CN109375030A - High-voltage overhead line disconnection fault identification method and device - Google Patents
High-voltage overhead line disconnection fault identification method and device Download PDFInfo
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- 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
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- G—PHYSICS
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- 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
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Abstract
The embodiment of the application provides a method and a device for identifying a broken line fault of a high-voltage overhead line, wherein the method comprises the steps of obtaining a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line; according to the three-phase voltage value, acquiring the measured voltage difference of two ends of the high-voltage overhead line at the same moment according to the single phase; according to the three-phase current value and the high-voltage overhead line model parameters, the calculated voltage difference of two ends of the high-voltage overhead line at the same moment is obtained according to a single phase, so that a plurality of vector groups with the measured voltage difference and the calculated voltage difference are formed; obtaining correlation coefficients of the vector groups according to the vector groups; and judging whether the high-voltage overhead line of the high-voltage overhead line has a broken line fault according to the correlation coefficient, so that the high-voltage overhead line of the high-voltage overhead line can be quickly judged.
Description
Technical Field
The invention relates to the field of relay protection of power systems, in particular to a method and a device for identifying a disconnection fault of a high-voltage overhead line.
Background
At present, high-voltage overhead lines and buildings, traffic lines and the like are crossed and spanned more, and after a line breaking fault occurs, if the high-voltage overhead lines fall to the ground in a charged state, personal injury, shutdown of an electrified railway and other safety accidents are easily caused. Therefore, after a disconnection fault occurs, the fault high-voltage overhead line is required to be identified and cut off before the fault high-voltage overhead line falls to the ground, so that more serious damage caused by the falling of the fault high-voltage overhead line is avoided.
Because the occurrence probability of the high-voltage overhead line disconnection fault is small, and the disconnection fault characteristic is light, the research in the related direction is insufficient at present, and the practicability of the provided method is not strong.
Disclosure of Invention
The embodiment of the application provides a method and a device for identifying a high-voltage overhead line disconnection fault, which can realize the rapid judgment of the high-voltage overhead line disconnection fault.
A method for identifying a broken line fault of a high-voltage overhead line comprises the steps of obtaining a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line;
according to the three-phase voltage value, acquiring the measured voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase;
according to the three-phase current value and the high-voltage overhead line model parameter, acquiring the calculated voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase to form a plurality of vector groups with the measured voltage difference and the calculated voltage difference;
obtaining correlation coefficients of the vector groups according to the vector groups;
and judging whether the high-voltage overhead line has a broken line fault according to the correlation coefficient.
In one embodiment, the obtaining the measured voltage difference of the two ends of the high-voltage overhead line at the same time according to the three-phase voltage value in a single phase includes:
carrying out low-pass filtering processing on the three-phase voltage value to obtain a three-phase filtering voltage value;
according to the three-phase filtering voltage value, acquiring the measured voltage values of the two ends of the high-voltage overhead line at the same moment for each phase;
and acquiring the measurement voltage difference according to the measurement voltage values of the two ends of the high-voltage overhead line at the same moment.
In one embodiment, the measured voltage difference is based on a formulaObtaining;
wherein,respectively representing a first phase, a second phase and a third phase of the high-voltage overhead line, t being the sampling moment,is the instantaneous value of the measured voltage at the moment t, m and n are two ends of the high-voltage overhead line respectively,representing the instantaneous value of the measured voltage at the m end of the high-voltage overhead line at the moment t,and represents the instantaneous value of the measured voltage at the n end of the high-voltage overhead line at the time t.
In one embodiment, obtaining the calculated voltage difference of the two ends of the high-voltage overhead line at the same time according to the three-phase current value and the high-voltage overhead line model parameter by a single phase includes:
carrying out low-pass filtering processing on the three-phase current value to obtain a three-phase filtering current value;
and acquiring the calculated voltage difference according to the three-phase filtering current value and the high-voltage overhead line model parameter.
In one of themIn the embodiment, the calculated voltage difference is obtained according to the three-phase filtering current value and the high-voltage overhead line model parameter and is obtained according to a formulaAcquiring the calculated voltage difference;
wherein,is the calculated voltage difference at time t,is the three-phase filtered current value at time t,is thatRepresents the calculated voltage difference calculated from the high voltage overhead line model parameters.
