CN113552442A - Power transmission line fault traveling wave analysis system based on LabVIEW and software development method - Google Patents
Power transmission line fault traveling wave analysis system based on LabVIEW and software development method Download PDFInfo
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Abstract
The invention discloses a power transmission line fault traveling wave analysis system based on LabVIEW, belonging to the technical field of power transmission line fault traveling wave ranging analysis and comprising a data acquisition module, wherein the data acquisition module comprises: the device comprises a data import module, a parameter setting module and a shape display module. The invention also discloses a software development method of the power transmission line fault traveling wave analysis system based on LabVIEW, which comprises the following steps: s1, developing and designing a data acquisition module; s2, developing and designing a traveling wave analysis and calculation module; s3, developing and designing a ranging result display module; s4, developing and designing a data storage and query module; s5, designing a front panel. The design and application of the invention provide a new thought and design method for transmission line fault traveling wave analysis software, provide reference for the improvement of future traveling wave analysis software, have complete functions, facilitate the later development and expansion, and provide guidance for the later development of the transmission line fault traveling wave analysis software.
Description
Technical Field
The invention relates to the technical field of power transmission line fault traveling wave distance measurement analysis, in particular to a power transmission line fault traveling wave analysis system and a software development method based on LabVIEW.
Background
Accurate power transmission line fault location is vital to on-site line patrol and rapid line fault repair. At present, a set of traveling wave distance measuring device and system is applied to an actual power transmission line, and reference and operation experience are provided for power transmission line fault location. However, the analysis software still has certain problems and complicated programming, which is not favorable for improving and expanding the software functions.
Disclosure of Invention
The invention aims to provide a power transmission line fault traveling wave analysis system and a software development method based on LabVIEW, and solves the problems in the background technology.
In order to achieve the purpose, the invention is realized by the following technical scheme: transmission line trouble traveling wave analytic system based on LabVIEW includes:
a data acquisition module, the data acquisition module comprising: the simulation system comprises a data import module, a parameter setting module and a shape display module, wherein the data acquisition module and the simulation system are connected with the data import module;
the traveling wave analysis and calculation module is designed with a manual mode and an automatic mode and is electrically connected with the data acquisition module;
the distance measurement result display module displays distance measurement results under different distance measurement methods, and is electrically connected with the traveling wave analysis and calculation module;
the data storage and query module realizes the storage of various required data and conveniently queries the fault information in a certain time period, and is electrically connected with the ranging result display module.
Furthermore, the data import module can acquire fault data obtained when the simulation transmission line is in fault, the parameter setting module is used for setting required parameters, and the waveform display module is used for displaying the waveform of voltage or current.
Furthermore, the manual mode of the traveling wave analysis and calculation module is to perform corresponding analysis and calculation to obtain a distance measurement result by manually calibrating the arrival time of the traveling wave surge, and the automatic mode is to perform fault traveling wave analysis and distance measurement calculation to obtain a result by acquiring the arrival time of the traveling wave surge through a wavelet transformation technology.
A software development method of a power transmission line fault traveling wave analysis system based on LabVIEW comprises the following steps:
s1, developing and designing a data acquisition module: the data acquisition module consists of a data import module, a parameter setting module and a waveform display module, and the data source of the development software programmed and designed in the text is mainly fault data of a simulation system built in PSCAD simulation software;
s2, developing and designing a traveling wave analysis and calculation module;
s3, distance measurement result display module development and design: the development design of the distance measurement result display module is mainly that the distance measurement result after traveling wave analysis and calculation is visually displayed on a front panel, so that an operator can conveniently and quickly read the distance measurement result, after the program design development of the module is completed, a sub VI is generated for calling two manual and automatic distance measurement programs, the results obtained by running in the manual mode and the automatic mode respectively have own result display areas in the front panel, the result display modules in the two modes are not interfered with each other, when the distance measurement is carried out in the manual mode, the area corresponding to the manual mode displays the result, and when the distance measurement is carried out in the automatic mode, the corresponding automatic result display area displays the result;
s4, developing and designing a data storage and query module: the transmission line fault traveling wave analysis software with complete functions can realize the functions of collecting, analyzing and calculating various data, displaying results and the like, and simultaneously has a perfect database, can store various data generated in the operation process in real time, and can inquire and manage at any time;
s5, design of the front panel: the front panel of the software is designed and reasonably distributed, so that the use of a user is more convenient, and the user can independently select a distance measuring method through operation in the front panel; the distance measurement result is visually observed, so that the complex process of manual calculation is omitted, the simulation result is convenient to analyze, and the data is more conveniently inquired.
Further, in step S2, the traveling wave analysis calculation module development design includes the following steps:
s201, a main calculation method of fault location;
s202, realizing a manual mode ranging function, wherein the manual mode ranging function is a function of calibrating the arrival time of a traveling wave surge on an output post-fault current oscillogram by means of an x scale of a oscillogram control in LabVIEW through manual operation, further analyzing fault data and giving a ranging result;
s203, realizing the automatic mode ranging function, wherein the automatic mode ranging function is to decompose and process the current traveling wave after the fault through a wavelet transform technology so as to position the arrival time of the fault traveling wave, automatically analyze and calculate by utilizing different traveling wave ranging methods, and give a ranging result, although a tool kit for wavelet processing is provided in LabVIEW, the wavelet in LabVIEW is not suitable for analyzing and processing the waveform after the fault of the power transmission line, so that the wavelet analysis method adopted in the mode is realized through reprogramming in LabVIEW. The partial program mainly completes the functions of multi-scale binary wavelet decomposition, waveform display and time calibration.
