Transformer vibration reduction optimization method considering temperature

Abstract

The invention discloses a transformer vibration reduction optimization method considering temperature, and the method comprises the steps: building an electromagnetic model of a transformer, building a transformer temperature-vibration model, taking the minimum vibration acceleration effective value a as a target based on the relation between the basic size of the transformer and the electromagnetic load and the vibration model, and taking the transformer mass Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax, Gmax and and optimizing and adjusting the iron core diameter D, the number of turns N, the axial height H of the winding and the maximum flux density Bm of the transformer by taking the coil voltage Us as a constraint, and finally solving the optimized D value and H value. According to the transformer designed through the method, at the same working temperature, the vibration noise level of the transformer can be effectively reduced, under the condition that other parameters are not changed, noise can be reduced by 7-10 dB, on the premise that the basic design parameters of the transformer are met, vibration suppression design is conducted on the transformer, the mute performance of the transformer is effectively improved, and the service life of the transformer is prolonged. And safe, mute and stable operation of an electrical system is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of transformer design, and in particular to a transformer vibration reduction optimization method taking temperature into consideration. Background Art

[0002] As one of the most important equipment in the ship's electrical system, the safe and stable operation of the transformer directly affects the reliability of the ship's electrical system. When the ship's power system is running, the transformer often generates large vibration noise. Transformer vibration accounts for the main component of the vibration of electromagnetic components in the ship's power system. Reducing the vibration acceleration of the transformer is an important guarantee for the low-vibration operation of the ship.

[0003] Traditional transformer vibration reduction methods mainly include the following:

[0004] 1. Use vibration damping pads: Installing vibration damping pads at the bottom of the transformer can effectively absorb and reduce the transmission of vibration to the infrastructure or building.

[0005] 2. Install vibration reduction support structure: Install vibration reduction support structure around the transformer, such as spring bracket, rubber vibration isolation pad, etc., to reduce vibration transmission, noise and vibration.

[0006] 3. Optimize the support of the transformer: Rationally design the support structure of the transformer to increase its rigidity and stability, which can reduce the occurrence of vibration and resonance.

[0007] 4. Control the vibration of insulating materials: Using insulating materials or anti-vibration measures inside the transformer can reduce the vibration of the windings and core.

[0008] The above methods are basically mainly concentrated on the process research of transformer noise reduction technology, while there is a lack of research on transformer design methods oriented towards transformer vibration suppression. Summary of the invention

[0009] In view of this, the present invention proposes a transformer vibration reduction optimization method taking temperature into consideration, which combines the transformer electromagnetic design, vibration suppression design and transformer temperature to establish a model, and uses the Lagrange multiplier method to solve the transformer design model, thereby effectively improving the quietness performance of the transformer.

[0010] The technical solution of the present invention is as follows:

[0011] A transformer vibration reduction optimization method considering temperature, the transformer is a three-phase transformer, including an iron core composed of three iron core columns and iron yokes at upper and lower ends, and a winding coil wound on the iron core column, characterized in that:

[0012] Step 1: Establish the electromagnetic model of the transformer.

[0013] G(D,H)=ρ Fe V(D,H)=C 1 ρ Fe HD 2 +C 2 ρ Fe D 2 +C 3 ρ Fe D 3

[0014] in,

[0015]

[0016] Where: Fe is the transformer core density, C 1 , C 2 , C 3 K is the transformer structure voltage coefficient D is the ratio of the effective cross-sectional area of ​​the core column to the actual cross-sectional area of ​​the core column, the diameter of the core column is D; m is the number of phases of the transformer; K Fe is the stacking coefficient of silicon steel sheets in the core column, h 1 is the distance from the coil end to the iron yoke, a z is the center distance between two adjacent core columns,

[0017] Step 2: Establish the transformer temperature-vibration model.

