CN110581020A - Capacitor and method for determining rigidity of rigidity resonance element - Google Patents
Capacitor and method for determining rigidity of rigidity resonance element Download PDFInfo
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- 229910000838 Al alloy Inorganic materials 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
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- G—PHYSICS
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- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/224—Housing; Encapsulation
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/32—Wound capacitors
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/38—Multiple capacitors, i.e. structural combinations of fixed capacitors
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Abstract
The application discloses a rigidity determining method for a capacitor and a rigidity resonant element, and relates to the technical field of power equipment. The capacitor comprises a capacitor shell and a capacitor core arranged in the capacitor shell, wherein a rigidity resonance element is arranged in the capacitor core, the distance from the rigidity resonance element to one end of the capacitor core is a first distance, the first distance is determined according to the rigidity of the rigidity resonance element, and the rigidity of the rigidity resonance element is determined according to the natural frequency of the capacitor and the electric field force frequency of the capacitor; the rigid resonator element comprises at least two resonator plates and a metal spring mounted between each two adjacent resonator plates. The capacitor provided by the embodiment of the application can remove the noise of the capacitor, which is reduced by the resonance of the natural frequency of the capacitor and the frequency of the electric field force.
Description
Technical Field
the present application relates to the field of power equipment technologies, and in particular, to a method for determining the stiffness of a capacitor and a stiffness resonant element.
background
Power capacitors are important devices for power systems and are widely used in various industries. However, power capacitors have a serious noise pollution problem.
In the related art, a method for improving noise pollution of a power capacitor includes: the sound-absorbing cavity is arranged in the capacitor core of the power capacitor and can absorb incident sound waves, so that the vibration isolation effect is achieved.
However, in the above-described technique, the capacitor core having the sound-absorbing cavity mounted therein is likely to resonate with other components of the capacitor, and thus noise of the capacitor does not decrease or increase.
Disclosure of Invention
in view of this, it is necessary to provide a method for determining the stiffness of a capacitor and a stiffness resonance element, which addresses the above-described problem of noise of the capacitor.
In a first aspect, an embodiment of the present application provides a capacitor, where the capacitor includes a capacitor case and a capacitor core installed in the capacitor case, a stiffness resonance element is disposed in the capacitor core, a distance from the stiffness resonance element to one end of the capacitor core is a first distance, the first distance is determined according to a stiffness of the stiffness resonance element, and the stiffness of the stiffness resonance element is determined according to a natural frequency of the capacitor and an electric field force frequency of the capacitor;
The rigid resonator element comprises at least two resonator plates and a metal spring mounted between each two adjacent resonator plates.
In one embodiment, the first distance satisfies a first formula; the first formula is:
cos kL-kLαcos kL1 sin k(L-L1)＝0
Wherein the content of the first and second substances,Omega is a tuning frequency, and the tuning frequency is determined according to the electric field force frequency of the capacitor;The wave velocity, E and rho are elastic modulus and mass density, and the elastic modulus and the mass density are determined according to the natural frequency of the capacitor; l is the envelope length of the capacitor core, L1The first distance is a distance between the first and second electrodes,A is a dimensionless parameter of the stiffness resonance element, A is a sectional area of the capacitor core, and K is the stiffness of the stiffness resonance element.
in one embodiment, the metal elastic member is a spring, a disc spring or a leaf spring.
In one embodiment, the metal elastic member is an arched elastic sheet.
In one embodiment, a top acoustic enclosure is mounted to a top surface location of the capacitor, a bottom acoustic enclosure is mounted to a bottom surface location of the capacitor, and plastic foam is disposed within the top acoustic enclosure and/or the bottom acoustic enclosure.
In one embodiment, the top and bottom of the capacitor housing are each provided with a damping element, the capacitor core is disposed between the top and bottom damping elements, and the damping elements are springs.
In a second aspect, an embodiment of the present application provides a method for determining a stiffness of a stiffness resonance element, the stiffness resonance element being disposed in a core of a capacitor, a distance from the stiffness resonance element to one end of the core being a first distance, the first distance being determined according to a stiffness of the stiffness resonance element, the stiffness resonance element including at least two resonance plates, and a metal elastic member being mounted between each two adjacent resonance plates, the method including:
Determining a mechanical characteristic parameter of the capacitor according to the natural frequency of the capacitor;
Determining a tuning frequency of the capacitor according to the electric field force frequency of the capacitor;
Obtaining the encapsulation length of the capacitor core and the sectional area of the capacitor core;
The stiffness of the stiffness resonance element is calculated from the mechanical property parameters, the tuning frequency, the envelope length and the cross-sectional area.
in one embodiment, calculating the stiffness of the stiff resonant element from the mechanical property parameters, the tuning frequency, the envelope length, and the cross-sectional area comprises:
obtaining a first set of distances, the first set of distances comprising a plurality of first distances, the first distances being distances from the rigid resonant element to one end of the capacitor core, the first distances being less than the envelope length;
Calculating the candidate stiffness of the stiffness resonance element according to the mechanical characteristic parameter, the tuning frequency, the first distance and the sectional area for each first distance;
Selecting a target stiffness from the candidate stiffnesses as the stiffness of the stiffness resonating element.