Further, in step S201, the main calculation method of the fault location includes:
(1) and a double-end distance measurement method:
the double-end traveling wave distance measurement is carried out by utilizing the arrival time of the initial wave head of the traveling wave recorded at the two ends of the disturbance line;
(2) the single-ended distance measurement method comprises the following steps:
1) under the condition that the second fault traveling wave received by the A-end bus is the reflected wave of the fault point, the second fault traveling wave received by the A-end bus is the traveling wave which is reflected by the A-end bus and then emitted by the fault point;
2) under the condition that the second fault traveling wave received by the bus at the end A is the reflected wave of the bus at the end B, the second fault traveling wave received by the bus at the end A is the traveling wave after the initial traveling wave at the fault point reaches the end B, is reflected by the bus at the end B and is refracted by the fault point;
3) the reflected wave of the fault point and the reflected wave of the B-end bus reach the A-end bus at the same time;
(3) the combined traveling wave distance measurement method comprises the following steps:
the combined traveling wave fault location is a method for location by combining single-end and double-end location methods and adding time criterion.
Further, in the step S4, the method includes the following steps:
s401, establishing a database, and connecting the database by using a UDL;
s402, designing a data storage subprogram;
and S403, designing a data query subprogram.
The invention provides a power transmission line fault traveling wave analysis system based on LabVIEW and a software development method. The method has the following beneficial effects:
(1) the analysis of the transmission line fault data can be realized. By changing the program code of the MATLAB script in the development tool, the simulation data which is established in the PACAD and is used when the power transmission line has faults can be received, and the data are analyzed and processed.
(2) The method has the advantages that the ranging is achieved in multiple modes, analysis software designed and developed by the method can conduct traveling wave ranging analysis in three different modes on power transmission line fault transient data, and single-ended, double-ended and combined traveling wave ranging can be achieved.
(3) The manual mode and the automatic mode are provided, the software can be selected from the manual mode and the automatic mode, and the ranging results in the two modes can be obtained. In the analysis and processing process in the automatic mode, a wavelet transformation technology is applied, the time when the traveling wave surge reaches A, B two ends is automatically positioned and obtained, and analysis and calculation are carried out, so that the function of automatic distance measurement is realized.
(4) The data storage and query software has a database and data storage and query functions, and adopts a LabVIEW toolkit to design and complete a data storage and data query program. The required information is respectively stored in the database, so that the operator can conveniently inquire and access the data in a certain time period.
(5) The method has the advantages of friendly interface and good openness, the front panel of the software is presented through reasonable and concise design, and various input parameters and display data are visually displayed. In addition, the user can add new functions according to new energy requirements, and further expand the module.
Drawings
FIG. 1 is a system diagram of a transmission line fault traveling wave analysis system based on LabVIEW according to the invention;
FIG. 2 is a block diagram of a data import module according to the present invention;
FIG. 3 is a wave refraction and reflection diagram of a transmission line fault;
FIG. 4 is a waveform display diagram of the present invention;
FIG. 5 is a diagram of the process for obtaining the x coordinate of the present invention;
FIG. 6 is a block diagram of a double ended traveling wave ranging analysis module according to the present invention;
FIG. 7 is a block diagram of a single-ended traveling wave ranging analysis module according to the present invention;
FIG. 8 is a partial block diagram of a combined traveling wave ranging analysis module according to the present invention;
FIG. 9 is a diagram of a parameter input and definition process of the present invention;
FIG. 10 is a block diagram of the present invention for determining coefficients of a wavelet decomposition filter for different orders;
FIG. 11 is a diagram of a wavelet coefficient and approximation coefficient solver of the present invention;
FIG. 12 is a diagram illustrating the process of decomposing waveforms and obtaining absolute time for each scale according to the present invention;
FIG. 13 is a front panel view of a ranging result display module according to the present invention;
FIG. 14 is a block diagram of a data link property dialog according to the present invention;
FIG. 15 is a diagram of a test line information storage routine of the present invention;
FIG. 16 is a diagram of a test line information query routine of the present invention;
fig. 17 is a layout diagram of a transmission line traveling wave analysis software front panel according to the present invention.
The reference numbers in the figures illustrate:
1. a data acquisition module; 101. according to the import module; 102. a parameter setting module; 103. a waveform display module; 2. a traveling wave analysis and calculation module; 3. a ranging result display module; 4. and the data storage and query module.
Detailed Description
The invention provides the technical scheme that: referring to fig. 1, the power transmission line fault traveling wave analysis system based on LabVIEW includes:
the traveling wave analysis and calculation module 2 is provided with a manual mode and an automatic mode, the traveling wave analysis and calculation module 2 is electrically connected with the data acquisition module 1, the traveling wave analysis and calculation module 2 is in the manual mode and performs corresponding analysis and calculation to obtain a distance measurement result by manually calibrating the arrival time of the traveling wave surge, and the automatic mode performs fault traveling wave analysis and distance measurement calculation to obtain a result by acquiring the arrival time of the traveling wave surge through a wavelet transformation technology;
the distance measurement result display module 3 is used for displaying the distance measurement results under different distance measurement methods, and the distance measurement result display module 3 is electrically connected with the traveling wave analysis and calculation module 2;
the data storage and query module 4 and the data storage and query module 4 realize the storage of various required data and the convenient query of fault information in a certain time period, and the data storage and query module 4 is electrically connected with the ranging result display module 3.