In one embodiment, the high voltage overhead line model parameters include a length of the high voltage overhead line, a self resistance per unit length of the high voltage overhead line, a mutual resistance, a self inductance, and a mutual inductance.
In one embodiment, the acquiring three-phase voltage values and three-phase current values at two ends of the high-voltage overhead line comprises:
acquiring the three-phase voltage value and the three-phase current value of two ends of the high-voltage overhead line at the same moment;
and acquiring a plurality of three-phase voltage values and a plurality of three-phase current values according to a preset sampling frequency in a preset time.
In one embodiment, the determining whether the high-voltage overhead line has a disconnection fault according to the correlation coefficient includes:
if the correlation coefficient calculation result is larger than the setting value, judging that the high-voltage overhead line has no disconnection fault; and if the correlation coefficient calculation result is smaller than the setting value, judging that the output high-voltage overhead line has a line break fault.
In one embodiment, according to a formulaObtaining the correlation coefficient;
where p is a correlation coefficient of the measured voltage difference vector and the calculated voltage difference vector,for the purpose of said measuring the voltage difference,for said calculated voltage difference, t0And T is the preset time when the disconnection fault occurs.
The application still provides a high-voltage overhead line broken string fault recognition device, the device includes:
the first acquisition module is used for acquiring a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line;
the second acquisition module is used for acquiring the measured voltage difference of the two ends of the high-voltage overhead line at the same moment according to the three-phase voltage value and the single phase;
a third obtaining module, configured to obtain, according to the three-phase current value and the high-voltage overhead line model parameter, a calculated voltage difference at the same time at two ends of the high-voltage overhead line for each phase, so as to form a plurality of vector groups having the measured voltage difference and the calculated voltage difference;
the analysis module is used for acquiring correlation coefficients of the vector groups according to the vector groups;
and the judging module is used for judging whether the high-voltage overhead line has a broken line fault according to the correlation coefficient.
According to the method for identifying the disconnection fault of the high-voltage overhead line, a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line are obtained; according to the three-phase voltage value, acquiring the measured voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase; according to the three-phase current value and the high-voltage overhead line model parameter, acquiring the calculated voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase to form a plurality of vector groups with the measured voltage difference and the calculated voltage difference; obtaining correlation coefficients of the vector groups according to the vector groups; and judging whether the high-voltage overhead line has a disconnection fault according to the correlation coefficient, so that the high-voltage overhead line disconnection fault can be quickly judged.
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In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic structural diagram of an electrical power system provided by an embodiment of the present application;
fig. 2 is a flowchart of a method for identifying a disconnection fault of a high-voltage overhead line according to an embodiment of the present application;
fig. 3 is a block diagram of a high-voltage overhead line disconnection fault recognition apparatus according to an embodiment of the present application;
fig. 4 shows that the power system provided by the embodiment of the application has a single-phase disconnection fault f at a forward 30% distance of the first relay protection device1Then, calculating correlation coefficient curve graphs at two ends of the high-voltage overhead line;
fig. 5 shows that a single-phase disconnection fault f occurs at a reverse outlet of a second relay protection device in the power system provided by the embodiment of the application2And (4) a correlation coefficient curve graph calculated at two ends of the high-voltage overhead line.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first client may be referred to as a second client, and similarly, a second client may be referred to as a first client, without departing from the scope of the present application. Both the first client and the second client are clients, but they are not the same client. In the description of the embodiments of the present application, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. In the description of the embodiments of the present application, "a plurality" means at least one, e.g., one, two, etc., unless specifically defined otherwise.
Fig. 1 is a schematic diagram of a power system structure provided in an embodiment of the present invention, and as shown in fig. 1, the power system structure includes: the protection device comprises a first equivalent power source (1), a first bus (2), a protected line (3), a second bus (4), a second equivalent power source (5), a first relay protection device (6) and a second relay protection device (7), wherein the first equivalent power source (1) is connected with the first bus (2), the first bus (2) is connected with the second bus (4) through the protected line (3), and the second bus (4) is connected with the second equivalent power source (5); the first relay protection device (6) is arranged at the outlet of the first bus (2),a second relay protection device (7) is arranged at the outlet of the second bus (4), f1Represents a distance f of 30% of the first relay protection device (6) in the forward direction2Showing the reverse outlet of the second relay protection device (7).
