Collector line fault location method and location system

Abstract

The present invention discloses a method and a system for fault location of a collector line. Among them, a method for fault location of a collector line includes the steps of: setting a plurality of nodes between the box-type substation and the booster station of the collector line; arranging current detectors at each of the nodes, and detecting the high-frequency current pulse amplitudes at each node on the collector line in the initial state through the current detectors as the initial current values; recording the real-time high-frequency current pulse amplitudes of the current detectors in the state to be detected as the measured current values; and locating the fault point of the collector line according to the change of the measured current values of each node relative to the initial current values. It can be understood that the technical solution of the present invention realizes the online fault location of the collector line.

Description

Technical Field

[0001] The present invention relates to the technical field of line fault detection, and particularly relates to a method and a system for locating faults in a collector line. Background Art

[0002] Most common faults in a wind farm are faults in the collector line. The line of the collector line is easily affected by factors such as the natural environment and the operation years, resulting in faults. Abnormal discharge of transformers, aging of cable insulation, and insulation damage caused by abnormal equipment, all of which can cause faults in the collector line, reduce the line reliability, and even cause the collapse of the entire system in severe cases. Therefore, it is of great significance to realize the fault detection of the collector line. The existing online fault location technologies for collector lines mainly include the traveling wave method and the intelligent ranging method. Among them, the wavefront rising speed of the traveling wave in the traveling wave method is slow and the traveling wave waveform is very complex, making it difficult to identify the wavefront time. Therefore, it is difficult to ensure the accuracy and reliability of traveling wave ranging. Compared with the traveling wave method, although the intelligent ranging method is highly innovative, its principle is not yet mature and perfect, and it cannot be put into practical application. Summary of the Invention

[0003] The main object of the present invention is to provide a method for locating faults in a collector line, aiming to realize the online fault location of the collector line.

[0004] To achieve the above object, the method for locating faults in a collector line proposed by the present invention includes the steps of:

[0005] Set a plurality of nodes between the box-type substation and the step-up substation of the collector line;

[0006] Install current detectors at each of the nodes, and detect the high-frequency current pulse amplitude at each node of the collector line in the initial state through the current detectors as the initial current value;

[0007] Record the real-time high-frequency current pulse amplitude of the current detectors in the state to be detected as the measured current value;

[0008] Locate the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value.

[0009] Optionally, the step of "locating the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value" includes:

[0010] Locate the node where the fault is located on the collector line according to the current change amount between the initial current value and the measured current value of each node, and record it as the fault node;

[0011] Determine the location of the fault point within the range of the fault node according to the current change amount of the nodes before and after the fault node.

[0012] Optionally, the step of "locating the node where the fault occurs on the collector line according to the current change amount between the initial current value and the measured current value of each node" includes:

[0013] Establish the correspondence between the location of each node and its current change amount according to the topological structure of the collector line;

[0014] Determine the location of the node with the largest current change amount according to the correspondence, which is the node where the fault occurs on the collector line.

[0015] Optionally, the step of "determining the location of the fault point within the range of the fault node according to the current change amount of the nodes before and after the fault node" includes:

[0016] According to the established correspondence, perform linear fitting on the nodes between the box transformer and the fault node of the collector line and the nodes between the fault node and the booster station respectively;

[0017] Determine the intersection point of the two linearly fitted lines, and locate the location of the intersection point, that is, the fault point of the collector line.

[0018] Optionally, the step of "performing linear fitting on the nodes between the box transformer and the fault node of the collector line and the nodes between the fault node and the booster station respectively" includes:

[0019] According to the topological structure of the collector line, establish a coordinate system of the distance between the location of each node and the box transformer of the collector line and the current change amount;

[0020] Corresponding to the position of each node in the coordinate system, perform linear fitting on the nodes between the box transformer and the fault node of the collector line in the coordinate system to obtain the first line;

[0021] Perform linear fitting on the nodes between the fault node and the booster station of the collector line in the coordinate system to obtain the second line.

[0022] Optionally, the step of "determining the intersection point of the two linearly fitted lines and locating the location of the intersection point" includes:

[0023] Determine the intersection point of the first line and the second line;

[0024] Determine the location of the intersection point relative to the previous node of the fault node, that is, the first location;

[0025] Determine the location of the intersection point relative to the next node of the fault node, that is, the second location;

[0026] Locate the intersection point based on the first position and the second position.

