Method and device for suppressing vibration of electric reactor and electric reactor

Abstract

The invention provides a method and device for restraining vibration of an electric reactor and the electric reactor, the method is applied to control equipment of the electric reactor, the electric reactor comprises an iron core, a magnetic field shielding body, an oil tank and the control equipment, a rubber vibration isolation device is arranged between the iron core and the oil tank, the iron core is of a lamination structure, and in the lamination structure, cushion blocks are arranged between adjacent laminations; and a non-magnetic conductive ring is arranged in the cushion block. The method comprises the following steps: acquiring the amplitude of the fundamental current of the reactor; according to the amplitude of the fundamental wave current, the amplitude of third harmonic current and the amplitude of fifth harmonic current are determined, the phase difference between the third harmonic current and the fundamental wave current is 180 degrees, and the phases of the fifth harmonic current and the third harmonic current are the same; and injecting the third harmonic current and the fifth harmonic current into the reactor. Through the synergistic effect of the vibration reduction structure, the shielding structure and the harmonic vibration reduction method, the effect of inhibiting the vibration of the reactor is achieved.

Description

Technical Field

[0001] This application relates to the field of electrical engineering, and in particular to a method, apparatus and reactor for suppressing reactor vibration. Background Technology

[0002] The requirements for the operational stability of key equipment in power systems are increasing. With the rapid development of high-voltage direct current (HVDC) transmission technology towards larger capacity and higher voltage levels, acoustic pollution generated during equipment operation is showing a significant aggravating trend. Research on reactor noise control technology has become an urgent technical challenge to overcome in achieving the goal of coordinated development of resource conservation and environmental friendliness in power systems.

[0003] As a key device in power systems for regulating reactive power, suppressing harmonics, and limiting short-circuit current, the long-term stable operation of reactors is crucial to the reliability of the power grid. However, reactors are prone to significant vibration under alternating magnetic fields, mainly due to magnetostriction, eddy current forces caused by leakage flux, and mechanical resonance between the windings and the core. Current technologies for vibration suppression often employ single methods, such as local structural reinforcement, passive magnetic field shielding, or vibration dampers. However, these methods have significant limitations: passive shielding materials are expensive and have poor heat dissipation; structural reinforcement struggles to balance lightweighting and vibration resistance requirements; and traditional vibration dampers have limited effectiveness in suppressing high-frequency vibrations. Furthermore, existing solutions often focus on mechanical or electromagnetic optimization alone, lacking systematic control over the coupling effects of electromagnetic, mechanical, and thermal multi-physics fields, resulting in low vibration suppression efficiency and a tendency to cause localized overheating.

[0004] Therefore, there is an urgent need for an efficient, economical and reliable method to suppress reactor vibration in order to improve the long-term operational stability of reactors under complex operating conditions. Summary of the Invention

[0005] This application provides a method, apparatus, and reactor for suppressing reactor vibration, so as to effectively suppress reactor vibration.

[0006] In a first aspect, this application provides a method for suppressing reactor vibration, applied to a reactor control device. The reactor includes an iron core, a magnetic field shield, an oil tank, and a control device. A rubber vibration isolation device is provided between the iron core and the oil tank. The iron core has a laminated structure, and a spacer is included between adjacent laminates in the laminated structure. The spacer contains a non-magnetic conductive ring. The method includes:

[0007] Obtain the amplitude of the fundamental current of the reactor;

[0008] Based on the amplitude of the fundamental current, the amplitudes of the third harmonic current and the fifth harmonic current are determined. The phase difference between the third harmonic current and the fundamental current is 180°, and the phases of the fifth harmonic current and the third harmonic current are the same.

[0009] The third harmonic current and the fifth harmonic current are injected into the reactor.

[0010] Furthermore, determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes:

[0011] The amplitude of the fundamental current is multiplied by a preset third harmonic coefficient to obtain the amplitude of the third harmonic current.

[0012] The amplitude of the fundamental current is multiplied by a preset fifth harmonic coefficient to obtain the amplitude of the fifth harmonic current.

[0013] Furthermore, determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes:

[0014] Based on the amplitude of the fundamental current, the amplitudes of the third harmonic current and the fifth harmonic current corresponding to the amplitude of the fundamental current are found from a preset offline mapping table; wherein, the offline mapping table is a combination of different fundamental currents and different harmonic currents obtained in advance under different load conditions.

[0015] Furthermore, the reactor also includes a vibration sensor, and the determination of the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes:

[0016] Obtain the vibration acceleration of the vibration sensor;

[0017] Based on the vibration acceleration, the amplitudes of the third harmonic current and the fifth harmonic current are optimized using a closed-loop optimization algorithm.

[0018] Furthermore, the optimization algorithm closed-loop optimizes the initial value of the amplitude of the third harmonic current to the amplitude of the fundamental current multiplied by a preset third harmonic coefficient.

