An external simulation method, device and equipment for the partial discharge sound source of a submarine cable

Abstract

The present invention relates to the technical field of partial discharge inspection of power equipment, and discloses an external simulation method, device and equipment for the partial discharge sound source of a submarine cable. The present invention conducts a sound source coupling and distribution test on the target submarine cable for partial discharge to construct a first sound-electric signal transfer function and a first sound signal distribution equation; conducts an external sound source characteristic inversion test on the target cable to construct a second sound-electric signal transfer function and a second sound signal distribution equation; compares the differences between the first sound-electric signal transfer function and the second sound-electric signal transfer function in the target frequency band, and compares the differences between the first sound signal distribution equation and the second sound signal distribution equation in the target frequency band. If the obtained difference comparison result meets the requirements of the preset difference value range, the external sound source configuration parameters corresponding to the external sound source characteristic inversion test are used as the target external sound source configuration parameters. The present invention realizes the acoustic vibration simulation of partial discharge signals for submarine cables.

Description

Technical Field

[0001] The present invention relates to the technical field of partial discharge inspection of power equipment, and particularly to an external simulation method, device and equipment for the sound source of partial discharge of submarine cables. Background Art

[0002] Submarine cables are important power equipment for offshore power transmission. They are laid on the seabed and can be dozens of kilometers long. Partial discharge detection is an important means to discover early insulation defects of cables, and can guide the operation and maintenance and replacement of submarine cables.

[0003] Partial discharge will generate effects such as sound, electricity, and heat. The thermal effect generated by partial discharge is relatively weak and the monitoring accuracy is not high. Therefore, the advantage of detecting based on vibration information is more obvious. According to the land cable monitoring technology, in a laboratory environment, generally defects are set inside the cable, and partial discharge is generated through a high-voltage test, so as to generate a sound source for subsequent processing. However, due to the high cost, complex structure, and long single-laying length of submarine cables, the method of setting defects inside the cable is costly, difficult and not universal.

[0004] If an external sound source array that can simulate the stress change generated by partial discharge of submarine cables on the optical fiber can be set, and this external sound source array is used for the partial discharge detection of submarine cables with optical fiber sensing, low-cost partial discharge detection for submarine cables can be achieved. However, there is currently no related technology for acoustic vibration simulation of partial discharge signals for submarine cables. Summary of the Invention

[0005] The present invention provides an external simulation method, device and equipment for the sound source of partial discharge of submarine cables, and solves the technical problem of how to perform acoustic vibration simulation of partial discharge signals for submarine cables.

[0006] The first aspect of the present invention provides an external simulation method for the sound source of partial discharge of submarine cables, including:

[0007] Obtaining first test data obtained from a sound source coupling and distribution test for partial discharge of a target submarine cable; the sound source coupling and distribution test for partial discharge applies a corresponding first simulation signal to the target cable by simulating a partial discharge source, and obtains an acoustic signal under the first simulation signal through a sound sensor array arranged on the optical fiber of the target cable;

[0008] Constructing a first acoustic-electric signal transfer function and a first acoustic signal distribution equation according to the first test data;

[0009] Obtain the second test data obtained from the external sound source characteristic inversion test on the target cable; the external sound source characteristic inversion test applies a second analog signal to the target cable through an external sound source, and obtains the sound signal under the second analog signal through a sound sensor array arranged on the optical fiber of the target cable;

[0010] Construct a second acoustic-electric signal transfer function and a second acoustic signal distribution equation according to the second test data;

[0011] Compare the differences between the first acoustic-electric signal transfer function and the second acoustic-electric signal transfer function in the target frequency band to obtain a first difference comparison result, and compare the differences between the first acoustic signal distribution equation and the second acoustic signal distribution equation in the target frequency band to obtain a second difference comparison result;

[0012] If the first difference comparison result and the second difference comparison result meet the requirements of the preset difference value range, use the external sound source configuration parameters corresponding to the external sound source characteristic inversion test as the target external sound source configuration parameters; the external sound source configuration parameters include the frequency shift of the external sound source and the included angle between the first connection line and the second connection line, the first connection line is the connection line between the center of the submarine cable and the optical fiber, and the second connection line is the connection line between the center of the submarine cable and the external sound source.

[0013] According to an implementable manner of the first aspect of the present invention, the simulated partial discharge source includes a high-voltage DC source and a discharge electrode connected to each other; in the acoustic source coupling and distribution test of the partial discharge, one of the cables of the target submarine cable is replaced with a copper pipe wrapped with an insulating layer on the outer wall, and the discharge electrode is arranged inside the copper pipe.

[0014] According to an implementable manner of the first aspect of the present invention, the constructing the first acoustic-electric signal transfer function and the first acoustic signal distribution equation according to the first test data includes:

[0015] Perform frequency-domain analysis on the first analog signal to obtain the frequency-domain form of the simulated partial discharge source;

[0016] Perform frequency-domain analysis on the obtained sound signal under the first analog signal, and couple the obtained frequency-domain analysis result with the first relative position parameter between the simulated partial discharge source and the optical fiber to obtain the first acoustic signal frequency-domain form; the first relative position parameter is the distance from the center of the simulated partial discharge source to the optical fiber;

[0017] Construct the first acoustic-electric signal transfer function according to the frequency-domain form of the simulated partial discharge source and the first acoustic signal frequency-domain form;

[0018] Construct the first acoustic signal distribution equation according to the first acoustic signal frequency-domain form.

