Reactor turn-to-turn deformation fault diagnosis method

Abstract

The invention discloses an electric reactor turn-to-turn deformation fault diagnosis method, and relates to the technical field of transformer fault diagnosis. According to the method, firstly, a mobile motor is controlled to enable a turn-to-turn deformation mechanism mobile module to reach a designated initial position, a micro-distance telescopic air rod is controlled according to feedback of a laser measuring instrument to enable a four-axis coordinated extrusion structure to reach a designated fault position, and the four-axis coordinated extrusion structure is controlled to work through a motor master control device to enable the reactor to be subjected to turn-to-turn deformation. And controlling an oscillatory wave detection signal generator to emit an oscillatory wave detection signal which passes through the reactor winding after fault simulation, and storing a fault signal. And then constructing a modal component of deformation fault data, and finally solving an energy loss factor and a correlation coefficient to diagnose the fault degree.

Description

Technical Field

[0001] This invention relates to the field of transformer fault diagnosis technology, specifically to a method for diagnosing inter-turn deformation faults in reactors. Background Technology

[0002] Reactors are crucial equipment in power systems, and their operating status directly affects the stability and safety of the power system. During short-circuit faults, reactors limit the magnitude of the short-circuit current, thereby reducing its impact on equipment and the system. This helps protect power equipment from damage and improves the stability and reliability of the power system. Furthermore, reactors can improve power quality, particularly in addressing harmonic issues. In AC power systems, reactors can also be used in combination with capacitors to form reactive power compensation devices. These devices can dynamically adjust the reactive power of the system, thereby improving the power factor, reducing reactive power losses in lines and transformers, and increasing the transmission capacity of the grid. With the development of power electronics technology, reactors are also widely used in flexible AC transmission systems. By controlling the impedance value of the reactor, flexible control of the AC power flow can be achieved, thus improving the flexibility and controllability of the power system.

[0003] The complex and harsh operating environment of reactors increases their probability of failure, with winding deformation faults being a common one. Reactor failures can generate high temperatures and intense electric arcs, conditions that can easily lead to fires. Fires not only cause equipment damage and property loss but also threaten personnel safety. Therefore, the safe operation of reactors is of paramount importance in preventing fires.

[0004] CN118914715A describes a method for simulating inter-turn and inter-phase deformation fault diagnosis of three-phase transformer windings. The method involves using a control track device to transport a deformation-controlled robotic arm to a suitable operable position. The robotic arm is then operated to induce different degrees of deformation between the turns and phases of the three-phase transformer windings, simulating possible deformations in actual power transformer windings. Furthermore, an oscillating wave test device is used to obtain oscillating wave test curve data under different deformation fault conditions. Finally, the stored data is analyzed and processed, and combined with a corresponding algorithm, a parameter λk is obtained. This parameter reflects the operational status of the three-phase transformer. This method is used to diagnose and analyze the deformation fault state of the three-phase transformer to be identified. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a method for diagnosing inter-turn deformation faults in reactors, thus solving the technical problems mentioned in the background section.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution: a method for diagnosing inter-turn deformation faults in reactors, used for simulating fault diagnosis or diagnosing real faults, comprising the following steps:

[0009] S1: Combining the data received by the pressure sensor and the signals collected by the signal acquisition device, the fault signal is defined as k modal functions u. k (t) Summation;

[0010] S2: First, for each mode function u k Performing the Hilbert transform on (t) yields the analytic signal of the mode function:

[0011]

[0012] S3: Utilizing the Correction Index The spectrum of each mode function is modulated onto its respective baseband;

[0013]

[0014] S4: Calculate the square of the gradient L of the demodulated signal. 2 Norms are used to estimate the bandwidth of each modal function, resulting in the corresponding constraint variational values ​​as follows:

[0015]

[0016] Where: {u k} represents the obtained variational mode components, {u k} = {u1, u2, ..., u k},{ω k} is the center frequency corresponding to each component, {ω k}={ω1,ω2,…,ω k}, where t is time, δ(t) is the partial derivative of t, δ(t) is the unit impulse function, ω is the cycle frequency, and K represents the total number of variational mode component decomposition layers.

[0017] S5: To ensure the accuracy of signal reconstruction and convergence under noisy conditions, a quadratic penalty factor α is introduced;

[0018] While ensuring the strictness of the constraints, the Lagrange multiplication operator is introduced to transform the constrained variational problem into an unconstrained problem;

[0019] The Lagrange expression, after introducing two parameters, is expanded as follows:

[0020]

[0021] Where: α represents the bandwidth parameter; λ (t) Represents the Lagrange multipliers;

[0022] S6: Solve the extended Lagrange expression using the alternating direction method of multiplication operators. The steps are as follows:

[0023] S61: Initialization n

[0024] S62: Execute the loop n = n + 1;

[0025] S63: For all ω≥0, update u k ω k ,λ;

[0026]

[0027] S7: Determine if the convergence condition is met. If it is, stop the iteration and obtain the deformation component with the smallest sum of the k bandwidths. Otherwise, return to S3.