[0019] The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the fifth harmonic current to the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

[0020] Furthermore, determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes:

[0021] Obtain the real-time voltage of the reactor;

[0022] The instantaneous power is determined based on the real-time voltage and the fundamental current;

[0023] Based on the instantaneous power change rate, the amplitudes of the third harmonic current and the fifth harmonic current are optimized using a closed-loop optimization algorithm.

[0024] Furthermore, the optimization algorithm closed-loop optimizes the initial value of the amplitude of the third harmonic current to the amplitude of the fundamental current multiplied by a preset third harmonic coefficient.

[0025] The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the fifth harmonic current to the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

[0026] Secondly, this application provides a device for suppressing reactor vibration, the device comprising:

[0027] The acquisition module is used to acquire the amplitude of the fundamental current of the reactor;

[0028] The harmonic determination module is used to determine the amplitude of the third harmonic current and the amplitude of the fifth harmonic current based on the amplitude of the fundamental current. The phase difference between the third harmonic current and the fundamental current is 180°, and the phase of the fifth harmonic current is the same as that of the third harmonic current.

[0029] The output module is used to inject the third harmonic current and the fifth harmonic current into the reactor.

[0030] Thirdly, this application provides a reactor, which includes a laminated iron core, a magnetic field shield, an oil tank, and a control device;

[0031] A rubber vibration isolation device is provided between the iron core and the oil tank, and a pad is included between adjacent iron cores of the laminated laminations. The pad includes a non-magnetic conductive ring inside.

[0032] The control device is used to perform the method described in any of the first aspects.

[0033] Furthermore, the magnetic field shield includes a passive shield and / or an active shield:

[0034] The active shield is a cylindrical shield, and the inner diameter of the cylindrical shield is 1.1-1.2 times the outer diameter of the reactor;

[0035] The passive shield has a layered structure, with an inner magnetic layer and an outer conductive layer. The magnetic layer and the conductive layer are separated by an insulating material, and the passive shield is attached to the magnetic leakage region.

[0036] Fourthly, this application provides an electronic device, including: a memory and a processor;

[0037] The memory stores computer-executed instructions;

[0038] The processor executes computer execution instructions stored in the memory, causing the processor to perform the first aspect and / or various possible implementations of the first aspect as described above.

[0039] Fifthly, this application provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the first aspect and / or various possible embodiments of the first aspect.

[0040] In a sixth aspect, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the first aspect and / or various possible implementations of the first aspect.

[0041] This application provides a method, apparatus, and reactor for suppressing reactor vibration. The method is applied to the control equipment of the reactor. The reactor includes a laminated core, a magnetic field shield, an oil tank, and control equipment. A rubber vibration isolation device is installed between the core and the oil tank. A spacer is included between adjacent laminates, and the spacer contains a non-magnetic conductive ring. The method includes: obtaining the amplitude of the fundamental current of the reactor; determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current, wherein the phase difference between the third harmonic current and the fundamental current is 180°, and the phases of the fifth harmonic current and the third harmonic current are the same; and injecting the third harmonic current and the fifth harmonic current into the reactor. Through the synergistic effect of the above-mentioned vibration reduction structure, shielding structure, and harmonic vibration reduction method, the reactor vibration is suppressed. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0043] Figure 1 This is a schematic diagram of the main vibration propagation path of the reactor;

[0044] Figure 2 This is a schematic diagram of the structure of a reactor;

[0045] Figure 3 A flowchart illustrating a method for suppressing reactor vibration provided in this application;

[0046] Figure 4 A schematic diagram of the power change rate acquisition circuit provided in this application;

[0047] Figure 5 This is a schematic diagram comparing the effects of magnetic density.

[0048] Figure 6 A schematic diagram of the structure of the device for suppressing reactor vibration provided in this application;

[0049] Figure 7 A schematic diagram of the structure of the electronic device provided in this application.

[0050] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0051] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0052] Reactors are important reactive power compensation and current limiting devices in power systems. They are mainly used to regulate reactive power, suppress harmonics, limit short-circuit current, or be used in conjunction with capacitors to form filtering devices. They are widely used in high-voltage power transmission and transformation, industrial reactive power compensation, and new energy access.

[0053] Vibration and noise problems are most prominent in reactors with iron cores (especially series-core and parallel-core reactors). Figure 1 This is a schematic diagram of the main vibration propagation path of the reactor, with reference to... Figure 1 The vibration propagation path and the main causes of the vibration are:

[0054] 1. Magnetostriction effect. Core materials (silicon steel sheets or amorphous alloys) undergo periodic, minute elongation and shortening in an alternating magnetic field (magnetostriction coefficient typically in the range of 5–30 ppm). This periodic change in material size directly causes the overall vibration of the core laminations, especially noticeable when the magnetic flux density is high or the material's magnetostriction coefficient is large.

[0055] 2. Maxwell Force. Under the excitation of the windings, the reactor core forms an alternating magnetic field system synchronized with the power frequency. To maintain linear impedance characteristics and suppress magnetic saturation, a non-magnetic air gap design is required in the core column structure to reduce the effective permeability. This air gap structure causes alternating Maxwell forces to be generated when the magnetic induction intensity between the core discs changes periodically.