The invention also provides a software development method of the power transmission line fault traveling wave analysis system based on LabVIEW, please refer to FIGS. 2-17, which comprises the following steps:
step one, according to the development and design of an acquisition module: the application function modules of the software mainly comprise: the system comprises a data acquisition module 1, a traveling wave analysis and calculation module 2, a ranging result display module 3 and a data storage and query module 4. The data acquisition module 1 comprises a data import module 101, a parameter setting module 102 and a waveform display module 103, wherein the data import module 101 can acquire fault data obtained when a simulation power transmission line fault occurs, the parameter setting module 102 is mainly used for setting required parameters, and the waveform display module 103 is used for displaying the waveform of voltage or current. The traveling wave analysis and calculation module 2 is the core of the whole software development, and the module is designed with two modes of manual and automatic, wherein the manual mode is to perform corresponding analysis and calculation by manually calibrating the arrival time of the traveling wave surge to obtain a distance measurement result, the automatic mode is to perform fault traveling wave analysis and distance measurement calculation by acquiring the arrival time of the traveling wave surge through a wavelet transformation technology to obtain a result, the distance measurement result display module 3 displays the distance measurement results under different distance measurement methods, and the data storage and query module 4 realizes the storage of various required data and the convenient query of fault information in a certain time period.
Step two, the traveling wave analysis and calculation module 2 is developed and designed: the data acquisition module 1 is composed of three sub-modules, namely a data import module 101, a parameter setting module 102 and a waveform display module 103. Since the data source of the development software programmed in the present document is mainly fault data of the simulation system built in the PSCAD simulation software, it is necessary to retrieve the simulation fault data in the LabVIEW environment for analysis and calculation in the design of the data import module 101. The development of the data import module 101 is to select an MATLAB script node under a LabVIEW development environment to acquire line fault current or voltage data from a simulation system built by PSCAD. The module programming is shown in figure 2.
Because the PSCAD can be closer to reality when simulating the transmission line fault, the module opens fault data generated after PSCAD simulation by using MATLAB statements, and leads the data into LabVIEW for use by subsequent programs. When different power transmission lines and different fault types are simulated in the PSCAD, fault data after the simulation is finished can be led into the LabVIEW through the module, and the next step of analysis and calculation is carried out in the LabVIEW. The module can obtain fault data of different simulations by changing load statement codes in MATLAB script nodes.
Data such as simulation frequency of a simulation system in the parameter setting module 102, the time of occurrence of a power transmission line fault, the length of the power transmission line, the wave speed and the like are manually input by adopting an input control in a LabVIEW front panel, and the time of occurrence of the fault is used as the starting time of acquiring the data. The simulation frequency and the fault moment are realized by arranging an input control in an MATLAB script node. Therefore, fault data to be analyzed can be acquired according to simulation input simulation frequencies and fault occurrence moments of different systems. Therefore, the module can conveniently modify required data according to different simulation systems, and does not influence the analysis and calculation functions of the analysis module.
The waveform display module 103 outputs the current data after the fault by writing a program statement in the MATLAB script node, and sets an output control in the MATLAB script node to perform graphical programming on the acquired data, so that the current waveform required after the fault can be displayed on the front panel, and the waveform diagram of the current waveform is obtained by intercepting and displaying 500 points after the fault occurrence time. The waveform diagram is displayed by taking the fault occurrence time as the starting time;
step three, the distance measurement result display module 3 is developed and designed:
1. main calculation method for fault location
The development of the software analysis and calculation module aims to realize the analysis of the current waveform after the power transmission line fails and the calculation by using different traveling wave distance measurement methods to obtain the fault distance. The module can independently adopt single-end and double-end traveling wave distance measurement methods to measure the distance and also can adopt a combined traveling wave analysis method to measure the distance.
When the transmission line breaks down, the fault point can generate a traveling wave signal which is transmitted along the line. When traveling waves propagate along the line, if impedance mismatching points such as disturbance points and the like are encountered, reflection and refraction phenomena of the traveling waves can occur. The folding and reflecting process of the transmission line fault traveling wave is shown in fig. 3.
In fig. 3, A, B are bus bars at two ends of the line respectively; f is a fault point; v is the wave velocity; l is the line length; LAF is the distance from the fault point to the A end of the bus; LBF is the distance from a fault point to the end B of the bus; tA and tB are respectively absolute time moments when the line fault traveling wave reaches bus ends on two sides; and tYi and tBi are respectively the time when the two ends of the bus receive the fault traveling wave.
(1) The double-end distance measurement method comprises the following steps:
the double-end traveling wave distance measurement is carried out by utilizing the arrival time of the initial wave head of the traveling wave recorded at the two ends of the disturbance line.
As shown in fig. 3, if point F of the line fails at absolute time, then:
(2) the single-ended distance measurement method comprises the following steps:
as shown in fig. 3, as can be seen from the path taken by the fault traveling wave during propagation, the first fault traveling wave reaching the a-side bus is emitted from the fault point. The second fault traveling wave reaching the bus at the A end is divided into three conditions. Three cases are discussed separately below.