[0019] In an implementable manner according to the first aspect of the present invention, multiple groups of external sound sources are provided in the external sound source characteristic inversion test; constructing the second acoustic-electric signal transfer function and the second acoustic signal distribution equation according to the second test data includes:

[0020] Constructing a corresponding acoustic-electric signal transfer function and an acoustic signal distribution equation for each group of external sound sources;

[0021] Superposing the acoustic-electric signal transfer functions corresponding to each group of external sound sources to obtain the second acoustic-electric signal transfer function;

[0022] Superposing the acoustic signal distribution equations corresponding to each group of external sound sources to obtain the second acoustic signal distribution equation.

[0023] In an implementable manner according to the first aspect of the present invention, constructing a corresponding acoustic-electric signal transfer function and an acoustic signal distribution equation for each group of external sound sources includes:

[0024] Taking any group of external sound sources as the target external sound source, performing frequency-domain analysis on the target analog signal of the target external sound source to obtain the frequency-domain form of the target external sound source;

[0025] Performing frequency-domain analysis on the acoustic signal under the obtained target analog signal, and coupling the obtained frequency-domain analysis result with the second relative position parameter between the target external sound source and the optical fiber to obtain the second acoustic signal frequency-domain form; the second relative position parameter includes the angle between the first connection line and the second connection line;

[0026] Constructing the acoustic-electric signal transfer function corresponding to the target external sound source according to the frequency-domain form of the target external sound source and the second acoustic signal frequency-domain form;

[0027] Constructing the acoustic signal distribution equation corresponding to the target external sound source according to the second acoustic signal frequency-domain form.

[0028] In an implementable manner according to the first aspect of the present invention, three groups of external sound sources are provided in the external sound source characteristic inversion test.

[0029] In an implementable manner according to the first aspect of the present invention, the requirement for the preset difference value range is:

[0030] Both the first difference comparison result and the second difference comparison result are less than 20%.

[0031] The second aspect of the present invention provides an external simulation device for a partial discharge sound source of a submarine cable, including:

[0032] The first acquisition module is used to acquire first test data obtained from a local discharge sound source coupling and distribution test on a target submarine cable; in the local discharge sound source coupling and distribution test, a corresponding first simulation signal is applied to the target cable by simulating a local discharge source, and an acoustic signal under the first simulation signal is acquired by a sound sensor array arranged on the optical fiber of the target cable.

[0033] The first construction module is used to construct a first acoustic-electric signal transfer function and a first acoustic signal distribution equation according to the first test data.

[0034] The second acquisition module is used to acquire second test data obtained from an external sound source characteristic inversion test on the target cable; in the external sound source characteristic inversion test, a second simulation signal is applied to the target cable by an external sound source, and an acoustic signal under the second simulation signal is acquired by a sound sensor array arranged on the optical fiber of the target cable.

[0035] The second construction module is used to construct a second acoustic-electric signal transfer function and a second acoustic signal distribution equation according to the second test data.

[0036] The comparison module is used to compare the difference between the first acoustic-electric signal transfer function and the second acoustic-electric signal transfer function in a target frequency band to obtain a first difference comparison result, and compare the difference between the first acoustic signal distribution equation and the second acoustic signal distribution equation in the target frequency band to obtain a second difference comparison result.

[0037] The determination module is used to, if the first difference comparison result and the second difference comparison result meet the requirements of a preset difference value range, use the external sound source configuration parameters corresponding to the external sound source characteristic inversion test as the target external sound source configuration parameters; the external sound source configuration parameters include the frequency shift of the external sound source and the included angle between a first connection line and a second connection line, the first connection line being the connection line between the center of the submarine cable and the optical fiber, and the second connection line being the connection line between the center of the submarine cable and the external sound source.

[0038] According to an implementable manner of the second aspect of the present invention, the simulated local discharge source includes a high-voltage DC source and a discharge electrode connected to each other; in the local discharge sound source coupling and distribution test, one phase cable of the target submarine cable is replaced with a copper pipe wrapped with an insulating layer on the outer wall, and the discharge electrode is arranged inside the copper pipe.

[0039] According to an implementable manner of the second aspect of the present invention, the first construction module includes:

[0040] The first analysis unit is used to perform frequency domain analysis on the first simulation signal to obtain the frequency domain form of the simulated local discharge source.

[0041] A second analysis unit for performing frequency-domain analysis on the acoustic signal under the acquired first analog signal, coupling the obtained frequency-domain analysis result with the first relative position parameter between the analog partial discharge source and the optical fiber to obtain the first acoustic signal in frequency-domain form; the first relative position parameter is the distance from the center of the analog partial discharge source to the optical fiber.

[0042] A first construction unit for constructing the first acoustic-electric signal transfer function according to the frequency-domain form of the analog partial discharge source and the frequency-domain form of the first acoustic signal.

[0043] A second construction unit for constructing the first acoustic signal distribution equation according to the frequency-domain form of the first acoustic signal.

[0044] According to an implementable manner of the second aspect of the present invention, multiple groups of external sound sources are set in the external sound source characteristic inversion test; the second construction module includes:

[0045] A third construction unit for constructing the corresponding acoustic-electric signal transfer function and acoustic signal distribution equation for each group of external sound sources.

[0046] A first superposition unit for superposing the acoustic-electric signal transfer functions corresponding to each group of external sound sources to obtain the second acoustic-electric signal transfer function.

[0047] A second superposition unit for superposing the acoustic signal distribution equations corresponding to each group of external sound sources to obtain the second acoustic signal distribution equation.