[0056] For parallel reactors or iron-core reactors with air gaps, the Maxwell force at the air gap is often the dominant oscillation source because the magnetic flux is highly concentrated there, and the magnitude of the force is proportional to the square of the magnetic flux density.

[0057] 3. Electromagnetic force caused by leakage magnetic field. The load current flowing through the winding experiences a force in the leakage magnetic field (F = I × L × B), causing radial or axial vibration of the winding (especially the outer sheath). The more severe the leakage magnetic field, the more intense the winding vibration.

[0058] 4. The effect of instantaneous power pulsation. Under pure sinusoidal excitation, the power changes drastically near the zero current crossing, resulting in a large rate of change of the excitation force.

[0059] 5. Mechanical resonance amplification. When the electromagnetic excitation frequency (100Hz, 150Hz, etc.) is close to the natural frequency of the reactor structure (core, winding, oil tank, pad, etc.), resonance will occur, and the vibration will be significantly amplified.

[0060] Since the operating magnetic flux density of a reactor is usually below 1.4T, and the magnetostrictive deformation level is 1-2 orders of magnitude lower than that of the Maxwell force, the Maxwell force of the core disc is generally considered to be the main excitation source of the reactor body vibration.

[0061] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.

[0062] First, the mechanical structure of the reactor is improved by adding a magnetic field shield to the leakage magnetic field area of ​​the reactor and adding a conductive ring to the pad to reduce the electromagnetic vibration of the reactor.

[0063] Figure 2 This is a schematic diagram of the structure of a reactor, which includes an iron core, a magnetic field shield, an oil tank, and control equipment.

[0064] A rubber vibration isolation device is installed between the iron core and the oil tank;

[0065] The core has a laminated structure, in which spacers are included between adjacent laminates, and non-magnetic conductive rings are included inside the spacers. The non-magnetic conductive rings can be made of copper alloy, aluminum alloy, conductive plastic, etc.

[0066] By adding conductive but non-magnetic materials to the pads, the damping force generated by the materials in the changing magnetic field can be used to counteract the stress on the reactor core, thereby reducing the vibration and noise of the reactor.

[0067] The control equipment is used to control the harmonic current input to the reactor.

[0068] Epoxy resin is selected as the material for reactor pads. Copper and aluminum, among others, are low-cost materials with good conductivity and can be used as conductive materials added to reactor pads. Adding conductive rings to the epoxy resin of the reactor pads significantly reduces the vibration acceleration of both the reactor core and the pads. Embedding conductive rings in the epoxy resin of the reactor pads primarily optimizes the electric field distribution, suppresses partial discharge, and improves equipment reliability. The conductive rings reduce charge accumulation on the surface of the insulating material by uniformly increasing the electric field strength, thus avoiding the risk of partial discharge. Simultaneously, they provide a low-impedance path to discharge static charge, reducing the risk of insulation breakdown. Their closed loop can also partially offset leakage flux to reduce eddy current losses and temperature rise, and enhance the mechanical strength of the pads to resist vibration or thermal stress.

[0069] Adding a conductive ring to the reactor pad to generate damping force can reduce electromagnetic vibration. The conductive ring should be made of a high conductivity material, and its thickness should match the skin effect. The conductive ring and the coil should be kept insulated to avoid short circuits. The annular conductive sheet is embedded inside the epoxy resin pad.

[0070] Installing a rubber vibration isolation device between the core and the oil tank can effectively reduce vibration transmission and also significantly prevent core resonance. The vibration isolation efficiency of the device mainly depends on the elastic modulus of the rubber material and the size of the device. For vibration isolation devices in ultra-high voltage reactors, a vibration isolation efficiency of not less than 75% can achieve good vibration control.

[0071] Magnetic field shielding includes passive shielding and / or active shielding. Passive shielding uses a high-permeability material bonded to the leakage magnetic field area.

[0072] Active shielding utilizes a cylindrical shield mounted outside the reactor body to shield against magnetic fields. The cylindrical shield ensures its inner diameter is 10%–20% larger than the reactor's outer diameter, and its height covers the reactor while extending to both ends to enhance shielding effectiveness. Structurally, it requires pre-drilled ventilation holes and ensures seamless joints. It is fixed using non-magnetic brackets, with single-point grounding and low grounding resistance. After installation, performance is verified through magnetic field attenuation testing, temperature rise monitoring, and insulation testing. Regular maintenance of the grounding and heat dissipation structures is essential to balance shielding effectiveness with safe equipment operation.

[0073] In some embodiments, the passive shield adopts a layered structure, with an inner magnetic layer (silicon steel sheet stacking) and an outer conductive layer (copper plate), and the magnetic layer and the conductive layer are isolated by an insulating material.

