Transformer fault monitoring device and monitoring method

Abstract

The invention relates to the technical field of electrical engineering, and discloses a transformer fault monitoring device and method.The method includes the steps that firstly, a sensor is installed on the side wall of an oil tank of a transformer, the measuring face of the sensor makes contact with the interior of the oil tank of the transformer, and the sensor does not need to be installed in the transformer with a complex space structure; direct influence of high temperature in the transformer on the sensor can be avoided, accurate real-time mechanical state data of the transformer can be acquired, data acquisition precision is improved, then fault simulation is performed through the fault simulation module, simulated mechanical state data under different fault types are obtained, and the fault simulation accuracy is improved. And finally, performing fault analysis according to the collected real-time mechanical state data and the simulation mechanical state data to determine the fault type of the transformer at the current moment. The technical problem of how to improve the transformer fault monitoring precision is solved.

Description

Technical Field

[0001] The present invention relates to the field of electrical engineering technology, and in particular to a transformer fault monitoring device and a monitoring method. Background Art

[0002] As a key device in the power system, the transformer undertakes important functions such as voltage conversion, power transmission and distribution. In all aspects of power generation, transmission and distribution, the normal operation of the transformer is crucial to ensure the stability and reliability of power supply, and transformer fault monitoring is an important part of power equipment status monitoring. Various sensors are used to obtain the operating status information of the transformer. After analyzing and processing the information collected by the sensor, it can be determined whether the transformer has a fault and the severity of the fault.

[0003] During the operation of the transformer, the temperature inside the transformer will fluctuate greatly with the change of load. At the same time, due to factors such as the insulating oil inside the transformer. For conventional pressure sensors, temperature changes will affect the physical properties of the elastic elements inside, resulting in the accuracy of pressure measurement being affected. For example, temperature increases may cause the elastic modulus of the elastic element to change, resulting in deviations in the measurement results of the pressure sensor; and for conventional vibration sensors, temperature changes may affect the sensitivity and stability of the sensor. High temperature may cause the performance of the fixing materials such as glue inside the sensor to deteriorate, affecting the fixing effect of the sensor core, and thus affecting the accuracy of vibration signal acquisition; and the complex spatial structure inside the transformer limits the selection of the sensor installation position, and it may not be installed in the most ideal position. Therefore, there is an urgent need for a sensor that can be used for accurate data acquisition in the complex environment inside the transformer, so as to improve the monitoring accuracy of transformer faults. Summary of the invention

[0004] The invention provides a transformer fault monitoring device and a monitoring method, which solve the technical problem of how to improve the transformer fault monitoring accuracy.

[0005] A first aspect of the present invention provides a transformer fault monitoring device, comprising:

[0006] It includes a sensor, a fault simulation module and a fault monitoring module, wherein the sensor and the fault simulation module are both communicatively connected with the fault monitoring module;

[0007] The sensor is mounted on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer;

[0008] The sensor is used to collect real-time mechanical status data of the transformer at the current moment;

[0009] The fault simulation module is used to perform fault simulation using pre-acquired transformer characteristic data to obtain simulated mechanical state data of each fault type;

[0010] The fault monitoring module is used to perform fault analysis based on the real-time mechanical state data and the simulated mechanical state data to determine the fault type of the transformer at the current moment.

[0011] Optionally, the real-time mechanical status data includes real-time vibration data and real-time oil pressure data;

[0012] The sensor comprises a packaging portion and a shielding portion;

[0013] The shielding portion abuts against the side wall of the oil tank;

[0014] The packaging part is arranged inside the shielding part;

[0015] The packaging part includes a first grating for measuring the real-time vibration data of the oil tank side wall, a second grating for measuring the real-time oil pressure data received by the measuring surface, and a sensitivity enhancement element;

[0016] The sensitivity enhancement element is encapsulated inside the encapsulation part, and the bottom end of the sensitivity enhancement element is the measuring surface of the sensor;

[0017] The first grating is packaged along the longitudinal direction of the sensitivity enhancement element, and the end of the first grating passes through the circumferential side of the sensitivity enhancement element;

[0018] The second grating is packaged along the lateral direction of the sensitivity enhancement element, and the end of the second grating passes through the circumferential side of the sensitivity enhancement element;

[0019] The first grating and the second grating are perpendicular to each other.

