A power transmission line distributed fault detection method and device

Abstract

The application discloses a power transmission line distributed fault detection method and device, solves the problem that the existing technology needs the participation of a cloud server in the judgment of the electromagnetic pulse generation position, and increases the waste of the cloud server. The power transmission line distributed fault detection method comprises the following steps: collecting an electric pulse signal; in response to the electric pulse signal originating from a first direction, generating and sending first effective information; in response to the electric pulse signal originating from a second direction, generating second effective information, receiving third effective information from a second direction collection point, and combining the second effective information and the third effective information to calculate the electromagnetic pulse generation position and the electromagnetic pulse generation time; and the effective information comprises collection electric pulse time and collection point position information. The application increases the identification capability of the distributed fault detection equipment and reduces the storage burden and communication burden of the cloud server.

Description

Technical Field

[0001] This application relates to the field of power transmission line detection technology, and in particular to a method and apparatus for distributed fault detection of power transmission lines. Background Technology

[0002] my country has a vast territory, with many high-voltage transmission lines exceeding 1,000 kilometers in length. During spring and summer, lightning often strikes these lines, causing damage. Besides lightning, foreign objects falling on the lines can also cause high-voltage discharges, indirectly damaging the transmission lines. To detect abnormal discharges on these high-voltage lines, distributed fault detection equipment has been installed on many high-voltage transmission lines in recent years. This equipment can detect abnormal electrical pulses on the high-voltage lines, store a segment of the pulse waveform data, record the time, and send it along with location information to a cloud server. The cloud server, based on the collected information from multiple detection points, can calculate the location of the abnormal discharge and, based on the waveform information, roughly determine the type of fault.

[0003] like Figure 1 As shown, if lightning strikes the transmission line between x2 and x3 near x3 at a certain moment, the lightning will generate a short-duration electrical pulse signal on the transmission line. This signal propagates from the point of impact to both sides at the speed of light. When the electrical pulse signal passes through... Figure 2 When the fault detection equipment is used, it records the time of receiving the pulse signal and the waveform data. This information, along with its own identification number, is then transmitted to the cloud server. The cloud server sorts the seven received times from smallest to largest, and selects the two smallest. Assuming the lightning strike location, the smallest should be T3, followed by T2. Assuming the distance from x2 to x3 is L, the lightning strike location is to the left of x3, at a distance of (Lc(T2-T3)) / 2. The time of the lightning strike is: (T2+T3) / 2-L / (2c).

[0004] Current distributed fault detection systems require cloud servers to determine the location of electromagnetic pulses (EMPs). When the number of detection points reaches a certain level, the overhead on the cloud server for this purpose becomes significant. The technology discussed in this application allows EMP location determination to be completed at the detection point, thus reducing the computational burden on the server. Summary of the Invention

[0005] This application provides a method and apparatus for distributed fault detection of power transmission lines, which solves the problem that the determination of the location of electromagnetic pulses in the prior art requires the participation of cloud servers, thus increasing the waste of cloud servers.

[0006] This application provides a method for distributed fault detection in transmission lines, comprising the following steps:

[0007] Acquire electrical pulse signals;

[0008] In response to an electrical pulse signal originating from a first direction, first valid information is generated and transmitted;

[0009] In response to the electric pulse signal originating from the second direction, second valid information is generated, and third valid information is received from the acquisition point in the second direction. The second valid information and the third valid information are combined to calculate the electromagnetic pulse occurrence position and electromagnetic pulse occurrence time.

[0010] The valid information includes the time of the acquired electrical pulse and the location information of the acquisition point.

[0011] Furthermore, the first device collects electrical pulse signals originating from a first direction, and the first device sends first valid information to the second device adjacent in the first direction; the electrical pulse signals originate from a second direction, and the first device receives third valid information sent by the third device adjacent in the second direction.