[0074] In some embodiments, the electromagnetic structure of the reactor is optimized by increasing the core cross-sectional area or the number of coil turns to reduce the magnetic flux density to below 1.0~1.3T, thereby reducing vibration at its source. A multi-layer segmented winding structure can also be used to reduce leakage flux. The core is made of silicon steel sheets or amorphous alloy laminations, which have the characteristics of low magnetostriction, high permeability, and low loss. The laminations of the core can be isolated by an insulating coating. All of the above-mentioned optimization measures in the electromagnetic structure can reduce the vibration of the reactor.

[0075] In addition to the structural improvements mentioned above, the vibration acceleration on the surface of the reactor core can be reduced by adding harmonic excitation to the reactor.

[0076] Based on the previous vibration analysis, the main cause of vibration force is Maxwell's force, and the principle is analyzed below.

[0077] For a transient magnetic field, the magnetic vector potential A is defined as follows:

[0078] (2.1)

[0079] In the formula, B is the magnetic flux density; μ is the magnetic permeability; and H is the magnetic field strength. This is the curl operator.

[0080] For a transient magnetic field with winding excitation current density J, the magnetic vector potential A can be obtained from equation (2.2), and then the magnetic flux density B can be obtained.

[0081] (2.2)

[0082] In the formula, σ is the electrical conductivity.

[0083] The electromagnetic force between the core discs is caused by the magnetic field and is the surface stress at the interface between the air gap and the core disc. By integrating the Maxwell stress tensor over the surface domain, the electromagnetic force can be expressed as:

[0084] (2.3)

[0085] In the formula, Ω is the integral domain of the interface between the air gap and the core disc; I is the identity matrix. Neglecting core damping, the vibration of the core can be calculated using the vibration differential equation of a continuous multi-degree-of-freedom system.

[0086] (2.4)

[0087] In the formula, x is the displacement vector; M is the mass matrix of the core; and K is the stiffness matrix, which is related to the structural and material parameters of the core. Let x be the second time derivative.

[0088] According to Equation 2.3, the magnitude of the electromagnetic attraction (or repulsion) is proportional to the square of the magnetic induction intensity B. For reactor windings, the magnetic field is mainly generated by the current and the number of turns; therefore, the magnitude of the electromagnetic attraction (or repulsion) is proportional to the square of the current.

[0089] When the current is a pure sine wave, i(t) = Im×sin(ωt);

[0090] Therefore, F(t) ∝(Im) 2 ×sin 2 (ωt);

[0091] By using trigonometric identities, we can obtain F(t) ∝ (Im). 2 / 2 - (Im) 2 / 2) ×cos(2ωt);

[0092] This derivation shows that the electromagnetic force consists of a constant component (average attraction) plus an alternating pulsating component with a frequency of 2ω. This further explains why the iron core vibrates at twice the frequency even when the current is purely sinusoidal and has no harmonics. The instantaneous power also exhibits a significant pulsation at twice the power frequency.

[0093] Therefore, adding appropriate out-of-phase 3rd and 5th harmonics can weaken i 2 The 2ω component in the equation reduces the amplitude of the pulsation.

[0094] The following section introduces how to inject the 3rd and 5th harmonics into a reactor.

[0095] Figure 3 This application provides a flowchart illustrating a method for suppressing reactor vibration, applied to a reactor control device. The method includes:

[0096] S1. Obtain the amplitude of the fundamental current of the reactor.

[0097] In one specific implementation, a high-precision current sensor (CT or Rogowski coil) is installed on the primary side of the reactor (or the secondary side of the current transformer). A fast Fourier transform is performed on the acquired steady-state waveform, which lasts from a few seconds to tens of seconds, to obtain the effective value or peak value of the sensor's fundamental component.

[0098] S2. Based on the amplitude of the fundamental current, determine the amplitudes of the third harmonic current and the fifth harmonic current. The phase difference between the third harmonic current and the fundamental current is 180°, and the phases of the fifth harmonic current and the third harmonic current are the same.

[0099] The third harmonic is out of phase with the fundamental frequency to allow the cross term 3ω - ω = 2ω to make a negative contribution, thus canceling the positive pulsations generated by the square of the fundamental frequency. The fifth harmonic is usually in phase (or nearly in phase) with the third harmonic to help cancel the remaining pulsations or higher-order components.

[0100] The amplitude of harmonics is generally small (usually less than 3% of the fundamental amplitude); too large an amplitude will introduce new components. If the ratio is too small, the vibration reduction will be insignificant. The optimal ratio depends on the specific reactor (air gap size, core saturation, load factor, etc.).

[0101] Therefore, the amplitudes of the third and fifth harmonic currents are related to the amplitude of the fundamental current.

[0102] In one implementation, the amplitudes of the third and fifth harmonic currents are in a fixed proportional relationship with the amplitude of the fundamental current.

[0103] In one implementation, the amplitudes of the third and fifth harmonic currents are adjusted relative to the amplitude of the fundamental current based on the rate of change of the fundamental current amplitude.

