CN115510725A - Converter transformer valve side sleeve insulation state analysis method and device - Google Patents
Converter transformer valve side sleeve insulation state analysis method and device Download PDFInfo
- Publication number
- CN115510725A CN115510725A CN202211332998.6A CN202211332998A CN115510725A CN 115510725 A CN115510725 A CN 115510725A CN 202211332998 A CN202211332998 A CN 202211332998A CN 115510725 A CN115510725 A CN 115510725A
- Authority
- CN
- China
- Prior art keywords
- temperature
- electric field
- distribution
- current
- calculation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- 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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/08—Thermal analysis or thermal optimisation
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
The application discloses a converter transformer valve side sleeve insulation state analysis method and device, a geometric model corresponding to a valve side sleeve is established according to finite element analysis software, then the geometric model is preprocessed based on boundary conditions to obtain grid division of electric field and temperature field calculation, current and voltage data at the current moment are further input into the corresponding electric field and temperature field to carry out coupling analysis of joule heat calculation and dielectric loss heating calculation, the temperature distribution condition at the current moment is obtained, whether temperature distribution is in an error boundary or not is judged, if the temperature distribution is in the error boundary, insulation damage distribution and accumulated value are calculated, whether the insulation damage accumulated value is out of limit or not is judged, and if the temperature distribution result is out of limit, the temperature distribution result is output. By comprehensively analyzing the insulation state from the electric field scene and the temperature field scene, the result of analyzing the insulation state of the valve side sleeve of the converter transformer is more accurate, and the safety and the reliability of the application of the valve side sleeve of the converter transformer in a power system are further improved.
Description
Technical Field
The invention relates to the technical field of detection of insulation states of electrical components, in particular to a method and a device for analyzing the insulation state of a valve-side sleeve of a converter transformer.
Background
In the high-voltage direct-current transmission project, the converter transformer and the converter valve hall are electrically connected and have related insulation functions through the converter transformer valve side sleeve, so that the converter transformer valve side sleeve plays a key role, and the operation safety and reliability directly determine the overall operation effect of the converter transformer and even the converter transformer system. In the prior art, as shown in fig. 1, a flow chart of an insulation state analysis method of a converter transformer valve side bushing is provided, which includes the steps of S101, extracting current data of a converter station; step S102, carrying out Fourier decomposition on the current data to obtain fundamental current data and harmonic current data at the moment; step S103, performing Joule heating analysis calculation according to the obtained current harmonic current data; step S104, taking the Joule heating value as an excitation heat source, and finishing temperature field distribution calculation according to a heat transfer formula; step S105, comparing the calculation results of the temperature field at different moments with the preset precision in the same time period to determine whether the precision reaches the standard or not; step S106, if the standard is reached, the distribution result of the temperature field can be directly obtained; and S107, if the accuracy does not reach the standard, updating the resistivity, and performing Joule heating analysis and calculation again until the accuracy reaches the standard.
At present, in the insulation state analysis process, current data of a converter station is extracted firstly, then, the temperature field distribution is analyzed and calculated according to harmonic current data, and the insulation state is determined according to the analysis result.
Disclosure of Invention
In view of the above, the present invention provides a method and an apparatus for analyzing an insulation state of a valve-side bushing of a converter transformer, which are used for calculating the distribution of an electric field and a temperature field of a main insulation portion having frequency and temperature dependencies of the converter transformer under the combined action of multiple harmonic currents and voltages, and performing accurate analysis on the insulation state of the main insulation structure based on the distribution.
In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:
the first aspect of the embodiments of the present invention provides a method for analyzing an insulation state of a valve-side bushing of a converter transformer, including:
establishing a geometric model corresponding to the characteristic parameter information of the valve side sleeve according to finite element analysis software; wherein the characteristic parameter information includes: size and material information;
setting corresponding boundary conditions for the geometric model; wherein the boundary conditions include: electric field and temperature field boundary conditions;
preprocessing the geometric model according to the boundary condition to obtain the grid division of electric field and temperature field calculation;
inputting current data at the current moment into the temperature field, and performing Joule heating calculation to obtain the distribution condition of the temperature field at the current moment;
inputting the voltage data of the current moment into the electric field, and performing dielectric loss heating calculation to obtain the electric field distribution condition of the current moment;
calculating to obtain the temperature distribution condition of the current moment according to the coupling analysis of the joule heating calculation and the dielectric loss heating calculation;
judging whether the temperature distribution is within an error bound or not according to the temperature distribution condition, and if so, calculating the insulation damage distribution and the accumulated value in the electric field and the temperature field;
and after the insulation damage distribution and the accumulated value in the electric field and the temperature field are calculated, judging whether the insulation damage accumulated value exceeds the limit, and if so, outputting the temperature distribution result at the current moment.