Fig. 2 is a flowchart of a method for identifying a disconnection fault of a high-voltage overhead line according to an embodiment of the present invention, where the method for identifying a disconnection fault of a high-voltage overhead line in one embodiment includes steps 210 to 250.
And step 210, acquiring a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line.
Specifically, a three-phase voltage value and a three-phase current value of two ends of a high-voltage overhead line at the same moment are obtained; and acquiring a plurality of three-phase voltage values and a plurality of three-phase current values according to a preset sampling frequency within a preset time. Specifically, the three-phase voltage value and the three-phase current value at the installation place of the relay protection devices at both ends of the high-voltage overhead wire may be acquired, for example, the three-phase voltage value and the three-phase current value acquired at the first relay protection device (6) are taken as the three-phase voltage value and the three-phase current value at one end of the high-voltage overhead wire, and the three-phase voltage value and the three-phase current value acquired at the second relay protection device (7) are taken as the three-phase voltage value and the three-phase current value at the other end of the high. Collecting three-phase voltage values and three-phase current values at a first relay protection device (6) and a second relay protection device (7) at the same time; and acquiring a plurality of three-phase voltage values and a plurality of three-phase current values according to a preset sampling frequency within a preset time.
In one embodiment, the preset time and the preset sampling frequency are selected according to actual situations, and the embodiment is not limited. In one embodiment, the predetermined sampling frequency is 24 points/cycle. The cycle, i.e. the time for the alternating current to complete one complete change (i.e. one sinusoidal waveform), is one cycle for each time it takes to complete one cycle of change.
Firstly, three-phase voltage values and three-phase current values of two ends of a high-voltage overhead line at the same moment are obtained, and then a plurality of three-phase voltage values and a plurality of three-phase current values within preset time are obtained according to preset sampling frequencyA plurality of three-phase current values. E.g. at t0The three-phase voltage value and the three-phase current value at two ends of the high-voltage overhead line are collected constantly, 24 three-phase voltage values and 24 three-phase current values are collected in one period according to preset sampling frequency, 2 cycles can be obtained after preset time, and the collected 48 three-phase voltage values and the corresponding 48 three-phase current values serve as the three-phase voltage values and the three-phase current values at two ends of the high-voltage overhead line.
And step 220, acquiring the measured voltage difference of the two ends of the high-voltage overhead line at the same moment according to the three-phase voltage value and the single phase.
In one embodiment, low-pass filtering is carried out on the three-phase voltage value to obtain a three-phase filtering voltage value; according to the three-phase filtering voltage value, acquiring the measured voltage values of the two ends of the high-voltage overhead line at the same moment for each phase; and acquiring a measurement voltage difference according to the measurement voltage value.
In one embodiment, the measured voltage difference is based on a formulaObtaining; wherein,respectively representing a first phase, a second phase and a third phase of the high-voltage overhead line, t being the sampling moment,is the instantaneous value of the measured voltage at the moment t, m and n are two ends of the high-voltage overhead line respectively,representing the instantaneous value of the measured voltage at the m end of the high-voltage overhead line at the moment t,and represents the instantaneous value of the measured voltage at the n end of the high-voltage overhead line at the time t.
Taking phase a as an example, at t0Constantly collecting high voltageThe voltage values at two ends of the overhead line are respectively Uam(t0) And Ubm(t0) According to the formula Δ Ua(t0)＝Uam(t0)-Uan(t0) Is obtained at t0The measured voltage difference at time t1Constantly collecting voltage values at two ends of the high-voltage overhead line, wherein the voltage values are respectively Uam(t1) And Ubm(t1) According to the formula Δ Ua(t1)＝Uam(t1)-Uan(t1) Is obtained at t1The measured voltage difference at a time. And analogizing, collecting voltage values of two ends of the high-voltage overhead line at multiple moments after preset time, thereby obtaining measurement voltage differences at multiple moments, and recording the measurement voltage differences as delta U1a。
In the formula, Δ Ua(t0) For high voltage overhead line at t0Measured voltage difference of phase a at time Uam(t0) Is at t0Measuring voltage of a-phase at one end of a high-voltage overhead line at any moment, Uan(t0) Is at t0Measuring voltage of a phase at the other end of the high-voltage overhead line at any moment; delta Ua(t1) For high voltage overhead line at t1Measured voltage difference of phase a at time Uam(t1) Is at t1Measuring voltage of a-phase at one end of a high-voltage overhead line at any moment, Uan(t1) Is at t1And (4) measuring the voltage of the phase a at the other end of the high-voltage overhead line at the moment. The method for obtaining the measured voltage of the phase b and the phase c is similar to that of the phase a, and is not described herein.