[0104] It should be noted that, under normal circumstances, the phase difference between harmonic current and fundamental current is 180°. However, in some scenarios, due to various physical limitations, the phase may be slightly offset. In such scenarios, the phase difference can be appropriately changed, for example, to 179°, 178°, 181°, etc.

[0105] S3. Inject the third harmonic current and the fifth harmonic current into the reactor.

[0106] In one implementation, a parallel active filter is connected in parallel to or near the reactor bus, and an inverted 3rd and 5th harmonic current is generated by a command current generator and injected into the reactor.

[0107] If the system containing the reactor already has an SVG, SVC, or frequency converter, its control algorithm can be modified to superimpose 3rd and 5th harmonic current commands with specified amplitude / phase on the basis of fundamental reactive power compensation.

[0108] This method reduces the amplitude of the pulsating component in the square of the current by superimposing a small number of out-of-phase third and fifth harmonics on the fundamental current, thereby reducing the electromagnetic force component and ultimately reducing the mechanical vibration of the iron core (especially at the air gap).

[0109] The following section further explains how to determine the amplitude of each harmonic current in step S2.

[0110] First scenario

[0111] S21. Multiply the amplitude of the fundamental current by the preset third harmonic coefficient to obtain the amplitude of the third harmonic current.

[0112] S22. Multiply the amplitude of the fundamental current by a preset fifth - harmonic coefficient to obtain the amplitude of the fifth - harmonic current.

[0113] In this embodiment, a third - harmonic coefficient k3 of the third - harmonic is preset in advance, for example, any value between 0.03 and 0.15, which can be determined according to the type, capacity, and main vibration cause experiment of the reactor. Similarly, a fifth - harmonic coefficient k5 is preset, and usually k5 < k3. After determining the harmonic coefficient, the amplitude of the harmonic to be injected can be calculated.

[0114] This implementation method is simple, has a small amount of calculation, good real - time performance, and does not require additional sensors.

[0115] The second scenario

[0116] S23. According to the amplitude of the fundamental current, look up the amplitude of the third - harmonic current and the amplitude of the fifth - harmonic current corresponding to the amplitude of the fundamental current in a preset off - line mapping table; where the off - line mapping table is an experimental combination of different fundamental currents and different harmonic currents obtained through experiments under different load conditions in advance.

[0117] In this embodiment, by using the empirical relationship between the optimal harmonic compensation amount and the fundamental current obtained from off - line experiments, it avoids real - time complex modeling, has fast open - loop calculation and good stability.

[0118] The third scenario

[0119] S24. Obtain the vibration acceleration of the vibration sensor.

[0120] In this step, highly sensitive vibration acceleration sensors (such as piezoelectric or MEMS) are installed at key positions of the reactor body (iron core, clamping parts, oil tank wall, etc.), with a measurement range of ±50g or higher, and the frequency response covers the main vibration frequencies such as 100Hz, 150Hz, 250Hz, etc.

[0121] S25. According to the vibration acceleration, close - loop optimize the amplitude of the third - harmonic current and the amplitude of the fifth - harmonic current through an optimization algorithm. [[ID=T30]]

[0122] Collect a segment of steady - state acceleration time - domain data at a fixed period (such as 0.5 - 5 seconds), perform a fast Fourier transform on the acceleration signal, and extract key vibration components, mainly including twice the power frequency, caused by the main pulsation of the 3 - harmonic electromagnetic force; three times the power frequency, with magnetostriction contributing; five times the power frequency, related to the 5 - harmonic.

[0123] Preset the expression form of the vibration evaluation index J, and use the vibration evaluation index as the cost function or objective function for subsequent optimization.

[0124] In one implementation, the vibration frequency component caused by the main pulsation of electromagnetic force generated by the third harmonic current is used as the vibration evaluation index J.

[0125] In one implementation, the vibration amplitudes of two key frequencies—the third harmonic dominant frequency and the fifth harmonic dominant frequency—are used as vibration evaluation indicators. For example, the vibration evaluation indicator J = A3 is the effective value of acceleration at the third harmonic frequency, and A5 is the effective value of acceleration at the fifth harmonic frequency.

[0126] Based on the above implementation method, different weights can be assigned to the two, and the vibration evaluation index can be calculated by weighted summation.

[0127] The amplitudes of the third and fifth harmonic currents are repeatedly adjusted using a closed-loop optimization algorithm to minimize the vibration evaluation index J.

[0128] In one implementation, the closed-loop optimization algorithm can be based on gradient descent or hill climbing, fine-tuning only one variable (or adjusting them in pairs) at a time.

[0129] For example, consider adjusting the amplitude I3 of the third harmonic current.

[0130] Current point: I3(k), measured J(k).

[0131] Positive trial: I3(k) + ΔI3, inject the amplitude of the harmonic current into the reactor, and measure J(k+1) after steady state.

[0132] If J(k+1) < J(k), then continue to increase the step size in the positive direction; otherwise, in the opposite direction.

[0133] Step size adaptation: Increase the step size on success, and decrease and reverse the step size on failure.