[0028]

[0029] S8: Due to the complexity and diversity of the measured signal, the key is how to select an appropriate number of decompositions κ and a penalty parameter α. The energy loss factor g is defined as the ratio of the energy difference between the current decomposition component and the previous decomposition component to the energy of the original signal, and the calculation formula is:

[0030]

[0031] Where: ∑u k Let ∑u be the energy of the current component. k-1 Let S(t) be the energy of the previous decomposition component and S(t) be the original signal. The number of decompositions is determined using the energy loss factor, with the energy loss factor threshold g set to 0.01. At the same time, the maximum decomposition modulus is set to 10. Therefore, by finding the minimum value of the energy loss factor, the number of decomposed deformation components can be determined.

[0032] S9: To determine the degree of correlation between the deformation component and the original signal, i.e., the degree of inter-turn deformation fault in the reactor, the correlation coefficient r is used, and its calculation method is as follows:

[0033]

[0034] Where: Cov(u k S) is u k The covariance of S, and σ s They are u k The variance of S.

[0035] Preferably, the value of r is between [0,1]. When r≥0.8, it is considered fault-4; when 0.5≤r<0.8, it is considered fault-3; when 0.3≤r<0.5, it is considered fault-2; and when 0.1≤r<0.3, it is considered fault-1. Fault-1, fault-2, fault-3, and fault-4 represent the degree of fault from smallest to largest.

[0036] Preferably, when simulating fault diagnosis, different degrees of inter-turn axial deformation faults are simulated at at least one location on the reactor.

[0037] Preferably, it includes an inter-turn axial deformation fault device, which is a rotating device whose end rotation can cause inter-turn axial deformation of the reactor.

[0038] Preferably, the rotation axis of the inter-turn axial deformation fault device is perpendicular to the axis of the reactor.

[0039] Preferably, the number of the inter-turn axial deformation fault devices is at least one, and it is used to simulate inter-turn axial deformation faults at at least different locations on the reactor.

[0040] Preferably, the different degrees of inter-turn axial deformation faults are faults simulated by different numbers of inter-turn axial deformation fault devices. The more inter-turn axial deformation fault devices used for fault simulation, the greater the fault.

[0041] Preferably, the inter-turn axial deformation fault device includes a reactor body, a reactor coil, an upper reactor clamp, a lower reactor clamp, a reactor core, an inter-turn deformation simulation mechanism, a motor control device, a longitudinal nested slide rail for the inter-turn deformation simulation mechanism, a longitudinal screw fixed to the rear side of the inter-turn deformation simulation mechanism, an upper sleeve of the longitudinal screw, an axial screw for axially moving the inter-turn deformation mechanism, an axially moving slide rod located below the axial screw, a moving module for the inter-turn deformation simulation mechanism, a rear support frame for the axial screw, a support frame located at the bottom of the axial screw, a moving motor for controlling the moving module of the inter-turn deformation simulation mechanism to move the inter-turn deformation simulation mechanism, and a fixed... Four-axis coordinated extrusion structure-1 on the inter-turn deformation simulation mechanism, four-axis coordinated extrusion structure-2 fixed on the inter-turn deformation simulation mechanism, four-axis coordinated extrusion structure-3 fixed on the inter-turn deformation simulation mechanism, four-axis coordinated extrusion structure-4 fixed on the inter-turn deformation simulation mechanism, upper gear set-1 of the four-axis coordinated extrusion structure, upper gear set-2 of the four-axis coordinated extrusion structure, upper gear set-3 of the four-axis coordinated extrusion structure, upper gear set-4 of the four-axis coordinated extrusion structure, stop rod-1 of the four-axis coordinated extrusion structure, stop rod-2 of the four-axis coordinated extrusion structure, stop rod-3 of the four-axis coordinated extrusion structure, stop rod-4 of the four-axis coordinated extrusion structure, micro-adjustment. Telescopic air rod, upper fixed sleeve of micro-adjustable telescopic air rod, fixed kit for inter-turn deformation simulation mechanism, power motor for inter-turn deformation simulation mechanism, bottom fixed frame of reactor inter-turn deformation simulation device, upper slide rail-1 of the bottom fixed frame of reactor inter-turn deformation simulation device, upper slide rail-2 of the bottom fixed frame of reactor inter-turn deformation simulation device, upper moving slide rod-1 of the bottom fixed frame of reactor inter-turn deformation simulation device, upper moving slide rod-2 of the bottom fixed frame of reactor inter-turn deformation simulation device, support frame sleeve-1 for moving slide rod and bottom of axial screw, support frame sleeve-2 for moving slide rod and bottom of axial screw. 1. Reactor axial fixing rod-1, 2. Reactor axial fixing rod-2, 3. Reactor axial fixing rod-4, 4. Reactor front and rear fixing module-1, 5. Laser measuring instrument for controlling the micro-distance adjustment of the telescopic air rod-1, 6. Laser measuring instrument for controlling the micro-distance adjustment of the telescopic air rod-2, 7. Pressure sensor fixed to the four-axis coordinated extrusion mechanism-1, 8. Pressure sensor fixed to the four-axis coordinated extrusion mechanism-2, 9. Pressure sensor fixed to the four-axis coordinated extrusion mechanism-3, 10. Pressure sensor fixed to the four-axis coordinated extrusion mechanism-4, oscillation wave signal generator, signal acquisition device, high-frequency high-voltage DC power supply.