[0020] Optionally, the shielding portion includes a shielding shell and a connecting fastener;

[0021] The shielding shell is provided with a signal connection port;

[0022] An end of the first grating and an end of the second grating are both connected with optical fibers;

[0023] The optical fiber passes through the signal connection port and is communicatively connected with the fault monitoring module;

[0024] The sensitizing element is bonded to the inside of the shielding shell, and the connecting fastener is arranged inside the shielding shell. The connecting fastener is used to fasten the outer side of the sensitizing element by adhesive.

[0025] Optionally, a threaded mounting hole communicating with the interior of the oil tank is provided on the side wall of the oil tank;

[0026] One end of the shielding shell close to the measuring surface of the sensor is a threaded end, and the end of the shielding shell close to the measuring surface of the sensor is threadedly connected to the threaded mounting hole through a hexagonal fastener;

[0027] A sealing gasket is arranged between one end of the shielding shell close to the measuring surface of the sensor and the hexagonal fastener, and the sealing gasket is used to fill the thread gap.

[0028] Optionally, the material of the sensitivity enhancement element is fluorosilicone rubber.

[0029] Optionally, the shielding shell and the connecting fastener are both made of epoxy resin, and the adhesive is epoxy resin adhesive.

[0030] Optionally, the fault simulation module includes a simulation model construction unit and a simulation data processing unit which are communicatively connected;

[0031] The simulation model building unit is used to build a simulation model of the transformer;

[0032] The simulation data processing unit is used to input the transformer characteristic data acquired in advance for simulating different fault conditions into the simulation model, and perform multi-physical field fault simulation on the simulation model to obtain simulated mechanical state data of each fault type;

[0033] The transformer characteristic data includes transformer structural parameters, transformer operating parameters and transformer fault parameters;

[0034] The simulated mechanical state data includes simulated vibration data and simulated oil pressure data.

[0035] Optionally, the fault monitoring module includes a demodulation unit, a first feature extraction unit and a feature comparison unit which are communicatively connected in sequence;

[0036] The demodulation unit is used to perform demodulation operations on the received real-time mechanical state data and the simulated mechanical state data of each fault type;

[0037] A first feature extraction unit is used to extract features from the demodulated real-time mechanical state data and the simulated mechanical state data of each fault type, respectively, to obtain real-time waveform data and simulated waveform data of each fault type;

[0038] The feature comparison unit is used to perform consistency comparison between the real-time waveform data and the simulation waveform data of each fault type, and use the fault type associated with the simulation waveform data with consistent comparison results as the target fault type of the transformer.

[0039] Optionally, the fault monitoring module further includes a noise reduction unit, a second feature extraction unit, a data operation unit and a fault warning unit which are communicatively connected in sequence;

[0040] The noise reduction unit is used to perform noise reduction operation on the demodulated real-time mechanical state data by using wavelet packet decomposition method;

[0041] The second feature extraction unit is used to extract features from the real-time mechanical state data after noise reduction to obtain real-time amplitude data at the current moment;

[0042] The data operation unit is used to perform a difference operation between the real-time amplitude data at the current moment and the real-time amplitude data at the previous moment to obtain a real-time amplitude change rate;

[0043] The fault warning unit is used to generate warning information when the real-time amplitude change rate is within a preset change rate warning interval.

[0044] A second aspect of the present invention provides a monitoring method applied to the transformer fault monitoring device, comprising:

[0045] Collect the real-time mechanical status data of the transformer at the current moment;

[0046] Using the transformer characteristic data acquired in advance to perform fault simulation, the simulated mechanical state data of each fault type is obtained;

[0047] Perform fault analysis based on real-time mechanical status data and simulated mechanical status data to determine the fault type of the transformer at the current moment.