In one embodiment, the method further comprises: and determining a first distance corresponding to the target rigidity as the installation position of the rigidity resonance element.
in one embodiment, the mechanical property parameters include modulus of elasticity and mass density.
The beneficial effects brought by the technical scheme provided by the embodiment of the application at least comprise:
The capacitor provided by the embodiment of the application can remove the noise of the capacitor, which is reduced by the resonance of the natural frequency of the capacitor and the frequency of the electric field force. The capacitor comprises a capacitor shell and a capacitor core arranged in the shell, wherein a rigidity resonance element is arranged in the capacitor core, the distance from the rigidity resonance element to one end of the capacitor core is a first distance, the first distance is determined according to the rigidity of the rigidity resonance element, the rigidity of the rigidity resonance element is determined according to the natural frequency of the capacitor and the electric field force frequency of the capacitor, and the rigidity resonance element comprises at least two resonance plates and a metal elastic piece arranged between every two adjacent resonance plates. In the embodiment of the application, the rigid resonant element is arranged in the capacitor core, the rigidity of the rigid resonant element and the first distance from the rigid resonant element to one end of the capacitor core are determined according to the natural frequency and the electric field force frequency of the capacitor, and the natural frequency of the capacitor can be changed according to the determined first distance and the rigidity of the rigid resonant element, so that the natural frequency of the capacitor and the electric field force frequency of the capacitor cannot resonate, and the purposes of removing the resonance effect and reducing the noise of the capacitor are achieved.
drawings
fig. 1 is a schematic structural diagram of a capacitor according to an embodiment of the present disclosure;
Fig. 2 is a flowchart of a stiffness determining method for a stiffness resonance element according to an embodiment of the present application;
FIG. 3 is a schematic diagram illustrating the measurement of the elastic modulus of a capacitor core provided in the embodiments of the present application;
Fig. 4 is a flowchart of a stiffness calculation process of a stiffness resonance element according to an embodiment of the present application;
Fig. 5 is a schematic structural diagram of a capacitor core according to an embodiment of the present disclosure;
FIG. 6 is a schematic structural diagram of a rigid resonant element provided in an embodiment of the present application;
Fig. 7 is a schematic diagram of a frequency sweep test provided in an embodiment of the present application;
FIG. 8 is a schematic diagram illustrating a vibration frequency response curve of a capacitor according to an embodiment of the present disclosure;
FIG. 9 is a graph illustrating a comparison of vibration frequency response curves of a capacitor with a resonating element having stiffness and a capacitor without a resonating element having stiffness according to an embodiment of the present application;
FIG. 10 is a graphical representation of the sound pressure level distribution of a capacitor with a rigid resonant element and a capacitor without a rigid resonant element under a 1# loading condition as provided by an embodiment of the present application;
FIG. 11 is a graphical representation of the sound pressure level distribution of a capacitor with a rigid resonant element and a capacitor without a rigid resonant element under a 2# loading condition as provided by an embodiment of the present application;
Fig. 12 is a flowchart of a stiffness determining method for a stiffness resonance element according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
the converter station is an energy conversion station for converting alternating current into direct current or converting direct current into alternating current in an extra-high voltage direct current transmission system. Important components of the converter station include power capacitors, whose main function is to filter and reactive-load compensate the power system. Along with the high-speed development of the power industry in China, the scale of the converter station is larger and larger, the number of power capacitors used in the converter station is larger and larger, the problem of noise pollution caused by the power capacitors is more prominent, and much interference is brought to residents around the converter station. The reason why the power capacitor generates noise is mainly as follows: under the action of the alternating electric field, the polar plates of the capacitor are subjected to the action of the electric field force to generate vibration, and the vibration is transmitted to the capacitor shell to cause the capacitor shell to vibrate and generate noise to radiate to the periphery.
In the related art, a method for improving noise pollution of a power capacitor includes: install in power capacitor's condenser core and inhale the sound cavity, when the polar plate of condenser received the electric field force effect to produce the vibration, this vibration is incited when inhaling the sound cavity, can be absorbed by inhaling the sound cavity, and the vibration that transmits capacitor case like this weakens for capacitor case's amplitude reduces, thereby reduces the noise.
However, in the above-described technology, when the mechanical fixed frequency of the capacitor is the same as or close to the electric field force frequency of the capacitor, the case of the capacitor resonates, and the amplitude of the case of the capacitor increases, thereby increasing the vibration. For noise generated by resonance, the sound absorption cavity has poor sound absorption effect, and noise cannot be effectively reduced. Moreover, researchers find that after long-term use, the sound absorption effect of a part of the sound absorption cavity is obviously attenuated, and after long-term use, impregnant in the power capacitor may permeate into the sound absorption cavity, so that the sound insulation function of the sound absorption cavity is disabled, the noise of the power capacitor cannot be reduced, and the internal impregnation of the power capacitor is insufficient, the insulativity is reduced, and the power capacitor has potential safety hazards.
