Converter transformer operation state monitoring method, system and device and medium

Abstract

The invention belongs to the technical field of power equipment, and discloses a converter transformer operation state monitoring method, system and device and a medium, and the method comprises the steps: constructing a two-dimensional geometric model of a converter transformer, and analyzing the oil flow circulation state of an oil duct of the converter transformer according to the two-dimensional geometric model; establishing an alkane molecule thermal decomposition equation set, and analyzing the evolution law of the fault characteristic gas in the converter transformer oil along with the temperature change; when the oil flow circulation state is a stable state, dissolved gas is introduced into an oil duct of the converter transformer, and transient simulation is performed on the process that the dissolved gas is diffused to balance in combination with the gas production condition of the converter transformer; and analyzing the operation state of the converter transformer, identifying discharge faults of the converter transformer and making response measures. By establishing the digital twinborn model and combining the dynamic deduction method, the operation state of the converter transformer can be monitored in real time, discharge faults can be detected, and potential problems can be predicted.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power equipment, and in particular to a method, system, device and medium for monitoring the operating status of a converter transformer. Background Art

[0002] For complex converter transformers in the field of power equipment, digital twin technology, as an emerging technical means, can display the structural information, sensor information, and operating characteristics of the converter transformer in real time through digital twins in virtual space, and dynamically deduce the evolution process of possible defects, which can greatly improve equipment reliability and reduce maintenance costs.

[0003] With the advancement of the digital transformation of power grids, the construction of digital twins of converter transformers still faces many challenges, including the lack of optimal layout methods for physical sensor networks to achieve effective coverage of various sensor monitoring technologies for converter transformers. In addition, it is difficult for sensors to interact and coexist with the digital twins of converter transformers, further affecting the effect of digital twins. Therefore, in order to promote the application of digital power grids, it is extremely necessary to take converter transformers as the main research object, realize the visualization of the spatiotemporal evolution of internal multi-physical fields, and support the daily operation and maintenance and fault tracing of converter transformers.

[0004] Therefore, how to provide a method, system, device and medium for monitoring the operating status of a converter transformer is a problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present invention provide a method, system, device and medium for monitoring the operating status of a converter transformer to solve the problem in the prior art that it is difficult for sensors to achieve interactive symbiosis with the digital twin of the converter transformer.

[0006] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended to be a general review, nor is it intended to identify key / important components or to delineate the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a preface to the detailed description that follows.

[0007] According to a first aspect of an embodiment of the present invention, a method for monitoring an operating state of a converter transformer is provided.

[0008] In one embodiment, the converter transformer operating status monitoring method includes:

[0009] Based on the pre-collected converter transformer structural parameters, a two-dimensional geometric model of the converter transformer is constructed, and the oil flow circulation state of the converter transformer oil channel is analyzed according to the two-dimensional geometric model;

[0010] Establish the alkane molecule thermal decomposition equations, analyze the evolution law of fault characteristic gas in converter transformer oil with temperature change, and predict the gas production of converter transformer based on the evolution law of fault characteristic gas;

[0011] When the oil circulation state is stable, the dissolved gas is introduced into the oil channel of the converter transformer, and the transient simulation of the dissolved gas diffusion to equilibrium process is carried out in combination with the gas production of the converter transformer;

[0012] Based on the transient simulation results of dissolved gas diffusion, the operating status of the converter transformer is analyzed. Based on the analysis results of the operating status of the converter transformer, the discharge faults of the converter transformer are identified and response measures are formulated.

[0013] In one embodiment, the constructing of a two-dimensional geometric model of the converter transformer based on the pre-collected converter transformer structural parameters, and analyzing the oil flow circulation state of the converter transformer oil channel according to the two-dimensional geometric model includes:

[0014] Collecting converter transformer structural parameters, building a two-dimensional geometric model of the converter transformer based on the converter transformer structural parameters, and designing the converter transformer oil channel in the two-dimensional geometric model;

[0015] Defining boundary conditions at the inlet and outlet of the oil passage of the converter transformer, and setting a preset pressure based on the boundary conditions of the inlet and outlet of the oil passage to adjust the flow rate of the inlet and outlet of the oil passage;

[0016] The two-dimensional geometric model of the converter transformer is divided into a number of grid units, and the oil flow circulation state of the oil channel of the converter transformer is analyzed based on the two-dimensional geometric model after the grid is divided.