[0027] Optionally, the step of "setting a plurality of nodes between the box-type substation and the step-up substation of the collector line" includes:

[0028] Determine the node setting positions of the collector line according to the topological structure and line parameters of the collector line;

[0029] Set nodes between the box-type substation and the step-up substation of the collector line according to the determined node setting positions.

[0030] The present invention also provides a collector line fault location system, including:

[0031] A plurality of current detectors, a plurality of nodes are set between the box-type substation and the step-up substation of the collector line, and each of the nodes is provided with the current detector, and the high-frequency current pulse amplitude in the initial state of each node on the collector line is detected by the current detector as the initial current value;

[0032] And a terminal, the terminal is connected to the current detector, records the real-time high-frequency current pulse amplitude in the state to be detected by the current detector as the measured current value, and the terminal locates the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value.

[0033] Optionally, the terminal includes a processor and a display, the processor is respectively connected to a plurality of the current detectors, the processor processes the high-frequency current pulse amplitude detected by the current detector to obtain a processing result, the display is connected to the processor, and the display displays the processing result of the processor.

[0034] Optionally, the terminal further includes an alarm, the alarm is communicatively connected to the processor, and the alarm is used to send an alarm message according to the processing result of the processor.

[0035] According to the technical solution of the present invention, when the line of the collector line is normal, the measured current value detected in real time is consistent with the initial current value; when the line of the collector line fails, the high-frequency current pulse amplitude of the collector line will change relative to the initial current value, and moreover, the change amplitude of its high-frequency current pulse amplitude will vary with the distance from the fault point. Thus, by setting current detectors at a plurality of nodes of the collector line to detect the change of the current value at different positions, the location of the fault point on the collector line is realized, that is, the technical solution of the present invention realizes the online fault location of the collector line. Description of the Drawings

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0037] Figure 1 It is the initial current value distribution diagram of each node in an embodiment of the present invention;

[0038] Figure 2 It is the current change amount distribution diagram of each node in an embodiment of the present invention;

[0039] Figure 3 It is the fault point location effect diagram of the collector line in an embodiment of the present invention;

[0040] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0042] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0043] The present invention proposes a method for fault location of a collector line, aiming to achieve online fault location of the collector line.

[0044] In an embodiment of the present invention, a method for fault location of a collector line includes the steps of:

[0045] Set a number of nodes between the box-type transformer and the booster station of the collector line;

[0046] Install current detectors at each of the nodes, and detect the high-frequency current pulse amplitudes of each node on the collector line in the initial state through the current detectors as the initial current values;

[0047] Record the real-time high-frequency current pulse amplitudes of the current detectors in the state to be detected as the measured current values;

[0048] Locate the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value.

[0049] In the technical solution of the present invention, a plurality of nodes are arranged between the box-type transformer and the booster station of the collector line, and current detectors are arranged at each of the nodes. The high-frequency current pulse amplitude in the initial state of each node on the collector line is detected by the current detector as the initial current value; the real-time high-frequency current pulse amplitude of the current detector in the state to be detected is recorded as the measured current value; the fault point of the collector line is located according to the change of the measured current value of each node relative to the initial current value. When the line of the collector line is normal, the measured current value detected in real time is consistent with the initial current value; when the line of the collector line fails, the measured current value detected in real time will change relative to the initial current value, and moreover, the change amplitude of its high-frequency current pulse amplitude will vary with the distance from the fault point. Thus, by arranging current detectors at a plurality of nodes of the collector line to detect the change of the current value at different positions, the positioning of the fault point on the collector line is achieved, that is, the technical solution of the present invention realizes the online fault location of the collector line. It can be understood that in the embodiment of the present invention, the high-frequency current pulse is detected by the current detector, and compared with the traveling wave method, the accuracy of fault location is higher. Moreover, the data required to be uploaded in the embodiment of the present invention is less, the communication burden is small, and the pressure on the master station and the power consumption of the terminal caused by a large amount of recorded wave data are avoided. The master station can realize the ranging and positioning of the fault point and the fault location according to the distribution of the multi-point terminals of the collector line, in combination with the topological structure of the collector line and the setting position of the nodes on the collector line. This method is economical, convenient and simple, does not require additional configuration of terminals, and can directly use the existing feeder terminals of the collector line, and has broad application prospects.