[0012] Furthermore, it also includes the following steps:

[0013] The device that completes the calculation of the location and time of electromagnetic pulse generation connects with the cloud and reports the electromagnetic pulse information.

[0014] Furthermore, the location of the electromagnetic pulse and the time of the lightning strike are as shown in formulas 1 to 4.

[0015] This application also provides a distributed fault detection device for transmission lines, used to implement the distributed fault detection method for transmission lines described in any of the above embodiments, comprising a first electrical pulse detection module, a second electrical pulse detection module, and a determination module. The first and second electrical pulse detection modules are respectively coupled to a cable via coupling coils. When one electrical pulse detection device detects a pulse, it causes the other electrical pulse detection device to shut down. The determination module is used to receive valid information from the current device and adjacent devices, and to calculate the location and time of the electromagnetic pulse occurrence.

[0016] Furthermore, the distance between the two coupled coils is greater than 20 centimeters.

[0017] Furthermore, the coupling coil is a hollow spiral coil without ferrite material.

[0018] Further, the first electrical pulse detection module includes a first coupling coil, a first field-effect transistor (FET), and a second FET. The second electrical pulse detection module includes a second coupling coil, a third FET, and a fourth FET. The first coupling coil is connected to the gate of the first FET, the drain of the first FET is connected to the gate of the second FET, and the drain of the second FET is connected to the gate of the first FET. The second coupling coil is connected to the gate of the fourth FET, the drain of the fourth FET is connected to the gate of the third FET, and the drain of the third FET is connected to the gate of the fourth FET. The drain of the second FET is connected to the gate of the third FET. The drain of the third FET is connected to the gate of the second FET. It also includes a microcontroller. The control terminals of the microcontroller are respectively connected to the drain of the first FET, the drain of the fourth FET, the gate of the second FET, and the gate of the third FET. One detection terminal of the microcontroller is connected to the gate of the first field-effect transistor and the gate of the fourth field-effect transistor, and the other detection terminal is connected to the drain of the second field-effect transistor and the drain of the third field-effect transistor.

[0019] Furthermore, the trigger signal generated by the coupling coil is detected by envelope detection. The detected signal is on the nanosecond level. The cutoff frequency of the field-effect transistor is ≥10 GHz.

[0020] This application also provides a distributed fault detection system for transmission lines, comprising any of the distributed fault detection devices described above. A plurality of distributed fault detection devices are evenly distributed along the transmission line.

[0021] The above-described technical solutions adopted in the embodiments of this application can achieve the following beneficial effects:

[0022] This application enhances the identification capability of distributed fault detection devices, as current market devices cannot identify the location and direction of electromagnetic pulse (EMP) occurrences. It reduces the computational burden on cloud servers; currently, the calculation of the location and timing of EMP occurrences is handled by the cloud server, while the novel device discussed in this application can handle this task itself. It also reduces the storage and communication burden on cloud servers. The original calculation method required all devices detecting fault pulses to report upwards, potentially resulting in hundreds or even thousands of communications for a single fault, and creating numerous records in the server's database. The improved method requires only one communication to create one record. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1A schematic diagram of a power transmission line equipped with distributed fault detection equipment using existing technology;

[0025] Figure 2 This is a flowchart of a distributed fault detection method for transmission lines according to an embodiment of this application;

[0026] Figure 3 A schematic diagram of a power transmission line equipped with a distributed fault detection device with direction recognition, as shown in an embodiment of this application;

[0027] Figure 4 This is a structural diagram of the dual-trigger circuit for positioning the direction of electrical pulses in an embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0030] Figure 2 This is a flowchart of a distributed fault detection method for power transmission lines according to an embodiment of this application.

[0031] This application provides a method for distributed fault detection in transmission lines, comprising the following steps:

[0032] Step 110: Acquire electrical pulse signals;

[0033] A distributed fault detection device collects electrical pulse signals.

[0034] Step 120: In response to the electrical pulse signal originating from the first direction, generate and send the first valid information;

[0035] The valid information includes the time of the acquired electrical pulse and the location information of the acquisition point.

