A transformer load noise calculation method and system

Abstract

The application discloses a transformer load noise calculation method and system, and the method comprises the following steps: S1, modal test is carried out on a transformer coil under inherent compression force of the transformer coil, and modal test parameters are obtained; S2, an equivalent model of the transformer coil is established, modal simulation is carried out on the equivalent model of the transformer coil, and modal simulation parameters are obtained; S3, the modal test parameters and the modal simulation parameters are compared, and equivalent material parameter values are determined; S4, a mapping relationship between the compression force and the equivalent material parameter values is established; S5, the electric power of the transformer coil is obtained by adopting three-dimensional magnetic field simulation; S6, the vibration amplitude of the transformer coil is calculated; S7, noise energy generated by the transformer coil is calculated; and S8, the sound power level of the transformer load is calculated. The mapping relationship between the compression force, material characteristics, vibration response and noise radiation is established, and more accurate load noise calculation is realized.

Description

Technical Field

[0001] This invention relates to the field of transformer load noise calculation technology, and in particular to a method and system for calculating transformer load noise. Background Technology

[0002] Noise is one of the key parameters of a transformer. Transformer noise mainly includes core noise caused by the magnetostrictive effect of silicon steel sheets, coil noise caused by the electrodynamic force generated by the interaction of the leakage magnetic field and current after the coil is energized, and noise from the cooling equipment. Currently, there are many studies on the calculation methods for core vibration noise, but the load noise generated by coil vibration is often neglected. When the coil is energized, it experiences Lorentz force generated by the interaction of the leakage magnetic field and current, causing structural vibration and radiating noise. However, the overall vibration behavior of the coil is closely related to the compression state of its insulation material. The stiffness, damping, and other characteristics of the insulation material change significantly with the compression force, resulting in a highly nonlinear dynamic response. Therefore, if the influence of the compression state on material parameters is ignored when calculating coil vibration and load noise, the calculation results will deviate from the actual operating conditions, making accuracy difficult to guarantee.

[0003] In the existing technology, there is no effective calculation method for coupling the compression state of insulating materials with coil vibration noise, which leads to a large error in the prediction of transformer load noise. Summary of the Invention

[0004] This invention provides a method and system for calculating transformer load noise. By establishing a mapping relationship between clamping force, material properties, vibration response, and noise radiation, more accurate load noise calculation can be achieved.

[0005] To achieve the above objectives, this invention proposes a method for calculating transformer load noise, the method comprising the following steps: S1. Under the inherent clamping force of the transformer coil, a modal test is performed on the transformer coil to obtain the modal test parameters of the transformer coil. The modal test parameters include at least the natural frequency and mode shape. S2. Establish an equivalent model of the transformer coil, which includes a conductor coil and an insulation structure. Apply the same clamping force as in the modal test and perform modal simulation on the equivalent model of the transformer coil to obtain the modal simulation parameters of the transformer coil. The modal simulation parameters include at least the simulated natural frequency and the simulated mode shape. S3. Set the equivalent material parameter values ​​for different insulation structures in the equivalent model of the transformer coil, compare the modal test parameters and the modal simulation parameters, and when the consistency of the comparison results meets the preset tolerance, determine the equivalent material parameter values ​​of the insulation structure set in the current equivalent model of the transformer coil as the equivalent material parameter values ​​of the actual insulation structure of the transformer coil. The equivalent material parameters include at least the equivalent elastic modulus, equivalent Poisson's ratio and equivalent density. S4. For transformer coils with different inherent clamping forces, repeat steps S1 to S3 to obtain the equivalent material parameter values ​​under different inherent clamping forces, and establish a mapping relationship between clamping force and equivalent material parameter values. S5. The electrodynamic force of the transformer coil is obtained by three-dimensional magnetic field simulation; S6. Assign the target clamping force and the equivalent material parameter values ​​obtained based on the mapping relationship to the transformer coil equivalent model, apply the electrodynamic force as an excitation load to the transformer coil equivalent model, perform harmonic response analysis on the transformer coil equivalent model, and calculate the vibration amplitude of the transformer coil. S7. Under the target clamping force, calculate the transformer load sound power level based on the noise energy, and evaluate the transformer load noise level based on the transformer load sound power level. S8. Under the target clamping force, calculate the transformer load noise based on the noise energy.