The capacitor provided by the embodiment of the application can remove the noise of the capacitor, which is reduced by the resonance of the natural frequency of the capacitor and the frequency of the electric field force. The capacitor comprises a capacitor shell and a capacitor core arranged in the shell, wherein a rigidity resonance element is arranged in the capacitor core, the distance from the rigidity resonance element to one end of the capacitor core is a first distance, the first distance is determined according to the rigidity of the rigidity resonance element, the rigidity of the rigidity resonance element is determined according to the natural frequency of the capacitor and the electric field force frequency of the capacitor, and the rigidity resonance element comprises at least two resonance plates and a metal elastic piece arranged between every two adjacent resonance plates. In the embodiment of the application, the rigid resonant element is arranged in the capacitor core, the rigidity of the rigid resonant element and the first distance from the rigid resonant element to one end of the capacitor core are determined according to the natural frequency and the electric field force frequency of the capacitor, and the natural frequency of the capacitor can be changed according to the determined first distance and the rigidity of the rigid resonant element, so that the natural frequency of the capacitor and the electric field force frequency of the capacitor cannot resonate, and the purposes of removing the resonance effect and reducing the noise of the capacitor are achieved.
Referring to fig. 1, a schematic structural diagram of a capacitor provided in an embodiment of the present application is shown, where the capacitor includes a capacitor case and a capacitor core installed in the capacitor case, and a stiffness resonance element is disposed in the capacitor core, where stiffness of the stiffness resonance element is determined according to a natural frequency and an electric field force frequency of the capacitor, and an installation position of the stiffness resonance element in the capacitor core is determined according to stiffness of the stiffness resonance element.
Specifically, the basic structure of the capacitor comprises a capacitor core 101, an impregnant, a fastener, a lead (not shown in fig. 1), a capacitor shell 102 and an outlet sleeve 103, wherein the capacitor core 101 is composed of a plurality of core units 105, the core units 105 are formed by rolling a solid medium with certain thickness and layers and aluminum foil electrodes, and the plurality of core units 105 are combined to form the capacitor core 101. The capacitor core 101 is placed in an impregnant, and the impregnant can improve the dielectric withstand voltage strength of the capacitor core and plays a role in insulation. The fastener is used to fix the capacitor element 101. One end of the lead is connected with the capacitor core 101, and the other end is connected with the outgoing line sleeve 103. The outlet sleeve 103 is typically welded to the top of the capacitor case 102. The capacitor case 102 is generally made of stainless steel or aluminum alloy or thin steel plate by welding, and the surface is coated with flame retardant paint.
in the embodiment of the present application, a stiffness resonance element 104 is disposed in a capacitor core, and the stiffness of the stiffness resonance element 104 is determined according to the natural frequency and the electric field force frequency of the capacitor, specifically, as shown in fig. 2, the determining process of the stiffness resonance element may include the following steps:
step 201, determining mechanical characteristic parameters of the capacitor according to the natural frequency of the capacitor.
wherein the natural frequency of the capacitor is the mechanical frequency of the capacitor core before the rigid resonant element is mounted on the capacitor core. The mechanical characteristic parameters of the capacitor include the elastic modulus E and the mass density ρ. The process of calculating the mechanical characteristic parameters of the capacitor core from the natural frequency of the capacitor may be:
The elastic modulus of the capacitor core is calculated according to the formula (1), the elastic modulus gives a relation between an acting force and a deformation amount, a determined uniform distribution pressure F (namely a compression force) is applied to the capacitor core, and the compression amount of the capacitor core is measured at the same time, so that the elastic modulus of the capacitor core can be obtained through the formula (1).
wherein E is the elastic modulus of the capacitor core; f is uniform pressure applied on the capacitor core; a is the sectional area of the capacitor core; Δ L is the compression of the capacitor core; l is the envelope length of the capacitor core.
In particular, no force can be applied to the capacitor element immersed in the impregnant due to the conventional elastic modulus tester. In the embodiment of the present application, to determine the elastic modulus of the capacitor core, as shown in fig. 3, an autotransformer 301 and a high voltage rectifier stack 302 are used to charge a capacitor core 303, a direct current voltage is applied to the capacitor core 303, an electrostatic force is generated to compress the capacitor core 303, and a dial indicator 304 is used to measure the absolute compression amount of the capacitor core 303. When a dc voltage is applied, the capacitor 30 is in a stable state, and the compressive displacement and the electric field force of the capacitor are not coupled as described above, so that the electrostatic force per unit area can be determined according to the dc voltage, and the elastic modulus of the capacitor core can be obtained by combining the measured deformation.
the capacitor core in the test was still immersed in the impregnant, with only the ends thereof exposed. The power frequency voltage can charge the capacitor core through the high-voltage silicon stack, and simultaneously, the deformation quantity of the capacitor core is measured by the dial indicator 304, and the measuring range can be as follows: 0-12.7 mm, resolution is: 0.001 mm.
when the capacitor core is loaded with direct-current voltage, the electric field force on each polar plate in the capacitor core is balanced, and the whole capacitor core only shows end stress. From the relationship between the electric field force and the capacitance value of the capacitor, equation (2) can be obtained:
Wherein: epsilon is the dielectric quantity of the single-layer capacitor; u is loaded direct current voltage; d0The distance between the polar plates of the single-layer capacitor; l is the envelope length of the capacitor core; Δ L is the compression of the capacitor core.
for the determined elastic modulus, the compression amount of the capacitor core is in direct proportion to the square of the loaded direct current voltage, and the elastic modulus of the capacitor core can be calculated by combining the size of the capacitor core and the electrical parameters.