[0048] According to an implementable manner of the second aspect of the present invention, the third construction unit includes:

[0049] A first analysis subunit for taking any group of external sound sources as the target external sound source and performing frequency-domain analysis on the target analog signal of the target external sound source to obtain the frequency-domain form of the target external sound source.

[0050] A second analysis subunit for performing frequency-domain analysis on the acoustic signal under the acquired target analog signal, coupling the obtained frequency-domain analysis result with the second relative position parameter between the target external sound source and the optical fiber to obtain the second acoustic signal in frequency-domain form; the second relative position parameter includes the angle between the first connection line and the second connection line.

[0051] A first construction subunit for constructing the acoustic-electric signal transfer function corresponding to the target external sound source according to the frequency-domain form of the target external sound source and the frequency-domain form of the second acoustic signal.

[0052] A second construction subunit for constructing the acoustic signal distribution equation corresponding to the target external sound source according to the frequency-domain form of the second acoustic signal.

[0053] In an implementable manner according to the second aspect of the present invention, three external sound sources are provided in the external sound source characteristic inversion test.

[0054] In an implementable manner according to the second aspect of the present invention, the requirement for the preset difference value range is as follows:

[0055] Both the first difference comparison result and the second difference comparison result are less than 20%.

[0056] The third aspect of the present invention provides an external simulation device for the partial discharge sound source of a submarine cable, including:

[0057] A memory for storing instructions; wherein, the instructions are used to implement the external simulation method for the partial discharge sound source of the submarine cable described in any one of the above implementable manners;

[0058] A processor for executing the instructions in the memory.

[0059] The fourth aspect of the present invention is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the external simulation method for the partial discharge sound source of the submarine cable described in any one of the above implementable manners.

[0060] It can be seen from the above technical solutions that the present invention has the following advantages:

[0061] The present invention conducts a sound source coupling and distribution test on the partial discharge of the target submarine cable, constructs a first sound-electric signal transfer function and a first sound signal distribution equation according to the obtained first test data; conducts an external sound source characteristic inversion test on the target cable, and constructs a second sound-electric signal transfer function and a second sound signal distribution equation according to the obtained second test data; compares the differences between the first sound-electric signal transfer function and the second sound-electric signal transfer function in the target frequency band to obtain a first difference comparison result, and compares the differences between the first sound signal distribution equation and the second sound signal distribution equation in the target frequency band to obtain a second difference comparison result; if the first difference comparison result and the second difference comparison result meet the requirements of the preset difference value range, the external sound source configuration parameters corresponding to the external sound source characteristic inversion test are used as the target external sound source configuration parameters; the present invention realizes the acoustic vibration simulation of the partial discharge signal of the submarine cable, and the external sound source based on the target external sound source configuration parameters can simulate the stress change generated by the partial discharge of the submarine cable on the optical fiber, and can be used in the fields of partial discharge detection and positioning of submarine cables for optical fiber sensing. Description of the Drawings

[0062] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the 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 these drawings.

[0063] Figure 1 Flowchart of an external simulation method for the partial discharge sound source of a submarine cable provided by an optional embodiment of the present invention;

[0064] Figure 2 Schematic diagram of the sound source coupling and distribution test of partial discharge provided by an optional embodiment of the present invention;

[0065] Figure 3 Schematic diagram of the position of the center of the discharge source and the optical fiber provided by an optional embodiment of the present invention;

[0066] Figure 4 Schematic diagram of the principle of the external sound source characteristic inversion test provided by an optional embodiment of the present invention;

[0067] Figure 5 Schematic diagram of the position of the center of the external sound source and the optical fiber provided by an optional embodiment of the present invention;

[0068] Figure 6 Schematic diagram of the layout of the external sound source array provided by an optional embodiment of the present invention;

[0069] Figure 7 Structural connection block diagram of an external simulation device for the partial discharge sound source of a submarine cable provided by an optional embodiment of the present invention.

[0070] Reference signs:

[0071] 1 - First acquisition module; 2 - First construction module; 3 - Second acquisition module; 4 - Second construction module; 5 - Comparison module; 6 - Determination module. Detailed implementation manners

[0072] The embodiments of the present invention provide an external simulation method, device and equipment for the partial discharge sound source of a submarine cable, which are used to solve the technical problem of how to perform acoustic vibration simulation on the partial discharge signal of a submarine cable.

[0073] In order to make the object, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0074] The present invention provides an external simulation method for the local discharge sound source of a submarine cable.

[0075] Please refer to Figure 1 , Figure 1 which shows a flowchart of an external simulation method for the local discharge sound source of a submarine cable provided by an embodiment of the present invention.

[0076] An external simulation method for the local discharge sound source of a submarine cable provided by an embodiment of the present invention includes steps S1 - S6.

[0077] Step S1, obtaining first test data obtained from a sound source coupling and distribution test for local discharge of a target submarine cable; the sound source coupling and distribution test for local discharge applies a corresponding first simulation signal to the target cable by simulating a local discharge source, and obtains a sound signal under the first simulation signal through a sound sensor array arranged on the optical fiber of the target cable.

[0078] Among them, to obtain better test results, a suitable submarine cable is selected as the target submarine cable. The selection principle of the submarine cable can be set according to the actual situation, and in this embodiment, it is not limited.

[0079] The purpose of the sound source coupling and distribution test for local discharge is to obtain the correspondence between the local discharge amount and the sound signal, as well as the sound signal difference at different positions of the optical fiber.

[0080] In an implementable manner, the simulated local discharge source includes a high - voltage DC source and a discharge electrode connected to each other; in the sound source coupling and distribution test for local discharge, one phase cable of the target submarine cable is replaced with a copper tube wrapped with an insulating layer on the outer wall, and the discharge electrode is arranged inside the copper tube.

[0081] Figure 2The schematic diagram of the sound source coupling and distribution test of partial discharge provided by the embodiment of the present invention is shown. When specifically conducting the sound source coupling and distribution test of partial discharge, a three-core submarine cable with an appropriate length can be selected, for example, a 1m long three-core submarine cable. One of the phase cables is taken out and replaced with an insulated copper pipe with an equal diameter and an outer wrap. The dimensions of the copper pipe are the same as those of the corresponding phase cable of the three-core submarine cable. The insulated copper pipe with an equal diameter and an outer wrap may include a copper pipe, an insulating layer, a copper shielding layer, and a rubber layer connected in sequence, as Figure 2 shown.

[0082] The discharge electrode is arranged in the copper pipe and led out by an insulated wire, and is externally connected to the high-voltage DC power supply to simulate partial discharge. Since the output of the high-voltage DC power supply is controllable, the setting here can achieve the control of the discharge amount.

[0083] As a specific implementation manner, sound insulation sponges are used to block both ends of the discharge electrode to reduce the diffusion of sound signals along the axial air gap of the copper pipe. A plurality of sound sensors are arranged on the outer skin of the three groups of optical fibers to form a sound sensor array. The center of the sound sensor array is preferably horizontally aligned with the discharge electrode. The outputs of the sound sensors of the sound sensor array are externally connected to a synchronous sampling device for analyzing sound signals.

[0084] As a specific implementation manner, the synchronous sampling device is a multi-channel synchronous sampling device as Figure 2 shown to achieve the synchronous sampling of each sound signal.

[0085] As a specific implementation manner, a plurality of patch-type sound sensors can be arranged at equal intervals on the outer skin of each group of optical fibers. The distance between two adjacent patch-type sound sensors can be set according to the length of the optical fiber. For example, for a 1m long optical fiber, the distance between two adjacent patch-type sound sensors is set to 10cm.

[0086] It should be noted that different types of discharges, such as air gap discharge, surface discharge, etc., can be simulated by changing the form of the discharge electrode.

[0087] Step S2, constructing a first acoustic-electric signal transfer function and a first sound signal distribution equation according to the first test data.

[0088] In a feasible manner, the constructing a first acoustic-electric signal transfer function and a first sound signal distribution equation according to the first test data includes:

[0089] Performing frequency domain analysis on the first analog signal to obtain the frequency domain form of the simulated partial discharge source;

[0090] Perform frequency-domain analysis on the acoustic signal under the obtained first analog signal, and couple the obtained frequency-domain analysis result with the first relative position parameter of the analog partial discharge source and the optical fiber to obtain the first acoustic signal in frequency-domain form; the first relative position parameter is the distance from the center of the analog partial discharge source to the optical fiber.

[0091] Construct the first acoustic-electric signal transfer function according to the frequency-domain form of the analog partial discharge source and the first acoustic signal in frequency-domain form.

[0092] Construct the first acoustic signal distribution equation according to the first acoustic signal in frequency-domain form.

[0093] The establishment of the first acoustic-electric signal transfer function and the first acoustic signal distribution equation can provide a reference for subsequent inversion of the external sound source. Assume that the discharge source is located at the center of a certain-phase cable, and the vertical distance from the center of the discharge source to different optical fibers is fixed. Take a certain optical fiber as an example for analysis. The straight-line distance between the discharge source and different positions of the optical fiber is L, the shortest distance is the vertical distance l, and the other side of the triangle is r, as Figure 3 shown. The sound propagation process is affected by the medium. For different lengths of L, there are differences in the sound propagation process.

[0094] Based on Figure 3 the shown positional relationship, since the cable structure is relatively consistent along the axial direction, the medium difference in the sound propagation to the optical fiber can be represented by the length L. Perform frequency-domain analysis on the analog partial discharge source and the obtained time-domain waveform of the sound signal, and the frequency-domain form E(ω) of the analog partial discharge source can be obtained. Coupling with the optical fiber gives the first acoustic signal in frequency-domain form V1(L, ω). E(ω) undergoes attenuation and deformation to obtain V1(L, ω). The relationship between the two is as follows

[0095] V1(L, ω) = E(ω)·A1(L, ω)·F1(L, ω)

[0096] In the formula, ω represents frequency, A1(L, ω) is the attenuation function of the signal, and F1(L, ω) is the phase transformation function of the signal.

[0097] Convert L to r for easy calculation and analysis. The above formula can be changed to

[0098] V1(r, ω) = E(ω)·A1(r, ω)·F1(r, ω)

[0099] Construct the transfer function of the acoustic-electric signal under the vertical distance (i.e., the first acoustic-electric signal transfer function) as:

[0100]

[0101] In the formula, |H1(ω)| is the attenuation factor of the transfer function, ψ1(ω) is the phase transformation factor of the transfer function, and j is the imaginary part.

[0102] The distribution equation of the acoustic signal on the optical fiber (i.e., the first acoustic signal distribution equation) is constructed as follows:

[0103]

[0104] In the formula, |D1(r,ω)| is the attenuation factor of the distribution equation, and φ1(r,ω) is the phase transformation factor of the distribution equation.

[0105] Step S3: Obtain the second test data obtained from the external sound source characteristic inversion test on the target cable; in the external sound source characteristic inversion test, a second simulation signal is applied to the target cable by an external sound source, and the acoustic signal under the second simulation signal is obtained through a sound sensor array arranged on the optical fiber of the target cable.

[0106] As a feasible way, as Figure 4 shown, an external sound source can be set on the test platform for the sound source coupling and distribution test of partial discharge, so as to obtain the transfer function and distribution equation between the external sound source and the optical fiber. As a specific implementation method, the external sound source consists of a signal generator, a signal conditioning circuit, and an electroacoustic transducer. The signal generator is used to generate the original electrical signal, and the electroacoustic transducer can be placed on the center line of the sound sensor array. By changing the position of the electroacoustic transducer, the signals of the sensors in different optical fibers can be obtained.

[0107] As a specific real-time method, the electroacoustic transducer is a piezoelectric electroacoustic transducer.

[0108] Step S4: Construct a second acoustic-electric signal transfer function and a second acoustic signal distribution equation according to the second test data.

[0109] In a feasible way, multiple groups of external sound sources are set in the external sound source characteristic inversion test; constructing the second acoustic-electric signal transfer function and the second acoustic signal distribution equation according to the second test data includes:

[0110] Construct a corresponding acoustic-electric signal transfer function and an acoustic signal distribution equation for each group of external sound sources;

[0111] Superimpose the acoustic-electric signal transfer functions corresponding to each group of external sound sources to obtain the second acoustic-electric signal transfer function;

[0112] Superimpose the acoustic signal distribution equations corresponding to each group of external sound sources to obtain the second acoustic signal distribution equation.

[0113] In a feasible way, constructing the corresponding acoustic-electric signal transfer function and acoustic signal distribution equation for each group of external sound sources includes:

[0114] Taking any set of external sound sources as the target external sound source, perform frequency-domain analysis on the target analog signal of the target external sound source to obtain the frequency-domain form of the target external sound source;

[0115] Perform frequency-domain analysis on the sound signal under the obtained target analog signal, and couple the obtained frequency-domain analysis result with the second relative position parameter between the target external sound source and the optical fiber to obtain the second sound signal frequency-domain form; the second relative position parameter includes the angle between the first connection line and the second connection line;

[0116] According to the frequency-domain form of the target external sound source and the second sound signal frequency-domain form, construct the acoustic-electric signal transfer function corresponding to the target external sound source;

[0117] Construct the sound signal distribution equation corresponding to the target external sound source according to the second sound signal frequency-domain form.

[0118] Since the cross-sectional structure of the cable is symmetrical, when a sound source is set at a certain point on the outer skin of the optical fiber, the straight-line distances between the sound source and the three internal optical fibers are different. Taking a certain optical fiber as an example, as Figure 5 shown, this distance can be represented by the angle θ between the center of the circle, the optical fiber, and the center of the circle and the sound source. The straight-line distance L between the external sound source and different positions of the optical fiber can still be represented by r. Based on Figure 5 the shown position relationship, in this embodiment, perform frequency-domain analysis on the target analog signal of the target external sound source to obtain the frequency-domain form S(ω) of the target external sound source. Let the second sound signal frequency-domain form V2(θ, r, ω) obtained by coupling with the optical fiber. S(ω) undergoes attenuation and deformation to obtain V2(θ, r, ω), then the relationship between the two is as follows:

[0119] V2(θ, r, ω) = S(ω)·A2(θ, r, ω)·F2(θ, r, ω)

[0120] In the formula, A2(θ, r, ω) is the attenuation function of the signal, and F2(θ, r, ω) is the phase transformation function of the signal.

[0121] Then the acoustic-electric signal transfer function corresponding to the constructed target external sound source is:

[0122]

[0123] In the formula, A2(θ, r, ω) is the attenuation factor of the acoustic-electric signal transfer function, and F2(θ, r, ω) is the phase transformation factor of the acoustic-electric signal transfer function;

[0124] The sound signal distribution equation corresponding to the constructed target external sound source is:

[0125]

[0126] Where, |D2(θ,r,ω)| is the attenuation factor of the acoustic signal distribution equation, and φ2(θ,r,ω) is the phase change factor of the acoustic signal distribution equation.

[0127] Due to the large differences between the two propagation paths, the transfer functions obtained are different. It is difficult to obtain the same strain effect through a single external sound source, and a multi-source collaborative method needs to be adopted. Among them, the number of external sound sources can be set according to the actual situation.

[0128] In a realizable way, three groups of external sound sources are set in the external sound source characteristic inversion test. Let the included angles corresponding to the three groups of external sound sources be θ1, θ2, and θ3 respectively. At the same time, certain frequency shifts, namely Δω1, Δω2, and Δω3, are set in the three external sound sources. Then, the acoustic-electric signal transfer function superimposed on a certain optical fiber is:

[0129] H(ω) = H2(ω + Δω1, θ1) + H2(ω + Δω2, θ2) + H2(ω + Δω3, θ3);

[0130] The acoustic signal distribution equation superimposed on a certain optical fiber is:

[0131] D(ω) = D2(ω + Δω1, θ1) + D2(ω + Δω2, θ2) + D2(ω + Δω3, θ3).

[0132] Step S5, compare the differences between the first acoustic-electric signal transfer function and the second acoustic-electric signal transfer function in the target frequency band to obtain a first difference comparison result, and compare the differences between the first acoustic signal distribution equation and the second acoustic signal distribution equation in the target frequency band to obtain a second difference comparison result.

[0133] Step S6, if the first difference comparison result and the second difference comparison result meet the requirements of the preset difference value range, use the external sound source configuration parameters corresponding to the external sound source characteristic inversion test as the target external sound source configuration parameters; the external sound source configuration parameters include the frequency shift of the external sound source and the included angle between the first connection line and the second connection line. The first connection line is the connection line between the center of the submarine cable and the optical fiber, and the second connection line is the connection line between the center of the submarine cable and the external sound source.

[0134] The requirements of the preset difference value range are set according to engineering experience. In a realizable way, the requirements of the preset difference value range are:

[0135] Both the first difference comparison result and the second difference comparison result are less than 20%.

[0136] It should be noted that in other embodiments, other preset difference value range requirements may be set based on actual experience, for example, the preset difference value range requirement is set to that both the first difference comparison result and the second difference comparison result are less than 15%.

[0137] When designing an external sound source array based on the target external sound source configuration parameters obtained by inversion analysis, the external sound source can be composed of a signal generator, a signal modulation module, and an electroacoustic converter. The signal generator generates the original electrical signal, and the signal modulation modules of different channels are used to achieve signal attenuation and frequency shift, and then power amplification is performed and applied to the electroacoustic converter to generate a sound signal. Figure 6 As shown, three groups of external sound sources constitute an external sound source array. For the external sound source array, when installing, the electroacoustic converter can be installed on a PVC board with an arc structure, wherein the distance between the electroacoustic converters is consistent with the configuration parameters of the target external sound source, and then the PVC board is installed on the outer surface of the target cable. Alternatively, the external sound source array can be fixed on the outer surface of the target cable by other feasible methods, which is not limited in this embodiment.

[0138] When modulating the external sound source array, the original signal generated by the local discharge and the simulated signal generated by the external sound source can be compared on the basis of the local discharge sound source coupling and distribution test platform, and the parameters such as the position of the external sound source can be appropriately adjusted according to the corresponding signal spectrum diagram to improve the signal restoration degree and ensure that the difference in the proportion of the main frequency bands meets the preset difference value range requirements.

[0139] In the above embodiment of the present invention, firstly, the acoustic source coupling and distribution test of partial discharge is carried out on the target submarine cable. Under the premise of not destroying the propagation of the acoustic signal as much as possible, a simulated partial discharge source is set in the submarine cable, and an acoustic sensor array is arranged in the optical fiber to obtain the acoustic source coupling and distribution characteristics of the partial discharge, and then the acquired time domain waveform is analyzed in the time and frequency domain to obtain the acoustic signal converted from the discharge signal and the transfer function coupled to the sensing optical fiber, and the distribution characteristics of the acoustic signal at different positions of the optical fiber are analyzed at the same time, and then under the above test platform, an external sound source characteristic inversion test is carried out to obtain the coupling relationship and distribution characteristics of the external sound source and the optical fiber; based on the two sets of transfer relationships, the influence of the external sound source position, configuration parameters, etc. on the inversion signal is analyzed, and finally a suitable configuration scheme is obtained. According to the configuration scheme, an external sound source array is designed, and by modulating the signal, strain information consistent with the partial discharge is obtained on the optical fiber, so that the partial discharge detection of the submarine cable can be effectively realized. Compared with the existing method of partial discharge detection of built-in defects, the method of the present application has the advantages of low cost, low operation difficulty and wider applicability.

[0140] The present invention also provides an external simulation device for the partial discharge sound source of a submarine cable, which can be used to execute the external simulation method for the partial discharge sound source of a submarine cable described in any of the above embodiments of the present invention.

[0141] Please refer to Figure 7 , Figure 7 which shows a structural connection block diagram of an external simulation device for the partial discharge sound source of a submarine cable provided by an embodiment of the present invention.

[0142] An external simulation device for the partial discharge sound source of a submarine cable provided by an embodiment of the present invention includes:

[0143] A first acquisition module 1, configured to acquire first test data obtained from a sound source coupling and distribution test for partial discharge of a target submarine cable; in the sound source coupling and distribution test for partial discharge, a corresponding first simulation signal is applied to the target cable by simulating a partial discharge source, and an acoustic signal under the first simulation signal is acquired through a sound sensor array arranged on the optical fiber of the target cable;

[0144] A first construction module 2, configured to construct a first acoustic-electric signal transfer function and a first acoustic signal distribution equation according to the first test data;

[0145] A second acquisition module 3, configured to acquire second test data obtained from an external sound source characteristic inversion test for the target cable; in the external sound source characteristic inversion test, a second simulation signal is applied to the target cable by an external sound source, and an acoustic signal under the second simulation signal is acquired through a sound sensor array arranged on the optical fiber of the target cable;

[0146] A second construction module 4, configured to construct a second acoustic-electric signal transfer function and a second acoustic signal distribution equation according to the second test data;

[0147] A comparison module 5, configured to compare the difference between the first acoustic-electric signal transfer function and the second acoustic-electric signal transfer function in a target frequency band to obtain a first difference comparison result, and compare the difference between the first acoustic signal distribution equation and the second acoustic signal distribution equation in the target frequency band to obtain a second difference comparison result;

[0148] A determination module 6, configured to, if the first difference comparison result and the second difference comparison result meet the requirements of a preset difference value range, use the external sound source configuration parameters corresponding to the external sound source characteristic inversion test as the target external sound source configuration parameters; the external sound source configuration parameters include the frequency shift of the external sound source and the included angle between a first connection line and a second connection line, the first connection line is the connection line between the center of the submarine cable and the optical fiber, and the second connection line is the connection line between the center of the submarine cable and the external sound source.

[0149] In a feasible implementation manner, the simulated partial discharge source includes a high-voltage DC source and a discharge electrode connected to each other; in the sound source coupling and distribution test of the partial discharge, one phase cable of the target submarine cable is replaced with a copper tube wrapped with an insulating layer on the outer wall, and the discharge electrode is arranged inside the copper tube.

[0150] In a feasible implementation manner, the first construction module 2 includes:

[0151] A first analysis unit, configured to perform frequency-domain analysis on the first analog signal to obtain the frequency-domain form of the simulated partial discharge source;

[0152] A second analysis unit, configured to perform frequency-domain analysis on the sound signal under the obtained first analog signal, couple the obtained frequency-domain analysis result with the first relative position parameter of the simulated partial discharge source and the optical fiber, and obtain the first sound signal frequency-domain form; the first relative position parameter is the distance from the center of the simulated partial discharge source to the optical fiber;

[0153] A first construction unit, configured to construct the first sound-electric signal transfer function according to the frequency-domain form of the simulated partial discharge source and the first sound signal frequency-domain form;

[0154] A second construction unit, configured to construct the first sound signal distribution equation according to the first sound signal frequency-domain form.

[0155] In a feasible implementation manner, multiple groups of external sound sources are arranged in the external sound source characteristic inversion test; the second construction module 4 includes:

[0156] A third construction unit, configured to construct a corresponding sound-electric signal transfer function and a sound signal distribution equation for each group of external sound sources;

[0157] A first superposition unit, configured to superpose the sound-electric signal transfer functions corresponding to each group of external sound sources to obtain the second sound-electric signal transfer function;

[0158] A second superposition unit, configured to superpose the sound signal distribution equations corresponding to each group of external sound sources to obtain the second sound signal distribution equation.

[0159] In a feasible implementation manner, the third construction unit includes:

[0160] A first analysis subunit, configured to use any group of external sound sources as the target external sound source, perform frequency-domain analysis on the target analog signal of the target external sound source, and obtain the frequency-domain form of the target external sound source;

[0161] A second analysis subunit, configured to perform frequency-domain analysis on the acoustic signal under the acquired target analog signal, and couple the obtained frequency-domain analysis result with a second relative position parameter between the target external sound source and the optical fiber to obtain a second frequency-domain form of the acoustic signal; the second relative position parameter includes an angle between the first connection line and the second connection line.

[0162] A first construction subunit, configured to construct an acoustic-electric signal transfer function corresponding to the target external sound source according to the frequency-domain form of the target external sound source and the second frequency-domain form of the acoustic signal.

[0163] A second construction subunit, configured to construct an acoustic signal distribution equation corresponding to the target external sound source according to the second frequency-domain form of the acoustic signal.

[0164] In an implementable manner, three groups of external sound sources are set in the external sound source characteristic inversion test.

[0165] In an implementable manner, the requirement for the preset difference value range is as follows:

[0166] Both the first difference comparison result and the second difference comparison result are less than 20%.

[0167] The present invention further provides an external simulation device for a partial discharge sound source of a submarine cable, including:

[0168] A memory, configured to store instructions; wherein, the instructions are used to implement the external simulation method for the partial discharge sound source of the submarine cable as described in any one of the above embodiments;

[0169] A processor, configured to execute the instructions in the memory.

[0170] The present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the external simulation method for the partial discharge sound source of the submarine cable as described in any one of the above embodiments is implemented.

[0171] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described devices, equipment, and modules can refer to the corresponding processes in the foregoing method embodiments, and the specific beneficial effects of the above-described devices, equipment, and modules can refer to the corresponding beneficial effects in the foregoing method embodiments, which will not be elaborated herein.

[0172] In several embodiments provided by this application, it should be understood that the disclosed devices, equipment, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling, direct coupling, or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the devices or modules can be in electrical, mechanical, or other forms.

[0173] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they can be located in one place or distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0174] In addition, in each embodiment of the present invention, the functional modules can be integrated into one processing module, or each module can exist physically alone, or two or more modules can be integrated into one module. The above-mentioned integrated modules can be implemented in the form of hardware or in the form of software functional modules.

[0175] If the above-mentioned integrated module is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0176] As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. And these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. An external simulation method for the partial discharge sound source of submarine cables, characterized in that, Including: Obtaining first test data from a local discharge sound source coupling and distribution test on a target submarine cable; In the local discharge sound source coupling and distribution test, a corresponding first simulation signal is applied to the target cable by simulating a local discharge source, and acoustic signals under the first simulation signal are obtained through a sound sensor array arranged on the optical fiber of the target submarine cable; Constructing a first acoustic-electric signal transfer function and a first acoustic signal distribution equation according to the first test data; Obtaining second test data from an external sound source characteristic inversion test on the target cable; in the external sound source characteristic inversion test, a second simulation signal is applied to the target cable by an external sound source, and acoustic signals under the second simulation signal are obtained through a sound sensor array arranged on the optical fiber of the target cable; Constructing a second acoustic-electric signal transfer function and a second acoustic signal distribution equation according to the second test data; Comparing the difference between the first acoustic-electric signal transfer function and the second acoustic-electric signal transfer function in a target frequency band to obtain a first difference comparison result, and comparing the difference between the first acoustic signal distribution equation and the second acoustic signal distribution equation in the target frequency band to obtain a second difference comparison result; If the first difference comparison result and the second difference comparison result meet the requirements of a preset difference value range, taking the external sound source configuration parameters corresponding to the external sound source characteristic inversion test as the target external sound source configuration parameters; the external sound source configuration parameters include the frequency shift of the external sound source and the angle between a first connection line and a second connection line, the first connection line being the connection line between the center of the submarine cable and the optical fiber, and the second connection line being the connection line between the center of the submarine cable and the external sound source.

2. The external simulation method for the partial discharge sound source of submarine cables according to claim 1, characterized in that, The simulated local discharge source includes a high-voltage DC source and a discharge electrode connected in series; in the local discharge sound source coupling and distribution test, one phase cable of the target submarine cable is replaced with a copper tube wrapped with an insulating layer on the outer wall, and the discharge electrode is arranged inside the copper tube.

3. The external simulation method for the partial discharge sound source of submarine cables according to claim 1, characterized in that, The constructing of the first acoustic-electric signal transfer function and the first acoustic signal distribution equation according to the first test data includes: Performing frequency-domain analysis on the first simulation signal to obtain the frequency-domain form of the simulated local discharge source; Performing frequency-domain analysis on the acoustic signals under the obtained first simulation signal, and coupling the obtained frequency-domain analysis result with the first relative position parameter between the simulated local discharge source and the optical fiber to obtain the first acoustic signal frequency-domain form; the first relative position parameter is the distance from the center of the simulated local discharge source to the optical fiber; Constructing the first acoustic-electric signal transfer function according to the frequency-domain form of the simulated local discharge source and the first acoustic signal frequency-domain form; Constructing the first acoustic signal distribution equation according to the first acoustic signal frequency-domain form.

4. The external simulation method for the partial discharge sound source of submarine cables according to claim 1, characterized in that, In the external sound source characteristic inversion test, multiple groups of external sound sources are set; the constructing of the second acoustic-electric signal transfer function and the second acoustic signal distribution equation according to the second test data includes: Constructing a corresponding acoustic-electric signal transfer function and an acoustic signal distribution equation for each group of external sound sources; Superimpose the acoustic-electric signal transfer functions corresponding to each group of external sound sources to obtain the second acoustic-electric signal transfer function; Superimpose the acoustic signal distribution equations corresponding to each group of external sound sources to obtain the second acoustic signal distribution equation.

5. The external simulation method for the partial discharge sound source of submarine cables according to claim 4, characterized in that, Constructing the corresponding acoustic-electric signal transfer function and acoustic signal distribution equation for each group of external sound sources includes: Taking any group of external sound sources as the target external sound source, performing frequency-domain analysis on the target analog signal of the target external sound source to obtain the frequency-domain form of the target external sound source; Performing frequency-domain analysis on the acoustic signal under the obtained target analog signal, and coupling the obtained frequency-domain analysis result with the second relative position parameter between the target external sound source and the optical fiber to obtain the second acoustic signal frequency-domain form; the second relative position parameter includes the included angle between the first connection line and the second connection line; Construct the acoustic-electric signal transfer function corresponding to the target external sound source according to the frequency-domain form of the target external sound source and the second acoustic signal frequency-domain form; Construct the acoustic signal distribution equation corresponding to the target external sound source according to the second acoustic signal frequency-domain form.

6. The external simulation method for the partial discharge sound source of submarine cables according to claim 4, characterized in that, Three groups of external sound sources are set in the external sound source characteristic inversion experiment.

7. The external simulation method for the partial discharge sound source of submarine cables according to claim 1, characterized in that, The requirement for the preset difference value range is: Both the first difference comparison result and the second difference comparison result are less than 20%.

8. An external simulation device for the partial discharge sound source of submarine cables, characterized in that, Including: A first acquisition module for acquiring first test data obtained from a sound source coupling and distribution experiment on partial discharge of a target submarine cable; In the sound source coupling and distribution experiment of partial discharge, a corresponding first analog signal is applied to the target cable by simulating a partial discharge source, and an acoustic signal under the first analog signal is acquired through a sound sensor array arranged on the optical fiber of the target cable; A first construction module for constructing a first acoustic-electric signal transfer function and a first acoustic signal distribution equation according to the first test data; A second acquisition module for acquiring second test data obtained from an external sound source characteristic inversion experiment on the target cable; in the external sound source characteristic inversion experiment, a second analog signal is applied to the target cable by an external sound source, and an acoustic signal under the second analog signal is acquired through a sound sensor array arranged on the optical fiber of the target cable; A second construction module for constructing a second acoustic-electric signal transfer function and a second acoustic signal distribution equation according to the second test data; A comparison module for comparing the difference between the first acoustic-electric signal transfer function and the second acoustic-electric signal transfer function in the target frequency band to obtain a first difference comparison result, and comparing the difference between the first acoustic signal distribution equation and the second acoustic signal distribution equation in the target frequency band to obtain a second difference comparison result; A determination module for, if the first difference comparison result and the second difference comparison result meet the requirement of the preset difference value range, using the external sound source configuration parameter corresponding to the external sound source characteristic inversion experiment as the target external sound source configuration parameter; the external sound source configuration parameter includes the frequency shift of the external sound source and the included angle between the first connection line and the second connection line, the first connection line is the connection line between the center of the submarine cable and the optical fiber, and the second connection line is the connection line between the center of the submarine cable and the external sound source.

9. An external simulation device for the partial discharge sound source of a submarine cable, characterized in that, Including: A memory for storing instructions; wherein, the instructions are used to implement the external simulation method of the partial discharge sound source of the submarine cable as described in any one of claims 1-7; A processor for executing the instructions in the memory.

10. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, it implements the external simulation method of the partial discharge sound source of the submarine cable as described in any one of claims 1-7.

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