[0050] It should be noted that in the embodiment of the present invention, as Figure 1 shown, the initial current value can be the high-frequency current pulse detection value of the current detector at the initial moment, or any other high-frequency current pulse detection value in any normal state to be detected, as long as it is the high-frequency current pulse detection value when the line in the normal state to be detected does not fail, it can be used as the initial current value. Supplementary explanation, high-frequency current is the current relative to the 50Hz alternating current of the power frequency. Changing the power frequency current to a relatively high-frequency current is also called high-frequency current. In this embodiment, the nodes can be arranged at equal intervals according to needs, or can be arranged according to the line parameters. The current detector is used to detect the current of the nodes. The current detector can be an ammeter, a current transformer, or a current sensor, as long as it can mainly realize the detection of the high-frequency current pulse of the line node. The embodiment of the present invention is not limited thereto, and the above are all within the protection scope of the present invention.

[0051] In an embodiment of the present invention, the step of "locating the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value" includes: locating the node where the fault is located on the collector line according to the current change amount between the initial current value and the measured current value of each node, and recording it as the fault node; determining the location of the fault point within the range of the fault node according to the current change amounts of the nodes before and after the fault node. It should be noted that during the transmission of high-frequency current from the box substation to the step-up substation, the closer to the fault node, the greater the degree of current attenuation, that is, the greater the current change amount. That is, the current change amounts of the nodes between the box substation of the collector line and the fault node show an upward trend, and the current change amounts of the nodes between the fault node and the step-up substation of the collector line show a downward trend. In this way, by detecting the current change amounts of the nodes set at different positions, the position of the fault node can be obtained according to the magnitude of the current change amount, thereby realizing the positioning of the fault node. As Figure 2 shown Figure 2 corresponds to three cases of node faults at three positions, namely the 3# node, the 3# node, and the 4# node. In this way, by positioning the fault node, the fault interval is locked. Of course, in order to further lock the specific position of the fault point, as Figure 2 (b) shown, the embodiment of the present invention further analyzes the change trend of the current change amounts of the nodes before and after the fault node. Of course, the analysis method can be mathematical modeling analysis or regression analysis. The embodiment of the present invention is not limited thereto, and the above are all within the protection scope of the embodiment of the present invention.

[0052] In an embodiment of the present invention, the step of "locating the node where the fault is located on the collector line according to the current change amount between the initial current value and the measured current value of each node" includes: establishing a correspondence between the location of each node and its current change amount according to the topological structure of the collector line; determining the location of the node with the largest current change amount according to the correspondence, which is the node where the fault is located on the collector line. In the embodiment of the present invention, the location of the box substation of the collector line is used as a reference point. Of course, other positions can also be used as reference points to simplify the calculation. In this way, the location of the node is determined by the distance from the reference point. In this way, a correspondence between the distance and the current change amount as Figure 2 shown is established. According to the correspondence, the location of the node with the current change amount is determined, thereby realizing the ranging and positioning of the fault node. Of course, the establishment of the above correspondence can also be in the form of a table. The embodiment of the present invention is not limited thereto, and the above are all within the protection scope of the present invention.

[0053] In an embodiment of the present invention, the step of "determining the location of the fault point within the fault node range according to the current change amount of the front and rear nodes of the fault node" includes: respectively performing linear fitting on the nodes between the box transformer of the collector line and the fault node and the nodes between the fault node and the booster station according to the established corresponding relationship; determining the intersection point of the two linearly fitted lines, and locating the location where the intersection point is located, that is, the fault point of the collector line. It should be noted that since the line parameters of the collector line are basically the same and the attenuation amplitude is basically the same, as Figure 2 shown, Figure 2 in (a), the fault node is the 3# node, Figure 2 in (c), the fault node is the 4# node, while Figure 2 in (b), although the fault node is the 3# node, the 3# node is not the fault point. Only among the set nodes, the 3# node is the closest to the fault point, resulting in the most severe current attenuation and the largest current change amount. Based on this, in order to further locate the location of the fault point within the fault node range, the embodiment of the present invention performs linear fitting on the nodes between the box transformer of the collector line and the fault node and the nodes between the fault node and the booster station, and obtains the location of the fault point through linear fitting, thereby achieving precise positioning of the fault point.