Taking the second fault traveling wave received by the bus at the A end as a reflected wave of a fault point:
in this case, the second fault traveling wave received by the a-side bus is a traveling wave that is reflected by the a-side bus from the initial traveling wave at the fault point and then transmitted by the fault point. According to the traveling wave transmission path, the distances from the fault point to the a terminal and the B terminal can be given by the following formula:
and (3) calculating the time difference of the fault initial traveling wave to reach the bus at the two ends of A, B according to the length and the parameters of the line:
secondly, the second fault traveling wave received by the bus at the A end is a reflected wave of the bus at the B end:
in this case, the second fault traveling wave received by the bus at the end a is a traveling wave after the initial traveling wave at the fault point reaches the end B, is reflected by the bus at the end B, and is refracted by the fault point. At this time, the distances from the fault point to the a terminal and the B terminal may be given by:
the time difference of the fault initial traveling wave reaching the A, B end bus can be calculated by the equation (3.3) and is counted as delta t 2.
And thirdly, the reflected wave of the fault point and the reflected wave of the bus at the B end reach the bus at the A end at the same time, and the distances from the fault point to the A end and the B end are as follows:
(3) combined traveling wave distance measuring method
The combined traveling wave fault location is a method for location by combining single-end and double-end location methods and adding time criterion.
After the transmission line is in fault, the difference of the absolute time when the initial fault traveling wave surge reaches the bus at the two ends of A, B is delta t, then:
Δt＝tA1-tB1 (3.6)
by analyzing three different conditions when the second fault traveling wave reaches the A-end bus, a time criterion can be listed, namely | delta t-delta t1I and | Δ t- Δ t2And l, determining the fault position by selecting a proper calculation formula according to the time criterion according to the size relation between the two. The method comprises the following steps:
if | Δ t- Δ t1|＜|Δt-Δt2L, the position can be determined by equation (3.2);
if delta t-delta t1|＞|Δt-Δt2The location of the fault point can be determined by equation (3.4);
③ if delta t-delta t1|＝|Δt-Δt2The location of the fault point should be determined by equation (3.5) in single-ended ranging.
The scheme is also suitable for analyzing the second fault traveling wave received by the bus at the B end, and can carry out accurate fault positioning according to the same principle.
2. The realization of the manual mode ranging function:
the manual mode ranging function is that the time when the traveling wave surge arrives is calibrated on the output current oscillogram after the fault through manual operation by means of an x scale of a oscillogram control in LabVIEW, so that fault data are analyzed, and a ranging result is given, wherein the output current waveform after the fault is shown in FIG. 4;
the position indicated by the arrow in fig. 4 is the position of the cursor in the waveform diagram, and the x coordinate of the position of the cursor can be seen in the cursor display frame in the manual mode by manually moving the cursor, so as to calibrate the arrival time of the traveling wave surge after the fault. By manually changing the size of the abscissa value in the oscillogram control, the output oscillogram can be properly amplified or reduced, the trend of the waveform can be observed more conveniently, and the calibration time can be more accurate. Since the software needs to use the calibrated time in the subsequent functions of analysis and calculation, the x coordinate value needs to be acquired in the program of the LabVIEW software, and the partial program is shown in FIG. 5;
in the design of the program in fig. 5, basic functions such as attribute nodes and group functions of LabVIEW are used. Firstly, right-clicking a oscillogram in a LabVIEW program diagram, selecting 'creation' in a popped menu, then selecting 'attribute nodes', creating and generating a cursor list, connecting the output ends of the attribute nodes with an 'index array' function, indexing the cursor position, connecting the output ends of the 'index array' function with a 'unbundling by name' control in a cluster control, changing the position of the control name, and then selecting an x coordinate, thereby obtaining the position of a cursor x.
The traveling wave ranging analysis and calculation function in the manual mode comprises three different ranging methods, namely single-ended, double-ended and combined traveling wave ranging, and the three ranging methods are independent and do not influence each other during analysis and calculation. Therefore, when the distance measurement is carried out in the manual mode, one distance measurement method can be independently selected for analysis and calculation, and multiple distance measurement methods can be simultaneously selected for calculation. By selecting different ranging methods, the program can run calculation according to the formula corresponding to the ranging method, so that the ranging result can be obtained. And after the final program is operated, the ranging results are respectively displayed and stored correspondingly according to the selected different ranging methods. The programmed programs of three different traveling wave ranging methods in the manual mode are respectively shown in fig. 6, 7 and 8.
In the programs shown in fig. 6 and 7, a conditional structure is used, a boolean control is provided at an input terminal, and when the boolean control is pressed and the input value is True, the formula in True is run to calculate the ranging result. And pressing the corresponding Boolean control to select the ranging method for ranging. The input end is also connected with a wave speed input control and a time X, X2 input control to provide required data for the formula. The output terminal is connected with a numerical value display control for displaying the ranging result.
In the procedure shown in fig. 8, the design of the combined traveling wave ranging analysis module uses numerical operation and comparison operation to determine time, connects the compared value to the "create array" function control, creates and generates a boolean array regarding the time determination result, and then connects the "boolean array to numerical conversion" function, where the function is to represent the array as a binary value, convert the boolean array into an integer or fixed point, connect to the condition structure after passing through the function, and there are four conditions in the condition structure, and determine the algorithm under which condition is executed according to the converted binary number, thereby completing the function of combined traveling wave ranging.
The programs written by the three distance measuring methods are all made into sub-VI, the generation of the sub-VI is not complex, after the programs are compiled in the front panel and the program block diagram, the icon at the upper right corner in the front panel is clicked, and the 'connecting line board' item is displayed in the shortcut menu. And clicking a terminal in the wiring board and a control in the front panel by using a wiring tool in the tool selection board to establish the one-to-one correspondence relationship between the controls and the wiring board. After the connection is finished, the icon is double-clicked, an icon editor can be started, the VI icon can be modified, the VI icon can be designed by the user, and an external icon file can be directly selected. The generation of these three VIs into sub-VIs can be easily invoked.