[0018] In the model, the acceleration of the core vibration caused by the magnetostriction of the silicon steel sheet is:

[0019]

[0020] Where: Bs is the saturation flux density of the core, ΔL is the axial expansion of the silicon steel sheet, B m is the maximum magnetic flux density of the core, L is the original axial size of the silicon steel sheet, α is the temperature coefficient of the magnetostriction of the core, which represents the change of magnetostriction caused by unit temperature change, ΔT is the difference between the current temperature of the core and the target working file, U s is the coil voltage, ω is the angular velocity of the transformer sinusoidal voltage, N is the number of turns of the winding coil, S is the actual cross-sectional area of ​​the core column,

[0021] Among them, the relationship between the core acceleration a, the core column diameter D, and the winding coil axial height H is as follows:

[0022]

[0023] The effective value of acceleration is expressed as:

[0024]

[0025] Where: ε 0 is the saturation magnetostriction of the core at zero temperature; k is the volume coefficient of the core, S N is the total capacity of the transformer, S is the cross-sectional area of ​​each core column;

[0026] Step 3: Based on the relationship between the basic size of the transformer and the electromagnetic load and the vibration model, the minimum effective value of the vibration acceleration |a| is taken as the goal, and the transformer mass G max , coil voltage U s As a constraint, the transformer core diameter D, number of turns N, winding axial height H and maximum magnetic flux density B m Make optimization adjustments.

[0027] The constraints are:

[0028]

[0029] a p is the transformer coil coefficient, ρ Fe is the material density of silicon steel sheet, k q is the additional leakage reactance coefficient, I is the rated current of the winding, μ 0 is the vacuum permeability, C 4 is the transformer structural impedance voltage coefficient. Combined with the optimization equation and constraints, the Lagrange multiplier method is used as an auxiliary function to write the acceleration effective value expression and constraints into the following form:

[0030]

[0031] The necessary conditions for a function to have an unconditional extreme value are as follows:

[0032]

[0033] The connection equation is:

[0034]

[0035] Solve the above algebraic equations simultaneously and finally obtain the optimized D and H values.

[0036] In a preferred implementation, the number of turns N and the magnetic flux density B are calculated based on the D value and the H value. m .

[0037] In a preferred implementation, the minimum effective value of acceleration |a| of the transformer core is obtained according to the following formula:

[0038]

[0039] The transformer vibration reduction optimization method considering temperature of the present invention takes the minimum vibration acceleration as the design goal, is based on the electromagnetic-temperature-vibration multi-physics field model, takes the transformer volume V and the coil voltage Us as constraints, and uses the Lagrange multiplier method to obtain the transformer core diameter, core window height, number of turns and maximum magnetic flux density when the vibration acceleration is the minimum at the target temperature. A transformer that can achieve the best vibration reduction effect at different operating temperatures can be obtained.

[0040] The beneficial effects of the present invention are:

[0041] The transformer designed by the method of the present invention can effectively reduce the vibration noise level of the transformer under the same operating temperature. When other parameters remain unchanged, the noise can be reduced by 7-10dB. The vibration suppression design of the transformer is realized under the premise of meeting the basic design parameters of the transformer, which effectively improves the quiet performance of the transformer and contributes to the safe, quiet and stable operation of the electrical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The advantages of the above and additional aspects of the present invention will become apparent and easily understood in the description of the embodiments in conjunction with the following drawings, in which:

[0043] Figure 1 The main structure diagram of the transformer is as follows:

[0044] Figure 2 The present invention is a flow chart of a transformer vibration reduction optimization method taking temperature into consideration.

[0045] Figure 3 A prototype machine constructed using the optimization method of the present invention DETAILED DESCRIPTION

[0046] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0047] The following is an embodiment of the transformer vibration reduction optimization method considering temperature in the present invention. In this embodiment, the main design principle process of the transformer is described in detail, and the technical route included in the present invention is described in detail in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited thereby.

[0048] Step 1: Establish the electromagnetic model of the transformer and use the basic principle of the transformer to deduce the relationship between the basic size of the transformer and the electromagnetic load. From the basic principle of the transformer, we can get:

[0049]

[0050] Where: N is the number of series turns of each phase of the winding; I is the winding line current; K D It is the ratio of the effective cross-sectional area of ​​the core column to the circular area determined by the core column diameter D; A is the line load; B m is the maximum magnetic flux density; m is the number of phases; H is the axial height of the winding; f is the frequency; Φ m is the maximum magnetic flux; E is the electromotive force, S N is the total capacity of the transformer.

[0051] Solving the above system of equations yields:

[0052]

[0053] Where: K T It represents the utilization factor of the transformer, k is the volume factor, and W is the volume of the transformer.

