of the first and second substances,
showing the superimposed components of the reclosing line mode travelling wave at the fault point,
represents the normalized line mode traveling wave containing the fault phase,
and expressing the line mode travelling wave formed by the normalized non-fault phase.
In this embodiment, since the amplitude of the line-mode traveling wave including the faulty phase after the phase-mode conversion is different from the amplitude of the line-mode traveling wave including the non-faulty phase, therefore, as shown in fig. 10 and fig. 11, the line mode traveling wave including the faulty phase and the line mode traveling wave including the non-faulty phase are respectively subjected to wavelet transformation to obtain a first modulus maximum value after wavelet transformation, and then the line mode traveling wave including the faulty phase and the line mode traveling wave including the non-faulty phase are subjected to normalization processing according to the first modulus maximum value, according to the superposition principle, the superposition component only reflecting the fault point information is obtained through the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave consisting of the non-fault phase, therefore, in the ranging process, normal line coincident wave recording data, data storage and data alignment are not needed, and switching-on impact on a power grid is reduced, wherein a fault point superposition component network is shown in fig. 6.
In one embodiment of the present invention, preferably, the distance between the fault point and the measurement point is determined by the following formula:
where x denotes the distance between the fault point and the measurement point, t1Indicating the reclosing time, t2And v represents the linear mode wave speed of the three-phase voltage traveling wave or the three-phase current traveling wave.
According to the technical scheme, the accurate distance between the fault point and the measuring point can be calculated according to the reclosing time, the time corresponding to the first mode maximum value of the superposition component of the reclosing line mode traveling wave at the fault point, namely the arrival time of the first fault point reflected wave and the wave speed of the line mode traveling wave. Thereby can pinpoint the fault point fast, alleviate the burden of patrolling the line, be favorable to troubleshooting with higher speed and resume the power supply, reduce the loss that the power failure brought, and the fault location result does not receive the influence of circuit branch point, transition resistance, system operation mode change and load, and simultaneously, fault location need not additionally install injection apparatus, and the hardware investment is few, all is suitable for to voltage travelling wave and electric current travelling wave, and application scope is extensive, and need not normal circuit coincidence record ripples data, and it is little to the electric wire netting impact, has good practicality and economic performance.
In an embodiment of the present invention, a Power Systems Computer Aided Design (PSCAD) is used to perform simulation research on an electric Power system, where the simulation system uses a T-junction high-voltage transmission line model with a voltage level of 220kV shown in fig. 7, M, N, P is a three-terminal Power supply, S is a measurement point of an M terminal, T is a line branch point, i.e., a wave impedance discontinuity point, F is a fault point, R is a transition resistor, a single-phase ground fault occurs in a line, the type and parameters of the line are shown in table 1, and the Power supply parameters of the line are shown in table 2.
Table 1 simulation line parameters
| Line | Line model | Line length (km) |
| LMT | GL/GIA-300/40 | 60 |
| LNT | GL/GIA-300/40 | 50 |
| LPT | GL/GIA-300/40 | 40 |
TABLE 2 Power supply parameters
A phase-to-ground fault occurs at a position 70km away from the end M of the line MN, and the transition resistance is 20 omega. Three-phase voltage original traveling wave U acquired by measuring point by taking reclosing moment as starting pointa、Ub、UcAs shown in fig. 8. And performing fault phase selection on the three-phase voltage, determining a fault phase and a non-fault phase, and performing phase-mode conversion on the three-phase voltage to obtain a line-mode traveling wave which corresponds to the three-phase voltage traveling wave and comprises the fault phase and a line-mode traveling wave which consists of the non-fault phase, as shown in fig. 9.
The line mode traveling wave containing fault phase and the line mode traveling wave formed by non-fault phase are respectively subjected to wavelet transformation by the following formula,
wherein f (n) represents data points of the line mode traveling wave containing the fault phase or the line mode traveling wave consisting of the non-fault phase, n is a sampling point,
representing the approximation component of the j-th scale,
wavelet components of a j-th scale are represented, h (k), g (k) represent filter parameters, j is a scale degree, k is a data point, and eta is a construction coefficient.