And step 230, acquiring the calculated voltage difference of the two ends of the high-voltage overhead line at the same moment according to the three-phase current value and the high-voltage overhead line model parameter to form a plurality of vector groups with the measured voltage difference and the calculated voltage difference.
In one embodiment, low-pass filtering processing is carried out on the three-phase current value to obtain a three-phase filtering current value; and acquiring the calculated voltage values of the two ends of the high-voltage overhead line at the same moment for each phase according to the three-phase filtering current value and the high-voltage overhead line model parameters.
In one embodiment, after the three-phase current value is low-pass filtered, a formula is used according to the three-phase filtered current value obtained after filteringAcquiring a calculated voltage difference; wherein,is the calculated voltage difference at time t,is the three-phase filtered current value at time t,is thatRepresents the calculated voltage difference calculated from the high voltage overhead line model parameters.
Specifically, taking the a-phase calculation method as an example, a differential equation algorithm based on an RL high-voltage overhead line model is adopted to obtain the calculated voltage difference:
in the formula, L is the length of the protected high-voltage overhead line; r issIs a self-resistance per unit length of the high-voltage overhead line, and rs＝(r0+2r1)/300π；rmIs a mutual resistance per unit length of the high voltage overhead line, and rm＝(r0-r1)/300π；lsIs a self-inductance per unit length of the high-voltage overhead line, ands＝(l0-2l1)/300π；lmis a mutual inductance per unit length of the high-voltage overhead line, andm＝(l0-l1)/300π；r0、r1、l0、l1respectively a zero sequence resistance, a positive sequence resistance, a zero sequence inductance and a positive sequence of the unit length of the high-voltage overhead lineAn inductance. I isma(t) is the three-phase filter current value of the a phase at one end of the high-voltage overhead line at the time of t, Imb(t0) Is at t0Three-phase filtering current value I of b-phase at the same end of high-voltage overhead line at momentmc(t0) Is at t0And (4) the three-phase filtering current value of the c phase at the same end of the high-voltage overhead line at the moment.
Calculating the slope between two points by using the difference of the sampling values of two adjacent points, and replacing the differential, namely:
where N is the number of sampling instants and Δ t is the sampling interval.
Meanwhile, averaging sampling values of two adjacent points to obtain a sampling value at the middle moment of the two points, wherein the sampling value corresponds to the slope moment, namely:
the calculation method of the calculated voltage difference between the phases b and c is similar to that of the phase a, and is not described herein again.
And forming a group of vectors with the measured voltage difference and the calculated voltage difference at each moment, and acquiring a plurality of groups of vectors with the measured voltage difference and the calculated voltage difference at a plurality of moments in a preset time. Each vector group corresponds to the measured voltage difference and the calculated voltage difference of the same phase at two ends of the high-voltage overhead line at the same moment, and the same phase can form a plurality of vector groups at different moments. E.g. at t0The a phase may form a vector group at time t1The time instant a phase may form yet another vector group; similarly, at t0The phase b at time t may form a vector group1The time instant b phase may form yet another vector group.
By carrying out low-pass filtering processing on the three-phase voltage value and the three-phase current value, interference signals such as harmonic waves can be filtered out, so that the calculation result can be more accurate, and the accuracy of identifying the broken line fault of the high-voltage overhead line is improved.
Step 240, obtaining a plurality of vector groups to calculate the correlation coefficient of the voltage difference according to the plurality of vector groups.