Optionally, the inputting the current data of the current moment into the temperature field, performing joule heating calculation, and obtaining the distribution condition of the temperature field of the current moment includes:
performing discrete Fourier decomposition on the obtained current data at the current moment to obtain harmonic current components in the current data at the current moment;
according to the harmonic current component, obtaining a multi-time harmonic current density distribution data set on the cross section of the current-carrying conductor rod by using a frequency domain magnetic field analysis method;
and performing the Joule heating calculation based on the multiple harmonic current density distribution data group to obtain the temperature field distribution condition at the current moment.
Optionally, the performing the joule heating calculation based on the multiple harmonic current density distribution data set to obtain the temperature field distribution at the current time includes:
according to the conductivity gamma of the copper material of the conduit Cu And performing the Joule heat calculation with the target current density rho (r) in the multiple harmonic current density distribution data set to obtain the joule heating value Q at the radius r of the current-carrying conductor rod r (r); wherein the content of the first and second substances,
the target current density ρ n (r) is the nth harmonic current density in the multiple harmonic current density distribution data set at a distance r from the center point of the current carrying conductor bar.
Optionally, the inputting the voltage data of the current moment into the electric field to perform dielectric loss heating calculation, and obtaining the electric field distribution condition of the current moment includes: the electric field is an alternating electric field;
obtaining effective value distribution data sets of the alternating electric field acted by the alternating voltage of each frequency by using a multi-physical field coupling analysis method;
and performing the medium loss heating calculation based on the effective value distribution data group of the alternating electric field to obtain the electric field distribution condition at the current moment.
Optionally, the calculating the dielectric loss heating based on the effective value distribution data set of the alternating electric field to obtain the electric field distribution condition at the current time includes:
according to fundamental frequency f and vacuum dielectric constant epsilon 0 And the relative dielectric constant ε of the insulating medium r A loss tangent tan delta of the insulating medium and an effective value E of the target electric field intensity in the effective value distribution data group of the alternating electric field n,rms (r, z) calculating the dielectric loss heat generation to obtain the dielectric loss heat generation Q when the radius of the current-carrying conductor rod is r and the temperature of the corresponding point r is T e (r, z); wherein the content of the first and second substances,
effective value E of the target electric field intensity n,rms And (r, z) is an effective value of the electric field intensity of the nth time in the effective value distribution data set of the alternating electric field when the distance from the center point of the current carrying conductor rod is r and the temperature at the corresponding point r is T.
Optionally, the obtaining, by calculation, a temperature distribution condition of the current time according to the coupling analysis of the joule heating calculation and the dielectric loss heating calculation includes:
based on the joule heat generation amount Q r And the dielectric loss heat generation amount Q e Combining the density rho of the analysis object at the current moment and the heat capacity C of the analysis object P And obtaining the temperature distribution condition of the current moment by the external field dependent variable u and the conduction thermal coefficient k.
Optionally, the determining, according to the temperature distribution condition, whether the temperature distribution is within an error bound further includes:
if the temperature distribution is not within the error bound, the method described above is continued.
Optionally, the determining whether the accumulated value of insulation damage is out of limit further includes:
and if the threshold is not exceeded, sending out alarm information.
Optionally, the electric field boundary condition is set based on the electric potential of each boundary of the electric field;
the temperature field boundary condition is set based on the temperature at the current time and the transformer operating temperature.
A second aspect of an embodiment of the present invention provides an insulation state analysis device for a valve-side bushing of a converter transformer, where the insulation state analysis device includes:
the model establishing module is used for establishing a geometric model corresponding to characteristic parameter information of the valve side sleeve according to finite element analysis software, wherein the characteristic parameter information comprises: size and material information;
a condition design module, configured to set a corresponding boundary condition for the geometric model, where the boundary condition includes: electric field and temperature field boundary conditions;
the mesh division module is used for preprocessing the geometric model according to the boundary condition to obtain mesh division of electric field and temperature field calculation;
the joule heat calculation module is used for inputting current data at the current moment into the temperature field, performing joule heat calculation and obtaining the distribution condition of the temperature field at the current moment;
the dielectric loss heating calculation module is used for inputting the voltage data at the current moment into the electric field to perform dielectric loss heating calculation so as to obtain the electric field distribution condition at the current moment;
the coupling analysis module is used for calculating and obtaining the temperature distribution condition of the current moment according to the coupling analysis of the joule heat calculation and the dielectric loss heating calculation;
the temperature distribution analysis module is used for judging whether the temperature distribution is within an error bound or not according to the temperature distribution condition, and calculating the insulation damage distribution and the accumulated value in the electric field and the temperature field if the temperature distribution is within the error bound;
and the result output module is used for judging whether the insulation damage accumulated value exceeds the limit or not after the insulation damage distribution and the accumulated value in the electric field and the temperature field are calculated, and outputting the temperature distribution result at the current moment if the insulation damage accumulated value exceeds the limit.