[0048] It can be seen from the above technical solutions that the present invention has the following advantages:

[0049] The transformer fault monitoring device of the present invention provides a sensor. First, the sensor is installed on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer. The sensor does not need to be installed inside the transformer with a complex spatial structure, which can avoid the direct impact of the high temperature inside the transformer on the sensor, thereby collecting accurate real-time mechanical state data of the transformer and improving data collection accuracy. Then, fault simulation is performed through a fault simulation module to obtain simulated mechanical state data under different fault types. Finally, fault analysis is performed based on the collected real-time mechanical state data and the simulated mechanical state data to determine the fault type of the transformer at the current moment; the technical problem of how to improve the accuracy of transformer fault monitoring is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0051] Figure 1 is a structural block diagram of a transformer fault monitoring device according to an embodiment of the present invention;

[0052] Figure 2 A front view of a sensor according to an embodiment of the present invention;

[0053] Figure 3 is a side view of a sensor according to an embodiment of the present invention;

[0054] Figure 4 A top view of a sensor according to an embodiment of the present invention;

[0055] Figure 5 is a schematic diagram of a first grating according to an embodiment of the present invention;

[0056] Figure 6 is a schematic diagram of a second grating according to an embodiment of the present invention;

[0057] Figure 7 is a schematic diagram of a hexagonal fastener according to an embodiment of the present invention;

[0058] Figure 8 A flowchart of a monitoring method applied to a transformer fault monitoring device according to an embodiment of the present invention;

[0059] The meanings of the reference numerals are as follows:

[0060] 1. Shielding part; 2. Packaging part; 3. First grating; 4. Second grating; 5. Sensitization element; 6. Optical fiber; 7. Shielding shell; 8. Connecting fastener; 9. Threaded end; 10. Hexagonal fastener. DETAILED DESCRIPTION

[0061] The embodiments of the present invention provide a transformer fault monitoring device and a monitoring method, which are used to solve the technical problem of how to improve the transformer fault monitoring accuracy.

[0062] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] See also Figure 1-Figure 7 , a transformer fault monitoring device provided by the present invention comprises a sensor, a fault simulation module and a fault monitoring module, wherein the sensor and the fault simulation module are both communicatively connected with the fault monitoring module;

[0064] The sensor is installed on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer;

[0065] Sensors, used to collect real-time mechanical status data of the transformer at the current moment;

[0066] A fault simulation module is used to perform fault simulation using pre-acquired transformer characteristic data to obtain simulated mechanical state data of each fault type;

[0067] The fault monitoring module is used to perform fault analysis based on real-time mechanical state data and simulated mechanical state data to determine the fault type of the transformer at the current moment.

[0068] In an embodiment of the present invention, the sensor is first installed on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer. The sensor does not need to be installed inside the transformer with a complex spatial structure, which can avoid the direct impact of the high temperature inside the transformer on the sensor, thereby collecting accurate real-time mechanical state data of the transformer and improving data collection accuracy. Then, fault simulation is performed through a fault simulation module to obtain simulated mechanical state data under different fault types. Finally, fault analysis is performed based on the collected real-time mechanical state data and the simulated mechanical state data to determine the fault type of the transformer at the current moment; the technical problem of how to improve the accuracy of transformer fault monitoring is solved.

[0069] See also Figure 2-Figure 6 , a transformer fault monitoring device provided by the present invention, the real-time mechanical state data includes real-time vibration data and real-time oil pressure data;

[0070] The sensor comprises a packaging part 2 and a shielding part 1;

[0071] The shielding part 1 abuts against the side wall of the oil tank;

[0072] The packaging part 2 is arranged inside the shielding part 1;

[0073] The packaging part 2 includes a first grating 3 for measuring the real-time vibration data of the oil tank side wall, a second grating 4 for measuring the real-time oil pressure data received by the measuring surface, and a sensitivity enhancement element 5;

[0074] The sensitizing element 5 is encapsulated inside the encapsulating part 2, and the bottom end of the sensitizing element 5 is the measuring surface of the sensor;

[0075] The first grating 3 is packaged along the longitudinal direction of the sensitivity enhancement element 5, and the end of the first grating 3 passes through the circumferential side of the sensitivity enhancement element 5;

[0076] The second grating 4 is encapsulated along the lateral direction of the sensitivity enhancement element 5, and the end of the second grating 4 passes through the circumferential side of the sensitivity enhancement element 5;

[0077] The first grating 3 and the second grating 4 are perpendicular to each other.