[0036] For example, if the electrical pulse signal originates from one side of the transmission line, the valid information of the current distributed fault detection device will be sent to another distributed fault detection device adjacent to the direction of the electrical pulse signal source.

[0037] Step 130: In response to the electric pulse signal originating from the second direction, generate second valid information, receive third valid information from the acquisition point in the second direction, and combine the second valid information with the third valid information to calculate the electromagnetic pulse occurrence position and electromagnetic pulse occurrence time;

[0038] For example, if the electromagnetic pulse signal originates from the other side of the transmission line, valid information from adjacent distributed fault detection devices on that side is received. By combining the valid information from two adjacent distributed fault detection devices, the location and time of the electromagnetic pulse occurrence are calculated.

[0039] Furthermore, the first device collects electrical pulse signals, which originate from a first direction, and the first device sends first valid information to the second device adjacent to the first direction;

[0040] The electrical pulse signal originates from the second direction, and the first device receives the third valid information sent by the third device adjacent to it in the second direction.

[0041] Furthermore, the lightning strike occurred between the X and Y points of the distributed fault detection device, with X located in the first direction of Y, and the distance between X and Y being L.

[0042] T X >T Y The distance Y from the location where the electromagnetic pulse occurs is:

[0043] (Lc(T X -T Y )) / 2 formula 1

[0044] The time of the lightning strike was:

[0045] (T X +T Y Formula 2

[0046] T X <T Y The distance X from the location where the electromagnetic pulse occurs is:

[0047] (Lc(T Y -T X )) / 2Formula 3

[0048] The time of the lightning strike was:

[0049] (T X +T Y Formula 4

[0050] T X T is the time it takes for the electromagnetic pulse signal from lightning to reach the acquisition point X. Y denoted as , where is the time it takes for the electromagnetic pulse signal from lightning to reach the acquisition point Y. c is the speed of light.

[0051] Figure 3 A schematic diagram of a power transmission line equipped with a distributed fault detection device with direction recognition, according to an embodiment of this application.

[0052] For example, such as Figure 3 As shown, when lightning strikes the transmission line between x2 and x3, the seven detection devices in the diagram can obtain seven time and seven direction values. To reduce the computational burden, each device here has short-distance interconnection capability and a certain computing power. The specific implementation methods of communication and computing capabilities are diverse and will not be further limited here.

[0053] The rules here are as follows:

[0054] Once an electrical pulse signal is received and determined to be left, the trigger time and its own position number are sent to the adjacent device on the left after the signal acquisition is completed.

[0055] All electrical pulse signals received and identified as right-handed are switched to the receiving state of the nearby device communication state for a suitable period of time.

[0056] If only valid information from the adjacent device on the right is received, the location and time of the electromagnetic pulse (EMP) are calculated. In this example, only device x2 needs to be calculated. Let the distance between x2 and x3 be L. If T2 > T3, then the distance x3 from the EMP location is (Lc(T2-T3)) / 2. The time of the lightning strike is (T2+T3) / 2-L / (2c). Conversely, if the distance x2 from the EMP location is less than T2, then the distance x2 from the EMP location is (Lc(T3-T2)) / 2. The time of the lightning strike is (T2+T3) / 2-L / (2c).

[0057] Furthermore, it also includes the following steps:

[0058] The device that completes the calculation of the location and time of electromagnetic pulse generation connects with the cloud and reports the electromagnetic pulse information.

[0059] Furthermore, the electromagnetic pulse information includes the electromagnetic pulse occurrence time, electromagnetic pulse occurrence location, and electromagnetic pulse waveform data.

[0060] Devices that only calculate the location and electromagnetic pulse (EMP) occurrence time connect to the cloud and report the EMP occurrence time, location, and waveform data.

[0061] Figure 4 This is a structural diagram of a distributed fault detection device for power transmission lines according to an embodiment of this application.