The invention provides a converter transformer valve side sleeve insulation state analysis method, which comprises the following steps of firstly, establishing a geometric model corresponding to characteristic parameter information of a valve side sleeve according to finite element analysis software, wherein the characteristic parameter information comprises the following steps: dimension and material information, and then setting corresponding boundary conditions for the geometric model; wherein the boundary conditions include: the method comprises the steps of obtaining electric field and temperature field boundary conditions, preprocessing a geometric model according to the boundary conditions to obtain grid division of electric field and temperature field calculation, further inputting current data of the current moment into a temperature field to perform Joule heating calculation to obtain temperature field distribution of the current moment, inputting voltage data of the current moment into the electric field to perform dielectric loss heating calculation to obtain electric field distribution of the current moment, calculating and obtain temperature distribution of the current moment according to coupling analysis of the Joule heating calculation and the dielectric loss heating calculation, judging whether the temperature distribution is within an error bound according to the temperature distribution, calculating insulation damage distribution and accumulated values in the electric field and the temperature field if the temperature distribution is within the error bound, judging whether the insulation damage accumulated value is out of limit or not after the insulation damage distribution and the accumulated value of the electric field and the temperature field are calculated, and outputting a temperature distribution result of the current moment if the temperature distribution and the accumulated value are out of limit. By considering the influence of the dielectric insulation state generated by the electric field of the converter transformer valve side bushing on the temperature field, the insulation state can be comprehensively analyzed from two scenes of the electric field and the temperature field.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a flowchart of a method for analyzing an insulation state of a valve-side bushing of a converter transformer according to the prior art;
fig. 2 is a flowchart of a method for analyzing an insulation state of a valve-side bushing of a converter transformer according to an alternative embodiment of the present invention;
fig. 3 to fig. 4 are flow charts of two other methods for analyzing the insulation state of the valve-side bushing of the converter transformer according to the embodiment of the present invention;
fig. 5 is a schematic block diagram of an apparatus for analyzing an insulation state of a valve-side bushing of a converter transformer according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention provides a method for analyzing the insulation state of a valve side sleeve of a converter transformer, which comprises the following steps of:
s201, establishing a geometric model corresponding to characteristic parameter information of the valve side sleeve according to finite element analysis software, wherein the characteristic parameter information comprises: size and material information.
Optionally, in an alternative embodiment of the present invention, the function related to the characteristic parameter information is defined on the corresponding geometric model by using finite element analysis software. Compared with other approximation methods for solving the boundary value problem, the finite element analysis method is fundamentally different in that the approximation is limited in a relatively small area, the calculation precision is high, and the method can adapt to various complex shapes, so that the method is adopted for constructing the geometric model, and the construction accuracy is enhanced.
Specifically, the characteristic parameter information may further include: the cell type, real constant, cross-sectional type, cell coordinate system, etc., depending on the specific application environment, are all within the scope of the present application.
S202, setting corresponding boundary conditions for the geometric model. Wherein the boundary conditions include: electric field and temperature field boundary conditions.
Optionally, the electric field boundary condition is set based on the electric potential of each boundary of the electric field, and generally, the boundary of the electric field is a zero potential boundary. Optionally, the temperature field boundary condition is set based on the temperature at the current time and the transformer operating temperature.
Specifically, by measuring the ambient environment and the operating temperature of the converter transformer at the present time using the ambient temperature sensor, if the temperature of a certain region of the geometric model is known, the temperature can be fixed to the value.
Specifically, the formula of the temperature field boundary condition can be as follows:
wherein λ is the thermal conductivity of the material used at the present moment; n' is the normal vector of the computed boundary.
Solving through the boundary condition of the temperature field to obtain T = C1; wherein C1 is the specific value of the temperature at the current moment.
Specifically, a problem solved for a geometric model can be generally represented by a set of differential equations containing the variable boundary conditions of the problem state, which are typically transformed into an equivalent functional form for finite element solution.
And S203, preprocessing the geometric model according to the boundary conditions to obtain the grid division of electric field and temperature field calculation.
Specifically, the preprocessing is to divide a finite element mesh into the geometric model, then obtain mesh division of electric field and temperature field calculation, and obtain the regions of the electric field and the temperature field corresponding to the result of the mesh division.
It should be noted that, in a practical application scenario, the preprocessing is implemented by finite element analysis software capable of performing electric field and temperature field coupling analysis. The above finite element analysis software may be various, for example: engineering simulation finite element software (ABAQUS) and computer aided engineering software (ANSYS). The invention does not limit and describe the concrete type and application mode of the software.
And S204, inputting the current data at the current moment into the temperature field, and performing Joule heating calculation to obtain the distribution condition of the temperature field at the current moment.
Optionally, the current data at the current time is input into the temperature field, joule heating calculation is performed, and the distribution condition of the temperature field at the current time is obtained, including the following steps:
(1) And carrying out discrete Fourier decomposition on the obtained current data at the current moment to obtain harmonic current components in the current data at the current moment.