In one embodiment, each vector group comprises a measured voltage difference and a calculated voltage difference at two ends of the high-voltage overhead line at the same time, and correlation coefficients of the vector groups are obtained for the vector groups of each phase. For example, the first correlation coefficient ρ is obtained from a plurality of vector groups of a-phaseaObtaining a second correlation coefficient rho according to a plurality of vector groups of the phase bbObtaining a third correlation coefficient rho according to a plurality of vector groups of the c phasec。
In one embodiment, according to a formulaObtaining a correlation coefficient; wherein,in order to measure the voltage difference,to calculate the voltage difference, t is the measurement time, t0T is preset time when the disconnection fault occurs.
Specifically, the calculation method of the correlation coefficient is as follows:
where x (t) is the measured voltage difference at time ty (t) is the calculated voltage difference at time tn0Is the start of the data window, nTIs the number of sample points within the data window.
And step 250, judging whether the high-voltage overhead line has a broken line fault according to the correlation coefficient.
In one embodiment, the setting value of the correlation coefficient is set to be psetTuning value rhosetLess than 1, alternatively, 0.5, 0.6, 0.7, etc., and the specific numerical values are not limited. If the correlation coefficient calculation result is larger than the setting value, judging that no disconnection fault occurs in the high-voltage overhead line; and if the calculation result of the correlation coefficient is smaller than the setting value, judging that the phase has the disconnection fault.
Specifically, if the correlation coefficient ρ is greater than the setting value, ρ>ρsetIf the measured voltage difference and the calculated voltage difference at the two ends of the high-voltage overhead line are consistent, judging that no line break fault or an out-of-area line break fault occurs, and protecting the line from action; if the correlation coefficient rho is smaller than the setting value, rho<ρsetNamely, the measured voltage difference and the calculated voltage difference at the two ends of the high-voltage overhead line are not consistent, the occurrence of the disconnection fault in the area is considered, and the action is protected.
For example, if the correlation coefficient of the phase a is greater than the setting value, that is, the measured voltage difference of the phase a is consistent with the measured voltage difference, it is determined that the phase a has no disconnection fault or has an out-of-area disconnection fault, and the protection does not act; and if the correlation coefficient of the phase a is smaller than the setting value, namely the measured voltage difference of the phase a is inconsistent with the measured voltage difference, judging that the phase a has an internal disconnection fault, and protecting the action. And similarly, judging whether the b phase and the c phase have the intra-area disconnection fault or not by calculating the correlation coefficient of the b phase and the c phase.
According to the embodiment of the application, a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of a high-voltage overhead line are obtained; according to the three-phase voltage value, acquiring the measured voltage difference of two ends of the high-voltage overhead line at the same moment according to the single phase; according to the three-phase current value and the high-voltage overhead line model parameters, obtaining the calculated voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase to form a plurality of vector groups with the measured voltage difference and the calculated voltage difference; obtaining correlation coefficients of the vector groups according to the vector groups; and judging whether the high-voltage overhead line has a line break fault according to the correlation coefficient, so that the high-voltage overhead line can be quickly judged.
It should be understood that, although the steps in the flowchart of fig. 2 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 2 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
Fig. 3 is a flowchart of a high-voltage overhead line disconnection fault identification device according to an embodiment of the present invention, where the device is used in a high-voltage overhead line disconnection fault identification method. As shown in fig. 3, the apparatus includes: a first obtaining module 310, a second obtaining module 320, a third obtaining module 330, an analyzing module 340, and a determining module 350.
The first obtaining module 310 is configured to obtain a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line;
the second obtaining module 320 is configured to obtain, according to the three-phase voltage value, a measured voltage difference at the same time at two ends of the high-voltage overhead line according to a single phase;
a third obtaining module 330, configured to obtain, according to the three-phase current value and the high-voltage overhead line model parameter, a calculated voltage difference at the same time at two ends of the high-voltage overhead line for each phase, so as to form a plurality of vector groups having the measured voltage difference and the calculated voltage difference;
an analyzing module 340, configured to obtain correlation coefficients of a plurality of vector groups according to the plurality of vector groups;
and the judging module 350 is configured to judge whether the high-voltage overhead line has a line break fault according to the correlation coefficient.