[0042] Preferably, the inter-turn axial deformation fault device simulates a fault according to the following steps:

[0043] 1) The main control device of the operating motor controls the moving motor to make the moving module of the inter-turn deformation mechanism reach the designated initial position along the longitudinal screw and the axial screw;

[0044] 2) The main control device of the operating motor controls the power motor to adjust the inter-turn deformation simulation mechanism to reach the working range of laser measuring instrument-1 and laser measuring instrument-2;

[0045] 3) Based on the feedback control of laser measuring instrument-1 and laser measuring instrument-2, the micro-distance telescopic air rod is used to make the four-axis coordinated extrusion structure-1, four-axis coordinated extrusion structure-2, four-axis coordinated extrusion structure-3, and four-axis coordinated extrusion structure-4 reach the designated fault position.

[0046] 4) The four-axis coordinated extrusion structure-1, four-axis coordinated extrusion structure-2, four-axis coordinated extrusion structure-3, and four-axis coordinated extrusion structure-4 are controlled by the motor control device to cause inter-turn deformation of the reactor. The degree of deformation failure is synchronized with the number of working operations of the four-axis coordinated extrusion mechanism, that is, fault-1, fault-2, fault-3, and fault-4 are set.

[0047] 5) Pressure sensor-1, pressure sensor-2, pressure sensor-3, and pressure sensor-4 fixed to the four-axis coordinated extrusion mechanism are used to monitor, record, and receive inter-turn deformation data in real time.

[0048] 6) The main control device of the motor controls the four-axis coordinated extrusion structure stop rod-1, four-axis coordinated extrusion structure stop rod-2, four-axis coordinated extrusion structure stop rod-3, and four-axis coordinated extrusion structure stop rod-4 to stop the inter-turn deformation fault and reset them;

[0049] 7) An oscillating wave detection signal is generated by an oscillating wave detection signal generator, and the fault signal is stored by a signal acquisition device through the reactor winding after the fault simulation.

[0050] 8) Control the micro-distance telescopic air rod to reset the inter-turn deformation simulation device, and operate the moving motor to reset the moving module of the inter-turn deformation simulation device.

[0051] (III) Beneficial Effects

[0052] This invention provides a method for diagnosing inter-turn deformation faults in reactors. It has the following beneficial effects:

[0053] (1) The core algorithm of the simulation method of this invention (VMD + correlation coefficient) successfully realized the quantitative diagnosis of inter-turn deformation faults in real reactors, and verified the effectiveness of the method in real-world scenarios.

[0054] (2) This invention uses a mechanical device to simulate inter-turn deformation faults in reactor windings, and combines it with diagnostic waveform testing to achieve fault diagnosis of axial deformation in the windings. This invention can more reliably and effectively diagnose reactor winding deformation faults. Attached Figure Description

[0055] Figure 1a This is a front view of a reactor inter-turn deformation fault simulation device according to the present invention;

[0056] Figure 1b This is a side view of a reactor inter-turn deformation fault simulation device according to the present invention;

[0057] Figure 1c This is a top view of a reactor inter-turn deformation fault simulation device according to the present invention;

[0058] Figure 2a This is a schematic diagram of an extrusion mechanism according to the present invention;

[0059] Figure 2b This is a structural diagram of an extrusion mechanism according to the present invention;

[0060] Figure 3 This is a flowchart of a reactor inter-turn deformation fault simulation device and diagnostic method according to the present invention. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Example 1: Simulated Inter-turn Deformation Fault Detection