Specifically, when the discrete Fourier decomposition is carried out on the current data, the fundamental current component i at the current moment is obtained sf And harmonic current component i sh As shown in the following equation:
wherein, the first and the second end of the pipe are connected with each other,
and
amplitude of the fundamental and harmonic components of the current, a i1 And b i1 Then the Fourier coefficient of the fundamental wave of the current, a in And b in The fourier coefficients of the current harmonics.
Specifically, in this embodiment, the obtained harmonic current component in the current data at the present time is one of the factors that affect the insulation state of the valve-side bushing of the converter transformer, because the harmonic current component may affect the normal operation of various electrical devices, and cause the transformer to be locally and severely overheated.
(2) And obtaining a multi-time harmonic current density distribution data set on the cross section of the current-carrying conductor rod by using a frequency domain magnetic field analysis method according to the harmonic current component.
(3) And performing Joule heat calculation based on the multiple harmonic current density distribution data group to obtain the temperature field distribution condition at the current moment.
Optionally, the joule heating calculation is performed based on the multiple harmonic current density distribution data set, so as to obtain the temperature field distribution condition at the current time, including:
according to the conductivity gamma of the copper material of the conduit Cu And target current density ρ in the multiple harmonic current density distribution data group n (r) performing Joule heating calculation to obtain the Joule heating value Q at the radius r of the current-carrying conductor rod r (r)。
Specifically, the target current density ρ n (r) is the nth harmonic current density in the multiple harmonic current density distribution data set at a distance r from the center point of the current carrying conductor bar.
Specifically, the formula for performing the joule heating calculation can be as follows:
the specific meanings of the different symbols in the formula have already been set forth in the above description, and are not repeated herein.
The present invention provides an exemplary way to perform joule heating calculation, and in practical applications, there may be many ways to represent joule heating calculation, and all of them are within the scope of the present application.
And S205, inputting the voltage data at the current moment into the electric field, and performing medium loss heating calculation to obtain the electric field distribution condition at the current moment.
Optionally, the electric field is an alternating electric field.
Optionally, inputting the voltage data at the current moment into the electric field, performing dielectric loss heating calculation, and obtaining the electric field distribution condition at the current moment, including the following steps:
(1) And obtaining an effective value distribution data set of the alternating electric field acted by the alternating voltage of each frequency by using a multi-physical field coupling analysis method.
Specifically, in order to simplify the analysis, the charge accumulation between the plates is ignored in the present model, that is, the volume charge in the corresponding region of the alternating electric field is considered to be zero, and both the alternating electric field and the temperature field are within the protection range of the present embodiment when the frequency of the applied voltage excitation is below kilohertz and cannot cause the loss of the capacitance effect, so that the electric field distribution in the electric field and the temperature field can be described by the laplace equation in the following formula:
specifically, it is considered that a capacitor plate formed by a conductor aluminum foil is also in an equipotential state under the action of an electric field, but the specific potential of the capacitor plate cannot be determined in advance because the two sides of the capacitor plate are respectively provided with an insulating plate, the capacitor plate is set to be a suspension potential in specific calculation, and specific values are to be specifically determined in the calculation process:
wherein the content of the first and second substances,
is the potential of the mth capacitor plate,
is the mth Undefined levitation potential, where ud is an abbreviation for (Undefined).
The capacitor plate with suspension potential is arranged in the valve side sleeve with higher voltage level, so that the electric field distribution on the surface of the valve side sleeve can be improved.
(2) And performing medium loss heating calculation based on the effective value distribution data group of the alternating electric field to obtain the electric field distribution condition at the current moment.
Optionally, the calculating of the dielectric loss heating is performed based on the effective value distribution data group of the alternating electric field, and the electric field distribution condition at the current moment is obtained, including:
according to fundamental frequency f and vacuum dielectric constant epsilon 0 And the relative dielectric constant ε of the insulating medium r A loss tangent tan delta of the insulating medium, and an effective value E of the target electric field intensity in the effective value distribution data group of the alternating electric field n,rms (r, z) calculating the dielectric loss heat generation to obtain the dielectric loss heat generation Q when the radius of the current-carrying conductor rod is r and the temperature of the corresponding point r is T e (r,z)。
Specifically, the effective value E of the target electric field intensity n,rms And (r, z) is the effective value of the electric field intensity of the nth time in the effective value distribution data set of the alternating electric field at a position r away from the central point of the current-carrying conductor rod and at the corresponding position r, wherein the temperature is T.
Specifically, the formula for calculating the heat generation due to dielectric loss can be as follows:
ε r ＝ε r (nf,T)
tanδ＝tanδ(nf,T)
the specific meanings of the different symbols in the formula have already been set forth in the above description, and are not repeated herein.
The invention provides an exemplary way for calculating the heat generation of the dielectric loss, and in practical application, various representation ways are available, and all the ways are within the protection scope of the present application.