[0078] In an embodiment of the present invention, the sensor includes a packaging part 2 and a shielding part 1. The packaging part 2 is arranged inside the shielding part 1. The packaging part 2 includes a first grating 3 for measuring the real-time vibration data of the side wall of the oil tank, a second grating 4 for measuring the real-time oil pressure data received by the measuring surface, and a sensitive element 5. The sensitive element 5 is packaged inside the packaging part 2, and the bottom end of the sensitive element 5 is the measuring surface of the sensor. The first grating 3 is used to measure the real-time vibration data transmitted from the side wall of the oil tank. Since the bottom end of the sensitive element 5 is the measuring surface of the sensor, the measuring surface faces the inside of the oil tank and is in direct contact with the inside of the oil tank. What is measured is the pressure of the oil pressure acting on the measuring surface, that is, the real-time oil pressure data.

[0079] It should be noted that the first grating 3 is packaged along the longitudinal direction of the sensitive element 5, and the end of the first grating 3 passes through the circumferential side of the sensitive element 5; the second grating 4 is packaged along the transverse direction of the sensitive element 5, and the end of the second grating 4 passes through the circumferential side of the sensitive element 5; the first grating 3 and the second grating 4 are perpendicular to each other; it can be understood that the first grating 3 and the second grating 4 are perpendicular to each other, forming a cross structure, and are packaged inside the sensitive element 5. Since the sensitive element 5 is a cylindrical structure, the ends of the first grating 3 and the second grating 4 pass through the circumferential side of the sensitive element 5. When the angle between the first grating 3 and the second grating 4 is 90°, the measurement sensitivity of the first grating 3 and the second grating 4 reaches the highest.

[0080] It is worth mentioning that the second grating 4 is parallel to the measuring surface, that is, it is set parallel to the force-bearing surface inside the fuel tank; the force can be more evenly distributed on the grating surface. Avoid the situation where the local force is too large or too small. During the measurement process, this uniform force helps to produce a more regular deformation of the second grating 4, so that the change of the light signal and the pressure change are more stable. At the same time, stress concentration may cause excessive or uneven deformation of the second grating 4 in some local areas, thereby affecting the accurate output of the light signal. When the second grating 4 is parallel to the force-bearing surface, the stress is relatively more evenly distributed in the second grating 4 structure, which can reduce the appearance of stress concentration points and help improve detection accuracy.

[0081] Therefore, when the angle between the first grating 3 and the second grating 4 is 90°, the measurement sensitivity of the first grating 3 and the second grating 4 reaches the highest, thereby achieving the effect of improving the measurement sensitivity. At the same time, the second grating 4 is parallel to the measuring surface, which can make the grating evenly stressed and reduce stress concentration, thereby achieving the effect of improving the measurement accuracy.

[0082] See also Figure 5 and Figure 6 , a transformer fault monitoring device provided by the present invention, the shielding part 1 includes a shielding shell 7 and a connecting fastener 8;

[0083] The shielding shell 7 is provided with a signal connection port;

[0084] The end of the first grating 3 and the end of the second grating 4 are both connected to an optical fiber 6;

[0085] Optical fiber 6 passes through the signal connection port and is connected to the fault monitoring module for communication;

[0086] The sensitizing element 5 is bonded to the inside of the shielding shell 7 , and a connecting fastener 8 is provided inside the shielding shell 7 , and the connecting fastener 8 is used to fasten the outer side of the sensitizing element 5 by means of an adhesive.

[0087] In an embodiment of the present invention, the shielding portion 1 includes a shielding shell 7 and a connecting fastener 8; a signal connection port is opened on the shielding shell 7; the end of the first grating 3 and the end of the second grating 4 are both connected to an optical fiber 6; the optical fiber 6 is a quartz optical fiber, which is connected to the first grating 3 and the second grating 4 by fusion splicing, and the optical fiber 6 passes through the signal connection port to communicate with the fault monitoring module; it is used to transmit real-time vibration data and real-time oil pressure data to the fault monitoring module.

[0088] It is worth mentioning that quartz optical fiber has the advantages of low loss, high bandwidth and resistance to electromagnetic interference.

[0089] In the embodiment of the present invention, the sensitizing element 5 is bonded to the inside of the shielding shell 7, and a connecting fastener 8 is provided inside the shielding shell 7. The connecting fastener 8 is used to fasten the outside of the sensitizing element 5 through an adhesive. The connecting fastener 8 includes four connecting and fixing columns of a cylindrical structure. The four connecting and fixing columns are arranged in a rectangular shape inside the shielding shell 7. After cleaning the surface of the connecting and fixing columns, a proper amount of epoxy adhesive is applied to the surface of the connecting and fixing columns and the surface of the internal structure of the sensor in contact therewith, and then the connecting and fixing columns are placed in a predetermined position. In the sensor, the peripheral side of the sensitizing element 5 abuts against the connecting and fixing columns. After curing, the epoxy adhesive can provide a certain bonding strength to firmly fix the sensitizing element 5 in the rectangular space formed by the four connecting and fixing columns.