[0054]

[0055] The volume of the core includes the volume of the core column, the part between the center distances of the two side columns, and the actual part of the four corners of the iron yoke. Its overall expression is:

[0056]

[0057] Where: A Fe is the effective cross-sectional area of ​​the iron yoke, K Fe is the overlap coefficient, h 1 is the distance from the coil end to the iron yoke, a z is the center distance between two adjacent core columns, C 1 , C 2 , C 3 is the transformer structure voltage coefficient.

[0058] Combining the above formulas, the total mass of the transformer can be obtained:

[0059] G(D,H)=ρ Fe V(D,H)=C 1 ρ Fe HD 2 +C 2 ρ Fe D 2 +C 3 ρ Fe D 3 #(10)Where: ρ Fe is the transformer core density.

[0060] Step 2: Establish the transformer temperature-vibration model. The iron core is the main vibration source of the transformer. Considering the influence of temperature and electromagnetic parameters on the iron core vibration, a transformer magnetostrictive model is established.

[0061] When the transformer core is exposed to an AC excitation source, the ferromagnetic material moves periodically due to the magnetostrictive effect and electromagnetic force. The magnetostrictive coefficient ε can be expressed as the ratio of the change in length due to the magnetostrictive effect to the original length.

[0062]

[0063] Where: L is the original axial dimension of the silicon steel sheet, and ΔL represents the axial expansion and contraction of the silicon steel sheet.

[0064] Saturation magnetostriction ε s The general relationship with temperature can be described by the following functional form:

[0065] ε s (T) = ε 0 +αΔT#(12)

[0066] Where: ε 0 is the saturation magnetostriction at zero temperature (degrees Celsius); α is the temperature coefficient of magnetostriction, which represents the change in magnetostriction caused by a unit temperature change; ΔT is the difference between the current temperature and the target operating temperature.

[0067] Under the action of the magnetic field, the small deformation of the silicon steel sheet meets the following conditions:

[0068]

[0069] By combining equation (13) and equation (14), the maximum axial expansion of the core silicon steel sheet caused by magnetostriction is:

[0070]

[0071] Combining the above formulas, the acceleration of the core vibration caused by the magnetostriction of the silicon steel sheet is:

[0072]

[0073] Where: Bs is the saturation magnetic flux density.

[0074] Then, the relationship between the core acceleration a, the core diameter D, and the winding axial height H is as follows:

[0075]

[0076] The effective value of acceleration can be expressed as:

[0077]

[0078] Where: S is the cross-sectional area of ​​the core; U s is the coil voltage.

[0079] Transformer short-circuit impedance voltage u x It is also the rated parameter of the transformer, and the constraint relationship between the short-circuit impedance voltage and the transformer structure can be obtained.

[0080]

[0081] In the formula, C 4 is the transformer structural impedance voltage coefficient, a p is the transformer coil coefficient, ρ 1 is the longitudinal Rockwell coefficient, k q is the additional leakage reactance coefficient, I is the rated current of the winding, μ 0 is the magnetic permeability of vacuum.

[0082] Step 3: Based on the relationship between the basic size of the transformer and the electromagnetic load and the vibration model, the minimum effective value of the vibration acceleration |a| is taken as the goal, and the transformer mass G max , coil voltage U s As a constraint, the transformer core diameter D, number of turns N, winding axial height H and maximum magnetic flux density B m Make a design.

[0083] The constraints are:

[0084]

[0085] Combining the optimization equation and constraints, the Lagrange multiplier method is used as an auxiliary function and written as follows:

[0086]

[0087] The necessary conditions for a function to have an unconditional extreme value are as follows:

[0088]

[0089]

[0090] The connection equation is:

[0091]

[0092] Solve the above algebraic equations together to finally obtain the optimized D and H values. Finally, the optimal number of turns N and the optimal magnetic flux density B are obtained from the D and H values. m ; According to formula (18), the minimum effective value of acceleration |a| of the transformer core is obtained.

[0093] Example

[0094] Based on the above transformer vibration reduction optimization method, a principle verification prototype is established (such as Figure 3), and verified the effectiveness and advancement of the above method by comparing the vibration acceleration results with those of the traditionally designed transformer.