The operation sequence of step S204 and step S205 may be determined according to the field situation, or may be performed simultaneously, which is not further limited herein.
And S206, calculating and obtaining the temperature distribution condition at the current moment according to the coupling analysis of the Joule heat calculation and the dielectric loss heating calculation.
Optionally, the step of obtaining the temperature distribution at the current time by calculation according to coupling analysis of joule heating calculation and dielectric loss heating calculation includes:
based on joule heating value Q r And dielectric loss heat generation amount Q e Combining the density rho of the analysis object at the current time and the heat capacity C of the analysis object P And obtaining the temperature distribution condition of the current moment by the external field dependent variable u and the conduction thermal coefficient k.
Specifically, the temperature distribution is consistent with the structural region involved in the electric field and temperature field coupling analysis.
Specifically, the formula for calculating the temperature distribution can be as follows:
specifically, performing the coupling analysis includes: indirect coupling analysis and direct coupling analysis, wherein the indirect coupling analysis is implemented in a manner that the result of the former analysis is applied as a boundary condition of the subsequent analysis, and correspondingly, the sequence of joule heat calculation and dielectric loss heating calculation is defined; the direct coupling analysis can realize the acquisition of the temperature distribution condition without limiting the sequence of the joule heat calculation or the dielectric loss heating calculation. In the present application, both of the above-mentioned coupling analysis methods are possible and are within the scope of the present application.
Specifically, in the analysis process, the ambient temperature is considered to be not changed obviously, harmonic voltage and current jointly act on the bushing in unit time, but in the analysis process, the application can only process current or voltage components at one harmonic frequency after decomposition, and further, in order to fully consider the temperature dependence of the insulating material, the temperature in the temperature field result obtained by the last calculation and the related heat source condition need to be considered as the background field of the calculation process in the iteration process. In consideration of the superposition effect of the medium under the action of alternating electric fields with different frequencies, reasonable superposition of calculation results under more iteration times needs to be considered.
And S207, judging whether the temperature distribution is within the error bound according to the temperature distribution condition.
Specifically, corresponding iteration conditions are required in the process of performing iterative computation, so that a reasonable result meeting the actual engineering requirement is obtained within a reasonable time length. The convergence of the temperature distribution at the key node is chosen as a criterion, taking into account the convergence and reasonableness of the iteration criterion. Specifically, when the difference of the temperature at the key node in the two previous iteration cycles and the difference of the temperature at the key node in the two previous iteration cycles enters an error bound, the calculation of the temperature field is considered to be converged, and the whole iteration process is ended.
And S208, if the error is within the error bound, calculating the insulation damage distribution and the accumulated value in the electric field and the temperature field.
And after the iterative process is finished, calculating the insulation damage distribution and the accumulated value condition in the electric field and the temperature field of the converter transformer valve side sleeve, and evaluating the insulation state of the converter transformer valve side sleeve.
Specifically, according to the temperature and the electric field distribution obtained by the above calculation, the electric field intensity E and the absolute temperature T, D at the absolute temperature T can be obtained correspondingly ID (t) represents the degree of dielectric damage of the medium over time t, which can be obtained by the following formula:
wherein b is a constant obtained according to the relevant properties of the material, and the constant is closely related to the activation energy required in the chemical explanation process of the corresponding insulating medium and the temperature of the material; n is a constant fitted to the relevant data measured using accelerated life testing. Meanwhile, the accumulated insulation damage degree can be obtained by adding the insulation damage degrees under different time spans. When the accumulation is greater than a certain threshold, the main insulation will fail, including electrical breakdown; the threshold value is also determined according to the relevant accelerated life test and the installation environment of the equipment.
S209, after the insulation damage distribution and the accumulated value in the electric field and the temperature field are calculated, whether the insulation damage accumulated value exceeds the limit is judged,
and S210, outputting a temperature distribution result at the current moment if the temperature distribution exceeds the limit.
Specifically, the threshold values of the insulation damage distribution and the accumulated value are preset in advance, whether the insulation damage distribution and the accumulated value in the electric field and the temperature field exceed the limit is judged according to the comparison between the obtained conditions of the insulation damage distribution and the accumulated value in the electric field and the temperature field and the threshold values, if the insulation damage distribution and the accumulated value exceed the limit, the process is ended, and the temperature distribution result at the current moment is output immediately.
On the basis of the above embodiment, the method further comprises: if the temperature distribution is not within the error bound, the method continues to be executed in step S206, and the corresponding flowchart is shown in fig. 3.
Specifically, the joule heat and the dielectric loss heat generated at the present time are returned to step S206 to perform the iterative solution calculation again, and the iteration is stopped until the temperature distribution obtained by the solution calculation is within the error bound, and the next step S208 is continued.
Further, judging whether the accumulated value of the insulation damage exceeds the limit, further comprises: if not, the alarm information is sent out, and the corresponding flow chart is shown in fig. 4.