[0090] It is worth mentioning that the sensitizing element 5 is fastened inside the shielding shell 7 by connecting fasteners 8. At the same time, the surface of the sensitizing element 5 is bonded to the inside of the shielding shell 7 by epoxy resin adhesive, and the two are fixed together, so that the cross structure composed of the first grating 3 and the second grating 4 encapsulated in the sensitizing element 5 can be further stabilized, thereby ensuring the effects of high sensitivity and high precision measurement, avoiding changes in the angles between the cross structures and the non-parallelism of the second grating 4, which in turn affects the measurement effect.

[0091] See also Figure 7 , a transformer fault monitoring device provided by the present invention, a threaded mounting hole communicating with the interior of the oil tank is provided on the side wall of the oil tank;

[0092] One end of the shielding shell 7 close to the measuring surface of the sensor is a threaded end 9, and the end of the shielding shell 7 close to the measuring surface of the sensor is threadedly connected to the threaded mounting hole through a hexagonal fastener 10;

[0093] A sealing gasket is arranged between one end of the shielding shell 7 close to the measuring surface of the sensor and the hexagonal fastener 10 , and the sealing gasket is used to fill the thread gap.

[0094] In the embodiment of the present invention, the end of the shielding shell 7 close to the measuring surface of the sensor is matched with the threaded mounting hole through the hexagonal fastener 10, and the sensor is installed on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer. The sensor does not need to be installed inside the transformer with a complex spatial structure, which solves the problem that the complex spatial structure inside the existing transformer limits the installation position selection of the sensor and may not be installed in the most ideal position.

[0095] It should be noted that a sealing gasket is provided between the end of the shielding shell 7 close to the measuring surface of the sensor and the hexagonal fastener 10. The sealing gasket is used to fill the thread gap to prevent leakage of fluid and liquid inside the oil tank, thereby ensuring the sealing of the oil tank.

[0096] It is worth mentioning that the position of the threaded mounting hole is set according to the size of the transformer oil tank, which will not be repeated here. The end of the shielding shell 7 close to the measuring surface of the sensor is a threaded end 9, and the thread length is adapted to the threaded mounting hole. The end of the shielding shell 7 close to the measuring surface of the sensor is a threaded end 9 with a hexagonal fastener 10 on it. When the sensor is installed on the side wall of the transformer oil tank, a sealing gasket is filled between the contact surface of the hexagonal fastener 10 and the threaded end 9, which is convenient for fixing the sensor and ensuring the sealing of the transformer. According to the thickness of the transformer tank wall of the sensor (for example, 5mm). The thread specification of the threaded end 9 at the end of the shielding shell 7 close to the measuring surface of the sensor is related to the thickness of the transformer oil tank side wall. For example, if the thickness of the transformer tank wall of the sensor is 5mm, when making the sensor, a threaded end 9 is set within 5mm from the head (that is, the end of the shielding shell 7 close to the measuring surface of the sensor), and a threaded mounting hole is opened at the installation position on the transformer tank wall. Then, the end of the shielding shell 7 close to the measuring surface of the sensor is rotated and screwed into the threaded mounting hole to ensure that the bottom end of the sensor's sensitizing element 5 is in the same plane as the inner wall of the transformer box to avoid the influence of depression or protrusion on the propagation of vibration waves, thereby affecting the measurement accuracy. The hexagonal fastener 10 is located behind the thread, similar to the nut on the screw, and is mainly used to facilitate installation.

[0097] In another optional solution of the present invention, a 1 mm space is reserved between the hexagonal fastener 10 and the outer side of the transformer tank wall, and a copper gasket is inserted to facilitate the installation of the sensor and cooperate with the sealing gasket to further enhance the sealing of the transformer.

[0098] It is worth mentioning that the hexagonal fastener 10 is located outside the transformer tank.

[0099] In the transformer fault monitoring device provided by the present invention, the material of the sensitizing element 5 is fluorosilicone rubber.