[0063] like Figure 1a , Figure 1b , Figure 1c , Figure 2aAs shown, a reactor inter-turn deformation fault simulation device includes: a reactor body (1), a reactor coil (2), an upper reactor clamp (3), a lower reactor clamp (4), a reactor core (5), an inter-turn deformation simulation mechanism (6), a motor control device (7), a longitudinal nested slide rail of the inter-turn deformation simulation mechanism (8), a longitudinal screw (9) fixed to the rear side of the inter-turn deformation simulation mechanism, a sleeve at the upper end of the longitudinal screw (10), an axial screw (11) for axially moving the inter-turn deformation mechanism, an axially moving slide rail located below the axial screw, a moving module (12) for the inter-turn deformation simulation mechanism, a rear support frame (13) for the axial screw, a support frame (14) located at the bottom of the axial screw, and a control module for the moving module of the inter-turn deformation simulation mechanism. 15. Moving motor for inter-turn deformation simulation mechanism; 16. Four-axis coordinated extrusion structure fixed on inter-turn deformation simulation mechanism; 2 (17) Four-axis coordinated extrusion structure fixed on inter-turn deformation simulation mechanism; 3 (18) Four-axis coordinated extrusion structure fixed on inter-turn deformation simulation mechanism; 4 (19) Four-axis coordinated extrusion structure fixed on inter-turn deformation simulation mechanism; 120. Upper gear set of four-axis coordinated extrusion structure; 21. Upper gear set of four-axis coordinated extrusion structure; 32. Upper gear set of four-axis coordinated extrusion structure; 4 (23) Upper gear set of four-axis coordinated extrusion structure; 1 (24) Stop bar of four-axis coordinated extrusion structure; 2 (25) Stop bar of four-axis coordinated extrusion structure. -3(26), Four-axis coordinated extrusion structure stop bar -4(27), Micro-adjustable telescopic air rod (28), Micro-adjustable telescopic air rod upper fixed sleeve (29), Inter-turn deformation simulation mechanism fixing kit (30), Inter-turn deformation simulation mechanism power motor 31, Reactor inter-turn deformation simulation device bottom fixed frame (32), Upper slide rail located on the bottom fixed frame of the reactor inter-turn deformation simulation device -1 (33), Upper slide rail located on the bottom fixed frame of the reactor inter-turn deformation simulation device -2 (34), Upper moving slide rod located on the bottom fixed frame of the reactor inter-turn deformation simulation device -1 35, Upper moving slide rod located on the bottom fixed frame of the reactor inter-turn deformation simulation device -2 36, Support frame at the bottom of the moving slide rod and the axial screw Jacket-1 (37), Support frame jacket-2 (38) for the bottom of the sliding rod and axial screw, Axial fixing rod-1 (39) for the reactor, Axial fixing rod-2 (40) for the reactor, Axial fixing rod-3 (41) for the reactor, Axial fixing rod-4 (42) for the reactor, Front and rear fixing module-1 (43) for the reactor, Front and rear fixing module-1 (44) for the reactor, Laser measuring instrument-1 (45) for controlling the micro-adjustment telescopic air rod, Laser measuring instrument-2 (46) for controlling the micro-adjustment telescopic air rod, Pressure sensor-1 (47) fixed to the four-axis coordinated extrusion mechanism, Pressure sensor-2 (48) fixed to the four-axis coordinated extrusion mechanism, Pressure sensor-3 (49) fixed to the four-axis coordinated extrusion mechanismThe pressure sensor-4 (50), oscillation wave signal generator (51), signal acquisition device (52), and high-frequency high-voltage DC power supply (53) are fixed to the four-axis coordinated extrusion mechanism.

[0064] The aforementioned reactor inter-turn deformation fault simulation device and diagnostic method include the following steps:

[0065] Step 1: Simulate inter-turn axial deformation faults of different degrees in the reactor;

[0066] Step 2: Conduct high-voltage oscillation wave testing and fault diagnosis of reactor windings.

[0067] Its characteristic is that step one includes:

[0068] 1. The main control device (7) controls the moving motor (15) to make the inter-turn deformation mechanism moving module (12) reach the specified initial position along the longitudinal screw (9) and the axial screw (11);

[0069] 2. Operate the motor control device (7) to control the power motor (31) and adjust the inter-turn deformation simulation mechanism (6) to reach the working range of laser measuring instrument-1 (45) and laser measuring instrument-2 (46);

[0070] 3. Based on the feedback control of laser measuring instrument-1 (45) and laser measuring instrument-2 (46), the micro-distance telescopic air rod (28) is used to make the four-axis coordinated extrusion structure-1 (16), four-axis coordinated extrusion structure-2 (17), four-axis coordinated extrusion structure-3 (18) and four-axis coordinated extrusion structure-4 (19) reach the designated fault position.

[0071] 4. The four-axis coordinated extrusion structure-1 (16), four-axis coordinated extrusion structure-2 (17), four-axis coordinated extrusion structure-3 (18), and four-axis coordinated extrusion structure-4 (19) are controlled by the motor control device to make the reactor inter-turn deformation. The degree of deformation fault is synchronized with the number of working operations of the four-axis coordinated extrusion mechanism, that is, fault-1, fault-2, fault-3, and fault-4 are set.

[0072] 5. Pressure sensor-1 (47), pressure sensor-2 (48), pressure sensor-3 (49), and pressure sensor-4 (50) fixed to the four-axis coordinated extrusion mechanism are used to monitor and record the inter-turn deformation data in real time.

[0073] 6. The main control device of the motor (7) controls the four-axis coordinated extrusion structure stop rod-1 (24), four-axis coordinated extrusion structure stop rod-2 (25), four-axis coordinated extrusion structure stop rod-3 (26), and four-axis coordinated extrusion structure stop rod-4 (27) to stop the inter-turn deformation fault and reset.

[0074] 7. An oscillating wave detection signal is generated by an oscillating wave detection signal generator (51), and the fault signal is stored by a signal acquisition device (52) through the reactor winding (2) after fault simulation.