[0062] This application also provides a distributed fault detection device for transmission lines, used to implement the distributed fault detection method for transmission lines described in any of the above embodiments, comprising a first electrical pulse detection module 1, a second electrical pulse detection module 2, and a determination module.

[0063] The first electrical pulse detection module and the second electrical pulse detection module are respectively coupled to a cable through a coupling coil.

[0064] When one electrical pulse detection device detects a pulse, it causes another electrical pulse detection device to shut down.

[0065] The determining module is used to receive valid information from the current device and adjacent devices, and to calculate the location and time of electromagnetic pulse occurrence.

[0066] Current distributed fault detection devices only have one set of electrical pulse detection devices, which cannot identify the direction from which the electrical pulse comes. The distributed fault detection device discussed in this application uses two sets of electrical pulse detection devices. Each device can lock itself when it detects a pulse. When an electrical pulse is detected, it will also reset the other detection device, thus ensuring that the other one will not be triggered by the electrical pulse. In this way, only one device is triggered each time an electrical pulse comes. If the triggered device is on the left, it means that the electrical pulse comes from the left, and vice versa. In this way, the novel distributed fault detection device discussed in this patent can determine the direction of fault current transmission.

[0067] Furthermore, the distance between the two coupled coils is greater than 20 centimeters.

[0068] For example, the distance between the two coupling coils should be as large as possible. The length of current distributed fault devices is generally 30 centimeters. Considering the actual size of the space, it needs to be more than 20 centimeters. The shorter the distance, the more difficult it is to implement the triggering circuit.

[0069] It should be noted that the 20 cm mentioned in this application is an approximate value. The length of a distributed fault detection device is generally 35 to 40 cm. Two high-frequency coupling coils need to be installed inside this device, which also includes a coupling power supply unit and a communication unit. Preferably, the two coupling coils used for triggering are as far apart as possible to maximize the time difference of the same electrical pulse on the two trigger circuits. The propagation speed of an electrical pulse along a wire is the speed of light; 1 ns can propagate 30 cm. Considering the delay in signal processing of the active circuit of the detection device, a large distance between the two coupling coils is desirable.

[0070] Furthermore, the coupling coil is a hollow spiral coil without ferrite material.

[0071] The coupling coil uses a hollow spiral coil without ferrite material, which is more suitable for coupling high-frequency electromagnetic fields.

[0072] Furthermore, the first electrical pulse detection module includes a first coupling coil 11, a first field-effect transistor 12, and a second field-effect transistor 13. The second electrical pulse detection module includes a second coupling coil 21, a third field-effect transistor 22, and a fourth field-effect transistor 23.

[0073] The first coupling coil is connected to the gate of the first field-effect transistor (FET). The drain of the first FET is connected to the gate of the second FET. The drain of the second FET is connected to the gate of the first FET. The second coupling coil is connected to the gate of the fourth FET. The drain of the fourth FET is connected to the gate of the third FET. The drain of the third FET is connected to the gate of the fourth FET. The drain of the second FET is connected to the gate of the third FET. The drain of the third FET is connected to the gate of the second FET.

[0074] It also includes a microcontroller 3.

[0075] The control terminal of the microcontroller is connected to the drain of the first field-effect transistor, the drain of the fourth field-effect transistor, the gate of the second field-effect transistor, and the gate of the third field-effect transistor, respectively.

[0076] One detection terminal of the microcontroller is connected to the gate of the first field-effect transistor and the gate of the fourth field-effect transistor, and the other detection terminal is connected to the drain of the second field-effect transistor and the drain of the third field-effect transistor.