After the modulus of elasticity of the capacitor core is determined, the mass density of the capacitor can be calculated according to equation (3). The formula (3) is:
in the formula: ρ is the mass density of the capacitor core; e is the modulus of elasticity of the capacitor core; f. of1Is the natural frequency of the capacitor; l is the envelope length of the capacitor core.
Step 202, determining a tuning frequency of the capacitor according to the electric field force frequency of the capacitor.
wherein the tuning frequency is not equal to the electric field force frequency, the multiple frequency of the electric field force frequency, and 0.5 multiple frequency of the electric field force frequency. The tuning frequency is the natural frequency of the capacitor after the rigid resonant element is arranged in the capacitor core, when the tuning frequency is equal to or close to the electric field force frequency (and the frequency multiplication and the 0.5 frequency multiplication of the electric field force frequency), the capacitor is easy to resonate, so that the noise is increased, and when the tuning frequency is not equal to the electric field force frequency (and the frequency multiplication and the 0.5 frequency multiplication of the electric field force frequency), the capacitor is not resonant, so that the vibration noise can be reduced. Based on the principle, in the embodiment of the application, the tuning frequency is not equal to the electric field force frequency, the frequency multiplication of the electric field force frequency and the 0.5 frequency multiplication of the electric field force frequency.
in the embodiment of the present application, the obtaining process of the electric field force frequency of the capacitor includes: the capacitor is loaded with single-frequency voltage, the harmonic frequency loaded by the capacitor under different working conditions is obtained, the corresponding electric field force frequency is calculated according to different harmonic frequencies, and a plurality of electric field force frequencies corresponding to the capacitor can be obtained. And calculating 0.5 frequency multiplication, 1 frequency multiplication and 2 frequency multiplication corresponding to each electric field force frequency.
generally, the electric field force frequencies of the capacitor are different in different application environments, the electric field force frequencies of the capacitor are generally 500Hz, 600Hz, and 700Hz, and the frequency multiplication and the 0.5 frequency multiplication of the corresponding electric field force frequencies are respectively: 1000Hz, 1200Hz, 1400Hz, 250Hz, 300Hz and 350 Hz. Therefore, the tuning frequency is not equal to or similar to the frequency value corresponding to the electric field force frequency.
Optionally, in the embodiment of the present application, the natural frequency of the capacitor is generally selected to be lowered, so that the natural frequency of the capacitor is not equal to or close to the frequency of the electric field force, thereby preventing the natural frequency and the frequency of the electric field force from generating resonance.
step 203, obtaining the encapsulation length of the capacitor core and the sectional area of the capacitor core.
the envelope length of the capacitor core is the envelope length before the rigid resonant element is disposed in the capacitor core.
and step 204, calculating the rigidity of the rigidity resonance element according to the mechanical characteristic parameters, the tuning frequency, the packaging length and the sectional area.
specifically, as shown in fig. 4, the process of calculating the stiffness of the stiffness resonance element from the elastic modulus E and the mass density ρ, the envelope length L of the tuning frequency condenser core, and the sectional area a of the condenser core may include the steps of:
Step 401, a first distance set is obtained.
in the present embodiment, as shown in fig. 5, the distance from rigid resonant element 502 to one end of capacitor core 501 is a first distance L1, one end of capacitor core 501 may be any one end, and the distance from corresponding rigid resonant element 502 to the other end of capacitor core is L-L1. Where L is the envelope length of the capacitor core 501, a known amount. It should be noted that, in the present embodiment, the thickness of the rigid resonant element is assumed to be negligible.
In the embodiment of the present application, the first distance L1 may be assigned to obtain a plurality of first distances L1, which form a first distance set. Wherein the first distance set comprises a plurality of first distances L1, and the first distance L1 is less than the envelope length L.
Step 402, calculating candidate stiffness of the stiffness resonance element according to the mechanical characteristic parameters, the tuning frequency, the first distance and the sectional area aiming at each first distance;
In the embodiment of the present application, the first distance satisfies a first formula, and the first formula is:
cos kL-kLαcos kL1 sin k(L-L1)＝0
Wherein the content of the first and second substances,Omega is a tuning frequency, and the tuning frequency is determined according to the electric field force frequency of the capacitor;the wave velocity, E and rho are elastic modulus and mass density, and the elastic modulus and the mass density are determined according to the natural frequency of the capacitor; l is the envelope length of the capacitor core, L1the first distance is a distance between the first and second electrodes,a is a dimensionless parameter of the stiffness resonance element, A is a sectional area of the capacitor core, and K is the stiffness of the stiffness resonance element.