[0075] 8. Control the micro-distance telescopic air rod (28) to reset the inter-turn deformation simulation device (6), and operate the moving motor (15) to reset the inter-turn deformation simulation device moving module (12);

[0076] 9. Repeat steps 1 to 8) to simulate inter-turn deformation faults at different locations;

[0077] The characteristic feature is that step two includes:

[0078] 1) Combining the data received by the pressure sensor and the signals collected by the signal acquisition device, the fault signal is defined as k modal functions u. k (t) Summation;

[0079] 2) First, for each mode function u k Performing the Hilbert transform on (t) yields the analytic signal of the mode function:

[0080]

[0081] (2) Using the correction index The spectrum of each mode function is modulated onto its respective baseband;

[0082]

[0083] (3) Calculate the square of the demodulated signal gradient L 2 Norms are used to estimate the bandwidth of each modal function, resulting in the corresponding constraint variational values ​​as follows:

[0084]

[0085] Where: {u k} represents the obtained variational mode components, {u k}={u1,u2,...,u k},{ω k} is the center frequency corresponding to each component, {ω k}={ω1,ω2,…,ω k}. t is time, Let δ(t) be the partial derivative of t, δ(t) be the unit impulse function, ω be the cycle frequency, and K be the total number of variational mode component decomposition layers.

[0086] (4) To ensure the accuracy of signal reconstruction and convergence under noisy conditions, a quadratic penalty factor α is introduced. While maintaining the strictness of the constraints, the Lagrange multiplication operator is introduced to transform the constrained variational problem into an unconstrained problem. The Lagrange expression, after introducing two parameters, is extended as follows:

[0087]

[0088] Where α represents the bandwidth parameter; λ(t) represents the Lagrange multiplier.

[0089] (5) The extended Lagrange expression is solved using the alternating direction method of multiplication operators. The steps are as follows:

[0090] initialization n

[0091] Execute the loop n = n + 1;

[0092] For all ω≥0, update u k ω k ,λ;

[0093]

[0094] Among them: supplements to the three formulas in (5)

[0095] Optimal solution in the frequency domain of modal components:

[0096]

[0097] By minimizing the Lagrange function on ω k The partial derivatives are used to derive the center frequency update rule:

[0098]

[0099] Derive the multiplier update rule from the saddle point condition of the Lagrange function:

[0100]

[0101] Step 4: Determine whether the convergence condition is met. If it is met, stop the iteration and obtain the deformation component with the smallest sum of K bandwidths. Otherwise, return to (2).

[0102]

[0103] Due to the complexity and diversity of the measured signal, the key is to select an appropriate number of decompositions K and a penalty parameter α. The energy loss factor g is defined as the ratio of the energy difference between the current decomposed component and the previous decomposed component to the energy of the original signal, and the calculation formula is:

[0104]

[0105] Where: ∑u k Let ∑u be the energy of the current component. k-1 Let S(t) be the energy of the previous decomposed component and S(t) be the original signal. The number of decomposers is determined using an energy loss factor, with the energy loss factor threshold g set to 0.01. Simultaneously, the maximum decomposed modulus is set to 10. Therefore, by finding the minimum value of the energy loss factor, the number of decomposed deformation components can be determined. To determine the correlation between the deformation components and the original signal, i.e., the degree of inter-turn deformation fault in the reactor, the correlation coefficient r is used, and its calculation method is as follows:

[0106]

[0107] Where: Cov(u k S) is u k The covariance of S, and σ s They are u k The variance of S. The value of r is usually between [0,1]. When r≥0.8, it is considered fault-4; when 0.5≤r<0.8, it is considered fault-3; when 0.3≤r<0.5, it is considered fault-2; and when 0.1≤r<0.3, it is considered fault-1.

[0108] Example 2: Detection of Actual Inter-turn Deformation Faults in Reactors

[0109] An abnormal noise was detected in the reactor of a 220kV substation during operation. Infrared thermography showed an abnormal increase in local temperature (8°C higher than the normal area), and it was initially determined that there might be an inter-turn deformation fault.

[0110] Implementation Step 1. On-site preparation and safety measures: Equipment shutdown and isolation: Remove the target reactor from the power grid, disconnect the high-voltage side from the low-voltage side, hang a "Do Not Close" sign, and ground discharge for more than 15 minutes to ensure the safety of the testing process.

[0111] Sensor deployment: Four pressure sensors (corresponding to 47-50 in the simulation device) are evenly pasted on the surface of the reactor coil (2) to monitor the mechanical stress changes during operation; an oscillation wave signal generator (51) and a high-frequency high-voltage DC power supply (53) are connected to the reactor output terminal, and a signal acquisition device (52) is connected to the coil neutral point with a sampling frequency of 1MHz to capture high-frequency fault characteristics.

[0112] Real fault signal acquisition excitation signal application: Apply a DC pre-voltage of 1.2 times the rated voltage through a high-frequency high-voltage DC power supply. After stabilizing for 5 minutes, a damped oscillation wave signal with a frequency of 500kHz is emitted by an oscillation wave signal generator, and the response signal (including voltage and current waveforms) is continuously acquired within 10 seconds.