[0054] In an embodiment of the present invention, the step of "respectively performing linear fitting on the nodes between the box transformer of the collector line and the fault node and the nodes between the fault node and the booster station" includes: establishing a coordinate system of the distance of each node's location relative to the box transformer of the collector line and the current change amount according to the topological structure of the collector line; corresponding to the positions of each node in the coordinate system, performing linear fitting on the nodes between the box transformer of the collector line and the fault node in the coordinate system to obtain a first line; performing linear fitting on the nodes between the fault node and the booster station of the collector line in the coordinate system to obtain a second line. It should be noted that the present invention establishes a coordinate system of the location of each node and the corresponding current change amount through the topological structure of the collector line. Thus, by performing linear fitting on the nodes within this coordinate system, the corresponding first line and second line can be obtained. The intersection point of the first line and the second line is the fault point of the collector line, and then the distance to the fault point is measured according to the coordinate system, thereby achieving precise positioning of the fault point of the collector line.

[0055] In an embodiment of the present invention, the step of "determining the intersection point of the two linearly fitted lines and locating the location where the intersection point is located" includes: determining the intersection point of the first line and the second line; determining the location of the intersection point relative to the location of the node before the fault node, that is, the first location; determining the location of the intersection point relative to the location of the node after the fault node, that is, the second location; positioning the intersection point according to the first location and the second location. In the embodiment of the present invention, as Figure 3As shown in the figure, the intersection point of the first straight line and the second straight line is point O, which is the fault point. The distance between point O and the previous node is L1, and the distance between point O and the next node is L2. In this way, the distance measurement of the fault point is achieved based on the first position with the distance L1 from the previous node and the second position with the distance L2 from the next node. By measuring the distance to the fault point, the precise positioning of the fault is realized. It can be understood that the embodiment of the present invention realizes the fault distance measurement function of the collector line. Compared with the traveling wave method, the accuracy of obtaining high-frequency current pulses in the embodiment of the present invention is higher, the positioning accuracy is higher, and it has a broader application prospect.

[0056] In an embodiment of the present invention, the step of "setting a plurality of nodes between the box-type substation and the step-up substation of the collector line" includes: determining the node setting positions of the collector line according to the topological structure and line parameters of the collector line; setting nodes between the box-type substation and the step-up substation of the collector line according to the determined node setting positions. It should be noted that in the embodiment of the present invention, the node setting positions of the collector line are determined according to the topological structure and line parameters of the collector line. By comprehensively covering the possible fault areas of the line through the node setting positions, the precise positioning of the collector line fault is ensured. Of course, for areas with complex lines and prone to faults, nodes can also be appropriately added. The embodiment of the present invention is not limited thereto, and the above are all within the protection scope of the embodiment of the present invention.

[0057] In an embodiment of the present invention, a collector line fault positioning system includes: a plurality of current detectors, with a plurality of nodes set between the box-type substation and the step-up substation of the collector line, and each of the current detectors is set at each node to detect the high-frequency current pulse amplitude in the initial state of each node on the collector line as the initial current value; and a terminal, the terminal is connected to the current detector and records the real-time high-frequency current pulse amplitude in the state to be detected as the measured current value. The terminal locates the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value. When the line of the collector line is normal, the measured current value detected in real time is consistent with the initial current value; when the line of the collector line fails, the high-frequency current pulse amplitude of the collector line will change relative to the initial current value, and moreover, the change amplitude of its high-frequency current pulse amplitude will vary with the distance from the fault point. In this way, by setting current detectors at a plurality of nodes of the collector line to detect the change of current values at different positions, the positioning of the fault point on the collector line is realized, that is, the technical solution of the present invention realizes the online fault positioning of the collector line.

[0058] In an embodiment of the present invention, the terminal includes a processor and a display. The processor is connected to the current detector. The processor processes the amplitude of the high-frequency current pulse detected by the current detector to obtain a processing result. The display is connected to the processor, and the display displays the processing result of the processor. The processing result includes the distribution of the amplitudes of the high-frequency current pulses at different position nodes on the collector line. When the processing result is obtained, the display displays the position of the fault point on the collector line. Moreover, the processor is further configured to communicate with an alarm to send an alarm message through the alarm. It should be noted that the processor is used to establish a correspondence between the position where each node is located and the change amount of the current according to the topological structure of the collector line. According to the correspondence, the position where the node with the largest change amount of the current is located is determined, which is the fault node on the collector line and is denoted as the fault node. According to the established correspondence, a coordinate system of the distance between the position where each node is located and the substation of the collector line and the change amount of the current is established. Corresponding to the position of each node in the coordinate system, the nodes between the substation of the collector line and the fault node in the coordinate system are linearly fitted to obtain a first straight line. The nodes between the fault node and the booster station of the collector line in the coordinate system are linearly fitted to obtain a second straight line. The intersection point of the first straight line and the second straight line is determined. The position of the node before the intersection point relative to the fault node is determined, that is, the first position. The position of the node after the intersection point relative to the fault node is determined, that is, the second position. The intersection point is located according to the first position and the second position, that is, the fault point of the collector line. It can be understood that the present invention measures the distance to the fault point through a coordinate system, thereby realizing the accurate positioning of the fault point on the collector line.