[0006] Further, in step S2, establishing an equivalent model of the transformer coil specifically includes: the insulation structure includes insulating pads arranged along the circumferential direction, the insulating pads are equivalent to annular bodies with the same inner and outer diameters as the conductor coil, and the conductor coil and the remaining structure of the insulation structure except for the insulating pads are modeled according to the actual dimensions.

[0007] Further, in step S5, the electrodynamic force of the transformer coil is obtained by three-dimensional magnetic field simulation, specifically including: obtaining the power frequency current excitation of the transformer coil, establishing a three-dimensional transient electromagnetic field analysis model of the transformer coil, calculating the leakage magnetic field distribution of the transformer coil under operating conditions based on the three-dimensional transient electromagnetic field analysis model and the power frequency current excitation, and calculating the electrodynamic force acting on the transformer coil according to the leakage magnetic field distribution.

[0008] Further, in step S7, under the target clamping force, the noise energy generated by the transformer coil is calculated based on the vibration amplitude, specifically including: Calculate the stiffness of the conductor coil under the target clamping force; Calculate the stiffness of the insulation structure under the target clamping force; Calculate the stiffness of the transformer coil under the target clamping force; The vibration energy of a single transformer coil is calculated based on the vibration amplitude of the transformer coil and the calculated stiffness of the transformer coil. Determine the ratio of noise energy generated by a single transformer coil to vibration energy, and calculate the noise energy generated by a single or at least two transformer coils based on the ratio and vibration energy.

[0009] Furthermore, the stiffness of the conductor coil under the target clamping force is calculated using the following formula: ; In the formula, This refers to the stiffness of the wire coil under the target clamping force. Let be the elastic modulus of the wire coil under the target clamping force. Let be the cross-sectional area of ​​the wire disc under the target clamping force. The height of the wire disc under the target clamping force.

[0010] Furthermore, the stiffness of the insulation structure under the target clamping force is calculated using the following formula: ; In the formula, This refers to the stiffness of the insulation structure under the target clamping force. This represents the elastic modulus of the insulating structure under the target clamping force. Let be the cross-sectional area of ​​the insulating structure under the target clamping force. The height of the insulating structure under the target clamping force.

[0011] Furthermore, the stiffness of the transformer coil under the target clamping force is calculated using the following formula: ; In the formula, This refers to the stiffness of the transformer coil under the target clamping force. This refers to the stiffness of the wire coil under the target clamping force. This refers to the stiffness of the insulating structure under the target clamping force.

[0012] Furthermore, based on the vibration amplitude of the transformer coil and the calculated stiffness of the transformer coil, the vibration energy of a single transformer coil is calculated, and the specific calculation formula is as follows: ; In the formula, The vibrational energy of a single transformer coil is expressed in J. This refers to the stiffness of the transformer coil under the target clamping force, expressed in N / m. This represents the vibration amplitude of the transformer coil under the target clamping force, and the unit is disregarded when taking the value. It is the product of the transformer coil structure type coefficient and the transformer coil weight coefficient; As the reference amplitude, =1 m; Determine the ratio of noise energy generated by a single transformer coil to vibration energy, and calculate the noise energy generated by a single or at least two transformer coils based on the ratio and vibration energy. The noise energy generated by a single transformer coil is specifically calculated using the following formula: = ; The noise energy generated by at least two of the transformer coils is specifically calculated using the following formula: ; In the formula, For the noise energy generated by all transformer coils, This represents the vibrational energy of the first transformer coil. This refers to the vibration energy of the second transformer coil. Let n be the vibration energy of the nth transformer coil. ~ This is the ratio of noise energy generated by a single transformer coil to vibration energy.

[0013] Further, in step S8, under the target clamping force, the transformer load noise is calculated based on the noise energy, specifically including: S101. Calculate the coil acoustic power. The specific calculation formula is as follows: In the formula, W The coil's acoustic power is T, and the period is T. , For frequency; S102. Calculate the coil sound power level. The specific calculation formula is as follows: In the formula, For the coil's acoustic power level, W For coil acoustic power, The reference sound power; S103. Calculate the sound power level of the transformer load. The specific calculation formula is as follows: ; In the formula, For transformer load sound power level, For the coil's acoustic power level, This refers to the sound power level of the cooling device.

