Power transmission line sound wave fault positioning method, device and system

Abstract

The invention provides a power transmission line sound wave fault positioning method, device and system, and the method comprises the steps: obtaining the working temperature, current and voltage waveforms and sound wave signals of a power transmission line in real time, and determining whether a fault current and voltage waveform and a fault sound wave occur on the power transmission line or not; if a fault occurs, heat generated by the fault on the power transmission line is calculated according to the fault current and voltage waveform, and then fault temperature rise caused by the fault on the power transmission line is calculated; then, according to the working temperature and the fault temperature rise corresponding to the power transmission line when the fault current and voltage waveform occurs, the fault sound wave propagation speed is calculated; and finally, according to the fault current and voltage waveform, the occurrence time of the fault sound wave and the propagation speed of the fault sound wave, calculating the distance between the fault position of the power transmission line and the sound wave detection point. Therefore, power transmission line fault positioning which is lower in cost and convenient for data analysis can be realized based on fault sound waves.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission line fault monitoring, and in particular to a method, device and system for locating acoustic faults in a power transmission line. Background Art

[0002] At present, the fault location of transmission lines usually adopts the traveling wave method or the impedance method; among them, the traveling wave method is based on the traveling wave transmission theory. When a transmission line fails, the fault point will generate traveling waves that propagate to both ends of the line. By detecting the time difference between the traveling wave reaching the measurement points at both ends of the line, combined with the propagation speed of the traveling wave in the transmission line, the distance from the fault point to the measurement point can be calculated; however, the extraction and analysis of the traveling wave signal is relatively complex and easily interfered, and the traveling wave will be reflected and refracted when passing through various equipment in the line (such as transformers, reactors, etc.), which increases the difficulty of analysis; moreover, the cost of using a traveling wave locator is relatively high, and it is only used in a few important lines. The impedance method is based on the concentrated parameter model or distributed parameter model of the transmission line, and uses the voltage and current measured at the time of the fault to calculate the impedance of the fault point. Faults at different locations will result in different impedance values. The fault location can be determined by the pre-established impedance and distance relationship curve. However, for complex network structures and fault conditions (such as high-resistance faults, grounding faults through transition resistance, etc.), the calculated impedance may have a large deviation, thereby affecting the accuracy of fault location.

[0003] Therefore, it is necessary to propose a transmission line fault location solution that is lower in cost and easier to process and analyze. Summary of the invention

[0004] In view of the deficiencies of the prior art mentioned above, the purpose of the present invention is to provide a transformer fault detection method based on the transformer grounding current, which can realize the monitoring of transformer multi-point grounding faults and local discharge faults based on the core and clamp grounding current, simplify the fault monitoring means of the power transformer, avoid the introduction of too many monitoring equipment, and realize the non-stop installation of the monitoring equipment. Moreover, it makes the inspection and maintenance of the monitoring equipment simpler, which can reduce the number of power outages of the power transformer during inspection and maintenance.

[0005] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions: A method for locating acoustic faults in a power transmission line, comprising: Acquire the operating temperature, current and voltage waveforms and acoustic wave signals of the transmission line in real time, and determine whether a fault current and voltage waveform and a fault acoustic wave appear on the transmission line; Calculate the heat generated by the fault on the transmission line according to the fault current and voltage waveforms, and calculate the fault temperature rise caused by the fault on the transmission line in combination with the mass and specific heat capacity of the transmission line; Calculating the fault sound wave propagation speed according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; The distance between the position where the transmission line fault occurs and the sound wave detection point is calculated according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the propagation speed of the fault sound wave.

[0006] According to a specific implementation, in the transmission line acoustic wave fault location method provided by the present invention, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is calculated as follows: Without considering the influence of the propagation speed of the fault current and voltage waveform, then:

[0007] When considering the influence of the propagation speed of the fault current and voltage waveform, then:

[0008] in, c represents the speed of light, v tr Expressed as the fault sound wave propagation speed, T rei is the occurrence time of the fault current and voltage waveform, T ac is the time when the fault sound wave appears.

[0009] According to a specific implementation, in the transmission line acoustic wave fault location method provided by the present invention, the fault acoustic wave propagation speed is calculated according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise as follows:

[0010]

[0011]

[0012] in, T nor is the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears, is the fault temperature rise; v l is the propagation speed of sound waves on the transmission line at room temperature, klt is the temperature coefficient; Q is the heat generated by the fault on the transmission line, m is the quality of the transmission line, C is the specific heat capacity of the transmission line.