The high-voltage overhead line disconnection fault recognition device acquires a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line; according to the three-phase voltage value, acquiring the measured voltage difference of two ends of the high-voltage overhead line at the same moment according to the single phase; according to the three-phase current value and the high-voltage overhead line model parameters, obtaining the calculated voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase to form a plurality of vector groups with the measured voltage difference and the calculated voltage difference; obtaining correlation coefficients of the vector groups according to the vector groups; and judging whether the high-voltage overhead line has a line break fault according to the correlation coefficient, so that the high-voltage overhead line can be quickly judged.
The division of each module in the high-voltage overhead line disconnection fault recognition device is only used for illustration, and in other embodiments, the high-voltage overhead line disconnection fault recognition device may be divided into different modules as needed to complete all or part of the functions of the high-voltage overhead line disconnection fault recognition device.
For specific limitations of the high-voltage overhead line disconnection fault identification device, reference may be made to the above limitations of the high-voltage overhead line disconnection fault identification method, and details are not described here. All or part of each module in the high-voltage overhead line disconnection fault identification device can be realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
Fig. 4 shows that the power system provided by the embodiment of the invention has a single-phase disconnection fault (f in fig. 1) at a distance of 30% in the forward direction of the first relay protection device (6)1In department), two high-voltage overhead linesEnd calculated correlation coefficient plot.
As is apparent from fig. 4, the second correlation coefficient ρbAnd a third phase relation number pcAre all 1, first correlation coefficient rhoaAfter 0.5s, gradually decreasing from 1 to-1 due to the setting value rhosetA number greater than 0 and smaller than 1, the second correlation number ρbAnd a third phase relation number pcAre all larger than a setting value and have a first correlation coefficient rhoaLess than setting value rhosetTherefore, the single-phase disconnection fault of the phase a in the high-voltage overhead line area is judged.
Fig. 5 shows that the single-phase disconnection fault (f in fig. 1) occurs at the reverse outlet of the second relay protection device (7) in the power system provided by the embodiment of the invention2Point), the correlation coefficient curve calculated at both ends of the high-voltage overhead line.
As is apparent from fig. 5, the first correlation coefficient ρaSecond correlation number ρbAnd a third phase relation number pcAre all 1, due to the setting value rhosetA number greater than 0 and smaller than 1, the first correlation coefficient ρaSecond correlation number ρbAnd a third phase relation number pcAll are larger than the setting value, so that the condition that the intra-area disconnection fault of the high-voltage overhead line does not occur is judged.
As can be seen from fig. 4 and 5, the method provided by the embodiment of the invention can effectively judge the disconnection fault of the high-voltage overhead line.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A high-voltage overhead line disconnection fault identification method is characterized by comprising the following steps:
acquiring a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of a high-voltage overhead line;
according to the three-phase voltage value, acquiring the measured voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase;
according to the three-phase current values and the high-voltage overhead line model parameters, acquiring the calculated voltage difference of two ends of the high-voltage overhead line at the same moment according to a single phase to form a plurality of vector groups with the measured voltage difference and the calculated voltage difference;
obtaining correlation coefficients of the vector groups according to the vector groups;
and judging whether the high-voltage overhead line has a broken line fault according to the correlation coefficient.
2. The method of claim 1, wherein the obtaining the measured voltage difference of the two ends of the high-voltage overhead line at the same moment in time by a single phase according to the three-phase voltage values comprises:
carrying out low-pass filtering processing on the three-phase voltage value to obtain a three-phase filtering voltage value;
according to the three-phase filtering voltage value, acquiring the measured voltage values of the two ends of the high-voltage overhead line at the same moment for each phase;
and acquiring the measurement voltage difference according to the measurement voltage value.
3. The method of claim 2, wherein the measured voltage difference is according to the formula
Obtaining;
wherein,b. c, respectively representing a first phase, a second phase and a third phase of the high-voltage overhead line, t being a sampling moment,is the instantaneous value of the measured voltage at the moment t, m and n are two ends of the high-voltage overhead line respectively,representing the instantaneous value of the measured voltage at the m end of the high-voltage overhead line at the moment t,and represents the instantaneous value of the measured voltage at the n end of the high-voltage overhead line at the time t.