[0113] Multi-condition data supplementation: Signals were repeatedly acquired under both cold (ambient temperature 25℃) and hot (after operating at 80% rated load for 30 minutes) conditions to eliminate temperature interference with fault characteristics. 3. Signal processing and fault diagnosis (based on VMD algorithm): Signal preprocessing: The acquired raw signals (including noise) were filtered (50Hz power frequency notch filter + 10kHz low-pass filter) to extract the effective fault characteristic frequency bands. Variational Mode Decomposition (VMD):

[0114] 1) Combining the data received by the pressure sensor and the signals collected by the signal acquisition device, the fault signal is defined as k modal functions u. k (t) Summation;

[0115] 2) First, for each mode function u k Performing the Hilbert transform on (t) yields the analytic signal of the mode function:

[0116]

[0117] (2) Using the correction index The spectrum of each mode function is modulated onto its respective baseband;

[0118]

[0119] (3) Calculate the square of the demodulated signal gradient L 2 Norms are used to estimate the bandwidth of each modal function, resulting in the corresponding constraint variational values ​​as follows:

[0120]

[0121] Where: {u k} represents the obtained variational mode components, {u k} = {u1, u2, ..., u k},{ω k} is the center frequency corresponding to each component, {ω k}={ω1,ω2,…,ω k}. t is time, Let δ(t) be the partial derivative of t, δ(t) be the unit impulse function, ω be the cycle frequency, and K be the total number of variational mode component decomposition layers.

[0122] (4) To ensure the accuracy of signal reconstruction and convergence under noisy conditions, a quadratic penalty factor α is introduced. While maintaining the strictness of the constraints, the Lagrange multiplication operator is introduced to transform the constrained variational problem into an unconstrained problem. The Lagrange expression, after introducing two parameters, is extended as follows:

[0123]

[0124] Where α represents the bandwidth parameter; λ(t) represents the Lagrange multiplier.

[0125] (5) The extended Lagrange expression is solved using the alternating direction method of multiplication operators. The steps are as follows:

[0126] initialization n

[0127] Execute the loop n = n + 1;

[0128] For all ω≥0, update u k ,≥ω k ,λ;

[0129]

[0130] Determine whether the convergence condition is met. If it is met, stop the iteration and obtain the deformation component with the smallest sum of the k bandwidths. Otherwise, return (2).

[0131]

[0132] Due to the complexity and diversity of the measured signal, the key is to select an appropriate number of decompositions k and a penalty parameter α. The energy loss factor g is defined as the ratio of the energy difference between the current decomposition component and the previous decomposition component to the energy of the original signal, and the calculation formula is:

[0133]

[0134] Where: ∑u k Let ∑u be the energy of the current component. k-1 Let S(t) be the energy of the previous decomposed component and S(t) be the original signal. The number of decomposers is determined using an energy loss factor, with the energy loss factor threshold g set to 0.01. Simultaneously, the maximum decomposed modulus is set to 10. Therefore, by finding the minimum value of the energy loss factor, the number of decomposed deformation components can be determined. To determine the correlation between the deformation components and the original signal, i.e., the degree of inter-turn deformation fault in the reactor, the correlation coefficient r is used, and its calculation method is as follows:

[0135]

[0136] Where: Cov(u k S) is u k The covariance of S, and σ s They are u k The variance of S. The value of r is usually between [0,1].

[0137] The correlation coefficient r between each modal component and the original signal was calculated, and the results are as follows:

[0138] The r of u1(t) and S(t) is 0.72, the r of u2(t) and S(t) is 0.15, and the r of u3(t) and u4(t) is <0.1.

[0139] According to the diagnostic criteria: 0.5≤r<0.8 corresponds to fault-3, indicating that the reactor has moderate inter-turn axial deformation (multi-turn insulation wear, local extrusion deformation).

[0140] Results Verification and Maintenance Recommendations Disassembly Verification: After power outage, the upper clamp (3) and lower clamp (4) of the reactor were removed. It was observed that there were 3 sets of adjacent turns of insulation paper damage about 1 / 3 of the distance from the upper end of the coil (2), and the wires had slight compression and indentation, which was consistent with the diagnosis results.

[0141] Repair measures: Replace the damaged insulation paper, adjust the clamping force, and perform vacuum drying again. Then, re-test using the VMD method. If the correlation coefficient of each modal component is less than 0.1, the fault is considered eliminated. Key points for implementation: The actual fault signal is greatly affected by electromagnetic interference and mechanical vibration at the scene. It is necessary to collect data multiple times (more than 3 times is recommended) and take the average value to reduce the error.

[0142] For older reactors, the correlation coefficient threshold needs to be adjusted by combining historical operating data (such as short-circuit impact records) to avoid misjudgment. Under high-voltage conditions, electrical safety regulations must be strictly followed, and the intensity of the oscillation signal should be controlled within the equipment's insulation tolerance range (not exceeding 1.5 times the rated voltage). This embodiment successfully achieved quantitative diagnosis of inter-turn deformation faults in real reactors through the core algorithm of the simulation method (VMD + correlation coefficient), verifying the effectiveness of the method in practical scenarios.

[0143] Among them: threshold selection logic and parameter joint optimization

[0144] Threshold condition for energy selection factor, and termination condition for decomposition number K.

[0145] and

[0146] θ is a preset threshold. When g(K)≤θ, the number of decompositions K is stopped.

[0147]

[0148] By combining the comprehensive criteria of energy loss factor and correlation coefficient, the synergistic effect between them can be strengthened.

[0149]

[0150] w1 and w2 are weighting coefficients, balancing energy loss and correlation. The optimal parameter K and α are determined by... Sure.