[0013] According to a specific implementation, in the transmission line acoustic wave fault location method provided by the present invention, the maximum error distance is calculated according to the current sampling frequency of the acoustic wave detection point for the fault acoustic wave and the propagation speed of the fault acoustic wave; According to the maximum error distance, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is corrected and calculated to obtain the location interval where the transmission line fault occurs.

[0014] Based on the same inventive concept, the present invention also provides a transmission line acoustic wave fault locating device, which comprises: An acquisition module is used to obtain the operating temperature, current and voltage waveforms, and acoustic wave signals of the transmission line in real time; A waveform occurrence determination module is used to determine whether a fault current and voltage waveform and a fault sound wave appear on the transmission line; A fault temperature rise calculation module is used to calculate the heat generated by the fault on the transmission line according to the fault current and voltage waveform, and to calculate the fault temperature rise caused by the fault on the transmission line in combination with the mass and specific heat capacity of the transmission line; A fault sound wave propagation speed calculation module, used to calculate the fault sound wave propagation speed according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; The fault location calculation module is used to calculate the distance between the location where the transmission line fault occurs and the sound wave detection point according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the propagation speed of the fault sound wave.

[0015] According to a specific implementation, in the power transmission line acoustic wave fault locating device provided by the present invention, the fault location calculation module is configured as follows: when the influence of the propagation speed of the fault current voltage waveform is not considered, the distance between the location where the fault occurs in the transmission line and the acoustic wave detection point is calculated in the following manner:

[0016] When considering the influence of the propagation speed of the fault current and voltage waveform, the distance between the location where the fault occurs in the transmission line and the acoustic wave detection point is calculated as follows:

[0017] in, crepresents the speed of light, v tr Expressed as the fault sound wave propagation speed, T rei is the occurrence time of the fault current and voltage waveform, T ac is the time when the fault sound wave appears.

[0018] According to a specific implementation, in the power transmission line acoustic wave fault locating device provided by the present invention, the fault acoustic wave propagation speed calculation module is configured as follows: The method for calculating the fault sound wave propagation velocity is:

[0019]

[0020]

[0021] in, T nor is the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears, is the fault temperature rise; v l is the propagation speed of sound waves on the transmission line at room temperature, k lt is the temperature coefficient; Q is the heat generated by the fault on the transmission line, m is the quality of the transmission line, C is the specific heat capacity of the transmission line.

[0022] According to a specific implementation, in the power transmission line acoustic wave fault locating device provided by the present invention, the fault location calculation module is configured as follows: Calculating a maximum error distance according to a current sampling frequency of the fault sound wave at the sound wave detection point and a propagation speed of the fault sound wave; According to the maximum error distance, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is corrected and calculated to obtain the location interval where the transmission line fault occurs.

[0023] Based on the same inventive concept, the present invention also provides a transmission line acoustic wave fault location system, which comprises: At least one acoustic wave detection device, used to detect acoustic wave signals propagating on the transmission line; At least one current and voltage detection device, used to detect the current and voltage waveforms on the transmission line; at least one temperature detection device for detecting the operating temperature of the transmission line; And, at least one transmission line acoustic wave fault locating device provided by the present invention; wherein, the transmission line acoustic wave fault locating device is used to respectively obtain in real time the acoustic wave signal propagating on the electric line, the current and voltage, and the operating temperature of the transmission line.