And the mode maximum value of the line mode traveling wave containing the fault phase and the line mode traveling wave composed of the non-fault phase after the wavelet transformation is calculated by the following formula, as shown in FIG. 11,
wherein the content of the first and second substances,
modulus maximum, n, representing the wavelet transform of the j-th scalekRepresenting the kth point data in the current scale,
the wavelet component of the j-th scale representing the kth point data in the current scale.
Then, according to the following formula, normalizing the line mode traveling wave containing the fault phase and the line mode traveling wave composed of the non-fault phase, and calculating the reclosing superposition component according to the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave composed of the non-fault phase, as shown in fig. 10,
wherein, YαRepresenting line-mode travelling waves, M, containing faulted phasesαRepresenting the first modal maximum, Y, of a line-mode travelling wave containing a faulted phaseγLine mode travelling wave, M, representing the constitution of a non-faulted phaseγRepresenting the first modal maximum of the line-mode traveling wave formed by the non-faulted phase,
represents the normalized line mode traveling wave containing the fault phase,
and expressing the line mode travelling wave formed by the normalized non-fault phase.
Calculating the superposed component of the reclosing line mode travelling wave at the fault point by the following formula:
wherein the content of the first and second substances,
showing the superimposed components of the reclosing line mode travelling wave at the fault point,
represents the normalized line mode traveling wave containing the fault phase,
and expressing the line mode travelling wave formed by the normalized non-fault phase.
In addition, in order to facilitate the comparative examination of the fault amount, the wavelet transformation is performed on the superposed component of the reclosing line mode travelling wave at the fault point, as shown in fig. 12.
Finally the distance between the fault point and the measuring point is determined by the following formula,
where x denotes the distance between the fault point and the measurement point, t1Indicating the reclosing time, t2And v represents the linear mode wave speed of the three-phase voltage traveling wave or the three-phase current traveling wave.
The distance measurement result obtained by the embodiment is 69.84km, the true value of the fault distance is 70km, the absolute error is 160m, the relative error is 0.2286%, the error of the fault distance measurement result is small, and the positioning is accurate.
In another embodiment of the present invention, to verify the performance of the ranging method, the fault ranging result is shown in table 3 for different locations and different transition resistances on the line MN.
TABLE 3 ranging results
The simulation experiment proves that the fault location method is not affected by the transition resistance, has high reliability, has the location error less than 0.5km, and can accurately and effectively determine the position of the fault point.
In the description herein, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance unless explicitly stated or limited otherwise; the terms "connected," "mounted," "secured," and the like are to be construed broadly and include, for example, fixed connections, removable connections, or integral connections; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A fault location method of a power transmission line is suitable for reclosing of a reclosing device after the power transmission line has a single-phase fault, and is characterized by comprising the following steps:
collecting the reclosing three-phase voltage traveling wave or the three-phase current traveling wave at a measuring point;
constructing a line mode traveling wave containing a fault phase and a line mode traveling wave consisting of a non-fault phase according to the three-phase voltage traveling wave or the three-phase current traveling wave;
determining the superposition component of the reclosing line mode traveling wave at the fault point according to the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase;
and determining the distance between the fault point and the measuring point according to the superimposed component of the reclosing line mode traveling wave at the fault point and the reclosing time.
2. The method according to claim 1, wherein the step of constructing a line mode traveling wave including a failed phase and a line mode traveling wave including a non-failed phase according to the three-phase voltage traveling wave or the three-phase current traveling wave specifically comprises:
performing fault phase selection on the three-phase voltage traveling wave or the three-phase current traveling wave, and determining a fault phase and a non-fault phase of the power transmission line;
and carrying out phase-mode conversion processing on the three-phase voltage traveling wave or the three-phase current traveling wave according to the fault phase and the non-fault phase to obtain the line-mode traveling wave containing the fault phase and the line-mode traveling wave formed by the non-fault phase.