Wherein the principle of the first formula is as follows: when the stiffness resonance element is provided at a position corresponding to the first distance in the condenser core, and the stiffness of the stiffness resonance element corresponds to the first distance, the natural frequency of the condenser may be equal to the resonance frequency. The natural frequency of the capacitor is equal to the resonance frequency, which means that the natural frequency of the capacitor is not equal to or close to the electric field force frequency and the multiple frequency of the electric field force frequency, i.e. that the capacitor does not resonate. Therefore, after the rigidity resonance element with corresponding rigidity is installed at the position corresponding to the first distance in the capacitor core, the fixed frequency of the capacitor is not equal to the electric field force frequency.
the stiffness of the corresponding stiffness resonance element may be calculated for each first distance in the set of first distances by a first formula, thereby obtaining a plurality of candidate stiffnesses for the stiffness resonance element.
And step 403, selecting a target rigidity from the candidate rigidities as the rigidity of the rigidity resonance element.
Limited by existing material processing techniques, some of the candidate stiffnesses calculated in step 402 may not be achievable, and the higher the stiffness of the stiff resonant element, the higher the production cost. In comprehensive consideration, it is necessary to select a stiffness value which is low in cost and easy to implement from the candidate stiffnesses as a target stiffness, and to take the target stiffness as the stiffness of the stiffness resonance element.
Further, in the embodiment of the present application, the mounting position of the rigidity resonance element in the condenser core is determined in accordance with the rigidity of the rigidity resonance element. Specifically, the determination process of the mounting position of the rigid resonance element in the capacitor core includes:
After step 403, a first distance corresponding to the target stiffness is determined as the mounting position of the stiffness resonance element.
further, as shown in fig. 6, the rigid resonant element in the embodiment of the present application has a structure that:
The stiff resonator element comprises at least two resonator plates 601 and a metal spring 602 mounted between each two adjacent resonator plates. The resonance plate is a plate with rigidity greater than a rigidity threshold value, the rigidity threshold value is 150GPa, the material for manufacturing the resonance plate is stainless steel or aluminum, optionally, the material for manufacturing the resonance plate is compatible with an impregnant, and the impregnant can be benzyltoluene. The length of the resonance plate is the same as the length of the cross section of the capacitor core, and the width of the resonance plate is the same as the width of the cross section of the capacitor core. Alternatively, the resonator plate may be formed in one step by using a grinding tool. Optionally, the metal elastic member may be a spring, a disc spring or a plate spring, and optionally, the metal elastic member may also be an arched elastic sheet.
In an alternative implementation, the stiff resonant element may comprise two resonator plates with at least one metal spring arranged between them.
In another alternative implementation, the rigid resonant element may further include three resonant plates, and at least one metal elastic member is disposed between two adjacent resonant plates between the three resonant plates.
In an alternative implementation, in the embodiment of the present application, a top soundproof cover is installed at the top surface position of the capacitor, a bottom soundproof cover is installed at the bottom surface position of the capacitor, and plastic foam is provided in the top soundproof cover and/or the bottom soundproof cover. The top surface position of the capacitor is the top position of the capacitor shell, namely the position of the wire outlet sleeve, the bottom surface position of the capacitor is the bottom of the outer side of the capacitor shell, and the plastic foam has a sound absorption effect.
according to the embodiment of the application, on the basis that the rigid resonant element is arranged in the capacitor core, the sound insulation covers are arranged on the top surface and the bottom surface of the shell of the capacitor and used for absorbing vibration caused by non-resonance, noise can be further absorbed, and noise pollution of the capacitor is reduced.
In an alternative implementation manner, in the embodiment of the present application, damping elements are disposed on both the top and the bottom of the housing of the capacitor, wherein the capacitor core is disposed between the damping elements on the top and the bottom, the damping elements are springs, specifically, the top of the housing of the capacitor is a position between the top surface of the capacitor core and the capacitor housing, and the bottom of the housing of the capacitor is a position between the bottom surface of the capacitor core and the capacitor housing. The capacitor core is provided with the rigidity resonance element, and the spring is arranged on the basis, so that when the capacitor core vibrates, the vibration amplitude can be reduced through the damping action of the spring, and the noise pollution of the capacitor is reduced.
The capacitor provided by the embodiment of the application can remove the noise of the capacitor, which is reduced by the resonance of the natural frequency of the capacitor and the frequency of the electric field force. The capacitor comprises a capacitor shell and a capacitor core arranged in the shell, wherein a rigidity resonance element is arranged in the capacitor core, the distance from the rigidity resonance element to one end of the capacitor core is a first distance, the first distance is determined according to the rigidity of the rigidity resonance element, the rigidity of the rigidity resonance element is determined according to the natural frequency of the capacitor and the electric field force frequency of the capacitor, and the rigidity resonance element comprises at least two resonance plates and a metal elastic piece arranged between every two adjacent resonance plates. In the embodiment of the application, the rigid resonant element is arranged in the capacitor core, the rigidity of the rigid resonant element and the first distance from the rigid resonant element to one end of the capacitor core are determined according to the natural frequency and the electric field force frequency of the capacitor, and the natural frequency of the capacitor can be changed according to the determined first distance and the rigidity of the rigid resonant element, so that the natural frequency of the capacitor and the electric field force frequency of the capacitor cannot resonate, and the purposes of removing the resonance effect and reducing the noise of the capacitor are achieved.