[0024] Compared with the prior art, the present invention has the following beneficial effects: In the transmission line acoustic wave fault location method provided by the present invention, the operating temperature, current and voltage waveforms and acoustic wave signals of the transmission line are obtained in real time, and it is determined whether a fault current and voltage waveform and a fault acoustic wave appear on the transmission line; then, according to the fault current and voltage waveform that appears, the heat generated by the fault on the transmission line is calculated, and then the fault temperature rise caused by the fault on the transmission line is calculated; then, according to the operating temperature and fault temperature rise corresponding to the transmission line when the fault current and voltage waveform appears, the fault acoustic wave propagation speed is calculated; finally, according to the appearance time of the fault current and voltage waveform and the fault acoustic wave and the fault acoustic wave propagation speed, the distance between the position where the fault occurs in the transmission line and the acoustic wave detection point is calculated. Therefore, the present invention can realize transmission line fault location with lower cost and convenient data analysis based on the fault acoustic wave. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 A flow chart of the transmission line acoustic wave fault location method provided by the present invention; Figure 2 A schematic diagram of the structure of the power transmission line acoustic wave fault locating device provided by the present invention; Figure 3 This is a schematic diagram of the structure of the power transmission line acoustic wave fault location system provided by the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0027] like Figure 1 As shown, the present invention provides a method for locating acoustic faults in a power transmission line, which comprises: Acquire the operating temperature, current and voltage waveforms and acoustic wave signals of the transmission line in real time, and determine whether a fault current and voltage waveform and a fault acoustic wave appear on the transmission line; Calculate the heat generated by the fault on the transmission line according to the fault current and voltage waveforms, and calculate the fault temperature rise caused by the fault on the transmission line in combination with the mass and specific heat capacity of the transmission line; Calculating the fault sound wave propagation speed according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; The distance between the position where the transmission line fault occurs and the sound wave detection point is calculated according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the propagation speed of the fault sound wave.

[0028] Specifically, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is calculated as follows: Without considering the influence of the propagation speed of the fault current and voltage waveform, then:

[0029] When considering the influence of the propagation speed of the fault current and voltage waveform, then:

[0030] in, c represents the speed of light, v tr Expressed as the fault sound wave propagation speed, T rei is the occurrence time of the fault current and voltage waveform, T ac is the time when the fault sound wave appears.

[0031] Specifically, according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise, the fault sound wave propagation speed is calculated as follows:

[0032]

[0033]

[0034] in, T nor is the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears, is the fault temperature rise; v l is the propagation speed of sound waves on the transmission line at room temperature, k lt is the temperature coefficient; Q is the heat generated by the fault on the transmission line, m is the quality of the transmission line, C is the specific heat capacity of the transmission line.

[0035] In practice, taking the steel core aluminum stranded wire as an example, when a fault occurs, the vibration occurs closer to the outer layer of metal aluminum, and the propagation speed of sound in metal aluminum is approximately 5000m / s (normal temperature). However, the transmission line has heat loss, and the fault temperature is higher; in the present invention, it is considered that the propagation speed of sound in metal aluminum increases linearly with the increase of temperature, that is, .

[0036] At the same time, the heat generated by the fault on the transmission line Q According to Joule's law, current passing through a conductor will generate heat, and its expression is: ;in Q represents heat (in joules), I The current intensity (in amperes), R is the resistance of the conductor (in ohms), and is the time (in seconds). When current passes through a wire with resistance, part of the electrical energy is converted into heat energy, causing the wire to heat up.

[0037] Specifically, considering that the actual sampling data of the project is discrete and has certain errors; and in order to quickly repair the transmission line, it is necessary to determine the location interval of the transmission line fault. For example, for the maintenance of high-voltage transmission lines, in the open field, the fault point can be accurately found as long as it reaches within one kilometer of the fault point; therefore, during implementation, the maximum error distance is calculated based on the current sampling frequency of the fault sound wave at the sound wave detection point and the propagation speed of the fault sound wave; and based on the maximum error distance, the distance between the location where the transmission line fault occurs and the sound wave detection point is corrected and calculated to obtain the location interval of the transmission line fault.

[0038] Among them, the maximum error distance L e The calculation method is: ; Among them, real-time acquisition of the operating temperature of the transmission line, current and voltage waveforms, and sampling frequency of the acoustic wave signal f str ; In the maintenance of distribution networks, in cities with tall buildings, the line of sight is blocked, and a more accurate location of the fault point is needed to locate the fault point; therefore, the error tolerance can be set according to different actual conditions. L eb Specifically, through tolerance L eb Calculate the ideal sampling frequency f s ,Right now ; Then, when the ideal sampling frequency is actually calculated f s Lower than the sampling frequency of the device itself to obtain data f str, the fault location result will have a certain reliability; if the ideal sampling frequency actually calculated is f s Greater than the sampling frequency of the device itself to obtain data f str ,, because the sampling frequency of the device itself to obtain data is not accurate enough to locate this fault, so the positioning result can only be a range: .