Specifically, if the insulation loss integrated value is not out of limit, step S301 is executed to send an alarm message, where the alarm message may be sent in the form of sound or an indicator light, and the process is ended directly after the alarm message is sent, so as to ensure the accuracy of the output temperature distribution result.
Fig. 5 is an insulation state analysis apparatus for a valve-side bushing of a converter transformer according to the present invention, and as shown in fig. 5, the insulation state analysis apparatus according to the present invention includes:
a model establishing module 401, configured to establish a geometric model corresponding to characteristic parameter information of the valve-side sleeve according to finite element analysis software, where the characteristic parameter information includes: size and material information.
A condition design module 402, configured to set corresponding boundary conditions for the geometric model, where the boundary conditions include: electric field and temperature field boundary conditions.
And a meshing module 403, configured to perform preprocessing on the geometric model according to the boundary condition, to obtain meshing for electric field and temperature field calculation.
And the joule heating calculation module 404 is configured to input the current data at the current moment into the temperature field, perform joule heating calculation, and obtain a distribution condition of the temperature field at the current moment.
And a dielectric loss heating calculation module 405, configured to input voltage data at the current time into the electric field, perform dielectric loss heating calculation, and obtain an electric field distribution condition at the current time.
And the coupling analysis module 406 is configured to calculate and obtain a temperature distribution condition at the current time according to coupling analysis of joule heating calculation and dielectric loss heating calculation.
And the temperature distribution analysis module 407 is configured to determine whether the temperature distribution is within an error bound according to the temperature distribution, and if the temperature distribution is within the error bound, calculate the insulation damage distribution and the accumulated value in the electric field and the temperature field.
The result output module 408 is configured to determine whether the accumulated value of the insulation damage exceeds the limit after calculating the insulation damage distribution and the accumulated value in the electric field and the temperature field, and output the temperature distribution result at the current time if the accumulated value of the insulation damage exceeds the limit.
According to the insulating state analysis device for the valve side sleeve of the converter transformer, provided by the invention, the condition of temperature distribution is obtained by analyzing Joule heat calculation in an electric field and dielectric loss heating calculation in a temperature field, and the insulating state is determined according to the analysis result, so that the analysis result is more accurate, and the safety and reliability of various electrical equipment during operation are improved.
Optionally, in the model establishing module 401, a geometric model is established in the finite element analysis software, and in the establishing process, the characteristic parameter information of the valve-side casing needs to be referred to, so as to improve the accuracy of establishing the geometric model.
Optionally, in the condition designing module 402, boundary conditions are set for the established geometric model in order to determine the types of state variables including the electric field and the temperature field.
Optionally, in the mesh partitioning module 403, the geometric model is partitioned by using a boundary condition to obtain a plurality of regions, and each region has a distribution condition of a corresponding electric field or temperature field.
Optionally, in the joule heating calculation module 404, the harmonic current component data is input into the temperature field for joule heating calculation, so as to obtain the distribution condition of the temperature field.
Optionally, in the dielectric loss heating calculation module 405, the voltage data is input into the alternating electric field to perform dielectric loss heating calculation, so as to obtain the electric field distribution condition.
Optionally, in the coupling analysis module 406, the temperature distribution condition is obtained by combining the coupling analysis of joule heating calculation and dielectric loss heating calculation in the temperature field and the electric field, and the factors affecting the temperature distribution are considered, so that the result of the insulation state analysis is more accurate.
Optionally, in the temperature distribution analyzing module 407, the obtained temperature distribution condition is compared with a preset error bound, and if the obtained temperature distribution condition is within the error bound, it may be calculated whether the insulation damage distribution and the accumulated value in the electric field and the temperature field are out of limit, so as to perform the next operation.
Optionally, in the result output module 408, if the insulation damage distribution and the accumulated value in the above are out of limit, the temperature distribution condition at the current time is output, and the accuracy of the output temperature distribution condition can be increased through the judgment of the out-of-limit.
With regard to the converter transformer valve-side bushing insulation state analysis apparatus in the above embodiments, the specific manner in which the respective modules perform operations has been described in detail in the above embodiments of the related method, and will not be described in detail here.
Finally, it should also be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.
The embodiments in the present description are mainly described as different from other embodiments, and the embodiments may be combined as needed, and the same and similar parts may be referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The method for analyzing the insulation state of the valve side sleeve of the converter transformer is characterized by comprising the following steps:
establishing a geometric model corresponding to the characteristic parameter information of the valve side sleeve according to finite element analysis software; wherein the characteristic parameter information includes: size and material information;
setting corresponding boundary conditions for the geometric model; wherein the boundary conditions include: electric field and temperature field boundary conditions;
preprocessing the geometric model according to the boundary condition to obtain the grid division of electric field and temperature field calculation;
inputting current data at the current moment into the temperature field, and performing Joule heating calculation to obtain the distribution condition of the temperature field at the current moment;
inputting the voltage data of the current moment into the electric field, and performing dielectric loss heating calculation to obtain the electric field distribution condition of the current moment;
calculating to obtain the temperature distribution condition of the current moment according to the coupling analysis of the joule heat calculation and the dielectric loss heating calculation;
judging whether the temperature distribution is within an error bound or not according to the temperature distribution condition, and if so, calculating the insulation damage distribution and the accumulated value in the electric field and the temperature field;
and after the insulation damage distribution and the accumulated value in the electric field and the temperature field are calculated, judging whether the insulation damage accumulated value exceeds the limit or not, and if so, outputting the temperature distribution result at the current moment.