The capacitor provided in the embodiments of the present application will be described below by way of example.
the type of the capacitor can be AAM8.9-268.4-1W, the rated voltage is 8.9kV, the rated current is 30.15A, and the nominal capacitance value is 10.786 muF. The envelope length of the capacitor core is 670mm and the cross-sectional dimensions of the capacitor core are 355mm x 155 mm. The rigid resonant element provided by the embodiment of the application is arranged in the capacitor core of the capacitor, and the rigidity of the rigid resonant element and the installation position of the rigid resonant element are determined, specifically:
A vibration sweep test was first performed on the capacitor before the rigid resonant element was placed. And loading single-frequency voltage to the capacitor core successively by adopting a sweep frequency loading mode, wherein the initial frequency is 50Hz, and the frequency interval is 50Hz till 1000 Hz. The corresponding electric field force frequency has a starting frequency of 100Hz, a frequency interval of 100Hz and an ending frequency of 2000 Hz. The voltage is changed, and the change of the frequency of the electric field force is realized. The amplitude of the capacitor case is proportional to the square of the voltage, and the frequency of the electric field force can be calculated according to the amplitude of the capacitor case.
as shown in fig. 7, under the above-mentioned loading condition, the vibration amplitude of the bottom surface center position of the capacitor case 702 is measured by using the laser vibrometer 701, and according to the measured loading voltage and vibration amplitude, the frequency response function of the capacitor case can be obtained, as shown in fig. 8, the 1 st order natural frequency of the capacitor appears at 1090Hz, wherein, the vibration frequency response curve in fig. 8 has a weak peak around 500Hz, because this frequency is approximately equal to 0.5 times the natural frequency of the capacitor, the capacitor generates significant super-harmonic resonance, so that the frequency response curve of the actual capacitor unit is raised.
further, the elastic modulus of the capacitor of the above type was 4.60X 109Pa, and the rigidity density was 1.84X 103kg/m 3. For a specific operation process, reference may be made to the content disclosed in step 201, which is not described herein again.
In the embodiment of the present application, the harmonic loading combination and the corresponding electric field force frequency related to the capacitor can be as shown in table 1:
TABLE 1
| Numbering | Harmonic frequencies and effective values | Frequency of electric field force |
| 1# | 50Hz(8A)+550Hz(6.4A) | (100Hz)、500Hz、600Hz、(1100Hz) |
| 2# | 50Hz(8A)+650Hz(6.4A) | (100Hz)、600Hz、700Hz、(1100Hz) |
In table 1, 1# and 2# indicate different loading conditions, and for the loading conditions of 1# and 2# the components with the largest electric field force frequency are 500Hz, 600Hz and 700Hz, and the frequency is just around 0.5 times of the natural frequency 1090Hz of the capacitor (in the embodiment of the present application, the natural frequency of 1 st order of the capacitor is the natural frequency of the capacitor), which is very easy to trigger the super-harmonic resonance to generate the multiple-frequency vibration. And therefore its natural frequency needs to be adjusted. In general, the natural frequency of the capacitor is lowered.
According to the electric field force frequency of the capacitor, the lowest point of the electric field force frequency is 500Hz, and an alternative implementation mode is to adjust the natural frequency of the capacitor to be less than 500Hz, so that the three electric field force frequencies are between the natural frequency of the 1 st order and the natural frequency of the 2 nd order, but the adjustment range is too large, the requirement on the rigidity of the rigidity resonance element is extremely high, and the rigidity resonance element is not suitable for industrial production and application. Another optional implementation is as follows: and a rigidity tuning element with a damping effect is introduced, and the vibration amplitude is further reduced through the damping effect on the basis of slightly adjusting the natural frequency to avoid the super-harmonic resonance. In the embodiment of the application, the resonance frequency is determined to be 900Hz according to the electric field force frequency, and is different from and not close to the three electric field force frequencies and the frequency doubling thereof. This avoids the generation of super-harmonic resonance.
the rigidity of the rigidity resonance element is calculated to be 2.87 multiplied by 108N/m according to the elastic modulus, the rigidity density, the resonance frequency, the packaging length of the capacitor core and the sectional area of the capacitor core, and the installation position parameter of the rigidity resonance element is L1/L which is 0.2.
In the embodiment of the present application, in order to not affect the specific structure of the capacitor core as much as possible and ensure the stability of the encapsulation of the capacitor core, the rigid resonant element includes at least two resonant plates and a metal elastic element installed between every two adjacent resonant plates, wherein the material for manufacturing the resonant plates is stainless steel or aluminum, the metal elastic element may be a spring, a disc spring or a leaf spring, and optionally, the metal elastic element may also be an arched elastic sheet.
next, in the embodiment of the present application, a sweep test is performed on the capacitor mounted with the rigid resonant element, and a vibration frequency response function corresponding to the capacitor provided in the embodiment of the present application is measured, as shown in fig. 9, a vibration frequency of the capacitor with the rigid resonant element is significantly lower than a vibration frequency of the capacitor without the rigid resonant element.