3. And (3) realizing the automatic mode ranging function:
the automatic mode ranging function is to decompose and process the current traveling wave after the fault through a wavelet transform technology so as to position the arrival time of the fault traveling wave, and to automatically analyze and calculate by utilizing different traveling wave ranging methods so as to give a ranging result. Although a wavelet processing tool kit is provided in LabVIEW, the wavelet therein is not suitable for analyzing and processing the waveform after the power transmission line fault, so the wavelet analysis method adopted in the mode is realized by reprogramming in LabVIEW. The partial program mainly completes the functions of multi-scale binary wavelet decomposition, waveform display and time calibration.
In the wavelet transform, coefficients of a dyadic wavelet decomposition filter are needed, and in the procedure of wavelet processing, the coefficients are fixed parameters, so the input and definition of the parameters are firstly completed in the programming, and the procedure is shown in fig. 9.
In the program of fig. 9, fixed parameters such as h3, h4, h5, g, etc. are assigned, they are coefficients of a binary wavelet decomposition filter in different orders, and "attribute nodes" are used, so that two output arrays of a wavelet coefficient Wav _ Coeffs and an approximation coefficient App _ Coeffs, a signal s, a decomposition scale MaxJ, a smoothing order wrder, etc. are defined, and thus, each parameter is conveniently assigned and used.
Then, the coefficients of the wavelet decomposition filter are selected according to the input order, and the partial procedure is as shown in fig. 10.
The local variables of the control are repeatedly used in the part of design, so that the control can be conveniently called and the amplitude or the read value of the control can be conveniently obtained. In addition, a conditional structure is used in the programming, and the wavelet decomposition filter coefficients are selected according to different input orders. That is, when a certain order is input into the current panel, the current panel enters the judgment area, so that a program meeting a certain condition is operated, the h and g parameters are assigned, and the corresponding wavelet decomposition filter coefficients defined before are assigned.
The calculation of wavelet coefficients and approximation coefficients is then started. For discrete fault travelling wave signals s (k), k ∈ Z, whose binary wavelet transform is also discrete, wavelet coefficients and approximation coefficients are obtained by the following fast algorithm:
in the formula: h islAnd glFor the decomposition filter coefficients used when inputting different orders.
aj(k) And wj(k) Respectively, the signals s (k) in the scale 2jThe lower approximation coefficients and the wavelet coefficients.
The partial program uses a cycle structure and a condition structure, and continuously judges the cycle of calculation according to an equation in a rapid algorithm to finally obtain the wavelet coefficient and the approximation coefficient. This part of the procedure is shown in FIG. 11.
After the wavelet coefficients and the approximation coefficients are obtained, the exploded view of each scale is displayed when different decomposition scales are selected by indexing and programming the wavelet coefficient array. After wavelet decomposition is carried out on fault waveform data, an exploded view under a certain scale is selected, the arrival time of the initial fault traveling wave is automatically searched, and distance measurement analysis and calculation are carried out. This part of the procedure is shown in figure 12.
In fig. 12, the wavelet coefficients are first programmed and processed to obtain the values of the wavelet coefficients at each scale. And then, after the wavelet coefficients are respectively bundled with the time arrays, displaying the waveform diagram under each decomposition scale by using an XY diagram. The sub VI indicated by "TA 11" is a sub program for acquiring the arrival time of the traveling wave surge, and the program can connect waveform data at different scales to perform processing for acquiring time values. By changing the connection position of the subprogram, the time of the first time and the second time of the wave surge reaching the A end under a certain scale after wavelet decomposition can be automatically indexed. When it is necessary to acquire the respective scale-resolved waveforms and absolute time at the B-end, the procedure shown in fig. 12 may be directly invoked.
And after the moment is obtained, calling the same ranging subprogram as that in the manual mode to finish the function of ranging single-ended, double-ended and combined traveling waves in the automatic mode.
Step three, the distance measurement result display module 3 is developed and designed: the development design of the result display module is mainly to visually display the distance measurement result after traveling wave analysis and calculation on a front panel, so that an operator can conveniently and quickly read the distance measurement result. After the programming development of the module is completed, a sub VI is generated for calling two ranging programs, namely manual ranging program and automatic ranging program. The results from the manual mode and the automatic mode have their own result display areas in the front panel. The result display modules in the two modes are not interfered with each other, when the distance measurement is carried out in the manual mode, the result is displayed in the area corresponding to the manual mode, and when the distance measurement is carried out in the automatic mode, the result is displayed in the corresponding automatic result display area. The front panel of the ranging result display module 3 is shown in fig. 13.
The distance measurement result display module 3 adopts a numerical value display control, a character string display control and a Boolean control, when the Boolean control for controlling and selecting the distance measurement mode is pressed down, an analysis module program is operated, and the calculated distance measurement result can be displayed on the display control. In the area of the combined travelling wave ranging, a character string display control is used for displaying the specific end from the fault point to the end A or the end B, and the subsequent numerical value display control displays the corresponding distance.
The module functions are simple in the front panel, provide only the functions of display, but are an indispensable part in developing software. The traveling wave analysis and calculation module 2 and the data storage and query module 4 are connected, and data connected in the traveling wave analysis and calculation module not only displays the final ranging result for the traveling wave analysis and calculation module 2, but also provides a part of original data for the data storage and query module 4.