[0077] For example, a microcontroller needs two input ports and one output port. The output port is tentatively named "R" (meaning reset), and the input ports are named "A" and "B". After the device circuit is powered on, the microcontroller first sends a high-level pulse to port "R". The duration of the high-level pulse is not particularly important; the purpose of this high level is to restore the device to an untriggered state. Then, the levels of ports "A" and "B" are detected. When both "A" and "B" are low, it indicates that the device has not been triggered; when one is high, it indicates that it has been triggered. If "A" is high, it means the trigger pulse comes from the left side of coupling coil A; if "B" is high, it means the trigger pulse comes from the right side of coupling coil B. The case where both are high will not exist, because triggering one will directly reset the other trigger circuit.

[0078] Specifically, such as Figure 4 As shown, during operation, the microcontroller first sends a high pulse to the R pin, and then the circuit enters the detection state, with A and B at low levels. When an electrical pulse arrives from the left side of coupling coil A, the gate of Q1 is momentarily pulled high, the drain of Q1 becomes low, and simultaneously the gate of Q2 becomes low, while the drain of Q2 becomes high. This high level can maintain the gate of Q1 at a high level, and it can also force the gate of Q3 to be high. At this time, even if Q4 is not triggered, the state of Q3 cannot be changed, and the microcontroller receives A as high and B as low. Similarly, if an electrical pulse signal arrives from the right side of coupling coil B, the microcontroller receives A as low and B as high. When it is necessary to restart the detection, the microcontroller only needs to send another high-level pulse to the R pin.

[0079] Furthermore, the trigger signal generated by the coupling coil is detected by envelope detection. The detected signal is on the order of nanoseconds.

[0080] The cutoff frequency of the field-effect transistor is ≥10 GHz.

[0081] Figure 4 The envelope detection constant is considered to be on the order of nanoseconds, and the cutoff frequency of the field-effect transistor used in the bistable circuit is considered to be above 10 GHz.

[0082] This application also provides a distributed fault detection system for transmission lines, comprising any of the distributed fault detection devices described above. A plurality of distributed fault detection devices are evenly distributed along the transmission line.

[0083] This application comprises two parts. The first part involves adding circuitry to the fault detection equipment to enable it to determine the direction of electrical pulses. The second part requires the novel fault detection equipment to have communication capabilities with adjacent devices. This can be achieved in many ways; even without adding any circuitry, current equipment can communicate with each other via telecommunications networks. After confirming that the devices can communicate, we optimize the equipment's accident handling process to reduce the computational, storage, and communication burden on the cloud server.

[0084] This application employs a dual-trigger circuit. Upon successful triggering, the trigger circuit immediately resets the trigger in the other direction to ensure that the other trigger cannot be triggered. This can be used in distributed fault detection equipment, or in conjunction with such equipment, for communication between adjacent devices. It can also be used in distributed fault detection equipment, or in conjunction with such equipment, to calculate the location and timing of electromagnetic pulse (EMP) occurrences. Each time a lightning strikes a power transmission cable, only one faulty device needs to report the location and timing of the EMP occurrence.

[0085] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0086] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for distributed fault detection in transmission lines, characterized in that, Includes the following steps: Acquire electrical pulse signals; Two sets of electrical pulse detection devices are used. Each device can lock itself when it detects a pulse. When an electrical pulse is detected, it will also reset the other detection device to ensure that the other device will not be triggered by the electrical pulse. Only one device is triggered each time an electrical pulse arrives. If the triggered device is on the left, it means that the electrical pulse comes from the left, and vice versa, thus determining the direction of the electrical pulse signal. In response to an electrical pulse signal originating from a first direction, first valid information is generated and transmitted; In response to the electric pulse signal originating from the second direction, second valid information is generated, and third valid information is received from the acquisition point in the second direction. The second valid information and the third valid information are combined to calculate the electromagnetic pulse occurrence position and electromagnetic pulse occurrence time. The valid information includes the time of the acquired electrical pulse and the location information of the acquisition point.

2. The distributed fault detection method for transmission lines according to claim 1, characterized in that, The first device collects electrical pulse signals, which originate from a first direction. The first device then sends first valid information to the second device adjacent to the first direction. The electrical pulse signal originates from the second direction, and the first device receives the third valid information sent by the third device adjacent to it in the second direction.