3. The method of fault location of an electric transmission line according to claim 2,
and carrying out phase-mode conversion processing on the three-phase voltage traveling wave or the three-phase current traveling wave by using the following formula, taking a phase-to-ground short circuit as an example:
Wherein, the phase a is the fault phase, the phases b and c are the non-fault phases, YαRepresenting said line-mode travelling wave, Y, containing a faulty phaseγRepresenting line mode travelling waves, U, of said non-faulted phaseaRepresenting a travelling wave, U, of the phase voltage ab、UcRepresents a traveling wave of the voltages of b and c phases, IaRepresents a traveling wave of a-phase current, Ib、IcThe b-phase current traveling wave and the c-phase current traveling wave are shown, respectively.
4. The method according to claim 1, wherein the step of determining the superimposed component of the reclosing line mode traveling wave at the fault point according to the line mode traveling wave including the faulty phase and the line mode traveling wave including the non-faulty phase specifically comprises:
respectively carrying out normalization processing on the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase;
and determining the superposition component of the reclosing line mode traveling wave at the fault point according to the normalized line mode traveling wave containing the fault phase and the normalized line mode traveling wave formed by the non-fault phase.
5. The method of fault location of an electric transmission line according to claim 4,
respectively carrying out normalization processing on the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase through the following formula:
wherein, YαRepresenting said line-mode travelling wave containing a faulty phase, MαRepresenting the first modal maximum, Y, of the line-mode travelling wave containing the faulted phaseγLine mode travelling wave, M, representing the composition of said non-faulted phaseγRepresenting the first modal maximum of the line-mode travelling wave formed by said non-faulted phase,
representing the normalized line mode travelling wave containing the fault phase,
and representing the normalized line mode travelling wave formed by the non-fault phase.
6. The method of fault location of an electric transmission line according to claim 4,
determining the superposed component of the reclosing line mode travelling wave at the fault point by the following formula:
wherein the content of the first and second substances,
showing the superimposed component of the reclosing line mode travelling wave at the fault point,
representing the normalized line mode travelling wave containing the fault phase,
and representing the normalized line mode travelling wave formed by the non-fault phase.
7. The method according to claim 5, wherein before the step of normalizing the line-mode traveling wave including the faulty phase and the line-mode traveling wave including the non-faulty phase, the method further comprises:
and respectively carrying out wavelet transformation on the line mode traveling wave containing the fault phase and the line mode traveling wave consisting of the non-fault phase to obtain a first modulus maximum value of the line mode traveling wave containing the fault phase and a first modulus maximum value of the line mode traveling wave consisting of the non-fault phase.
8. The method of fault location of an electric transmission line according to claim 7,
respectively carrying out wavelet transformation on the line mode traveling wave containing the fault phase and the line mode traveling wave formed by the non-fault phase through the following formula:
wherein f (n) represents the line mode travelling wave containing the fault phase or the line mode travelling wave consisting of the non-fault phase, n is a sampling point,
representing the approximation component of the j-th scale,
wavelet components of a j-th scale are represented, h (k), g (k) represent filter parameters, j is a scale degree, k is a data point, and eta is a construction coefficient.
9. The method of fault location of an electric transmission line according to claim 8,
determining a modulus maximum after wavelet transform by the following formula:
wherein the content of the first and second substances,
modulus maximum, n, representing the wavelet transform of the j-th scalekRepresenting the kth point data in the current scale,
the wavelet component of the j-th scale representing the kth point data in the current scale.