[0100] In the embodiment of the present invention, the sensitizing element 5 is made of a polymer, specifically a fluorosilicone rubber material, which has excellent high and low temperature resistance and mechanical properties of general rubber, and has a low dielectric constant. The sensitizing element 5 is cylindrical as a whole, with a radius of 10 mm and a length of 30 mm, wherein the side facing the inside of the oil tank is the measuring side.

[0101] In a transformer fault monitoring device provided by the present invention, the shielding shell 7 and the connecting fastener 8 are both made of epoxy resin, and the adhesive is epoxy resin adhesive.

[0102] In the embodiment of the present invention, the materials of the shielding shell 7 and the connecting fastener 8 are both epoxy resin, and the adhesive used for bonding inside the shielding shell 7 is epoxy resin adhesive. By using the same type of materials, they have the same chemical structure basis and good chemical compatibility. The epoxy resin adhesive can form a strong chemical bond with the surface of the epoxy resin material, which is much stronger than simple physical adsorption, and can significantly improve the strength and stability of the bond. At the same time, when the material and the adhesive are the same type of epoxy resin, chemical reactions will not occur at the bonding point due to chemical incompatibility, thereby preventing deterioration caused by chemical reactions.

[0103] The present invention provides a transformer fault monitoring device, wherein the fault simulation module includes a simulation model building unit and a simulation data processing unit connected in communication;

[0104] A simulation model building unit, used for building a simulation model of the transformer;

[0105] A simulation data processing unit, used to input the transformer characteristic data acquired in advance for simulating different fault conditions into the simulation model, and perform multi-physical field fault simulation on the simulation model to obtain simulated mechanical state data of each fault type;

[0106] The transformer characteristic data includes transformer structural parameters, transformer operating parameters and transformer fault parameters;

[0107] The simulated mechanical state data includes simulated vibration data and simulated oil pressure data.

[0108] In an embodiment of the present invention, a finite element method is used to simulate a transformer model, a simulation model of the transformer is constructed, pre-acquired transformer structural parameters, transformer operating parameters and transformer fault parameters for simulating different fault conditions are input into the simulation model, and multi-physical field fault simulation is performed on the simulation model to obtain simulated mechanical state data of each fault type.

[0109] Transformer structural parameters such as core size parameters, number of winding turns, wire diameter and other parameters; transformer operating parameters such as transformer input voltage amplitude, phase, frequency, load type and size and other parameters; transformer fault parameters such as turn-to-turn short circuit, phase-to-phase short circuit, insulation breakdown and other parameters.

[0110] The multi-physics field is an electric-thermal-magnetic-mechanical multi-physics field. By combining electromagnetic-thermal coupling, electromagnetic-mechanical coupling and thermal-mechanical coupling, the fault simulation of the multi-physics field is realized.

[0111] The present invention provides a transformer fault monitoring device, wherein the fault monitoring module comprises a demodulation unit, a first feature extraction unit and a feature comparison unit which are sequentially connected in communication;

[0112] A demodulation unit, used for demodulating the received real-time mechanical state data with the simulated mechanical state data of each fault type;

[0113] A first feature extraction unit is used to extract features from the demodulated real-time mechanical state data and the simulated mechanical state data of each fault type, respectively, to obtain real-time waveform data and simulated waveform data of each fault type;

[0114] The feature comparison unit is used to perform consistency comparison between the real-time waveform data and the simulation waveform data of each fault type, and take the fault type associated with the simulation waveform data with consistent comparison results as the target fault type of the transformer.

[0115] In an embodiment of the present invention, the demodulation unit performs a demodulation operation on the real-time mechanical state data received and the simulated mechanical state data of each fault type, and the first feature extraction unit performs feature extraction on the demodulated real-time mechanical state data and the simulated mechanical state data of each fault type respectively to obtain real-time waveform data and simulated waveform data of each fault type, and the feature comparison unit performs consistency comparison between the real-time waveform data and the simulated waveform data of each fault type, and uses the fault type associated with the simulated waveform data with consistent comparison results as the target fault type of the transformer.