3. The distributed fault detection method for transmission lines according to claim 1, characterized in that, It also includes the following steps: The device that completes the calculation of the location and time of electromagnetic pulse generation connects with the cloud and reports the electromagnetic pulse information.

4. The distributed fault detection method for transmission lines according to claim 1, characterized in that, Lightning strikes between data collection points X and Y of the distributed fault detection device, with X located in the first direction of Y and the distance between X and Y being L. T X >T Y The distance Y from the location where the electromagnetic pulse occurs is (Lc(T)). X -T Y )) / 2, the time point of the lightning strike is: (T X +T Y ) / 2-L / (2c); T X <T Y The distance X from the location where the electromagnetic pulse occurs is (Lc(T)). Y -T X )) / 2, the time point of the lightning strike is: (T X +T Y ) / 2-L / (2c); T X T is the time it takes for the electromagnetic pulse to travel from its origin to the acquisition point X. Y denoted as , where is the time it takes for the electromagnetic pulse to travel from its origin to the acquisition point Y, and c is the speed of light.

5. A distributed fault detection device for transmission lines, characterized in that, The method for implementing the distributed fault detection method for transmission lines according to any one of claims 1-4 includes a first electrical pulse detection module, a second electrical pulse detection module, and a determination module. The first electrical pulse detection module and the second electrical pulse detection module are respectively coupled to a cable via coupling coils; When one electrical pulse detection module detects a pulse, it causes another electrical pulse detection module to shut down. The determining module is used to determine the source direction of the electric pulse; send valid information of the current device; receive valid information of neighboring devices; and calculate the location and time of the electromagnetic pulse occurrence based on the valid information of the current device and neighboring devices.

6. The distributed fault detection system for transmission lines according to claim 5, characterized in that, The distance between the two coupled coils is greater than 20 centimeters.

7. The distributed fault detection system for transmission lines according to claim 5, characterized in that, The coupling coil is a hollow spiral coil made of ferrite-free material.

8. The distributed fault detection system for transmission lines according to claim 5, characterized in that, The first electrical pulse detection module includes a first coupling coil, a first field-effect transistor, and a second field-effect transistor; The second electrical pulse detection module includes a second coupling coil, a third field-effect transistor, and a fourth field-effect transistor; The first coupling coil is connected to the gate of the first field-effect transistor, the drain of the first field-effect transistor is connected to the gate of the second field-effect transistor, and the drain of the second field-effect transistor is connected to the gate of the first field-effect transistor. The second coupling coil is connected to the gate of the fourth field-effect transistor, the drain of the fourth field-effect transistor is connected to the gate of the third field-effect transistor, and the drain of the third field-effect transistor is connected to the gate of the fourth field-effect transistor. The drain of the second field-effect transistor is connected to the gate of the third field-effect transistor; The drain of the third field-effect transistor is connected to the gate of the second field-effect transistor; It also includes a microcontroller; The control terminal of the microcontroller is connected to the drain of the first field-effect transistor, the drain of the fourth field-effect transistor, the gate of the second field-effect transistor, and the gate of the third field-effect transistor, respectively. One detection terminal of the microcontroller is connected to the gate of the first field-effect transistor and the gate of the fourth field-effect transistor, and the other detection terminal is connected to the drain of the second field-effect transistor and the drain of the third field-effect transistor.

9. The distributed fault detection system for transmission lines according to claim 8, characterized in that, The trigger signal generated by the coupling coil is detected by envelope detection; The detected signal is at the nanosecond level; The cutoff frequency of the field-effect transistor is ≥10 GHz.

10. A distributed fault detection system for transmission lines, characterized in that, The device includes the distributed fault detection equipment for transmission lines as described in any one of claims 5-9; Several distributed fault detection devices for power transmission lines are evenly distributed along the power transmission lines.

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