[0039] like Figure 2 As shown, the present invention also provides a transmission line acoustic wave fault locating device, which comprises: An acquisition module is used to obtain the operating temperature, current and voltage waveforms, and acoustic wave signals of the transmission line in real time; A waveform occurrence determination module is used to determine whether a fault current and voltage waveform and a fault sound wave appear on the transmission line; A fault temperature rise calculation module is used to calculate the heat generated by the fault on the transmission line according to the fault current and voltage waveform, and to calculate the fault temperature rise caused by the fault on the transmission line in combination with the mass and specific heat capacity of the transmission line; A fault sound wave propagation speed calculation module, used to calculate the fault sound wave propagation speed according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; The fault location calculation module is used to calculate the distance between the location where the transmission line fault occurs and the sound wave detection point according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the propagation speed of the fault sound wave.

[0040] Specifically, the fault location calculation module is configured to: without considering the influence of the propagation speed of the fault current and voltage waveform, calculate the distance between the location where the fault occurs in the transmission line and the acoustic wave detection point in the following manner:

[0041] When considering the influence of the propagation speed of the fault current and voltage waveform, the distance between the location where the fault occurs in the transmission line and the acoustic wave detection point is calculated as follows:

[0042] in, c represents the speed of light, v tr Expressed as the fault sound wave propagation speed, T rei is the occurrence time of the fault current and voltage waveform, T ac is the time when the fault sound wave appears.

[0043] Specifically, the fault sound wave propagation speed calculation module is configured as follows: The method for calculating the fault sound wave propagation velocity is:

[0044]

[0045]

[0046] in, T nor is the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears, is the fault temperature rise; v l is the propagation speed of sound waves on the transmission line at room temperature, k lt is the temperature coefficient; Q is the heat generated by the fault on the transmission line, m is the quality of the transmission line, C is the specific heat capacity of the transmission line.

[0047] Specifically, the fault location calculation module is configured as follows: Calculating a maximum error distance according to a current sampling frequency of the fault sound wave at the sound wave detection point and a propagation speed of the fault sound wave; According to the maximum error distance, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is corrected and calculated to obtain the location interval where the transmission line fault occurs.

[0048] like Figure 3 As shown, the present invention also provides a transmission line acoustic wave fault location system, which includes: At least one acoustic wave detection device, used to detect acoustic wave signals propagating on the transmission line; At least one current and voltage detection device, used to detect the current and voltage waveforms on the transmission line; at least one temperature detection device for detecting the operating temperature of the transmission line; And, at least one transmission line acoustic wave fault locating device provided by the present invention; wherein, the transmission line acoustic wave fault locating device is used to respectively obtain in real time the acoustic wave signal propagating on the electric line, the current and voltage, and the operating temperature of the transmission line.

[0049] Moreover, the transmission line acoustic fault locating device determines whether a fault current and voltage waveform and a fault sound wave appear on the transmission line based on the real-time acquisition of the acoustic wave signal, current and voltage propagated on the line and the operating temperature of the transmission line; calculates the heat generated on the transmission line by the fault according to the fault current and voltage waveform, and calculates the fault temperature rise on the transmission line caused by the fault in combination with the mass and specific heat capacity of the transmission line; calculates the fault sound wave propagation speed based on the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; calculates the distance between the location where the transmission line fault occurs and the sound wave detection point according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the fault sound wave propagation speed.

[0050] It should be understood that the device or apparatus disclosed in the present invention can be implemented in other ways. For example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the communication connection between modules can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical or other forms.

[0051] In addition, each functional module in each embodiment of the present invention may be integrated into one processing unit, each module may exist physically separately, or two or more modules may be integrated into one processing unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional unit.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for locating faults in power transmission lines by acoustic waves, comprising: Acquire the operating temperature, current and voltage waveforms and acoustic wave signals of the transmission line in real time, and determine whether a fault current and voltage waveform and a fault acoustic wave appear on the transmission line; Calculate the heat generated by the fault on the transmission line according to the fault current and voltage waveforms, and calculate the fault temperature rise caused by the fault on the transmission line in combination with the mass and specific heat capacity of the transmission line; Calculating the fault sound wave propagation speed according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; The distance between the position where the transmission line fault occurs and the sound wave detection point is calculated according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the propagation speed of the fault sound wave.