[0134] Convergence condition: J is lower than the target value.

[0135] Amplitude limiting: I3≤20% I1, I5≤10% I1, to prevent overcompensation from causing new problems. Wherein, I1 is the amplitude of the fundamental current and I5 is the amplitude of the fifth harmonic current.

[0136] The amplitude of the fifth harmonic current can be adjusted separately, similar to the amplitude of the third harmonic current, or the amplitude of the fifth harmonic current can be iterated once after the amplitude of the third harmonic current is iterated once.

[0137] In one implementation, vibration acceleration is treated as the controlled object and adjusted by constructing a virtual PI controller to bring the critical third harmonic vibration component as close to 0 as possible.

[0138] The closed-loop optimization method in this embodiment has the highest accuracy and can adapt to various operating conditions (temperature, load, aging).

[0139] In some embodiments, in the third scenario, the initial values ​​of the third and fifth harmonic current amplitudes optimized by the closed-loop optimization algorithm can be calculated using the methods described in the first or second scenario above. For example, the initial value of the third harmonic current amplitude is the amplitude of the fundamental current multiplied by a preset third harmonic coefficient. The initial value of the fifth harmonic current amplitude is the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

[0140] The fourth scenario

[0141] S26. Obtain the real-time voltage of the reactor.

[0142] S27. Determine the instantaneous power based on the real-time voltage and fundamental current.

[0143] Instantaneous power p(t) = u(t) × i(t).

[0144] S28. Based on the rate of change of instantaneous power, optimize the amplitude of the third harmonic current and the amplitude of the fifth harmonic current through a closed-loop optimization algorithm.

[0145] We process p(t) to calculate the instantaneous power change rate dp / dt. dp / dt has a strong positive correlation with the vibration acceleration. We optimize dp / dt using a closed-loop optimization algorithm, aiming to minimize it. The optimization algorithm is similar to the one used in the third scenario, except that the vibration acceleration is replaced by dp / dt; details will not be elaborated here.

[0146] This embodiment does not require the installation of a vibration sensor, making it suitable for situations where it is inconvenient to install a vibration sensor.

[0147] In some embodiments, under the fourth scenario, the initial values ​​of the third and fifth harmonic current amplitudes optimized by the closed-loop optimization algorithm can also be calculated using the methods described in the first or second scenario above. For example, the initial value of the third harmonic current amplitude is the amplitude of the fundamental current multiplied by a preset third harmonic coefficient. The initial value of the fifth harmonic current amplitude is the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

[0148] Figure 4 A schematic diagram of the power change rate acquisition circuit provided in this application is shown below. Figure 4 As shown, the power change rate acquisition circuit after harmonic injection is as follows: Figure 4 As shown, the resistor and inductor simulate the internal impedance of the reactor winding, and the amount of harmonic injection can be adjusted by changing the peak value of I.

[0149] Figure 5 This is a schematic diagram comparing the effects of magnetic density. Figure 5 In the reactor, the magnetic flux density is the highest and the vibration is the strongest when no magnetic field shield is added; the magnetic flux density and vibration are reduced when an annular shield (i.e., an outer cylindrical shield) is added; the magnetic flux density and vibration are reduced when a composite annular shield (i.e., a composite structure of shield, conductive ring, and rubber vibration isolation device, using closed-loop optimization control based on vibration acceleration) is added.

[0150] When installing cylindrical shields around reactors, the shielding structure must be designed according to the type of interference, ensuring that the inner diameter is 10% to 20% larger than the outer diameter of the reactor, with height coverage and extension at both ends to enhance the shielding effect. Structurally, ventilation holes must be provided, and joint continuity must be addressed. Non-magnetic brackets should be used for fixing, with single-point grounding and low grounding resistance. After installation, performance should be verified through magnetic field attenuation testing, temperature rise monitoring, and insulation testing. The grounding and heat dissipation structures should be maintained regularly, balancing shielding effectiveness with safe equipment operation. A rubber vibration isolation device should be installed between the core and the tank to effectively reduce vibration transmission and significantly prevent core resonance.

[0151] The vibration isolation efficiency of a reactor's vibration isolation device mainly depends on the elastic modulus of the rubber material and the size of the isolation device. For vibration isolation devices of ultra-high voltage reactors, a vibration isolation efficiency of not less than 75% can achieve a better vibration control effect.

[0152] Injecting harmonics into a reactor reduces the rate of change of the reactor's input power, thereby reducing its vibration acceleration. The principle will be further explained below.

[0153] The magnetic field of the reactor operates in the linear region, and its vibration is mainly caused by the Maxwell electromagnetic force at the air gap of the iron core. Therefore, the vibration acceleration of the series reactor is... It also has a certain direct proportional relationship with the rate of change of its input power P over time, that is:

[0154] (2.5)

[0155] The reactor is excited by an AC power supply. To obtain the relationship between the rate of change of the reactor's input power and the excitation current i, according to the power balance equation:

[0156] (2.6)

[0157] Where R is the equivalent resistance of the reactor winding, and i is the excitation current. t represents the magnetic flux (unit: Weber-turn, abbreviated as Wb), and t represents time.