2. The method of claim 1, wherein the inputting the current data of the current moment into the temperature field for joule heating calculation to obtain the distribution of the temperature field of the current moment comprises:
performing discrete Fourier decomposition on the obtained current data at the current moment to obtain harmonic current components in the current data at the current moment;
according to the harmonic current component, obtaining a multi-time harmonic current density distribution data set on the cross section of the current-carrying conductor rod by using a frequency domain magnetic field analysis method;
and performing the Joule heating calculation based on the multiple harmonic current density distribution data group to obtain the temperature field distribution condition at the current moment.
3. The method of claim 2, wherein said performing said joule heating calculation based on said multiple harmonic current density distribution data set to obtain said temperature field distribution at said present time comprises:
according to the conductivity gamma of the copper material of the conduit Cu Performing joule heat calculation with the target current density ρ n (r) in the multiple harmonic current density distribution data group to obtain a joule heating value Qr (r) at the radius r of the current carrying conductor rod; wherein the content of the first and second substances,
the target current density ρ n (r) is an nth harmonic current density in the multiple harmonic current density distribution data group at a distance r from the current carrying conductor bar center point.
4. The method according to claim 1, wherein the inputting the voltage data of the current time into the electric field, performing a dielectric loss heating calculation, and obtaining the electric field distribution of the current time comprises: the electric field is an alternating electric field;
obtaining effective value distribution data sets of the alternating electric field acted by the alternating voltage of each frequency by using a multi-physical field coupling analysis method;
and performing the medium loss heating calculation based on the effective value distribution data group of the alternating electric field to obtain the electric field distribution condition at the current moment.
5. The method according to claim 4, wherein the calculating the heating value of the dielectric loss based on the data set of the distribution of the effective values of the alternating electric field to obtain the electric field distribution at the current moment comprises:
according to fundamental frequency f, vacuum dielectric constant epsilon 0 And the relative dielectric constant ε of the insulating medium r A loss tangent tan delta of the insulating medium and an effective value E of a target electric field intensity in an effective value distribution data group of the alternating electric field n,rms (r, z) calculating the dielectric loss heat generation to obtain the dielectric loss heat generation Q when the radius of the current-carrying conductor rod is r and the temperature of the corresponding point r is T e (r, z); wherein the content of the first and second substances,
the above-mentionedEffective value E of target electric field intensity n,rms And (r, z) is an effective value of the electric field intensity of the nth time in the effective value distribution data set of the alternating electric field when the distance from the center point of the current carrying conductor rod is r and the temperature at the corresponding point r is T.
6. The method according to any one of claims 2 to 5, wherein the calculating and obtaining the temperature distribution condition of the current time according to the coupling analysis of the joule heating calculation and the dielectric loss heating calculation comprises:
based on the joule heat generation amount Qr and the dielectric loss heat generation amount Q e Combining the density rho of the analysis object at the current moment and the heat capacity C of the analysis object P And obtaining the temperature distribution condition of the current moment by the external field dependent variable u and the conduction thermal coefficient k.
7. The method of claim 1, wherein the determining whether the temperature distribution is within the error bound according to the temperature distribution condition further comprises:
if the temperature distribution is not within the error bound, continuing to perform the method as recited in claim 6.
8. The method of claim 1, wherein said determining if the accumulated insulation damage value is out of limit further comprises:
and if the threshold is not exceeded, sending out alarm information.
9. The method according to claim 1, wherein the electric field boundary condition is set based on a potential of each boundary of the electric field;
the temperature field boundary condition is set based on the temperature at the current time and the transformer operating temperature.