The audible noise of the capacitor provided with the stiffness resonance element under the 1# loading condition is shown in fig. 10. In FIG. 10, the sound pressure level of the capacitor at the site is marked at the site of the test point, where the unbracketed data corresponds to the capacitor of the resonating element with stiffness and the unbracketed data corresponds to the capacitor of the resonating element without stiffness. Calculating to obtain the average sound pressure level of 51.91dB and the sound power level of 66.29dB on the measuring surface of the capacitor without the rigidity resonance element; the measured surface average sound pressure level of the capacitor with the rigid resonant element was 42.09dB, and the sound power level was 56.47 dB. Under the 1# loading condition, the rigid resonant element reduces the acoustic power of the capacitor by 9.82 dB.
The audible noise of the capacitor provided with the rigid resonant element under the 2# loading condition is shown in fig. 11. In FIG. 11, the sound pressure level of the capacitor at the site is marked at the site of the test point, where the unbracketed data corresponds to the capacitor of the resonating element with stiffness and the unbracketed data corresponds to the capacitor of the resonating element without stiffness. The average sound pressure level of a capacitor without the rigidity resonant element on a measuring surface is calculated to be 53.65dB, and the sound power level is calculated to be 68.02 dB; the measured surface average sound pressure level of the capacitor with the stiff resonating element was 45.78dB, and the sound power level was 60.16 dBdB. Under the 2# loading condition, the rigid resonant element reduces the acoustic power of the capacitor by 7.87 dB.
As can be seen from the above measurement data of fig. 10 and 11, the stiffness resonance element can effectively reduce the audible noise of the capacitor unit. In the frequency range of 500Hz to 700Hz, the capacitor without the rigidity resonance element is easy to generate super harmonic resonance, and the noise reduction of the rigidity resonance element is 7.8 to 10 dB.
in summary, the capacitor provided by the embodiment of the present application can effectively reduce capacitor noise caused by resonance.
As shown in fig. 12, a flowchart of a stiffness determining method for a stiffness resonance element according to an embodiment of the present application is shown, where the stiffness resonance element is disposed in a core of a capacitor, a distance from the stiffness resonance element to one end of the core is a first distance, the first distance is determined according to a stiffness of the stiffness resonance element, the stiffness resonance element includes at least two resonance plates, and a metal elastic member is disposed between each two adjacent resonance plates, and the method includes:
Step 1201, determining mechanical characteristic parameters of the capacitor according to the natural frequency of the capacitor;
Step 1202, determining the tuning frequency of the capacitor according to the electric field force frequency of the capacitor;
step 1203, obtaining the encapsulation length of the capacitor core and the sectional area of the capacitor core;
and 1204, calculating the rigidity of the rigidity resonance element according to the mechanical characteristic parameters, the tuning frequency, the packaging length and the sectional area.
in one embodiment, calculating the stiffness of the stiff resonant element from the mechanical property parameters, the tuning frequency, the envelope length, and the cross-sectional area comprises:
Obtaining a first set of distances, the first set of distances comprising a plurality of first distances, the first distances being distances from the rigid resonant element to one end of the capacitor core, the first distances being less than the envelope length;
Calculating the candidate stiffness of the stiffness resonance element according to the mechanical characteristic parameter, the tuning frequency, the first distance and the sectional area for each first distance;
selecting a target stiffness from the candidate stiffnesses as the stiffness of the stiffness resonating element.
In one embodiment, a first distance corresponding to the target stiffness is determined as the mounting position of the stiffness resonating element.
In one embodiment, the mechanical property parameters include modulus of elasticity and mass density.
the technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A capacitor, comprising a capacitor case and a capacitor core mounted in the capacitor case, wherein a rigid resonance element is arranged in the capacitor core, the rigid resonance element is at a first distance from one end of the capacitor core, the first distance is determined according to the rigidity of the rigid resonance element, and the rigidity of the rigid resonance element is determined according to the natural frequency of the capacitor and the electric field force frequency of the capacitor;
the rigid resonator element comprises at least two resonator plates and a metal spring mounted between each two adjacent resonator plates.
2. the capacitor of claim 1, wherein the first distance satisfies a first formula, the first formula being:
coskL-kLαcoskL1 sink(L-L1)＝0
Wherein the content of the first and second substances,Omega is a tuning frequency, and the tuning frequency is determined according to the electric field force frequency of the capacitor;Is the wave velocity, E is the elastic modulus, ρ is the mass density, the elastic modulus and the mass density being determined from the natural frequency of the capacitor; l is the envelope length of the capacitor core, L1in order to be said first distance, the first distance,A is a dimensionless parameter of the stiffness resonance element, A is a sectional area of the capacitor core, and K is a stiffness of the stiffness resonance element.
3. The capacitor of claim 1 wherein said metal spring is a spring or a disc spring or a leaf spring.
4. The capacitor of claim 1, wherein the metal spring is an arched leaf spring.
5. The capacitor of claim 1, wherein a top acoustic enclosure is mounted in a top surface location of the capacitor and a bottom acoustic enclosure is mounted in a bottom surface location of the capacitor, and wherein the top acoustic enclosure and/or the bottom acoustic enclosure have plastic foam disposed therein.
6. a capacitor according to claim 1, wherein the top and bottom of the capacitor case are each provided with a damping element, the capacitor core is disposed between the damping elements of the top and bottom, and the damping elements are springs.