Step four, the data storage and query module 4 develops and designs: the transmission line fault traveling wave analysis software with complete functions can realize the functions of collecting, analyzing and calculating various data, displaying results and the like, and simultaneously has a perfect database, can store various data generated in the operation process in real time, and can inquire and manage the data at any time.
1. Establishment of database and data source
Currently, the LabVIEW-based database connection toolkit does not provide a method for creating a database, but the database may be created by other tools, such as Access, VB and the like in Office.
1) Establishing a database
The database is established by utilizing Microsoft Office Access 2000 to make a database of transmission line fault traveling wave analysis software in a computer. The preparation method comprises the following steps: making a database of transmission line fault traveling wave analysis software, wherein the name of the database is 'database storage', and the database mainly comprises: a test line information table, a parameter setting table, a ranging result table and the like. The test circuit information table, the parameter setting table and the ranging result table have the following structures.
Test line information table (the name of the table is "TestLine"), and the field name includes: test time, test line name, test line type, and test line length.
A parameter setting table (the name of the table is "ParameterSettings"), and the field name includes: test time, simulation frequency, wave speed, fault occurrence time and actual fault distance.
Manual mode ranging result table (name of table is "relocation result"), field name includes: test time, single-ended ranging, double-ended ranging LAF, double-ended ranging LBF, combined traveling wave ranging result, and combined traveling wave ranging result 2.
Auto mode ranging result table (the name of the table is "autolocationresult"), field name includes: test time, single-ended ranging, double-ended ranging LAF, double-ended ranging LBF, combined traveling wave ranging result, and combined traveling wave ranging result 2.
2) Connecting databases using UDL
In programming herein, ADO techniques are employed to accomplish database access. ADO is an object-oriented interface developed by microsoft with automation service technology. The ADO model includes a plurality of objects, the hierarchical relationship between the objects is obvious, and the objects are created according to the upper and lower layers when created. In LabVIEW, an ADO interface is packaged, so that the user can use the device conveniently. ADO supports both relational and non-relational databases.
According to the model of the ADO, the database can be used and operated only if a connection relationship is established with the database. There are various ways to establish a database connection, and here, a connection string is used to create a connection with the database. Different types of database files require different drivers, which results in a complicated composition of the connection string. Thus, a data connection tool is used herein to automatically create connection strings.
The connection string of the ADO can be specified using a UDL (universal database connection) file. There are three common methods for creating UDL files.
Firstly, copying the existing UDL file, changing the name of the UDL file after copying, then double-clicking the file, and connecting the file to the database file through a 'connection attribute' dialog box.
Selecting 'create database connection (UDL)' item through shortcut menu of operating system.
And thirdly, opening LabVIEW, selecting a 'Create Data Link' item under a 'tool' menu in a menu bar, and creating the UDL.
No matter which way the UDL file is created, after the UDL file is created, the file needs to be double-clicked, a "connection properties" dialog box is opened and database connection properties are configured. Since different database files have different providers, the corresponding providers are correctly selected for the different types of database files. And selecting a database file to be connected on the connection tab, and testing the connection state. After the test connection is successful, the UDL file automatically records the relevant information of the connection database.
The creation of UDLs herein is as follows:
after creating the database named "database store", open LabVIEW, click the "Create Data Link" item under the "tools" menu in VI, pop up the "database connection properties" dialog, select "Microsoft Jet 4.0OLE DB Provider", click "next", then go to the "connect" tab, select the created database file in this tab, click "test connect". As shown in fig. 14.
After the test connection is successful, a "database store. udl" is generated, which is opened using a notepad, and the following contents are contained therein:
[oledb]
；Everything after this line is an OLE DB initstring
provider ═ microsoft. jet. oledb.4.0; data Source ═ D: \ design \ database storage mdb; persist Security Info ═ False
By this, the UDL creation is complete.
2. Data storage subroutine design
Since four tables about data information are established in the database, the data storage program designs four stored subroutines to store the specific information of each table respectively. The design idea and method of these four sub-programs are consistent, and the test circuit information storage program is taken as an example to be described below. This subroutine is shown in fig. 15.
The program uses a database toolkit in LabVIEW, and a connection character string' Provider ═ Microsoft.jet.OLEDB.4.0 in the built UDL file is copied; data Source ═ D: \ design \ database storage mdb; the persistence Security Info ═ False ", is connected to the Connection information terminal of DB Tools Open Connection. It is worth noting that the name and data type connected to the "input cluster" terminal of the "bind by name" function and to the "data" terminal of the "DB Tools Insert data.vi" are to be consistent with the field names in the database table and the data type corresponding to the column.
3. Data query subprogram design
After the program runs, the storage program stores the required information and data in a table corresponding to the database. To facilitate viewing of this information, a subroutine of data query is devised herein.
Because the information of the four tables is recorded in the database, the program needs to query the information in the four tables respectively, the design idea of each query program is consistent with that of the method, and in the data query subprogram, a tiled sequential structure is adopted to query the information in the four tables respectively. The programming for inquiring the test line information is shown in fig. 16, and the inquiry procedure will be described by taking this part of the procedure as an example.
As shown in fig. 16, a boolean control is provided in the program, and whether or not to perform an operation of querying data is determined by a condition structure. When the Boolean control is pressed, the program executes the program under "True" in the condition structure. The query subprogram is provided with a query starting time field and a query ending time field, and data of a certain time period can be queried through manually inputting time. Like the storage subprogram, the query program also uses a database toolkit in LabVIEW, the connection is carried out according to the connection rule of VI in each toolkit, and finally the information of each table in the database is output in a table form.