[0158] when When working in the linear part, there is =L·i, where L is the inductance. Then equation (2.6) can be written as:

[0159] (2.7)

[0160] In the formula, x is the air gap length; For electromagnetic force. As shown in equation (2.7), the input energy of the reactor during operation is mainly distributed in three parts: conductor heat loss, magnetic field energy storage, and mechanical vibration energy consumption. Actual operating data shows that copper loss and vibration energy consumption account for a significantly lower proportion of the total input power. Therefore, more than 90% of the input energy is ultimately stored in the electromagnetic system as magnetic field energy. Thus, equation (2.7) can be simplified to:

[0161] (2.8)

[0162] Therefore, differentiating both sides of equation (2.8) yields:

[0163] (2.9)

[0164] make ,have to:

[0165] (2.10)

[0166] Based on equations (2.5) and (2.10), we get

[0167] (2.11)

[0168] Therefore, if If the input power of the reactor decreases, the rate of change of the reactor's input power will be... If the frequency of harmonics is reduced, the vibration acceleration 'a' of the reactor will also decrease. Injecting harmonics into the reactor will change the waveform of its input current, and the waveform of its power change rate will also change. Therefore, appropriately injecting harmonics into the reactor will reduce the rate of change of the reactor's input power, thereby reducing its vibration acceleration.

[0169] To reduce vibration and noise in reactors, conductive but non-magnetic materials are added to the reactor pads. These materials utilize the damping force generated in a changing magnetic field to counteract the stress on the reactor core, thus reducing vibration and noise. Epoxy resin, copper, and aluminum are commonly used as materials for the reactor pads due to their low production cost and good conductivity. Adding conductive rings to the epoxy resin in the reactor pads significantly reduces the vibration acceleration of both the reactor core and the pads. Embedding conductive rings in the epoxy resin primarily optimizes the electric field distribution, suppresses partial discharge, and improves equipment reliability. The conductive rings reduce charge accumulation on the insulating material surface by providing a uniform electric field strength, avoiding the risk of partial discharge. They also provide a low-impedance path to discharge static charge, reducing the risk of insulation breakdown. Their closed loop can partially offset leakage flux, reducing eddy current losses and temperature rise, and enhancing the mechanical strength of the pads to resist vibration or thermal stress. The design must ensure the adhesion between the conductive ring and the epoxy resin and a reasonable grounding path to avoid introducing electromagnetic interference. It is suitable for high-voltage reactors and other applications with high requirements for insulation stability and heat dissipation.

[0170] Figure 6 A schematic diagram of the structure of the device for suppressing reactor vibration provided in this application is shown below. Figure 6 As shown, the device 40 for suppressing reactor vibration provided in this embodiment includes:

[0171] The acquisition module 401 is used to acquire the amplitude of the fundamental current of the reactor;

[0172] The harmonic determination module 402 is used to determine the amplitude of the third harmonic current and the amplitude of the fifth harmonic current based on the amplitude of the fundamental current. The phase difference between the third harmonic current and the fundamental current is 180°, and the phase of the fifth harmonic current is the same as that of the third harmonic current.

[0173] Output module 403 is used to inject third harmonic current and fifth harmonic current into the reactor.

[0174] In some embodiments, the harmonic determination module 402 is specifically used for:

[0175] Multiply the amplitude of the fundamental current by the preset third harmonic coefficient to obtain the amplitude of the third harmonic current;

[0176] Multiply the amplitude of the fundamental current by the preset fifth harmonic coefficient to obtain the amplitude of the fifth harmonic current.

[0177] In some embodiments, the harmonic determination module 402 is specifically used for:

[0178] Based on the amplitude of the fundamental current, the amplitudes of the third and fifth harmonic currents corresponding to the amplitude of the fundamental current are found from a pre-set offline mapping table. The offline mapping table is a pre-set experimental combination of different fundamental currents and different harmonic currents obtained under different load conditions.

[0179] In some embodiments, the harmonic determination module 402 is specifically used for:

[0180] Obtain the vibration acceleration from the vibration sensor;

[0181] Based on the vibration acceleration, the amplitudes of the third and fifth harmonic currents are optimized using a closed-loop optimization algorithm.

[0182] In some embodiments, the initial value of the amplitude of the third harmonic current in the closed-loop optimization algorithm is the amplitude of the fundamental current multiplied by a preset third harmonic coefficient.

[0183] The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the fifth harmonic current as the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

[0184] In some embodiments, the harmonic determination module 402 is specifically used for:

[0185] Obtain the real-time voltage of the reactor;

[0186] Determine the instantaneous power based on the real-time voltage and fundamental current;

[0187] Based on the rate of change of instantaneous power, the amplitudes of the third and fifth harmonic currents are optimized through a closed-loop optimization algorithm.