[0095] The basic design parameters of the transformer in the traditional design and the design of the present invention are shown in the following table:

[0096]

[0097]

[0098] Using the above transformer vibration reduction optimization design method, under the condition of the rated operating temperature of the transformer core at 70°C, the parameters of the optimized transformer are shown in the following table:

[0099]

[0100] The core column diameter and core window height of the optimized transformer are determined according to the parameters. The DH5981 distributed network dynamic signal test and analysis system and the universal piezoelectric acceleration sensor 1A116E are used to measure the vibration acceleration of the transformer. The transformer is subjected to a vibration test under rated test conditions and compared with the previous generation prototype without low vibration design. The average acceleration is shown in the following table.

[0101]

[0102] In the short-circuit experiment, the vibration acceleration of the transformer was reduced from about 82dB of the previous generation prototype to about 75dB of the principle prototype designed by the proposed method, and the vibration acceleration was reduced by 55.56%, which proved the effectiveness of the proposed transformer optimization design method.

[0103] The steps in the present invention can be adjusted in order, combined or deleted according to actual needs.

[0104] The units in the device of the present invention can be combined, divided and deleted according to actual needs.

[0105] Although the present invention is disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely exemplary and are not intended to limit the application of the present invention. The scope of protection of the present invention is defined by the appended claims and may include various modifications, alterations and equivalents made to the invention without departing from the scope and spirit of the present invention.

Claims

1. A transformer vibration reduction optimization method considering temperature, the transformer is a three-phase transformer, including an iron core composed of three iron core columns and iron yokes at upper and lower ends, and a winding coil wound on the iron core column, characterized in that: Step 1: Establish the electromagnetic model of the transformer. G(D,H)=ρ Fe V(D,H)=C1ρ Fe HD 2 +C2ρ Fe D 2 +C3ρ Fe D 3 in, Where: Fe is the core column density of the transformer, C1, C2, C3 are the transformer structure voltage coefficient K D is the ratio of the effective cross-sectional area of ​​the core column to the actual cross-sectional area of ​​the core column, the diameter of the core column is D; m is the number of phases of the transformer; K Fe is the stacking coefficient of silicon steel sheets in the core column, h1 is the distance from the coil end to the iron yoke, a z is the center distance between two adjacent core columns, Step 2: Establish the transformer temperature-vibration model. In the model, the acceleration of the core vibration caused by the magnetostriction of the silicon steel sheet is: Where: Bs is the saturation flux density of the core, ΔL is the axial expansion of the silicon steel sheet, B m is the maximum magnetic flux density of the core, L is the original axial size of the silicon steel sheet, α is the temperature coefficient of the magnetostriction of the core, which represents the change of magnetostriction caused by unit temperature change, ΔT is the difference between the current temperature of the core and the target working file, U s is the coil voltage, ω is the angular velocity of the transformer sinusoidal voltage, N is the number of turns of the winding coil, S is the actual cross-sectional area of ​​the core column, Among them, the relationship between the core acceleration a, the core column diameter D, and the winding coil axial height H is as follows: The effective value of acceleration is expressed as: Where: ε0 is the saturation magnetostriction of the core at zero temperature, A is the line load, k is the core volume coefficient, S N is the total capacity of the transformer, S is the cross-sectional area of ​​each core column; Step 3: Based on the relationship between the basic size of the transformer and the electromagnetic load and the vibration model, the minimum effective value of the vibration acceleration |a| is taken as the goal, and the transformer mass G max , coil voltage U s As a constraint, the transformer core diameter D, number of turns N, winding axial height H and maximum magnetic flux density B m Make optimization adjustments. The constraints are: a p is the transformer coil coefficient, ρ Fe is the material density of silicon steel sheet, k q is the additional leakage reactance coefficient, I is the rated current of the winding, μ0 is the vacuum permeability, C4 is the transformer structural impedance voltage coefficient, and the acceleration effective value expression and the constraint conditions are written as follows by combining the optimization equation and the constraint conditions and using the Lagrange multiplier method as an auxiliary function: The necessary conditions for a function to have an unconditional extreme value are as follows: The connection equation is: Solve the above algebraic equations simultaneously and finally obtain the optimized D and H values.

2. The optimization method according to claim 1, wherein: Calculate the number of turns N and magnetic flux density B based on the D value and H value m .

3. The optimization method according to claim 1, wherein: The constraint relationship between the short-circuit impedance voltage and the transformer structure is:

4. The optimization method according to claim 1, wherein: The optimization method is used to optimize the vibration of the transformer core.

5. A transformer designed using the method according to any one of claims 1 to 4.

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