Step five, designing a front panel: the front panel of the software is designed and reasonably distributed, so that the software is more convenient for users to use. Through the operation in the front panel, the user can autonomously select a ranging method; the distance measurement result is visually observed, so that the complex process of manual calculation is omitted, and the simulation result is convenient to analyze; data is more conveniently queried. The front panel layout of the software is shown in fig. 17.
The upper part of the front panel visually displays the current waveform after the fault, the abscissa of the oscillogram can be directly modified, the time interval is shortened, and the amplified waveform of a certain time period after the fault is checked. The front panel is respectively designed with a manual mode option and an automatic mode option. The selection of the distance measuring method in different modes and the distance measuring result using the distance measuring method are correspondingly displayed in the front panel. The right side of the front panel is used for setting parameters required by analysis and calculation of a simulation system and software, and the query operation options of the database are also arranged in the right column, so that the time period required to be queried can be manually input to query the information in the database. The software automatically acquires the required data for storage without manual selection. In addition, the oscillograms of the scales after wavelet decomposition in the automatic mode can also be seen in the front panel.
After the design and layout of the front panel are finished, the transmission line fault traveling wave analysis software can be operated and operated.
Firstly, according to the simulation system, a series of parameters of the name of a test line, the type of the test line, the actual fault distance of the simulation system, the wave speed, the simulation frequency, the fault moment and the line length are input in a parameter setting column of a front panel.
In the manual mode operation, the data import module 101 of the software is first run, and the current waveform after the fault is displayed on the front panel. And then analyzing the waveform, manually dragging a cursor on the waveform diagram to calibrate the time, also changing the value of the horizontal coordinate on the waveform diagram, amplifying the waveform diagram, and calibrating the time point more accurately, wherein after the cursor is fixed, the corresponding time value is displayed in a cursor attribute frame, and the absolute time of the first and second traveling wave surges reaching A, B two ends after the power transmission line is in fault can be visually seen. And then selecting a manual mode option and a required ranging method, and clicking to run, namely displaying a corresponding ranging result. Fig. 17 shows ranging results obtained after three ranging methods, namely single-ended ranging, double-ended ranging and combined traveling wave ranging, are selected simultaneously.
In the automatic mode operation, the decomposed scale and the order need to be set, as shown in fig. 17, the scale is set to be 2, the order is set to be 5, the 'automatic mode' option and the required ranging method are clicked, and the waveform diagram after the fault waveform at the two ends is decomposed is displayed A, B in the front panel when the operation is clicked.
In fig. 17, the two scales on the left side are waveform diagrams after wavelet decomposition of the fault waveform acquired at the a end, and the two scales on the right side correspond to waveform diagrams after wavelet decomposition of the fault waveform acquired at the B end. And analyzing and calculating the waveform after the dimension decomposition through a program in an automatic mode, displaying absolute time of the first and second traveling wave surges reaching A, B two ends after the transmission line fails in a front panel, and simultaneously selecting three different distance measurement methods to obtain corresponding distance measurement results.
Compared with a manual mode, the automatic mode is simpler in operation, the calibration time is not needed to be manually set, the fault waveform is processed through a wavelet transform technology, and the time value needed by calculation is automatically searched for analysis and calculation. Therefore, after the decomposition scale and the order are set, the distance measurement result can be obtained automatically only by clicking the 'automatic mode' option in the front panel, selecting the required distance measurement mode and clicking for operation. The automatic mode saves time for calculation and program operation, and is more convenient to operate.
A set of fault traveling wave analysis software suitable for laboratory power transmission line simulation is developed based on LabVIEW, a wavelet transformation technology is integrated to analyze and process fault data, the ranging precision is improved, and feasibility reference is provided for improving functions of used traveling wave analysis software in the future.
The invention discloses a method for testing the fault traveling wave analysis of a power transmission line, which comprises the following steps of completing all functions of traveling wave analysis software through programming design, connecting and combining all function modules into a complete power transmission line fault traveling wave analysis software, building a simulation system in PSCAD, simulating and simulating power transmission line faults to obtain fault data, testing the functions and the performance of development software through the simulated power transmission line fault data, testing the functions of software data acquisition, analysis and calculation and distance measurement result display aiming at a single-phase fault at a certain point, and verifying the feasibility and the effectiveness of the software analysis function through error analysis of the distance measurement result; the realization of the database function is verified through the tests of data storage and the information of each table in the query database.
The design and application provide a new thought and design method for transmission line fault traveling wave analysis software, and provide reference for improvement of future traveling wave analysis software. The completion of the method provides guidance for the research and development of power transmission line fault traveling wave analysis software.
The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, many variations and modifications can be made without departing from the inventive concept of the present invention, which falls into the protection scope of the present invention.
Claims (7)
1. Transmission line trouble traveling wave analytic system based on LabVIEW, its characterized in that includes:
a data acquisition module (1), the data acquisition module (1) comprising: the simulation system comprises a data import module (101), a parameter setting module (102) and a shape display module (103), wherein the data acquisition module (1) and the simulation system;
the traveling wave analysis and calculation module (2) is designed with a manual mode and an automatic mode, and the traveling wave analysis and calculation module (2) is electrically connected with the data acquisition module (1);
the distance measurement result display module (3) displays distance measurement results under different distance measurement methods, and the distance measurement result display module (3) is electrically connected with the traveling wave analysis and calculation module (2);
the data storage and query module (4) realizes the storage of various required data and conveniently queries the fault information in a certain time period, and the data storage and query module (4) is electrically connected with the ranging result display module (3).