10. Converter transformer valve side sleeve pipe insulation state analytical equipment, its characterized in that includes:
the model establishing module is used for establishing a geometric model corresponding to characteristic parameter information of the valve side sleeve according to finite element analysis software, wherein the characteristic parameter information comprises: size and material information;
a condition design module, configured to set a corresponding boundary condition for the geometric model, where the boundary condition includes: electric field and temperature field boundary conditions;
the mesh division module is used for preprocessing the geometric model according to the boundary condition to obtain mesh division of electric field and temperature field calculation;
the joule heating calculation module is used for inputting current data at the current moment into the temperature field to perform joule heating calculation so as to obtain the distribution condition of the temperature field at the current moment;
the dielectric loss heating calculation module is used for inputting the voltage data at the current moment into the electric field to perform dielectric loss heating calculation so as to obtain the electric field distribution condition at the current moment;
the coupling analysis module is used for calculating and obtaining the temperature distribution condition of the current moment according to the coupling analysis of the joule heat calculation and the dielectric loss heating calculation;
the temperature distribution analysis module is used for judging whether the temperature distribution is within an error bound or not according to the temperature distribution condition, and calculating the insulation damage distribution and the accumulated value in the electric field and the temperature field if the temperature distribution is within the error bound;
and the result output module is used for judging whether the insulation damage accumulated value exceeds the limit or not after the insulation damage distribution and the accumulated value in the electric field and the temperature field are calculated, and outputting the temperature distribution result at the current moment if the insulation damage accumulated value exceeds the limit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211332998.6A CN115510725A (en) | 2022-10-28 | 2022-10-28 | Converter transformer valve side sleeve insulation state analysis method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211332998.6A CN115510725A (en) | 2022-10-28 | 2022-10-28 | Converter transformer valve side sleeve insulation state analysis method and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115510725A true CN115510725A (en) | 2022-12-23 |
Family
ID=84511652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211332998.6A Pending CN115510725A (en) | 2022-10-28 | 2022-10-28 | Converter transformer valve side sleeve insulation state analysis method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115510725A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117434407A (en) * | 2023-12-20 | 2024-01-23 | 南京中鑫智电科技有限公司 | Time-frequency domain feature fusion converter transformer valve side sleeve insulation analysis method and system |
-
2022
- 2022-10-28 CN CN202211332998.6A patent/CN115510725A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117434407A (en) * | 2023-12-20 | 2024-01-23 | 南京中鑫智电科技有限公司 | Time-frequency domain feature fusion converter transformer valve side sleeve insulation analysis method and system |
| CN117434407B (en) * | 2023-12-20 | 2024-02-20 | 南京中鑫智电科技有限公司 | Time-frequency domain feature fusion converter transformer valve side sleeve insulation analysis method and system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lusuardi et al. | Partial discharge phenomena in electrical machines for the more electrical aircraft. Part II: Impact of reduced pressures and wide bandgap devices | |
| CN108319781B (en) | GIS/GIL internal insulation part optimization method based on multiple physical fields | |
| CN107506511B (en) | Finite element-based dynamic analysis method for leakage current of mine XLPE cable | |
| CN115510725A (en) | Converter transformer valve side sleeve insulation state analysis method and device | |
| Shazly et al. | Thermal analysis of high‐voltage cables with several types of insulation for different configurations in the presence of harmonics | |
| Jin et al. | Charge transport in oil impregnated paper insulation under temperature gradient using transient upstream FEM | |
| Liang et al. | Improved space charge transport model in bi‐layer dielectrics—considering carrier dynamic equilibrium | |
| Duchesne et al. | Prediction of PDIV in motor coils using finite element method | |
| Stosur et al. | Thermal behaviour analyses of gas‐insulated switchgear compartment using thermal network method | |
| Shariatinasab et al. | Probabilistic assessment of insulator failure under contaminated conditions | |
| Li et al. | Influence of geometry and operation conditions on the surface charge characteristics of DC‐GIL spacer | |
| Chrysochos et al. | Rigorous calculation method for resonance frequencies in transmission line responses | |
| Mokhtari et al. | The effect of soil ionization on transient grounding electrode resistance in non‐homogeneous soil conditions | |
| Morsalin et al. | Recovery voltage response of XLPE cables based on polarisation and depolarisation current measurements | |
| Abomailek et al. | Feasibility analysis of reduced‐scale visual corona tests in high‐voltage laboratories | |
| Faria et al. | Accurate evaluation of indoor triplex cable capacitances taking conductor proximity effects into account | |
| Krajewski et al. | Some aspects of medium voltage switchgear designing with aid of numerical analysis | |
| Wang et al. | Precise multi‐dimensional temperature‐rise characterisation of switchgear based on multi‐conditional experiments and LPTN model for high‐capacity application | |
| Huang et al. | Real-time electric field estimation for HVDC cable dielectrics | |
| Sabatier et al. | An HVDC line parameters estimation method without optimization | |
| Poluyanovich et al. | The influence of the electromagnetic field on the neural network monitoring of insulation materials for electric cable networks | |
| Abimouloud et al. | Prediction of DC flashover voltage of cap‐and‐pin polluted insulator | |
| Gouda et al. | Algorithm for load cycling correction to minimise the dry zone influences on the cross‐linked polyethylene (XLPE) cable insulation | |
| CN112711823A (en) | Method for calculating surface charge of extra-high voltage sleeve supporting insulator and optimization method | |
| Tag et al. | A Study on the Impact of Thermal Stresses and Voids on the Partial Discharge Inception Voltage in HVDC Power Cables |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |