Method, device and system for determining the state of transformer winding and core

Abstract

Embodiments of the present invention disclose a method, device, and system for determining the state of a transformer winding and core. The method comprises: obtaining a vibration signal of the transformer collected by a fiber-optic acceleration sensor, the vibration signal including vibration signals of each phase of the transformer under no-load and load conditions; performing spectral analysis on the vibration signal based on the vibration signal to obtain the amplitude and proportion of the characteristic frequency components of the vibration signal, and determining the vibration value of the vibration signal; and determining the state of the transformer winding and the core, as well as the fault location, based on the amplitude and proportion of the characteristic frequency components of the vibration signal and the vibration value. The method, device, and system for determining the state of the transformer winding and core provided by embodiments of the present invention can improve the reliability of determining the state of the transformer winding and core.

Description

Technical Field

[0001] The embodiments of the present invention relate to transformer technology, and more particularly to a method, device, and system for determining the status of a transformer winding and core. Background Art

[0002] Transformers, such as large power transformers, are critical equipment in power systems. They primarily consist of an iron core, windings, oil tanks, insulating bushings, voltage regulators, cooling devices, and protective devices. The iron core and windings are key components of the transformer. During operation, the iron core is subjected to steady-state forced excitation forces, while the windings are subjected to alternating electric forces. These forces alter the mechanical structure of the core, windings, and their fasteners, leading to common faults such as loosening, displacement, tilting, and deformation. These are also a major cause of sudden, serious transformer failures and damage. Therefore, determining the condition of the transformer's iron core and windings, promptly detecting faults, and performing condition-based maintenance on the transformer are crucial.

[0003] Currently, existing methods for determining the status of transformer windings and cores typically employ piezoelectric accelerometers placed on the transformer's oil tank wall for monitoring. However, the reliability of the transformer vibration signals obtained with this approach is poor. Furthermore, the accuracy of feature extraction and fault diagnosis based on the vibration signals needs to be improved, impacting the reliability of transformer winding and core status determination. Summary of the Invention

[0004] Embodiments of the present invention provide a method, device, and system for determining the status of transformer windings and cores, so as to improve the reliability of determining the status of transformer windings and cores.

[0005] In a first aspect, an embodiment of the present invention provides a method for determining the status of a transformer winding and a core, comprising:

[0006] Obtaining a vibration signal of the transformer collected by a fiber optic acceleration sensor, the vibration signal including vibration signals of each phase of the transformer under no-load and load conditions;

[0007] According to the vibration signal, the vibration signal is subjected to spectrum analysis to obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and the vibration value of the vibration signal is determined;

[0008] The state of the transformer winding, the state of the core, and the fault location are determined based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value.

[0009] Optionally, determining the transformer winding state, the core state, and the fault location based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value includes:

[0010] If, among the vibration values of the vibration signals of each phase of the transformer when the transformer is no-loaded, the difference between the vibration value of at least one phase vibration signal and a preset first vibration value exceeds a preset first difference threshold, then the phase corresponding to the difference exceeding the preset first difference threshold is determined to be the fault location of the iron core;

[0011] Among the vibration values of the vibration signals of each phase of the transformer under load, if the difference between the vibration value of at least one phase vibration signal and the preset second vibration value exceeds the preset second difference threshold, the phase corresponding to the difference exceeding the preset second difference threshold is determined to be the fault position of the transformer winding.

[0012] Optionally, the preset first vibration value is determined by a preset core vibration parameter model, and the preset second vibration value is determined by a preset winding vibration parameter model.

[0013] Optionally, determining the transformer winding state, the core state, and the fault location based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value includes:

[0014] In the vibration signals of each phase of the transformer under no-load conditions, if the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold, the state of the core is determined to be abnormal;

[0015] In the vibration signals of each phase of the transformer under load, if the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold, the state of the transformer winding is determined to be abnormal.

[0016] Optionally, the above method further includes:

[0017] According to the vibration signal, energy analysis and singular value decomposition are performed on the vibration signal to obtain the energy distribution and singular value spectrum entropy of the vibration signal;

[0018] The status of the transformer winding and core as well as the fault location are determined based on the energy distribution and singular value spectral entropy of the vibration signal.

[0019] Optionally, the above method further includes:

[0020] Get the voltage, current and oil temperature of the transformer;

[0021] Determine whether the temperature rise of the transformer is normal based on the voltage, current and oil temperature of the transformer.

[0022] In a second aspect, an embodiment of the present invention further provides a device for determining the state of a transformer winding and an iron core, comprising:

[0023] A signal acquisition module is used to acquire the vibration signal of the transformer collected by the optical fiber acceleration sensor, wherein the vibration signal includes the vibration signal of each phase of the transformer under no-load and load conditions;

[0024] A signal processing module is used to perform spectrum analysis on the vibration signal according to the vibration signal, obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and determine the vibration value of the vibration signal;

[0025] The state determination module is used to determine the state of the transformer winding and the state of the core and the fault location based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value.

[0026] In a third aspect, an embodiment of the present invention provides a system for determining the state of a transformer winding and core, comprising: a fiber optic acceleration sensor, a data acquisition module, and a controller electrically connected in sequence, wherein the state determination device described in the second aspect is integrated in the controller.

[0027] Optionally, the fiber optic acceleration sensor includes a modulation module and a probe, the modulation module includes a laser emitting unit, a control unit and a photoelectric conversion unit electrically connected in sequence, the laser emitting unit and the photoelectric conversion unit are both connected to the probe through optical fibers, and the control unit is electrically connected to the data acquisition module.

[0028] Optionally, the above system further includes a transformer and a sealing flange arranged on the transformer, the modulation module is arranged in the sealing flange, and the probe is arranged in the transformer.

[0029] The method, device, and system for determining the status of a transformer winding and core provided by embodiments of the present invention acquire a transformer vibration signal collected by a fiber optic accelerometer. The vibration signal includes vibration signals of each phase of the transformer under no-load and load conditions. Based on the vibration signal, the vibration signal is spectrally analyzed to obtain the amplitude and proportion of the characteristic frequency components of the vibration signal, and the vibration value of the vibration signal is determined. The status of the transformer winding and core, as well as the location of the fault, are determined based on the amplitude and proportion of the characteristic frequency components of the vibration signal and the vibration value. The method, device, and system for determining the status of a transformer winding and core provided by embodiments of the present invention acquire the transformer vibration signal using a fiber optic accelerometer, resulting in a highly accurate vibration signal. On the one hand, the status of the transformer winding and core can be determined based on the amplitude and proportion of the characteristic frequency components of the vibration signal. On the other hand, the fault location can be determined based on the vibration value. If an abnormality is determined in either of these two aspects, the abnormality is present, thereby improving the reliability of determining the status of the transformer winding and core. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a flow chart of a method for determining the state of a transformer winding and core provided in the first embodiment of the present invention;

[0031] Figure 2 This is a flow chart of a method for determining the status of a transformer winding and core provided by a second embodiment of the present invention;

[0032] Figure 3 This is a structural block diagram of a device for determining the state of a transformer winding and core provided by a third embodiment of the present invention;

[0033] Figure 4 This is a structural block diagram of a system for determining the state of a transformer winding and core provided by a fourth embodiment of the present invention;

[0034] Figure 5 This is a structural block diagram of a fiber optic acceleration sensor provided by the fourth embodiment of the present invention;

[0035] Figure 6 This is a structural block diagram of another transformer winding and core state determination system provided in a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0037] Example 1

[0038] Figure 1 This is a flow chart of a method for determining the state of a transformer winding and core provided by a first embodiment of the present invention. This embodiment is applicable to aspects such as determining the state of a transformer winding and core. The method can be performed by a device for determining the state of a transformer winding and core. The device can be implemented in the form of software and / or hardware. The device can be integrated into a controller of a system for determining the state of a transformer winding and core. The method specifically includes the following steps:

[0039] Step 110: Obtain a vibration signal of the transformer collected by the optical fiber acceleration sensor, where the vibration signal includes vibration signals of each phase of the transformer under no-load and load conditions.

[0040] Multiple fiber-optic acceleration sensors can be provided, with each phase of a transformer, such as a three-phase transformer, being equipped with one. These multiple fiber-optic acceleration sensors can collect vibration signals from each phase of the transformer, such as phase A, phase B, and phase C, both when unloaded and loaded. A device for determining the state of the transformer windings and core can be electrically connected to the fiber-optic acceleration sensors to obtain the signals collected by them.

[0041] Step 120 : Perform spectrum analysis on the vibration signal to obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and determine the vibration value of the vibration signal.

[0042] Specifically, the device for determining the state of the transformer winding and core can perform a Fourier transform on the vibration signal to obtain the amplitude and proportion of the characteristic frequency component of the vibration signal. The vibration value of the vibration signal can be directly determined from the vibration signal. The spectral distribution of the vibration signal is usually concentrated on 100 Hz and its multiple frequency components, and is mainly composed of the 100 Hz spectral component (which can be regarded as the main frequency component). Among them, the amplitude and proportion of the characteristic frequency component can be the amplitude of the main frequency component and the ratio of the main frequency component to the sum of the main frequency component and other spectral components.

[0043] Step 130 : Determine the state of the transformer winding, the state of the core, and the fault location based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value.

[0044] Specifically, if the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal of the transformer when it is unloaded are both higher than the corresponding preset threshold value, it can be determined that the state of the transformer core is abnormal, such as the core is loose. If the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal of the transformer when it is loaded are both higher than the corresponding preset threshold value, it can be determined that the state of the transformer winding is abnormal, such as the winding is loose. If the difference between the vibration value of the B-phase vibration signal of the transformer when it is unloaded and the preset first vibration value exceeds the preset first difference threshold value, it can be determined that the fault position of the transformer core is phase B.

[0045] The method for determining the status of a transformer winding and core provided in this embodiment uses a fiber-optic accelerometer to collect transformer vibration signals, resulting in a highly accurate vibration signal. The amplitude and proportion of the characteristic frequency components of the vibration signal can be used to determine the status of the transformer winding and core. Furthermore, the vibration value can be used to determine the fault location. If an abnormality is detected in either of these two aspects, the fault is identified, thereby improving the reliability of determining the status of the transformer winding and core.

[0046] Example 2

[0047] Figure 2 This is a flow chart of a method for determining the state of a transformer winding and core provided by a second embodiment of the present invention. This embodiment is applicable to aspects such as determining the state of a transformer winding and core. The method can be executed by a device for determining the state of a transformer winding and core. The device can be implemented in the form of software and / or hardware. The device can be integrated into a controller of a system for determining the state of a transformer winding and core. The method specifically includes the following steps:

[0048] Step 210: Obtain a vibration signal of the transformer collected by the optical fiber acceleration sensor, where the vibration signal includes vibration signals of each phase of the transformer under no-load and load conditions.

[0049] Multiple fiber-optic accelerometers can be directly mounted and fixed to the transformer windings and core clamps, with at least one installed on each of the high-voltage and low-voltage sides of the A, B, and C phases of the windings, and at least one installed on each of the high-voltage and low-voltage sides of the core clamps. These multiple fiber-optic accelerometers can collect vibration signals from each phase of the transformer, such as the A, B, and C phase vibration signals, when the transformer is unloaded and loaded. A device for determining the state of the transformer windings and core can be electrically connected to the fiber-optic accelerometers to obtain the signals collected by the fiber-optic accelerometers.

[0050] In addition, the transformer winding and core state determination device can also obtain the voltage, current and oil temperature of the transformer through the data acquisition module in the transformer winding and core state determination system, and determine whether the temperature rise of the transformer is normal based on the voltage, current and oil temperature of the transformer.

[0051] Step 220 : Perform spectrum analysis on the vibration signal to obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and determine the vibration value of the vibration signal.

[0052] Specifically, the device for determining the state of the transformer winding and core can perform a Fourier transform on the vibration signal to obtain the amplitude and proportion of the characteristic frequency component of the vibration signal. The vibration value of the vibration signal can be directly determined from the vibration signal. The spectral distribution of the vibration signal is usually concentrated on 100 Hz and its multiple frequency components, and is mainly composed of the 100 Hz spectral component (which can be regarded as the main frequency component). Among them, the amplitude and proportion of the characteristic frequency component can be the amplitude of the main frequency component and the ratio of the main frequency component to the sum of the main frequency component and other spectral components.

[0053] Step 230: Among the vibration values of the vibration signals of each phase of the transformer under no-load conditions, if the difference between the vibration value of at least one phase vibration signal and the preset first vibration value exceeds the preset first difference threshold, determine that the phase corresponding to the difference exceeding the preset first difference threshold is the fault position of the core.

[0054] The preset first vibration value is determined by a preset core vibration parameter model. The preset core vibration parameter model can be obtained by fitting the no-load voltage square sum vibration signal using the least squares method based on the normal operating parameters of the transformer, such as voltage, current, and oil temperature, and the vibration signal. For example, the core vibration parameter model inputs the vibration value of the transformer's no-load B-phase vibration signal and compares the input vibration value with the preset first vibration value. If the difference between the input vibration value and the preset first vibration value exceeds a preset first difference threshold, then phase B is determined to be the core fault location.

[0055] Step 240: If, among the vibration values of the vibration signals of each phase of the transformer under load, the difference between the vibration value of at least one phase vibration signal and the preset second vibration value exceeds the preset second difference threshold, determine that the phase corresponding to the difference exceeding the preset second difference threshold is the fault location of the transformer winding.

[0056] The preset second vibration value is determined by a preset winding vibration parameter model. The preset winding vibration parameter model can be obtained by fitting the load current square sum vibration signal using the least squares method based on the normal operating parameters of the transformer, such as voltage, current, and oil temperature, and the vibration signal. For example, the preset winding vibration parameter model inputs the vibration value of the transformer's no-load C-phase vibration signal. The input vibration value can be compared with the preset second vibration value. If the difference between the input vibration value and the preset second vibration value exceeds a preset second difference threshold, then phase C is determined to be the fault location of the winding.

[0057] In addition, if the vibration value of the B-phase vibration signal of the transformer is higher than the vibration value of the A-phase vibration signal when the transformer is unloaded, and the vibration values of the A-phase vibration signal and the C-phase vibration signal are substantially equal, then the transformer core can be determined to be in a normal state. If the vibration value of the B-phase vibration signal of the transformer is lower than the vibration value of the A-phase vibration signal when the transformer is loaded, and the vibration values of the A-phase vibration signal and the C-phase vibration signal are substantially equal, then the transformer winding can be determined to be in a normal state.

[0058] It should be noted that the specific numerical values of the preset first vibration value, the preset first difference threshold, the preset second vibration value and the preset second difference threshold can be set according to actual transformer requirements and are not limited here.

[0059] Step 250: If, among the vibration signals of each phase of the transformer under no-load conditions, the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold, it is determined that the state of the core is abnormal.

[0060] For example, if the amplitude and proportion of the characteristic frequency component of the A-phase vibration signal of the transformer under no-load are both higher than the corresponding preset threshold, it can be determined that the state of the transformer core is abnormal, such as the core is loose.

[0061] Step 260: If, among the vibration signals of each phase of the transformer under load, the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold, it is determined that the state of the transformer winding is abnormal.

[0062] For example, if the amplitude and proportion of the characteristic frequency component of the C-phase vibration signal of the transformer under load are both higher than the corresponding preset threshold, it can be determined that the state of the transformer winding is abnormal, such as the winding is loose.

[0063] Furthermore, the vibration signal can be subjected to energy analysis and singular value decomposition to obtain its energy distribution and singular value spectral entropy. Based on this energy distribution and singular value spectral entropy, the transformer winding and core conditions, as well as the fault location, can be determined. For example, wavelet packet decomposition and ensemble average empirical mode decomposition can be used to analyze the energy characteristics of the transformer vibration signal to determine the core and winding conditions. For example, the energy distribution of the wavelet-based high- and low-frequency envelope spectrum can be used to extract vibration signal features, allowing comparison of the energy distribution under normal and fault conditions. Furthermore, singular value decomposition can be performed on the vibration signal to extract its singular spectral entropy as a characteristic for determining the core or winding condition. A support vector machine (SVM) can then be used to classify and identify the SVM. Abnormal core or winding conditions, such as looseness, can result in a decrease in the SVM. Using a SVM, the core or winding condition can be accurately determined and the fault location can be performed. For example, if the singular spectral entropy of at least one phase vibration signal of the transformer when no-load is lower than the corresponding preset threshold, it can be determined that the state of the transformer core is abnormal, such as the core is loose. The state determination and fault location of the transformer core are similar to the state determination process and fault location process in the above steps, and will not be repeated here.

[0064] The method for determining the status of a transformer winding and core provided in this embodiment uses a fiber-optic accelerometer to collect transformer vibration signals, resulting in a highly accurate vibration signal. The amplitude and proportion of the characteristic frequency components of the vibration signal can be used to determine the status of the transformer winding and core. Furthermore, the vibration value can be used to determine the fault location. If an abnormality is detected in either of these two aspects, the fault is identified, thereby improving the reliability of determining the status of the transformer winding and core.

[0065] Example 3

[0066] Figure 3 This is a structural block diagram of a device for determining the state of a transformer winding and an iron core provided in a third embodiment of the present invention, the device comprising: a signal acquisition module 310, a signal processing module 320 and a state determination module 330; wherein, the signal acquisition module 310 is used to obtain the vibration signal of the transformer collected by the optical fiber acceleration sensor, and the vibration signal includes the vibration signal of each phase of the transformer under no-load and load; the signal processing module 320 is used to perform spectrum analysis on the vibration signal according to the vibration signal, obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and determine the vibration value of the vibration signal; the state determination module 330 is used to determine the state of the transformer winding and the state of the iron core and the fault location according to the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value.

[0067] On the basis of the above embodiment, the signal processing module 320 includes a core fault position determination unit and a winding fault position determination unit; wherein, the core fault position determination unit is used to determine that the phase corresponding to the difference exceeding the preset first difference threshold is the fault position of the core if the difference between the vibration value of at least one phase vibration signal and the preset first vibration value exceeds the preset first difference threshold among the vibration values of the vibration signals of each phase of the transformer when it is no-loaded; the winding fault position determination unit is used to determine that the phase corresponding to the difference exceeding the preset second difference threshold is the fault position of the transformer winding if the difference between the vibration value of at least one phase vibration signal and the preset second vibration value exceeds the preset second difference threshold among the vibration values of the vibration signals of each phase of the transformer when it is loaded.

[0068] Preferably, the state determination module 330 includes: a core state determination unit and a winding state determination unit; wherein, the core state determination unit is used to determine that the state of the core is abnormal if, in the vibration signals of each phase when the transformer is no-loaded, the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold value; the winding state determination unit is used to determine that the state of the transformer winding is abnormal if, in the vibration signals of each phase when the transformer is loaded, the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold value.

[0069] Preferably, the above-mentioned device also includes: an analysis and decomposition module and a fault location determination module. The analysis and decomposition module is used to perform energy analysis and singular value decomposition on the vibration signal according to the vibration signal to obtain the energy distribution and singular value spectral entropy of the vibration signal; the fault location determination module is used to determine the state of the transformer winding, the state of the iron core and the fault location according to the energy distribution and singular value spectral entropy of the vibration signal.

[0070] Preferably, the above-mentioned device also includes: a data acquisition module and a temperature rise determination module, the data acquisition module is used to obtain the voltage, current and oil temperature of the transformer; the temperature rise determination module is used to determine whether the temperature rise of the transformer is normal based on the voltage, current and oil temperature of the transformer.

[0071] The device for determining the state of the transformer winding and the core provided in this embodiment and the method for determining the state of the transformer winding and the core provided in any embodiment of the present invention belong to the same inventive concept and have corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the method for determining the state of the transformer winding and the core provided in any embodiment of the present invention.

[0072] Example 4

[0073] Figure 4This is a structural block diagram of a transformer winding and core state determination system provided in a fourth embodiment of the present invention, the system comprising: an optical fiber acceleration sensor 10, a data acquisition module 20 and a controller 30 electrically connected in sequence, and a transformer winding and core state determination device as described in any embodiment of the present invention is integrated in the controller 30.

[0074] The data acquisition module 20 can collect data such as the voltage, current, and oil temperature of the transformer, as well as receive the vibration signal of the transformer transmitted by the optical fiber acceleration sensor, and transmit the data and vibration signal. The controller 30 performs spectrum analysis, stability analysis, and energy analysis on the vibration signal based on the data and vibration signal transmitted by the data acquisition module 20 to determine the state of the transformer winding and the state of the core, as well as the fault location. The spectrum analysis, stability analysis, and energy analysis are all described in detail in Example 2. The description of the spectrum analysis can be referred to steps 270 and 280, the description of the stability analysis can be referred to steps 250 and 260, and the description of the energy analysis can be referred to step 280, and will not be repeated here.

[0075] Furthermore, when the controller 30 performs spectrum analysis, stability analysis, and energy analysis on the vibration signal, if at least one of the above analyses indicates an abnormality, the controller 30 determines that the condition of the transformer winding is abnormal. For example, even if the controller 30 performs spectrum analysis on the vibration signal and determines that the transformer winding condition is normal, the controller 30 still outputs the result that the transformer winding condition is abnormal and may issue a corresponding prompt.

[0076] Optionally, the fiber optic acceleration sensor 10 includes a modulation module 11 and a probe 12, the modulation module 11 includes a laser emitting unit 13, a control unit 14 and a photoelectric conversion unit 15 electrically connected in sequence, the laser emitting unit 13 and the photoelectric conversion unit 15 are both connected to the probe 12 via optical fibers, and the control unit 14 is electrically connected to the data acquisition module 20.

[0077] For example, Figure 5 This is a structural block diagram of a fiber optic acceleration sensor provided by the fourth embodiment of the present invention. Figure 5The control unit 14 can power and control the laser emitting unit 13 and the photoelectric conversion unit 15. The fiber optic acceleration sensor 10 includes two parallel input optical fibers 16 and a reflection optical fiber 17. The input optical fiber 16 is connected to the laser emitting unit 13, and the incident light generated by the laser emitting unit 13 is transmitted through the optical fiber. The reflection optical fiber 17 is connected to the photoelectric conversion unit 15, which receives the reflected light from the reflection optical fiber 17 and measures the amount of reflected light to measure the magnitude of acceleration and convert the optical signal into an electrical signal. When the amount of reflected light is constant, the vibration acceleration is zero. The vibration of the transformer causes the probe 12 to vibrate. When the probe 12 vibrates, a force is applied to the mass block 18 (non-metallic insulating material) in the probe 12. This force acts on the reflection optical fiber 17, and the magnitude of this force is proportional to the acceleration. This force bends the optical fiber in the probe 12, thereby changing the amount of reflected light received by the reflection optical fiber 17, thereby measuring the magnitude of the vibration acceleration. The reflective surface 19 of the fiber-optic accelerometer 10 utilizes a ceramic concave mirror structure. This mirrored surface converges the laser beam emitted by the laser emitting unit 13. Even with minimal vibration, even a slight displacement of the incident optical fiber 16 will be reflected by the concave mirror and received by the reflective optical fiber 17, thereby capturing the transformer's vibration signal.

[0078] Optionally, the system further includes a transformer 40 and a sealing flange 50 disposed in the transformer 40 , the modulation module 11 is disposed in the sealing flange 50 , and the probe 12 is disposed in the transformer 40 .

[0079] For example, Figure 6 This is a structural block diagram of another transformer winding and core state determination system provided by the fourth embodiment of the present invention. Figure 6 The sealing flange 50 is provided on the transformer 40 and is used to seal the dielectric between the interior and exterior of the transformer 40. The sealing flange 50 has excellent sealing properties and can prevent oil leakage or seepage from the transformer 40. The above system also includes a display module 60, which is electrically connected to the controller 30. The controller 30 can transmit the determined status results to the display module 60, and the display module 60 can display the status results, allowing relevant personnel to intuitively understand the status results.

[0080] The transformer winding and core state determination system provided in this embodiment and the transformer winding and core state determination method provided in any embodiment of the present invention belong to the same inventive concept and have corresponding beneficial effects. For technical details not detailed in this embodiment, please refer to the transformer winding and core state determination method provided in any embodiment of the present invention.

[0081] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations, and substitutions are possible for those skilled in the art without departing from the scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for determining the state of transformer windings and core, characterized in that: include: Obtaining a vibration signal of the transformer collected by a fiber optic acceleration sensor, wherein the vibration signal includes vibration signals of each phase of the transformer under no-load and load conditions; According to the vibration signal, performing a spectrum analysis on the vibration signal to obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and determining the vibration value of the vibration signal; Determining the state of the transformer winding, the state of the core, and the fault location based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value; Among them, among the vibration values of the vibration signals of each phase of the transformer under load, if the difference between the vibration value of at least one phase vibration signal and a preset second vibration value exceeds a preset second difference threshold, then the phase corresponding to the difference exceeding the preset second difference threshold is determined to be the fault position of the transformer winding; the preset second vibration value is determined by a preset winding vibration parameter model, and the preset winding vibration parameter model is obtained by fitting the load current square sum vibration signal based on the voltage, current, oil temperature and vibration signal of the transformer.

2. The state determination method according to claim 1, characterized in that: The determining of the state of the transformer winding, the state of the core, and the fault location according to the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value includes: Among the vibration values of the vibration signals of each phase of the transformer when it is no-load, if the difference between the vibration value of at least one phase vibration signal and the preset first vibration value exceeds the preset first difference threshold, then the phase corresponding to the difference exceeding the preset first difference threshold is determined to be the fault position of the iron core.

3. The state determination method according to claim 2, characterized in that: The preset first vibration value is determined by a preset core vibration parameter model.

4. The state determination method according to claim 1, characterized in that: The determining of the state of the transformer winding, the state of the core, and the fault location according to the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value includes: If, among the vibration signals of each phase of the transformer under no-load conditions, both the amplitude and the proportion of the characteristic frequency component of at least one phase vibration signal are higher than corresponding preset thresholds, it is determined that the state of the iron core is an abnormal state; Among the vibration signals of each phase of the transformer under load, if the amplitude and proportion of the characteristic frequency component of at least one phase vibration signal are both higher than the corresponding preset threshold, the state of the transformer winding is determined to be abnormal.

5. The state determination method according to claim 1, characterized in that: Also includes: According to the vibration signal, performing energy analysis and singular value decomposition on the vibration signal to obtain energy distribution and singular value spectral entropy of the vibration signal; The state of the transformer winding, the state of the iron core and the fault location are determined according to the energy distribution and singular value spectral entropy of the vibration signal.

6. The state determination method according to claim 1, characterized in that: Also includes: Obtaining the voltage, current and oil temperature of the transformer; Determine whether the temperature rise of the transformer is normal based on the voltage, current and oil temperature of the transformer.

7. A device for determining the state of transformer windings and cores, characterized in that: include: A signal acquisition module is used to acquire a vibration signal of the transformer collected by a fiber optic acceleration sensor, wherein the vibration signal includes vibration signals of each phase of the transformer under no-load and load conditions; a signal processing module, configured to perform spectrum analysis on the vibration signal according to the vibration signal, obtain the amplitude and proportion of the characteristic frequency component of the vibration signal, and determine the vibration value of the vibration signal; a state determination module, configured to determine a state of the transformer winding, a state of the core, and a fault location based on the amplitude and proportion of the characteristic frequency component of the vibration signal and the vibration value; Among them, the state determination module is specifically used to determine that among the vibration values of the vibration signals of each phase of the transformer under load, if the difference between the vibration value of at least one phase vibration signal and the preset second vibration value exceeds the preset second difference threshold, the phase corresponding to the difference exceeding the preset second difference threshold is determined as the fault position of the transformer winding; the preset second vibration value is determined by a preset winding vibration parameter model, and the preset winding vibration parameter model is obtained by fitting the load current square sum vibration signal based on the voltage, current, oil temperature and vibration signal of the transformer.

8. A system for determining the state of transformer windings and cores, characterized in that: include: The optical fiber acceleration sensor, the data acquisition module and the controller are electrically connected in sequence, and the state determination device according to claim 7 is integrated into the controller.

9. The state determination system according to claim 8, characterized in that The fiber optic acceleration sensor includes a modulation module and a probe. The modulation module includes a laser emitting unit, a control unit and a photoelectric conversion unit electrically connected in sequence. The laser emitting unit and the photoelectric conversion unit are both connected to the probe through optical fibers. The control unit is electrically connected to the data acquisition module.

10. The state determination system according to claim 9, characterized in that It also includes a transformer and a sealing flange arranged on the transformer, the modulation module is arranged in the sealing flange, and the probe is arranged in the transformer.

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