[0188] In some embodiments, the initial value of the amplitude of the third harmonic current in the closed-loop optimization algorithm is the amplitude of the fundamental current multiplied by a preset third harmonic coefficient.

[0189] The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the fifth harmonic current as the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

[0190] The apparatus provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0191] Figure 7 This is a schematic diagram of the structure of the electronic device provided in this application, which can be a control device for a reactor. For example... Figure 7 As shown, the electronic device 50 provided in this embodiment includes at least one processor 501 and a memory 502. Optionally, the device 50 further includes a communication component 503. The processor 501, memory 502, and communication component 503 are connected via a bus 504.

[0192] In a specific implementation, at least one processor 501 executes computer execution instructions stored in memory 502, causing at least one processor 501 to perform the above-described method.

[0193] The specific implementation process of processor 501 can be found in the above method embodiments, and its implementation principle and technical effect are similar. It will not be repeated here.

[0194] In the above embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0195] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage device.

[0196] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0197] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0198] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above-described method.

[0199] The aforementioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0200] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an Application Specific Integrated Circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0201] The division of units is merely a logical functional division; in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0202] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0203] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0204] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0205] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0206] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for suppressing reactor vibration, characterized in that, A control device for a reactor, the reactor comprising a core, a magnetic field shield, an oil tank, and a control device, wherein a rubber vibration isolation device is provided between the core and the oil tank, the core having a laminated structure, wherein adjacent laminates are separated by spacers, and each spacer contains a non-magnetic conductive ring, the method comprising: Obtain the amplitude of the fundamental current of the reactor; Based on the amplitude of the fundamental current, the amplitudes of the third harmonic current and the fifth harmonic current are determined. The phase difference between the third harmonic current and the fundamental current is 180°, and the phases of the fifth harmonic current and the third harmonic current are the same. The third harmonic current and the fifth harmonic current are injected into the reactor.

2. The method according to claim 1, characterized in that, The step of determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes: The amplitude of the fundamental current is multiplied by a preset third harmonic coefficient to obtain the amplitude of the third harmonic current. The amplitude of the fundamental current is multiplied by a preset fifth harmonic coefficient to obtain the amplitude of the fifth harmonic current.

3. The method according to claim 1, characterized in that, The step of determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes: Based on the amplitude of the fundamental current, the amplitudes of the third harmonic current and the fifth harmonic current corresponding to the amplitude of the fundamental current are found from a preset offline mapping table; wherein, the offline mapping table is a combination of different fundamental currents and different harmonic currents obtained in advance under different load conditions.

4. The method according to claim 1, characterized in that, The reactor also includes a vibration sensor. The step of determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes: Obtain the vibration acceleration of the vibration sensor; Based on the vibration acceleration, the amplitudes of the third harmonic current and the fifth harmonic current are optimized using a closed-loop optimization algorithm.

5. The method according to claim 4, characterized in that, The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the third harmonic current to the amplitude of the fundamental current multiplied by a preset third harmonic coefficient. The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the fifth harmonic current to the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

6. The method according to claim 1, characterized in that, The step of determining the amplitudes of the third harmonic current and the fifth harmonic current based on the amplitude of the fundamental current includes: Obtain the real-time voltage of the reactor; The instantaneous power is determined based on the real-time voltage and the fundamental current; Based on the instantaneous power change rate, the amplitudes of the third harmonic current and the fifth harmonic current are optimized using a closed-loop optimization algorithm.

7. The method according to claim 6, characterized in that, The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the third harmonic current to the amplitude of the fundamental current multiplied by a preset third harmonic coefficient. The optimization algorithm uses a closed-loop optimization method to initialize the amplitude of the fifth harmonic current to the amplitude of the fundamental current multiplied by a preset fifth harmonic coefficient.

8. A device for suppressing reactor vibration, characterized in that, The device includes: The acquisition module is used to acquire the amplitude of the fundamental current of the reactor; The harmonic determination module is used to determine the amplitude of the third harmonic current and the amplitude of the fifth harmonic current based on the amplitude of the fundamental current. The phase difference between the third harmonic current and the fundamental current is 180°, and the phase of the fifth harmonic current is the same as that of the third harmonic current. The output module is used to inject the third harmonic current and the fifth harmonic current into the reactor.

9. A reactor, characterized in that, The reactor includes a laminated iron core, a magnetic field shield, an oil tank, and control equipment; A rubber vibration isolation device is provided between the iron core and the oil tank, and a pad is included between adjacent iron cores of the laminated laminations. The pad includes a non-magnetic conductive ring inside. The control device is used to perform the method according to any one of claims 1-7.

10. The reactor according to claim 9, characterized in that, The magnetic field shield includes a passive shield and / or an active shield: The active shield is a cylindrical shield, and the inner diameter of the cylindrical shield is 1.1-1.2 times the outer diameter of the reactor; The passive shield has a layered structure, with an inner magnetic layer and an outer conductive layer. The magnetic layer and the conductive layer are separated by an insulating material, and the passive shield is attached to the magnetic leakage region.

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