2. The method for locating a power transmission line acoustic fault according to claim 1, wherein the distance between the position where the transmission line fault occurs and the acoustic wave detection point is calculated by: Without considering the influence of the propagation speed of the fault current and voltage waveform, then: When considering the influence of the propagation speed of the fault current and voltage waveform, then: in, c represents the speed of light, v tr Expressed as the fault sound wave propagation speed, T rei is the occurrence time of the fault current and voltage waveform, T ac is the time when the fault sound wave appears.

3. The transmission line acoustic wave fault location method according to claim 2, wherein the fault acoustic wave propagation speed is calculated according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise in the following manner: in, T nor is the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears, is the fault temperature rise; v l is the propagation speed of sound waves on the transmission line at room temperature, k lt is the temperature coefficient; Q is the heat generated by the fault on the transmission line, m is the quality of the transmission line, C is the specific heat capacity of the transmission line.

4. The method for locating a power transmission line acoustic fault according to any one of claims 1 to 3, wherein: Calculating a maximum error distance according to a current sampling frequency of the fault sound wave at the sound wave detection point and a propagation speed of the fault sound wave; According to the maximum error distance, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is corrected and calculated to obtain the location interval where the transmission line fault occurs.

5. A transmission line acoustic fault location device, characterized in that: include: An acquisition module is used to obtain the operating temperature, current and voltage waveforms, and acoustic wave signals of the transmission line in real time; A waveform occurrence determination module is used to determine whether a fault current and voltage waveform and a fault sound wave appear on the transmission line; A fault temperature rise calculation module is used to calculate the heat generated by the fault on the transmission line according to the fault current and voltage waveform, and to calculate the fault temperature rise caused by the fault on the transmission line in combination with the mass and specific heat capacity of the transmission line; A fault sound wave propagation speed calculation module, used to calculate the fault sound wave propagation speed according to the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears and the fault temperature rise; The fault location calculation module is used to calculate the distance between the location where the transmission line fault occurs and the sound wave detection point according to the appearance time of the fault current and voltage waveform, the appearance time of the fault sound wave and the propagation speed of the fault sound wave.

6. A transmission line acoustic wave fault location device as claimed in claim 5, characterized in that: The fault location calculation module is configured to calculate the distance between the location where the fault occurs in the transmission line and the acoustic wave detection point in the following manner without considering the influence of the propagation speed of the fault current and voltage waveform: When considering the influence of the propagation speed of the fault current and voltage waveform, the distance between the location where the fault occurs in the transmission line and the acoustic wave detection point is calculated as follows: in, c represents the speed of light, v tr Expressed as the fault sound wave propagation speed, T rei is the occurrence time of the fault current and voltage waveform, T ac is the time when the fault sound wave appears.

7. A transmission line acoustic wave fault location device as claimed in claim 6, characterized in that: The fault sound wave propagation velocity calculation module is configured as follows: The method for calculating the fault sound wave propagation velocity is: in, T nor is the operating temperature corresponding to the transmission line when the fault current and voltage waveform appears, is the fault temperature rise; v l is the propagation speed of sound waves on the transmission line at room temperature, k lt is the temperature coefficient; Q is the heat generated by the fault on the transmission line, m is the quality of the transmission line, C is the specific heat capacity of the transmission line.

8. A transmission line acoustic wave fault location device as claimed in claims 5 to 7, characterized in that: The fault location calculation module is configured as follows: Calculating a maximum error distance according to a current sampling frequency of the fault sound wave at the sound wave detection point and a propagation speed of the fault sound wave; According to the maximum error distance, the distance between the location where the transmission line fault occurs and the acoustic wave detection point is corrected and calculated to obtain the location interval where the transmission line fault occurs.

9. A transmission line acoustic fault location system, characterized in that: include: At least one acoustic wave detection device, used to detect acoustic wave signals propagating on the transmission line; At least one current and voltage detection device, used to detect the current and voltage waveforms on the transmission line; at least one temperature detection device for detecting the operating temperature of the transmission line; And, at least one transmission line acoustic wave fault locating device as claimed in any one of claims 5 to 8; wherein, the transmission line acoustic wave fault locating device is used to respectively obtain in real time the acoustic wave signal propagating on the electric line, the current and voltage, and the operating temperature of the transmission line.

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