10. Method for fault location of an electric transmission line according to one of claims 1 to 9,
determining a distance between the fault point and the measurement point by the following formula:
wherein x represents the distance between the fault point and the measurement point, t1Indicating the reclosing time, t2And v represents the time corresponding to the first mode maximum value of the superposed component of the reclosing line mode traveling wave at the fault point, and the line mode wave speed of the three-phase voltage traveling wave or the three-phase current traveling wave.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910780586.0A CN110456228B (en) | 2019-08-22 | 2019-08-22 | Fault location method for power transmission line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910780586.0A CN110456228B (en) | 2019-08-22 | 2019-08-22 | Fault location method for power transmission line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110456228A CN110456228A (en) | 2019-11-15 |
| CN110456228B true CN110456228B (en) | 2021-01-29 |
Family
ID=68488647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910780586.0A Active CN110456228B (en) | 2019-08-22 | 2019-08-22 | Fault location method for power transmission line |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110456228B (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3462646A (en) * | 1967-06-23 | 1969-08-19 | Gen Electric | Circuit breaker with high speed circuit restoring means |
| CN103207351B (en) * | 2013-03-12 | 2015-09-30 | 西安工程大学 | A kind of power transmission line fault locating method based on reclosing |
| CN103809082B (en) * | 2014-02-17 | 2016-06-22 | 四川大学 | A kind of distance-finding method of the one-phase earthing failure in electric distribution network based on the sudden change of line line ripple |
| CN106841913B (en) * | 2017-01-13 | 2020-07-07 | 清华大学 | Distribution line fault location method |
| CN106841914B (en) * | 2017-01-13 | 2020-07-07 | 清华大学 | Fault distance measuring device of distribution line |
| CN208386118U (en) * | 2018-06-25 | 2019-01-15 | 国网江苏省电力有限公司 | A kind of transmission line of electricity self-adapting automatic recloser |
-
2019
- 2019-08-22 CN CN201910780586.0A patent/CN110456228B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110456228A (en) | 2019-11-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101188354B (en) | Test simulation method for failure line selection of small current ground system | |
| US20150073735A1 (en) | Method for adaptive fault location in power system networks | |
| CN102590703B (en) | Single-phase grounding failure route selection method of resonance grounding system based on zero-sequence transient charge | |
| CN106841913B (en) | Distribution line fault location method | |
| CN105738769B (en) | Series compensation double line down localization method based on distributed parameter model | |
| CN106054023A (en) | Method for estimating system impedances at two sides in single-ended range finding of power transmission line | |
| CN104865498A (en) | Parameter identification-based arc suppression coil grounding system single-phase grounding fault location technology | |
| CN103018632A (en) | Small current grounding system single-phase ground fault line selection method based on fisher information | |
| CN110456226B (en) | Fault location system of power transmission line | |
| CN103941149A (en) | Fault location method for electrified railway traction network | |
| CN110456227B (en) | Single-ended traveling wave distance measurement method for distribution line | |
| CN104820133A (en) | Online measurement method for impedance parameter of three-phase asymmetric power transmission line | |
| CN111381130A (en) | T-connection line fault positioning method and system considering traveling wave velocity | |
| CN111308271B (en) | Fault distance measuring method for high-voltage direct-current transmission line | |
| CN105116294A (en) | Traveling wave polarity measure based power distribution network cable fault monitoring method | |
| CN110456228B (en) | Fault location method for power transmission line | |
| CN113358979B (en) | Phase selection method and phase selection device for single-phase disconnection fault of power distribution network | |
| CN110456229B (en) | Single-ended traveling wave distance measuring device of distribution line | |
| CN105548783A (en) | Precise measurement method for zero-sequence parameters of four power transmission lines on same ultrahigh-voltage alternating-current tower | |
| CN104865452A (en) | Harmonic-component-based anti-interference capacitance measurement method for untransposed transmission line | |
| CN112363009B (en) | Single-ended fault location method and system for same-tower line ground fault | |
| CN112083282B (en) | New energy station outgoing line fault location method based on electromagnetic time reversal method | |
| CN114089117A (en) | Power distribution network fault location method and device based on double-end traveling wave method | |
| CN113640615A (en) | Small current ground fault line selection method based on evidence combined transient state information | |
| Zhang et al. | Longitudinal protection method based on voltage waveform comparison for AC/DC hybrid system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | 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 |