[0151] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0152] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for diagnosing inter-turn deformation faults in reactors, used for simulated fault diagnosis or real fault diagnosis, characterized in that: Includes the following steps: S1: Combining the data received by the pressure sensor and the signals collected by the signal acquisition device, the fault signal is defined as k modal functions u. k (t) Summation; S2: First, for each mode function u k Performing the Hilbert transform on (t) yields the analytic signal of the mode function: S3: Utilizing the Correction Index The spectrum of each mode function is modulated onto its respective baseband; S4: Calculate the square of the gradient L of the demodulated signal. 2 Norms are used to estimate the bandwidth of each modal function, resulting in the corresponding constraint variational values ​​as follows: Where: {u k } represents the obtained variational mode components, {u k } = {u1, u2, ..., u k },{ω k } is the center frequency corresponding to each component, {ω k }={ω1,ω2,…,ω k }, where t is time, δ(t) is the partial derivative of t, δ(t) is the unit impulse function, ω is the cycle frequency, and K represents the total number of variational mode component decomposition layers. S5: To ensure the accuracy of signal reconstruction and convergence under noisy conditions, a quadratic penalty factor α is introduced; While ensuring the strictness of the constraints, the Lagrange multiplication operator is introduced to transform the constrained variational problem into an unconstrained problem; The Lagrange expression, after introducing two parameters, is expanded as follows: Where: α represents the bandwidth parameter; λ(t) represents the Lagrange multiplier; S6: Solve the extended Lagrange expression using the alternating direction method of multiplication operators. The steps are as follows: S61: Initialization n S62: Execute loop n = n + 1; S63: For all ω≥0, update u k ω k ,λ; S7: Determine if the convergence condition is met. If it is, stop the iteration and obtain the deformation component with the smallest sum of the k bandwidths. Otherwise, return to S3. S8: Due to the complexity and diversity of the measured signal, the key is how to select the appropriate decomposition number k and the penalty parameter α; The energy loss factor g is defined as the ratio of the energy difference between the current decomposed component and the previous decomposed component to the energy of the original signal. The calculation formula is as follows: Where: ∑u k Let ∑u be the energy of the current component. k-1 Let S(t) be the energy of the previous decomposition component and S(t) be the original signal. The number of decompositions is determined using the energy loss factor, with the energy loss factor threshold g set to 0.

01. At the same time, the maximum decomposition modulus is set to 10. Therefore, by finding the minimum value of the energy loss factor, the number of decomposed deformation components can be determined. S9: To determine the degree of correlation between the deformation component and the original signal, i.e., the degree of inter-turn deformation fault in the reactor, the correlation coefficient r is used, and its calculation method is as follows: Where: Cov(u k S) is u k The covariance of S, and σ s They are u k The variance of S.

2. The method for diagnosing inter-turn deformation faults in a reactor according to claim 1, characterized in that: The value of r is between [0,1]. When r≥0.8, it is considered fault-4; when 0.5≤r<0.8, it is considered fault-3; when 0.3≤r<0.5, it is considered fault-2; and when 1.1≤r<0.3, it is considered fault-1. Fault-1, fault-2, fault-3, and fault-4 represent the degree of fault from smallest to largest.

3. The method for diagnosing inter-turn deformation faults in a reactor according to claim 1, characterized in that: When used to simulate fault diagnosis, different degrees of inter-turn axial deformation faults are simulated at at least one location on the reactor.

4. The method for diagnosing inter-turn deformation faults in a reactor according to claim 3, characterized in that: It includes an inter-turn axial deformation fault device, which is a rotating device whose end rotation can cause inter-turn axial deformation of the reactor.

5. The method for diagnosing inter-turn deformation faults in a reactor according to claim 4, characterized in that: The rotation axis of the inter-turn axial deformation fault device is perpendicular to the axis of the reactor.

6. The method for diagnosing inter-turn deformation faults in a reactor according to claim 4, characterized in that: The number of inter-turn axial deformation fault devices is at least one, and they are used to simulate inter-turn axial deformation faults at at least different locations on the reactor.

7. The method for diagnosing inter-turn deformation faults in a reactor according to claim 4, characterized in that: Different degrees of inter-turn axial deformation faults are faults simulated by different numbers of inter-turn axial deformation fault devices. The more inter-turn axial deformation fault devices used for fault simulation, the greater the fault.