[0014] The present invention further proposes a transformer load noise calculation system, the system being used to implement the above-mentioned method, comprising: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the following modules: The modal testing module is used to perform modal tests on the transformer coil under the inherent clamping force of the transformer coil, and to obtain the modal test parameters of the transformer coil, wherein the modal test parameters include at least the natural frequency and mode shape; The equivalent modal simulation module is used to establish an equivalent model of the transformer coil. The equivalent model of the transformer coil includes a conductor coil and an insulation structure. The same clamping force as the modal test is applied to the equivalent model of the transformer coil to perform modal simulation and obtain the modal simulation parameters of the transformer coil. The modal simulation parameters include at least the simulated natural frequency and the simulated mode shape. The equivalent material parameter acquisition module is used to set the equivalent material parameter values ​​for different insulation structures in the equivalent model of the transformer coil, compare the modal test parameters and the modal simulation parameters, and when the consistency of the comparison results meets the preset tolerance, determine the equivalent material parameter values ​​of the insulation structure set in the current equivalent model of the transformer coil as the equivalent material parameter values ​​of the actual insulation structure of the transformer coil. The equivalent material parameters include at least the equivalent elastic modulus, equivalent Poisson's ratio and equivalent density. The mapping module acquires the equivalent material parameter values ​​under different inherent clamping forces for transformer coils, and establishes a mapping relationship between clamping force and equivalent material parameter values. The electrodynamic force acquisition module uses three-dimensional magnetic field simulation to acquire the electrodynamic force of the transformer coil; The harmonic response calculation module is used to assign the target clamping force and the equivalent material parameters obtained based on the mapping relationship to the transformer coil equivalent model, apply the electrodynamic force as an excitation load to the transformer coil equivalent model, perform harmonic response analysis on the transformer coil equivalent model, and calculate the vibration amplitude of the transformer coil. The noise energy calculation module is used to calculate the noise energy generated by the transformer coil based on the vibration amplitude under the target clamping force. The load noise calculation module is used to calculate the transformer load sound power level based on the noise energy under the target clamping force, and to evaluate the transformer load noise level based on the transformer load sound power level.

[0015] The beneficial effects of this invention are: This invention obtains the natural frequencies and mode shapes of transformer coils under different clamping forces through modal testing of transformer coils. An equivalent model of the transformer coil is established, and equivalent material parameters under different inherent clamping forces are obtained through three-dimensional simulation. The electrodynamic force of the transformer coil is obtained using three-dimensional magnetic field simulation. Using the obtained equivalent material parameters and the electrodynamic force of the transformer coil as excitation, the vibration amplitude of the transformer coil under a certain clamping state is calculated through harmonic response. Furthermore, the vibration energy of the transformer coil is obtained, and combined with the proportion of noise energy, the noise energy generated by the transformer coil is obtained. Finally, the sound power level of the transformer load under this clamping state can be obtained. The noise level is assessed using the transformer load sound power level, thus providing a reference value for transformer vibration reduction and noise reduction. Attached Figure Description

[0016] Figure 1 This is a flowchart of the transformer load noise calculation for the present invention.

[0017] Figure 2 This is a schematic diagram of the original transformer coil structure of the present invention.

[0018] Figure 3 This is a schematic diagram of the equivalent model of the transformer coil of the present invention.

[0019] Figure 4 This is a schematic diagram of the original insulating pad structure in the transformer coil of the present invention.

[0020] Figure 5 This is a schematic diagram of the equivalent structure of the insulating pad block of the present invention.

[0021] Reference numerals: 1. Conductor disc; 2. Insulating pad; 3. Ring. Detailed Implementation

[0022] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] See Figures 1-5 This invention proposes a method for calculating transformer load noise, the method comprising the following steps: S1. Under the inherent clamping force of the transformer coil, a modal test is performed on the transformer coil to obtain the modal test parameters of the transformer coil. The modal test parameters include at least the natural frequency and mode shape.

[0024] In this embodiment, when the transformer coil is energized, it will be excited by periodic electric force. When the frequency of the excitation force coincides with or is very close to the natural frequency of the transformer coil, resonance will occur. The natural frequency is obtained in order to avoid resonance. When designing the transformer coil, the natural frequency of the transformer coil is far away from the excitation frequency, and the mode shape can clearly show the vibration amplitude of a specific part of the transformer coil at a specific frequency.

[0025] In this embodiment, the transformer coil is composed of a conductor coil 1, an insulating pad 2, and inter-turn insulation. In order to make the overall structure robust and reliable and able to withstand a certain impact, the compression degree of the transformer coil needs to be considered in the design so that the transformer coil can meet the electrical and mechanical performance requirements.

[0026] S2. Establish an equivalent model of the transformer coil, which includes a conductor coil 1 and an insulation structure. Apply the same clamping force as in the modal test and perform modal simulation on the equivalent model of the transformer coil to obtain the modal simulation parameters of the transformer coil. The modal simulation parameters include at least the simulated natural frequency and the simulated mode shape.

[0027] In this embodiment, the inherent clamping force is a clamping force determined during the design of the transformer coil to ensure the integrity of the transformer coil structure and the vibration characteristics of the transformer coil structure itself. The same clamping force needs to be applied during simulation, and the clamping force load is applied symmetrically at the upper and lower ends of the transformer coil.

[0028] S3. Set the equivalent material parameter values ​​for different insulation structures in the equivalent model of the transformer coil, compare the modal test parameters and the modal simulation parameters, and when the consistency of the comparison results meets the preset tolerance, determine the equivalent material parameter values ​​of the insulation structure set in the current equivalent model of the transformer coil as the equivalent material parameter values ​​of the actual insulation structure of the transformer coil. The equivalent material parameters include at least the equivalent elastic modulus, equivalent Poisson's ratio and equivalent density.

[0029] In this embodiment, an equivalent model of the transformer coil is established, and the simulated natural frequency of the transformer coil is obtained through simulation, so that the simulation results are basically consistent with the test results. The equivalent material parameters of the insulation structure are then deduced. Among them, the equivalent elastic modulus reflects the overall stiffness of the transformer coil structure, and the equivalent density affects the weight, which in turn affects the weight coefficient of the transformer coil. Both of these affect the vibration characteristics of the transformer coil structure, which in turn affects the noise results. The equivalent Poisson's ratio is the ratio of transverse strain to longitudinal strain. In three-dimensional simulation, Poisson's ratio is an indispensable material parameter.

[0030] In this embodiment, comparing the modal test parameters and the modal simulation parameters refers to comparing the natural frequencies of the transformer coil structure itself to ensure that the frequencies and mode shapes are basically the same, while allowing for some errors.

[0031] S4. For transformer coils with different inherent clamping forces, repeat steps S1 to S3 to obtain the equivalent material parameter values ​​under different inherent clamping forces, and establish a mapping relationship between clamping force and equivalent material parameter values.

[0032] S5. The electrodynamic force of the transformer coil is obtained by three-dimensional magnetic field simulation.

[0033] S6. Assign the target clamping force and the equivalent material parameter values ​​obtained based on the mapping relationship to the transformer coil equivalent model, apply the electrodynamic force as an excitation load to the transformer coil equivalent model, perform harmonic response analysis on the transformer coil equivalent model, and calculate the vibration amplitude of the transformer coil.

[0034] In this embodiment, the natural frequency of the transformer coil structure and the mode shapes of the transformer coil structure at different frequencies are first obtained through modal analysis. The harmonic response analysis adopts the modal superposition method to obtain the vibration amplitude of the transformer coil structure at different frequencies under sinusoidal load.

[0035] S7. Under the target clamping force, calculate the noise energy generated by the transformer coil based on the vibration amplitude.

[0036] S8. Under the target clamping force, calculate the transformer load noise based on the noise energy.

[0037] Further, in step S2, establishing an equivalent model of the transformer coil specifically includes: the insulation structure includes insulating pads 2 arranged along the circumferential direction; the insulating pads 2 are equivalent to an annular body 3 with the same inner and outer diameters as the conductor coil 1, and the thickness is the same as before the equivalence; and the conductor coil 1 and the remaining structure of the insulation structure except for the insulating pads 2 are modeled according to actual dimensions, as shown in the original transformer coil structure. Figure 2 As shown, the equivalent model of the transformer coil is as follows: Figure 3 As shown, the original insulating pad 2 in the transformer coil has the following structure. Figure 4 As shown, the equivalent structure of insulating pad 2 is as follows: Figure 5 As shown.

[0038] In this embodiment, the transformer coil mainly includes a conductor coil 1, an insulating pad 2, and inter-turn insulation. The insulation structure includes the insulating pad 2 and the inter-turn insulation. In the equivalent model of the transformer coil, the conductor coil 1 and the inter-turn insulation are modeled according to their actual dimensions. Only the insulating pad 2 needs to be equivalent. Multiple dispersed insulating pads 2 are equivalent to a continuous circular ring 3 of the overall structure.

[0039] Further, in step S5, the electrodynamic force of the transformer coil is obtained by three-dimensional magnetic field simulation, specifically including: obtaining the power frequency current excitation of the transformer coil, establishing a three-dimensional transient electromagnetic field analysis model of the transformer coil, calculating the leakage magnetic field distribution of the transformer coil under operating conditions based on the three-dimensional transient electromagnetic field analysis model and the power frequency current excitation, and calculating the electrodynamic force acting on the transformer coil according to the leakage magnetic field distribution.

[0040] Further, in step S7, under the target clamping force, the noise energy generated by the transformer coil is calculated based on the vibration amplitude, specifically including: Calculate the stiffness of the conductor coil under the target clamping force; Calculate the stiffness of the insulation structure under the target clamping force; Calculate the stiffness of the transformer coil under the target clamping force; The vibration energy of a single transformer coil is calculated based on the vibration amplitude of the transformer coil and the calculated stiffness of the transformer coil. The proportion of noise energy generated by a single transformer coil to vibration energy, i.e., the sound radiation efficiency, is determined by existing acoustic calculation formulas. The noise energy generated by a single or at least two transformer coils is calculated based on the proportion and vibration energy.

[0041] In this embodiment, part of the vibration energy is converted into noise energy, and another part is converted into heat energy.

[0042] Furthermore, the stiffness of the conductor coil under the target clamping force is calculated using the following formula: ; In the formula, This refers to the stiffness of the wire coil under the target clamping force. Let be the elastic modulus of the wire coil under the target clamping force. Let be the cross-sectional area of ​​the wire disc under the target clamping force. The height of the wire disc under the target clamping force.

[0043] Furthermore, the stiffness of the insulation structure under the target clamping force is calculated using the following formula: ; In the formula, This refers to the stiffness of the insulation structure under the target clamping force. This represents the elastic modulus of the insulating structure under the target clamping force. Let be the cross-sectional area of ​​the insulating structure under the target clamping force. The height of the insulating structure under the target clamping force.

[0044] Furthermore, the stiffness of the transformer coil under the target clamping force is calculated using the following formula: ; In the formula, This refers to the stiffness of the transformer coil under the target clamping force. This refers to the stiffness of the wire coil under the target clamping force. This refers to the stiffness of the insulating structure under the target clamping force.

[0045] Furthermore, based on the vibration amplitude of the transformer coil and the calculated stiffness of the transformer coil, the vibration energy of a single transformer coil is calculated, and the specific calculation formula is as follows: ; In the formula, The vibrational energy of a single transformer coil is expressed in J. This refers to the stiffness of the transformer coil under the target clamping force, expressed in N / m. This represents the vibration amplitude of the transformer coil under the target clamping force, and the unit is disregarded when taking the value. It is an index related to the transformer coil structure type and transformer coil weight, specifically the product of the transformer coil structure type coefficient and the transformer coil weight coefficient; As the reference amplitude, =1 m.

[0046] In this embodiment, The value of the coefficient is determined based on the structure and weight of the transformer coil, ranging from 0.81 to 1.1. Common structural types include continuous coils, helical coils, entangled coils, and layered coils. Different structural types correspond to different values: the coefficient for continuous coils is 1.1, for helical coils it is 1.05, for entangled coils it is 0.9, and for layered coils it is 1. Different weight ranges also have different values: when the transformer coil weight is less than 10t, the coefficient is 0.9; when the transformer coil weight is greater than 10t, the coefficient is 1.

[0047] Determine the ratio of noise energy generated by a single transformer coil to vibration energy, i.e., the acoustic radiation efficiency, which is obtained based on existing acoustic calculation formulas. Calculate the noise energy generated by a single or at least two transformer coils based on the ratio and vibration energy. The noise energy generated by a single transformer coil is specifically calculated using the following formula: = ; The noise energy generated by at least two of the transformer coils is specifically calculated using the following formula: ; In the formula, For the noise energy generated by all transformer coils, This represents the vibrational energy of the first transformer coil. This refers to the vibration energy of the second transformer coil. Let n be the vibration energy of the nth transformer coil. ~ This is the ratio of noise energy generated by a single transformer coil to vibration energy. Its value is related to the position and size of the transformer coil and ranges from 0.3 to 0.7.

[0048] In this embodiment, the proportion of vibration energy of a single coil converted into noise energy is approximately 30% to 70%. When there are multiple transformer coils, their different positions have a certain impact. The inner transformer coil, being sandwiched between other structures, needs to overcome greater friction during vibration, thus generating more heat energy and converting relatively less energy into noise. Currently, without a voltage regulating coil, the outermost coil has a value of 0.4, and the innermost coil has a value of 0.3; with a voltage regulating coil, the outermost regulating coil has a value of 0.6.

[0049] Further, in step S8, under the target clamping force, the transformer load sound power level is calculated based on the noise energy, and the transformer load noise level is evaluated based on the transformer load sound power level, specifically including: S101. Calculate the coil acoustic power. The specific calculation formula is as follows: In the formula, W The coil's acoustic power is T, and the period is T. , f For frequency; S102. Calculate the coil sound power level. The specific calculation formula is as follows: In the formula, For the coil's acoustic power level, W For coil acoustic power, The reference sound power has a value of The unit is watt; S103. Calculate the sound power level of the transformer load. The specific calculation formula is as follows: ; In the formula, For transformer load sound power level, For the coil's acoustic power level, This refers to the sound power level of the cooling device.

[0050] In this embodiment, load noise is represented in two ways: load sound power level or load sound pressure level. In this invention, load sound power level is used to represent load noise. Load noise includes coil noise and cooling device noise. The transformer load sound power level is obtained by combining the sound power level of the transformer coil and the sound power level of the cooling device. The sound power level of the cooling device is provided by the cooling device manufacturer.

[0051] The transformer load noise calculation method proposed in this invention takes into account the influence of the compression state on the overall stiffness of the transformer coil, and can effectively obtain the noise generated by the electrodynamic force of the transformer coil, making the calculation of transformer load noise more accurate and providing technical support for the subsequent performance improvement of products.

[0052] This invention obtains the parameter values ​​of the insulating material under different clamping forces by combining the test results of the natural frequency of the transformer coil under different clamping forces with three-dimensional simulation, obtains the electrodynamic force of the transformer coil by three-dimensional magnetic field simulation, calculates the overall stiffness of the transformer coil under a certain clamping state, obtains the vibration amplitude of the transformer coil under that clamping state, further obtains the vibration energy of the transformer coil, and obtains the noise energy generated by the transformer coil by combining the noise energy and the proportion of vibration energy. Finally, the transformer load noise under that clamping state can be obtained, thus providing a reference value for transformer vibration reduction and noise reduction.

[0053] The present invention further proposes a transformer load noise calculation system, the system being used to implement the above-mentioned method, comprising: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the following modules: The modal testing module is used to perform modal tests on the transformer coil under the inherent clamping force of the transformer coil, and to obtain the modal test parameters of the transformer coil, wherein the modal test parameters include at least the natural frequency and mode shape; The equivalent modal simulation module is used to establish an equivalent model of the transformer coil. The equivalent model of the transformer coil includes a conductor coil and an insulation structure. The same clamping force as the modal test is applied to the equivalent model of the transformer coil to perform modal simulation and obtain the modal simulation parameters of the transformer coil. The modal simulation parameters include at least the simulated natural frequency and the simulated mode shape. The equivalent material parameter acquisition module is used to set the equivalent material parameter values ​​for different insulation structures in the equivalent model of the transformer coil, compare the modal test parameters and the modal simulation parameters, and when the consistency of the comparison results meets the preset tolerance, determine the equivalent material parameter values ​​of the insulation structure set in the current equivalent model of the transformer coil as the equivalent material parameter values ​​of the actual insulation structure of the transformer coil. The equivalent material parameters include at least the equivalent elastic modulus, equivalent Poisson's ratio and equivalent density. The mapping module acquires the equivalent material parameter values ​​under different inherent clamping forces for transformer coils, and establishes a mapping relationship between clamping force and equivalent material parameter values. The electrodynamic force acquisition module uses three-dimensional magnetic field simulation to acquire the electrodynamic force of the transformer coil; The harmonic response calculation module is used to assign the target clamping force and the equivalent material parameters obtained based on the mapping relationship to the transformer coil equivalent model, apply the electrodynamic force as an excitation load to the transformer coil equivalent model, perform harmonic response analysis on the transformer coil equivalent model, and calculate the vibration amplitude of the transformer coil. The noise energy calculation module is used to calculate the noise energy generated by the transformer coil based on the vibration amplitude under the target clamping force. The load noise calculation module is used to calculate the transformer load sound power level based on the noise energy under the target clamping force, and to evaluate the transformer load noise level based on the transformer load sound power level.

[0054] The transformer load noise calculation system of the present invention, since it can implement the steps of the above-described transformer load noise calculation method, has at least all the beneficial effects brought about by the technical solution of the above-described transformer load noise calculation method embodiment.