4. The method of claim 1, wherein the obtaining the calculated voltage difference across the high voltage overhead line at the same time for a single phase based on the three phase current values and the high voltage overhead line model parameters comprises:
carrying out low-pass filtering processing on the three-phase current value to obtain a three-phase filtering current value;
and acquiring the calculated voltage values of the two ends of the high-voltage overhead line at the same time for each phase according to the three-phase filtering current value and the high-voltage overhead line model parameter.
5. The method of claim 1, wherein obtaining the calculated voltage difference based on the three-phase filtered current value and a model parameter of the high-voltage overhead line is based on a formula
Acquiring the calculated voltage difference;
wherein,is the calculated voltage difference at time t,is the three-phase filtered current value at time t,is thatRepresents the calculation of said calculated voltage difference from the parameters of the model of the high-voltage overhead line。
6. The method of claim 5, wherein the high voltage overhead line model parameters include a length of the high voltage overhead line, a self resistance, a mutual resistance, a self inductance, and a mutual inductance per unit length of the high voltage overhead line.
7. The method of claim 1, wherein obtaining a plurality of three-phase voltage values and a plurality of three-phase current values across a high voltage overhead line comprises:
acquiring the three-phase voltage value and the three-phase current value of two ends of the high-voltage overhead line at the same moment;
and acquiring a plurality of three-phase voltage values and a plurality of three-phase current values according to a preset sampling frequency in a preset time.
8. The method according to claim 1, wherein the determining whether the high voltage overhead line has a disconnection fault according to the correlation coefficient comprises:
if the correlation coefficient calculation result is larger than the setting value, judging that the high-voltage overhead line has no disconnection fault; and if the correlation coefficient calculation result is smaller than the setting value, judging that the high-voltage overhead line has a line breaking fault.
9. The method of claim 8, wherein the method is based on a formula
Obtaining the correlation coefficient;
wherein p is a correlation coefficient of the measured voltage difference vector and the calculated voltage difference vector,for the purpose of said measuring the voltage difference,for said calculated voltage difference, t0T is preset time when the disconnection fault occurs.
10. A high voltage overhead line disconnection fault identification device, the device comprising:
the first acquisition module is used for acquiring a plurality of three-phase voltage values and a plurality of three-phase current values at two ends of the high-voltage overhead line;
the second acquisition module is used for acquiring the measured voltage difference of the two ends of the high-voltage overhead line at the same moment according to the three-phase voltage value and the single phase;
a third obtaining module, configured to obtain, according to the three-phase current value and the high-voltage overhead line model parameter, a calculated voltage difference at the same time at two ends of the high-voltage overhead line for each phase, so as to form a plurality of vector groups having the measured voltage difference and the calculated voltage difference;
the analysis module is used for acquiring correlation coefficients of the vector groups according to the vector groups;
and the judging module is used for judging whether the high-voltage overhead line has a broken line fault according to the correlation coefficient.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110676825A (en) * | 2019-11-28 | 2020-01-10 | 国网江苏省电力有限公司镇江供电分公司 | Circuit disconnection protection method based on voltage vector difference and backup power automatic switching and application |
| CN110676826A (en) * | 2019-11-28 | 2020-01-10 | 国网江苏省电力有限公司镇江供电分公司 | Line disconnection protection method for comparing vector difference of voltages at two sides of line and application |
| CN116087693A (en) * | 2023-04-13 | 2023-05-09 | 昆明理工大学 | LCC-HVDC power transmission line single-ended distance measurement method and system |
| CN117706281A (en) * | 2024-02-05 | 2024-03-15 | 昆明理工大学 | Fault line selection method, system and storage medium for power distribution network based on phase asymmetry |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5481195A (en) * | 1992-06-19 | 1996-01-02 | Siemens Aktiengesellschaft | Method for finding a fault on an electrical transmission line |
| CN104614644A (en) * | 2015-02-02 | 2015-05-13 | 广东电网有限责任公司电力科学研究院 | High-voltage overhead transmission line icing diagnosis method |
| CN104795801A (en) * | 2015-04-29 | 2015-07-22 | 南京南瑞继保电气有限公司 | Method and device for circuit breaker open-phase discrimination based on voltage |
| CN106771804A (en) * | 2016-12-08 | 2017-05-31 | 南京南瑞继保电气有限公司 | A kind of transmission line of electricity broken string area judging method based on zero-sequence network |
| CN107015114A (en) * | 2017-04-11 | 2017-08-04 | 国网河南省电力公司电力科学研究院 | The broken string recognition methods compared based on non-faulting phase current correlation |
| CN107153149A (en) * | 2017-05-11 | 2017-09-12 | 西安交通大学 | Power distribution network single-phase disconnection fault recognition method based on negative sequence voltage current characteristic |
| CN107367669A (en) * | 2017-07-12 | 2017-11-21 | 南京南瑞继保电气有限公司 | The method that broken string transmission line of electricity is locked based on negative sequence network |
| CN107677919A (en) * | 2017-09-14 | 2018-02-09 | 深圳供电局有限公司 | Double-end-quantity-based disconnection fault identification method for high-voltage alternating current line |
-
2018
- 2018-09-06 CN CN201811036254.3A patent/CN109375030A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5481195A (en) * | 1992-06-19 | 1996-01-02 | Siemens Aktiengesellschaft | Method for finding a fault on an electrical transmission line |
| CN104614644A (en) * | 2015-02-02 | 2015-05-13 | 广东电网有限责任公司电力科学研究院 | High-voltage overhead transmission line icing diagnosis method |
| CN104795801A (en) * | 2015-04-29 | 2015-07-22 | 南京南瑞继保电气有限公司 | Method and device for circuit breaker open-phase discrimination based on voltage |
| CN106771804A (en) * | 2016-12-08 | 2017-05-31 | 南京南瑞继保电气有限公司 | A kind of transmission line of electricity broken string area judging method based on zero-sequence network |
| CN107015114A (en) * | 2017-04-11 | 2017-08-04 | 国网河南省电力公司电力科学研究院 | The broken string recognition methods compared based on non-faulting phase current correlation |
| CN107153149A (en) * | 2017-05-11 | 2017-09-12 | 西安交通大学 | Power distribution network single-phase disconnection fault recognition method based on negative sequence voltage current characteristic |
| CN107367669A (en) * | 2017-07-12 | 2017-11-21 | 南京南瑞继保电气有限公司 | The method that broken string transmission line of electricity is locked based on negative sequence network |
| CN107677919A (en) * | 2017-09-14 | 2018-02-09 | 深圳供电局有限公司 | Double-end-quantity-based disconnection fault identification method for high-voltage alternating current line |
Non-Patent Citations (2)
| Title |
|---|
| 刘本旺: "《参政议政实务集》", 31 December 2015, 北京：群言出版社 * |
| 贺威俊 等: "《晶体管与计算机继电保护原理》", 31 March 1990, 西南交通大学出版社 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110676825A (en) * | 2019-11-28 | 2020-01-10 | 国网江苏省电力有限公司镇江供电分公司 | Circuit disconnection protection method based on voltage vector difference and backup power automatic switching and application |
| CN110676826A (en) * | 2019-11-28 | 2020-01-10 | 国网江苏省电力有限公司镇江供电分公司 | Line disconnection protection method for comparing vector difference of voltages at two sides of line and application |
| CN110676826B (en) * | 2019-11-28 | 2021-03-23 | 国网江苏省电力有限公司镇江供电分公司 | Line disconnection protection method for comparing vector difference of voltages at two sides of line and application |
| CN110676825B (en) * | 2019-11-28 | 2021-04-27 | 国网江苏省电力有限公司镇江供电分公司 | Circuit disconnection protection method based on voltage vector difference and backup power automatic switching and application |
| CN116087693A (en) * | 2023-04-13 | 2023-05-09 | 昆明理工大学 | LCC-HVDC power transmission line single-ended distance measurement method and system |
| CN116087693B (en) * | 2023-04-13 | 2023-08-04 | 昆明理工大学 | LCC-HVDC power transmission line single-ended distance measurement method and system |
| CN117706281A (en) * | 2024-02-05 | 2024-03-15 | 昆明理工大学 | Fault line selection method, system and storage medium for power distribution network based on phase asymmetry |
| CN117706281B (en) * | 2024-02-05 | 2024-06-07 | 昆明理工大学 | Fault line selection method, system and storage medium for power distribution network based on phase asymmetry |
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