2. The LabVIEW-based transmission line fault traveling wave analysis system according to claim 1, wherein: the data importing module (101) can obtain fault data obtained when the simulation transmission line faults occur, the parameter setting module (102) is used for setting required parameters, and the waveform display module (103) is used for displaying the waveforms of the voltage or the current.
3. The LabVIEW-based transmission line fault traveling wave analysis system according to claim 1, wherein: the traveling wave analysis and calculation module (2) is in a manual mode, corresponding analysis and calculation are carried out to obtain a distance measurement result by manually calibrating the arrival time of the traveling wave surge, and in an automatic mode, the arrival time of the traveling wave surge is obtained through a wavelet transformation technology to carry out fault traveling wave analysis and distance measurement calculation to obtain a result.
4. A software development method for a transmission line fault traveling wave analysis system based on LabVIEW, which is characterized in that the transmission line fault traveling wave analysis system based on LabVIEW according to any one of claims 1 to 3 is used, and the software development method comprises the following steps: the method comprises the following steps:
s1, developing and designing a data acquisition module: the data acquisition module (1) is composed of a data import module (101), a parameter setting module (102) and a waveform display module (103), and the data source of the development software programmed in the data acquisition module is mainly fault data of a simulation system built in PSCAD simulation software;
s2, developing and designing a traveling wave analysis and calculation module (2);
s3, a distance measurement result display module (3) is developed and designed: the development design of the ranging result display module (3) is mainly that the ranging result after traveling wave analysis and calculation is visually displayed on a front panel, so that an operator can conveniently and quickly read the ranging result, after the program design development of the module is completed, a sub VI is generated for calling two manual and automatic ranging programs, the results obtained by running in the manual mode and the automatic mode respectively have own result display areas in the front panel, the result display modules in the two modes are not interfered with each other, when the manual mode is selected for ranging, the area corresponding to the manual mode displays the result, and when the automatic mode is selected for ranging, the corresponding automatic result display area displays the result;
s4, developing and designing a data storage and query module (4): the transmission line fault traveling wave analysis software with complete functions can realize the functions of collecting, analyzing and calculating various data, displaying results and the like, and simultaneously has a perfect database, can store various data generated in the operation process in real time, and can inquire and manage at any time;
s5, design of the front panel: the front panel of the software is designed and reasonably distributed, so that the use of a user is more convenient, and the user can independently select a distance measuring method through operation in the front panel; the distance measurement result is visually observed, so that the complex process of manual calculation is omitted, the simulation result is convenient to analyze, and the data is more conveniently inquired.
5. The software development method of the power transmission line fault traveling wave analysis system based on LabVIEW as claimed in claim 4, wherein: in the step S2, the development and design of the traveling wave analysis and calculation module (2) includes the following steps:
s201, a main calculation method of fault location;
s202, realizing a manual mode ranging function, wherein the manual mode ranging function is a function of calibrating the arrival time of a traveling wave surge on an output post-fault current oscillogram by means of an x scale of a oscillogram control in LabVIEW through manual operation, further analyzing fault data and giving a ranging result;
s203, realizing the automatic mode ranging function, wherein the automatic mode ranging function is to decompose and process the current traveling wave after the fault through a wavelet transform technology so as to position the arrival time of the fault traveling wave, automatically analyze and calculate by utilizing different traveling wave ranging methods, and give a ranging result, although a tool kit for wavelet processing is provided in LabVIEW, the wavelet in LabVIEW is not suitable for analyzing and processing the waveform after the fault of the power transmission line, so that the wavelet analysis method adopted in the mode is realized through reprogramming in LabVIEW. The partial program mainly completes the functions of multi-scale binary wavelet decomposition, waveform display and time calibration.
6. The software development method of the power transmission line fault traveling wave analysis system based on LabVIEW as claimed in claim 5, wherein: in step S201, the main calculation method of the fault location includes:
(1) and a double-end distance measurement method:
the double-end traveling wave distance measurement is carried out by utilizing the arrival time of the initial wave head of the traveling wave recorded at the two ends of the disturbance line;
(2) the single-ended distance measurement method comprises the following steps:
1) under the condition that the second fault traveling wave received by the A-end bus is the reflected wave of the fault point, the second fault traveling wave received by the A-end bus is the traveling wave which is reflected by the A-end bus and then emitted by the fault point;
2) under the condition that the second fault traveling wave received by the bus at the end A is the reflected wave of the bus at the end B, the second fault traveling wave received by the bus at the end A is the traveling wave after the initial traveling wave at the fault point reaches the end B, is reflected by the bus at the end B and is refracted by the fault point;
3) the reflected wave of the fault point and the reflected wave of the B-end bus reach the A-end bus at the same time;
(3) the combined traveling wave distance measurement method comprises the following steps:
the combined traveling wave fault location is a method for location by combining single-end and double-end location methods and adding time criterion.
7. The software development method of the power transmission line fault traveling wave analysis system based on LabVIEW as claimed in claim 4, wherein: in the step S4, the method includes the steps of:
s401, establishing a database, and connecting the database by using a UDL;
s402, designing a data storage subprogram;
and S403, designing a data query subprogram.
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