[0055] The above description is only a part or preferred embodiment of the present invention. Neither the text nor the drawings should limit the scope of protection of the present invention. All equivalent structural transformations made using the content of the present invention specification and drawings under the overall concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A method for calculating transformer load noise, characterized in that, The method includes the following steps: S1. Under the inherent clamping force of the transformer coil, a modal test is performed on the transformer coil to obtain the modal test parameters of the transformer coil. The modal test parameters include at least the natural frequency and mode shape. S2. Establish an equivalent model of the transformer coil, which includes a conductor coil and an insulation structure. Apply the same clamping force as in the modal test and perform modal simulation on the equivalent model of the transformer coil to obtain the modal simulation parameters of the transformer coil. The modal simulation parameters include at least the simulated natural frequency and the simulated mode shape. S3. Set the equivalent material parameter values ​​for different insulation structures in the equivalent model of the transformer coil, compare the modal test parameters and the modal simulation parameters, and when the consistency of the comparison results meets the preset tolerance, determine the equivalent material parameter values ​​of the insulation structure set in the current equivalent model of the transformer coil as the equivalent material parameter values ​​of the actual insulation structure of the transformer coil. The equivalent material parameters include at least the equivalent elastic modulus, equivalent Poisson's ratio and equivalent density. S4. For transformer coils with different inherent clamping forces, repeat steps S1 to S3 to obtain the equivalent material parameter values ​​under different inherent clamping forces, and establish a mapping relationship between clamping force and equivalent material parameter values. S5. The electrodynamic force of the transformer coil is obtained by three-dimensional magnetic field simulation; S6. Assign the target clamping force and the equivalent material parameter values ​​obtained based on the mapping relationship to the transformer coil equivalent model, apply the electrodynamic force as an excitation load to the transformer coil equivalent model, perform harmonic response analysis on the transformer coil equivalent model, and calculate the vibration amplitude of the transformer coil. S7. Under the target clamping force, calculate the noise energy generated by the transformer coil based on the vibration amplitude; S8. Under the target clamping force, calculate the transformer load sound power level based on the noise energy, and evaluate the transformer load noise level based on the transformer load sound power level.

2. The transformer load noise calculation method according to claim 1, characterized in that, In step S2, establishing an equivalent model of the transformer coil specifically includes: the insulation structure includes insulating pads arranged along the circumferential direction, the insulating pads are equivalent to annular bodies with the same inner and outer diameters as the conductor coil, and the conductor coil and the remaining structure of the insulation structure except for the insulating pads are modeled according to the actual dimensions.

3. The transformer load noise calculation method according to claim 1, characterized in that, In step S5, the electrodynamic force of the transformer coil is obtained by three-dimensional magnetic field simulation. Specifically, this includes: obtaining the power frequency current excitation of the transformer coil, establishing a three-dimensional transient electromagnetic field analysis model of the transformer coil, calculating the leakage magnetic field distribution of the transformer coil under operating conditions based on the three-dimensional transient electromagnetic field analysis model and the power frequency current excitation, and calculating the electrodynamic force acting on the transformer coil according to the leakage magnetic field distribution.

4. The transformer load noise calculation method according to claim 1, characterized in that, In step S7, under the target clamping force, the noise energy generated by the transformer coil is calculated based on the vibration amplitude, specifically including: Calculate the stiffness of the conductor coil under the target clamping force; Calculate the stiffness of the insulation structure under the target clamping force; Calculate the stiffness of the transformer coil under the target clamping force; The vibration energy of a single transformer coil is calculated based on the vibration amplitude of the transformer coil and the calculated stiffness of the transformer coil. Determine the ratio of noise energy generated by a single transformer coil to vibration energy, and calculate the noise energy generated by a single or at least two transformer coils based on the ratio and vibration energy.

5. The transformer load noise calculation method according to claim 4, characterized in that, The stiffness of the conductor coil under the target clamping force is calculated using the following formula: ； In the formula, This refers to the stiffness of the wire coil under the target clamping force. Let be the elastic modulus of the wire coil under the target clamping force. Let be the cross-sectional area of ​​the wire disc under the target clamping force. The height of the wire coil under the target clamping force.

6. The transformer load noise calculation method according to claim 4, characterized in that, The stiffness of the insulation structure under the target clamping force is calculated using the following formula: ； In the formula, This refers to the stiffness of the insulation structure under the target clamping force. This represents the elastic modulus of the insulating structure under the target clamping force. This represents the cross-sectional area of ​​the insulating structure under the target clamping force. The height of the insulating structure under the target clamping force.