[0059] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the description and drawings of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A method for fault location of a collector line, characterized in that, Including the steps: Set several nodes between the box-type substation and the step-up substation of the collector line; Install current detectors at each of the said nodes, and detect the high-frequency current pulse amplitudes at each node on the collector line under the initial state through the current detectors, which are used as the initial current values; Record the real-time high-frequency current pulse amplitudes of the current detectors in the state to be detected, which are used as the measured current values; Locate the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value; The step of "locating the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value" includes: Locate the node where the fault is located on the collector line according to the current change amount between the initial current value and the measured current value of each node, which is recorded as the fault node; Determine the location of the fault point within the range of the fault node according to the current change amounts of the nodes before and after the fault node; The step of "locating the node where the fault is located on the collector line according to the current change amount between the initial current value and the measured current value of each node" includes: Establish the corresponding relationship between the location of each node and its current change amount according to the topological structure of the collector line; Determine the location of the node with the largest current change amount according to the corresponding relationship, which is the node where the fault is located on the collector line.

2. The method for locating a fault in a current collection line according to claim 1, wherein, The step of "determining the location of the fault point within the range of the fault node according to the current change amounts of the nodes before and after the fault node" includes: Perform linear fitting on the nodes between the box-type substation of the collector line and the fault node and the nodes between the fault node and the step-up substation respectively according to the established corresponding relationship; Determine the intersection point of the two linearly fitted lines and locate the location of the intersection point, which is the fault point of the collector line.

3. The method for locating a fault in a current collection line according to claim 2, wherein, The step of "performing linear fitting on the nodes between the box-type substation of the collector line and the fault node and the nodes between the fault node and the step-up substation respectively" includes: Establish a coordinate system of the distance between the location of each node and the box-type substation of the collector line and the current change amount according to the topological structure of the collector line; Corresponding to the position of each node in the coordinate system, perform linear fitting on the nodes between the box-type substation of the collector line and the fault node in the coordinate system to obtain the first line; Perform linear fitting on the nodes between the fault node and the step-up substation of the collector line in the coordinate system to obtain the second line.

4. The method for locating a fault in a current collector line according to claim 3, characterized in that, The step of "determining the intersection point of the two linearly fitted lines and locating the location of the intersection point" includes: Determine the intersection point of the first line and the second line; Determine the location of the intersection point relative to the previous node of the fault node, which is the first location; Determine the location of the intersection point relative to the next node of the fault node, which is the second location; Locate the intersection point according to the first location and the second location.

5. The method for locating a fault in a current collection line according to claim 1, wherein The step of "setting several nodes between the box-type substation and the step-up substation of the collector line" includes: Determine the node setting positions of the collector line according to the topological structure and line parameters of the collector line; Set nodes between the box-type substation and the step-up substation of the collector line according to the determined node setting positions.

6. A collector line fault location system, characterized in that, For implementing the collector line fault location method described in any one of claims 1 to 5, including: A number of current detectors, a number of nodes are set between the transformer substation and the step-up substation of the collector line, and the current detectors are set at each of the nodes, and the high-frequency current pulse amplitude at each node on the collector line in the initial state is detected by the current detectors as the initial current value; And a terminal, the terminal is connected to the current detectors, records the real-time high-frequency current pulse amplitude of the current detectors in the state to be detected as the measured current value, and the terminal locates the fault point of the collector line according to the change of the measured current value of each node relative to the initial current value.

7. The collector line fault location system according to claim 6, wherein The terminal includes a processor and a display, the processor is respectively connected to a number of the current detectors, the processor processes the high-frequency current pulse amplitude detected by the current detectors to obtain a processing result, the display is connected to the processor, and the display displays the processing result of the processor.

8. The fault location system for the current collection line according to claim 7, wherein The terminal further includes an alarm, the alarm is communicatively connected to the processor, and the alarm is used to send an alarm message according to the processing result of the processor.

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