8. The method for diagnosing inter-turn deformation faults in a reactor according to claim 4, characterized in that: The inter-turn axial deformation fault device includes a reactor body (1), a reactor coil (2), an upper reactor clamp (3), a lower reactor clamp (4), a reactor core (5), an inter-turn deformation simulation mechanism (6), a motor control device (7), a longitudinal nested slide rail of the inter-turn deformation simulation mechanism (8), a longitudinal screw (9) fixed to the rear side of the inter-turn deformation simulation mechanism, a sleeve at the upper end of the longitudinal screw (10), an axial screw (11) for axial movement of the inter-turn deformation mechanism, an axial movement slide bar located below the axial screw, a moving module of the inter-turn deformation simulation mechanism (12), a rear support frame of the axial screw (13), a support frame located at the bottom of the axial screw (14), and a module for controlling the movement of the inter-turn deformation simulation mechanism to move the inter-turn deformation simulation mechanism. The moving motor (15), the four-axis coordinated extrusion structure-1 (16) fixed on the inter-turn deformation simulation mechanism, the four-axis coordinated extrusion structure-2 (17) fixed on the inter-turn deformation simulation mechanism, the four-axis coordinated extrusion structure-3 (18) fixed on the inter-turn deformation simulation mechanism, the four-axis coordinated extrusion structure-4 (19) fixed on the inter-turn deformation simulation mechanism, the upper gear set-1 (20) of the four-axis coordinated extrusion structure, the upper gear set-2 (21) of the four-axis coordinated extrusion structure, the upper gear set-3 (22) of the four-axis coordinated extrusion structure, the upper gear set-4 (23) of the four-axis coordinated extrusion structure, the stop rod-1 (24) of the four-axis coordinated extrusion structure, the stop rod-2 (25) of the four-axis coordinated extrusion structure, and the stop rod-3 of the four-axis coordinated extrusion structure. (26) Four-axis coordinated extrusion structure stop bar-4 (27) Micro-adjustable telescopic air rod (28) Micro-adjustable telescopic air rod upper fixed sleeve (29) Inter-turn deformation simulation mechanism fixing kit (30) Inter-turn deformation simulation mechanism power motor (31) Reactor inter-turn deformation simulation device bottom fixed frame (32) Slide rail-1 located at the upper end of the bottom fixed frame of the reactor inter-turn deformation simulation device (33) Slide rail-2 located at the upper end of the bottom fixed frame of the reactor inter-turn deformation simulation device (34) Moving slide rod-1 located at the upper end of the bottom fixed frame of the reactor inter-turn deformation simulation device (35) Moving slide rod-2 located at the upper end of the bottom fixed frame of the reactor inter-turn deformation simulation device (36) Support for the bottom of the moving slide rod and the axial screw Frame sleeve-1 (37), support frame sleeve-2 (38) for the bottom of the sliding rod and axial screw, reactor axial fixing rod-1 (39), reactor axial fixing rod-2 (40), reactor axial fixing rod-3 (41), reactor axial fixing rod-4 (42), reactor front and rear fixing module-1 (43), reactor front and rear fixing module-1 (44), laser measuring instrument-1 (45) for controlling the micro-adjustment telescopic air rod, laser measuring instrument-2 (46) for controlling the micro-adjustment telescopic air rod, pressure sensor-1 (47) fixed to the four-axis coordinated extrusion mechanism, pressure sensor-2 (48) fixed to the four-axis coordinated extrusion mechanism, pressure sensor-3 (49) fixed to the four-axis coordinated extrusion mechanism.The pressure sensor-4 (50), oscillation wave signal generator (51), signal acquisition device (52), and high-frequency high-voltage DC power supply (53) are fixed to the four-axis coordinated extrusion mechanism.

9. The method for diagnosing inter-turn deformation faults in a reactor according to claim 8, characterized in that: The inter-turn axial deformation fault device simulates a fault according to the following steps: 1) The main control device (7) controls the moving motor (15) to make the inter-turn deformation mechanism moving module (12) reach the specified initial position along the longitudinal screw (9) and the axial screw (11); 2) Operate the motor control device (7) to control the power motor (31) and adjust the inter-turn deformation simulation mechanism (6) to reach the working range of laser measuring instrument-1 (45) and laser measuring instrument-2 (46); 3) Based on the feedback control of laser measuring instrument-1 (45) and laser measuring instrument-2 (46), the micro-distance telescopic air rod (28) is used to make the four-axis coordinated extrusion structure-1 (16), four-axis coordinated extrusion structure-2 (17), four-axis coordinated extrusion structure-3 (18) and four-axis coordinated extrusion structure-4 (19) reach the designated fault position. 4) The four-axis coordinated extrusion structure-1 (16), four-axis coordinated extrusion structure-2 (17), four-axis coordinated extrusion structure-3 (18), and four-axis coordinated extrusion structure-4 (19) are controlled by the motor control device to make the reactor inter-turn deformation. The degree of deformation fault is synchronized with the number of working operations of the four-axis coordinated extrusion mechanism, that is, fault-1, fault-2, fault-3, and fault-4 are set. 5) Pressure sensor-1 (47), pressure sensor-2 (48), pressure sensor-3 (49), and pressure sensor-4 (50) fixed to the four-axis coordinated extrusion mechanism are used to monitor and record the inter-turn deformation data in real time. 6) Operate the motor control device (7) to control the four-axis coordinated extrusion structure stop rod-1 (24), four-axis coordinated extrusion structure stop rod-2 (25), four-axis coordinated extrusion structure stop rod-3 (26), and four-axis coordinated extrusion structure stop rod-4 (27) to stop the inter-turn deformation fault and reset; 7) An oscillating wave detection signal is generated by the oscillating wave detection signal generator (51), and the fault signal is stored by the signal acquisition device (52) through the reactor winding (2) after the fault simulation. 8) Control the micro-distance telescopic air rod (28) to reset the inter-turn deformation simulation device (6), and operate the moving motor (15) to reset the inter-turn deformation simulation device moving module (12).

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