7. The transformer load noise calculation method according to claim 4, characterized in that, The stiffness of the transformer coil under the target clamping force is calculated using the following formula: ； In the formula, This refers to the stiffness of the transformer coil under the target clamping force. This refers to the stiffness of the wire coil under the target clamping force. This refers to the stiffness of the insulating structure under the target clamping force.

8. The transformer load noise calculation method according to claim 4, characterized in that, Based on the vibration amplitude of the transformer coil and the calculated stiffness of the transformer coil, the vibration energy of a single transformer coil is calculated. The specific calculation formula is as follows: ； In the formula, The vibrational energy of a single transformer coil is expressed in J. This refers to the stiffness of the transformer coil under the target clamping force, expressed in N / m. This represents the vibration amplitude of the transformer coil under the target clamping force, and the unit is disregarded when taking the value. It is the product of the transformer coil structure type coefficient and the transformer coil weight coefficient; As the reference amplitude, =1 m; Determine the ratio of noise energy generated by a single transformer coil to vibration energy, and calculate the noise energy generated by a single or at least two transformer coils based on the ratio and vibration energy. The noise energy generated by a single transformer coil is specifically calculated using the following formula: = ； The noise energy generated by at least two of the transformer coils is specifically calculated using the following formula: ； In the formula, For the noise energy generated by all transformer coils, This represents the vibrational energy of the first transformer coil. The vibration energy of the second transformer coil. Let n be the vibration energy of the nth transformer coil. ~ This is the ratio of noise energy generated by a single transformer coil to vibration energy.

9. The transformer load noise calculation method according to claim 8, characterized in that, In step S8, under the target clamping force, the transformer load sound power level is calculated based on the noise energy, and the transformer load noise level is evaluated based on the transformer load sound power level. Specifically, this includes: S101. Calculate the coil acoustic power. The specific calculation formula is as follows: In the formula, W For coil acoustic power, The noise energy generated by all transformer coils, where T is the period; S102. Calculate the coil sound power level. The specific calculation formula is as follows: In the formula, For the coil's acoustic power level, W For coil acoustic power, The reference sound power; S103. Calculate the sound power level of the transformer load. The specific calculation formula is as follows: ； In the formula, For transformer load sound power level, For the coil's acoustic power level, This refers to the sound power level of the cooling device.

10. A transformer load noise calculation system, said system being used to implement the method as described in any one of claims 1 to 9, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the following modules: The modal testing module is used to perform modal tests on the transformer coil under the inherent clamping force of the transformer coil, and to obtain the modal test parameters of the transformer coil, wherein the modal test parameters include at least the natural frequency and mode shape; The equivalent modal simulation module is used to establish an equivalent model of the transformer coil. The equivalent model of the transformer coil includes a conductor coil and an insulation structure. The same clamping force as the modal test is applied to the equivalent model of the transformer coil to perform modal simulation and obtain the modal simulation parameters of the transformer coil. The modal simulation parameters include at least the simulated natural frequency and the simulated mode shape. The equivalent material parameter acquisition module is used to set the equivalent material parameter values ​​for different insulation structures in the equivalent model of the transformer coil, compare the modal test parameters and the modal simulation parameters, and when the consistency of the comparison results meets the preset tolerance, determine the equivalent material parameter values ​​of the insulation structure set in the current equivalent model of the transformer coil as the equivalent material parameter values ​​of the actual insulation structure of the transformer coil. The equivalent material parameters include at least the equivalent elastic modulus, equivalent Poisson's ratio and equivalent density. The mapping module acquires the equivalent material parameter values ​​under different inherent clamping forces for transformer coils, and establishes a mapping relationship between clamping force and equivalent material parameter values. The electrodynamic force acquisition module uses three-dimensional magnetic field simulation to acquire the electrodynamic force of the transformer coil; The harmonic response calculation module is used to assign the target clamping force and the equivalent material parameters obtained based on the mapping relationship to the transformer coil equivalent model, apply the electrodynamic force as an excitation load to the transformer coil equivalent model, perform harmonic response analysis on the transformer coil equivalent model, and calculate the vibration amplitude of the transformer coil. The noise energy calculation module is used to calculate the noise energy generated by the transformer coil based on the vibration amplitude under the target clamping force. The load noise calculation module is used to calculate the transformer load sound power level based on the noise energy under the target clamping force, and to evaluate the transformer load noise level based on the transformer load sound power level.

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