7. A rigidity determining method of a rigidity resonance element, wherein the rigidity resonance element is provided in a condenser core of a condenser, a distance from the rigidity resonance element to one end of the condenser core is a first distance determined according to rigidity of the rigidity resonance element, the rigidity resonance element includes at least two resonance plates and a metal elastic member installed between each two adjacent resonance plates, the method comprising:
determining a mechanical characteristic parameter of the capacitor from the natural frequency of the capacitor;
determining a tuning frequency of the capacitor according to the electric field force frequency of the capacitor;
Obtaining an envelope length of the capacitor core and a cross-sectional area of the capacitor core;
Calculating a stiffness of the stiffness resonating element from the mechanical property parameter, the tuning frequency, the envelope length, and the cross-sectional area.
8. the method of claim 7, wherein said calculating a stiffness of said stiffness resonating element from said mechanical characteristic parameter, said tuned frequency, said envelope length, and said cross-sectional area comprises:
Obtaining a first set of distances, the first set of distances comprising a plurality of first distances, the first distances being distances from the rigid resonant element to an end of the capacitor core, the first distances being less than the envelope length;
calculating, for each of the first distances, a candidate stiffness of the stiffness resonance element from the mechanical characteristic parameter, the tuning frequency, the first distance, and the cross-sectional area;
Selecting a target stiffness from the candidate stiffnesses as the stiffness of the stiffness resonating element.
9. The method of claim 8, further comprising:
and determining a first distance corresponding to the target rigidity as the installation position of the rigidity resonance element.
10. the method according to any one of claims 7 to 9,
the mechanical property parameters include modulus of elasticity and mass density.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5563763A (en) * | 1994-06-21 | 1996-10-08 | Asea Brown Boveri Ab | Capacitor |
| JP2003318057A (en) * | 2002-04-25 | 2003-11-07 | Taiyo Yuden Co Ltd | Method for mounting capacitor on circuit board, and capacitor mounted circuit board |
| US20070025058A1 (en) * | 2005-07-27 | 2007-02-01 | Cardona Albert H | Dampening of electric field-induced resonance in parallel plate capacitors |
| CN201518280U (en) * | 2009-09-30 | 2010-06-30 | 桂林电力电容器有限责任公司 | Capacitor device with noise reduction function |
| CN106783167A (en) * | 2016-12-26 | 2017-05-31 | 中国西电电气股份有限公司 | A kind of power capacitor with denoising device |
| CN109103017A (en) * | 2018-08-28 | 2018-12-28 | 桂林电子科技大学 | Metal rubber shock absorber and its setting method for power capacitor vibration and noise reducing |
| CN210429559U (en) * | 2019-10-15 | 2020-04-28 | 西安交通大学 | Capacitor with a capacitor element |
-
2019
- 2019-10-15 CN CN201910979332.1A patent/CN110581020A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5563763A (en) * | 1994-06-21 | 1996-10-08 | Asea Brown Boveri Ab | Capacitor |
| JP2003318057A (en) * | 2002-04-25 | 2003-11-07 | Taiyo Yuden Co Ltd | Method for mounting capacitor on circuit board, and capacitor mounted circuit board |
| US20070025058A1 (en) * | 2005-07-27 | 2007-02-01 | Cardona Albert H | Dampening of electric field-induced resonance in parallel plate capacitors |
| CN201518280U (en) * | 2009-09-30 | 2010-06-30 | 桂林电力电容器有限责任公司 | Capacitor device with noise reduction function |
| CN106783167A (en) * | 2016-12-26 | 2017-05-31 | 中国西电电气股份有限公司 | A kind of power capacitor with denoising device |
| CN109103017A (en) * | 2018-08-28 | 2018-12-28 | 桂林电子科技大学 | Metal rubber shock absorber and its setting method for power capacitor vibration and noise reducing |
| CN210429559U (en) * | 2019-10-15 | 2020-04-28 | 西安交通大学 | Capacitor with a capacitor element |
Non-Patent Citations (2)
| Title |
|---|
| WU PENG;ET AL.: ""Study on an Audible Noise Reduction Measure for Filter Capacitors Based on Compressible Space Absorber"", 《IEEE TRANSACTIONS ON POWER DELIVERY》, vol. 26, no. 1, 14 October 2010 (2010-10-14), pages 438 - 445, XP011340594, DOI: 10.1109/TPWRD.2010.2070880 * |
| 王娇娇等: ""基于电力电容器芯子结构改进的振动控制方法"", 《装备制造技术》, no. 2019, 28 February 2019 (2019-02-28), pages 4 - 9 * |
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Effective date of registration: 20231019 Address after: No. 28, Xianning West Road, Beilin District, Xi'an, Shaanxi 710001 Applicant after: XI'AN JIAOTONG University Applicant after: CHINA ELECTRIC POWER RESEARCH INSTITUTE Co.,Ltd. Applicant after: WUHAN BRANCH, CHINA ELECTRIC POWER Research Institute Address before: No. 28, Xianning West Road, Beilin District, Xi'an, Shaanxi 710001 Applicant before: XI'AN JIAOTONG University |