[0116] It should be noted that the mechanical state data contains vibration data and oil pressure data. Therefore, it is necessary to compare the real-time waveform corresponding to the real-time vibration data with the simulated waveform corresponding to the simulated vibration data, and the real-time waveform corresponding to the real-time oil pressure data with the simulated waveform corresponding to the simulated oil pressure data. If they are consistent, then the comparison is determined to be consistent.

[0117] The present invention provides a transformer fault monitoring device, wherein the fault monitoring module further comprises a noise reduction unit, a second feature extraction unit, a data operation unit and a fault early warning unit which are sequentially connected in communication;

[0118] A noise reduction unit, used for performing noise reduction operation on the demodulated real-time mechanical state data by using a wavelet packet decomposition method;

[0119] A second feature extraction unit is used to extract features from the real-time mechanical state data after noise reduction to obtain real-time amplitude data at the current moment;

[0120] A data calculation unit, used to perform a difference calculation using the real-time amplitude data at the current moment and the real-time amplitude data at the previous moment to obtain a real-time amplitude change rate;

[0121] The fault warning unit is used to generate warning information when the real-time amplitude change rate is within a preset change rate warning interval.

[0122] In an embodiment of the present invention, a noise reduction unit uses a wavelet packet decomposition method to perform noise reduction operations on the demodulated real-time mechanical state data to obtain a time domain waveform of a real signal that is restored as much as possible. A second feature extraction unit performs feature extraction on the real-time mechanical state data after noise reduction to obtain real-time amplitude data at the current moment. A difference operation is performed between the real-time amplitude data at the current moment and the real-time amplitude data at the previous moment to obtain a real-time amplitude change rate. When the real-time amplitude change rate is in a preset change rate warning interval, a warning message is generated.

[0123] It is worth mentioning that the monitoring results of the oil pressure data in the mechanical status data have two characteristics: the internal pressure of the transformer rises slowly, and there is an obvious pressure oscillation process when high-energy arc discharge occurs. When the above two situations occur, the amplitude characteristics of the oil pressure data can be compared to the amplitude change in different time periods. The waveform characteristics at different times have no reference value. Therefore, the amplitude characteristics are used here for early warning, and the early warning information is "fault warning" or "request to trip".

[0124] See also Figure 8 The present invention provides a monitoring method for a transformer fault monitoring device, comprising:

[0125] Step 101: Collect the real-time mechanical status data of the transformer at the current moment.

[0126] Step 102: Perform fault simulation using the transformer characteristic data acquired in advance to obtain simulated mechanical state data of each fault type.

[0127] Step 103: Perform fault analysis based on the real-time mechanical state data and the simulated mechanical state data to determine the fault type of the transformer at the current moment.

[0128] In an embodiment of the present invention, the sensor is first installed on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer. The sensor does not need to be installed inside the transformer with a complex spatial structure, which can avoid the direct impact of the high temperature inside the transformer on the sensor, thereby collecting accurate real-time mechanical state data of the transformer and improving data collection accuracy. Then, fault simulation is performed through a fault simulation module to obtain simulated mechanical state data under different fault types. Finally, fault analysis is performed based on the collected real-time mechanical state data and the simulated mechanical state data to determine the fault type of the transformer at the current moment; the technical problem of how to improve the accuracy of transformer fault monitoring is solved.

[0129] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0130] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0131] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transformer fault monitoring device, characterized in that: It includes a sensor, a fault simulation module and a fault monitoring module, wherein the sensor and the fault simulation module are both communicatively connected with the fault monitoring module; The sensor is mounted on the side wall of the oil tank of the transformer, and the measuring surface of the sensor is in contact with the inside of the oil tank of the transformer; The sensor is used to collect real-time mechanical status data of the transformer at the current moment; The fault simulation module is used to perform fault simulation using pre-acquired transformer characteristic data to obtain simulated mechanical state data of each fault type; The fault monitoring module is used to perform fault analysis based on the real-time mechanical state data and the simulated mechanical state data to determine the fault type of the transformer at the current moment.

2. The transformer fault monitoring device according to claim 1, characterized in that: The real-time mechanical status data includes real-time vibration data and real-time oil pressure data; The sensor comprises a packaging portion and a shielding portion; The shielding portion abuts against the side wall of the oil tank; The packaging part is arranged inside the shielding part; The packaging part includes a first grating for measuring the real-time vibration data of the oil tank side wall, a second grating for measuring the real-time oil pressure data received by the measuring surface, and a sensitivity enhancement element; The sensitivity enhancement element is encapsulated inside the encapsulation part, and the bottom end of the sensitivity enhancement element is the measuring surface of the sensor; The first grating is packaged along the longitudinal direction of the sensitivity enhancement element, and the end of the first grating passes through the circumferential side of the sensitivity enhancement element; The second grating is packaged along the lateral direction of the sensitivity enhancement element, and the end of the second grating passes through the circumferential side of the sensitivity enhancement element; The first grating and the second grating are perpendicular to each other.

3. The transformer fault monitoring device according to claim 2, characterized in that: The shielding part includes a shielding shell and a connecting fastener; The shielding shell is provided with a signal connection port; An end of the first grating and an end of the second grating are both connected with optical fibers; The optical fiber passes through the signal connection port and is communicatively connected with the fault monitoring module; The sensitizing element is bonded to the inside of the shielding shell, and the connecting fastener is arranged inside the shielding shell. The connecting fastener is used to fasten the outer side of the sensitizing element through an adhesive.

4. The transformer fault monitoring device according to claim 3, characterized in that: The side wall of the oil tank is provided with a threaded mounting hole connected to the interior of the oil tank; One end of the shielding shell close to the measuring surface of the sensor is a threaded end, and the end of the shielding shell close to the measuring surface of the sensor is threadedly connected to the threaded mounting hole through a hexagonal fastener; A sealing gasket is arranged between one end of the shielding shell close to the measuring surface of the sensor and the hexagonal fastener, and the sealing gasket is used to fill the thread gap.

5. The transformer fault monitoring device according to claim 2, characterized in that: The material of the sensitizing element is fluorosilicone rubber.

6. The transformer fault monitoring device according to claim 3, characterized in that: The shielding shell and the connecting fastener are both made of epoxy resin, and the adhesive is epoxy resin adhesive.

7. The transformer fault monitoring device according to claim 1, characterized in that: The fault simulation module includes a simulation model building unit and a simulation data processing unit that are communicatively connected; The simulation model building unit is used to build a simulation model of the transformer; The simulation data processing unit is used to input the transformer characteristic data acquired in advance for simulating different fault conditions into the simulation model, and perform multi-physical field fault simulation on the simulation model to obtain simulated mechanical state data of each fault type; The transformer characteristic data includes transformer structural parameters, transformer operating parameters and transformer fault parameters; The simulated mechanical state data includes simulated vibration data and simulated oil pressure data.

8. The transformer fault monitoring device according to claim 1, characterized in that: The fault monitoring module comprises a demodulation unit, a first feature extraction unit and a feature comparison unit which are communicatively connected in sequence; The demodulation unit is used to perform demodulation operations on the received real-time mechanical state data and the simulated mechanical state data of each fault type; A first feature extraction unit is used to extract features from the demodulated real-time mechanical state data and the simulated mechanical state data of each fault type, respectively, to obtain real-time waveform data and simulated waveform data of each fault type; The feature comparison unit is used to perform consistency comparison between the real-time waveform data and the simulation waveform data of each fault type, and use the fault type associated with the simulation waveform data with consistent comparison results as the target fault type of the transformer.

9. The transformer fault monitoring device according to claim 8, characterized in that: The fault monitoring module also includes a noise reduction unit, a second feature extraction unit, a data operation unit and a fault warning unit which are communicatively connected in sequence; The noise reduction unit is used to perform noise reduction operation on the demodulated real-time mechanical state data by using wavelet packet decomposition method; The second feature extraction unit is used to extract features from the real-time mechanical state data after noise reduction to obtain real-time amplitude data at the current moment; The data operation unit is used to perform a difference operation between the real-time amplitude data at the current moment and the real-time amplitude data at the previous moment to obtain a real-time amplitude change rate; The fault warning unit is used to generate warning information when the real-time amplitude change rate is within a preset change rate warning interval.

10. A monitoring method applied to the transformer fault monitoring device according to any one of claims 1 to 9, characterized in that: include: Collect the real-time mechanical status data of the transformer at the current moment; Using the transformer characteristic data acquired in advance to perform fault simulation, obtain simulated mechanical state data of each fault type; Perform fault analysis based on real-time mechanical status data and simulated mechanical status data to determine the fault type of the transformer at the current moment.

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