[0017] In one embodiment, the establishment of the alkane molecule thermal decomposition equation group and the analysis of the evolution law of the fault characteristic gas in the converter transformer oil as the temperature changes include:

[0018] Introduce predefined chemical equilibrium constants and molar constants to analyze the thermal decomposition process of alkane molecules, and derive the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the results of thermal decomposition analysis of alkane molecules;

[0019] The conservation equations of carbon and hydrogen atoms are established, and the equilibrium constant expression of alkane molecules under standard atmospheric pressure and the atomic conservation equation are paralleled to form a set of thermal decomposition equations of alkane molecules with temperature as input and the mole fraction of gas produced during thermal decomposition as output;

[0020] Based on the alkane molecular thermal decomposition equations, the evolution law of fault characteristic gas in converter transformer oil as temperature changes is simulated and analyzed.

[0021] In one embodiment, the introduction of predefined chemical equilibrium constants and molar constants, analysis of the thermal decomposition process of alkane molecules, and derivation of the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the results of the thermal decomposition analysis of alkane molecules include:

[0022] Based on the definition of gas partial pressure, the equilibrium constant expression between gas phase partial pressure and molar percentage is established, and based on the equilibrium constant expression, the initial expression of the alkane molecule thermal decomposition equation group is established;

[0023] The thermal decomposition process of alkane molecules is analyzed based on the initial expression, and the predefined initial molar number and competition factor of the alkane molecules are introduced to analyze the production amount of reaction products in different reaction paths during the thermal decomposition of alkane molecules;

[0024] The mole fraction of the reaction product is calculated based on the amount of reaction product generated, and the mole fractions of the reaction products are summed to obtain the total mole number of alkane molecules in the thermal decomposition process.

[0025] In one embodiment, the equilibrium constant expression between the gas phase partial pressure and the molar percentage is:

[0026]

[0027] In the formula, represents the standard equilibrium constant under standard atmospheric pressure; p Θ represents standard atmospheric pressure; p represents the total pressure of the gas; x D 、x E and x F Respectively represent the molar percentage of reactant D, product E and product F; v B represents the stoichiometric coefficient.

[0028] In one embodiment, the initial expression of the alkane molecule thermal decomposition equation group is:

[0029]

[0030] In the formula, D represents the alkane molecule reactant, E and F represent the product, and v 1 、v 11 、v 12 They represent the stoichiometric coefficients of reactant D, product E, and product F respectively.

[0031] In one embodiment, the alkane molecule thermal decomposition equation set with temperature as input and the mole fraction of gas generated during the thermal decomposition process as output is:

[0032]

[0033] In the formula, α irepresents the competitive factor, N represents the total number of moles of alkane molecules D during thermal decomposition, α i represents the competition factor, v ij represents the product, ξ represents the progress of the reaction, and x represents the number of moles when decomposition occurs.

[0034] According to a second aspect of an embodiment of the present invention, a converter transformer operating status monitoring system is provided.

[0035] In one embodiment, the converter transformer operating status monitoring system includes:

[0036] A geometric structure analysis module is used to construct a two-dimensional geometric model of the converter transformer based on pre-collected converter transformer structural parameters, and analyze the oil flow circulation state of the converter transformer oil channel according to the two-dimensional geometric model;

[0037] Thermal decomposition analysis module, used to establish the thermal decomposition equations of alkane molecules, analyze the evolution law of fault characteristic gas in converter transformer oil as temperature changes, and predict the gas production of converter transformer based on the evolution law of fault characteristic gas;

[0038] The gas diffusion simulation module is used to introduce dissolved gas into the oil channel of the converter transformer when the oil flow circulation state is stable, and to perform transient simulation of the dissolved gas diffusion to equilibrium process in combination with the gas production of the converter transformer;

[0039] The operating status analysis module is used to analyze the operating status of the converter transformer based on the transient simulation results of dissolved gas diffusion, identify the discharge faults of the converter transformer based on the analysis results of the operating status of the converter transformer and formulate response measures.

[0040] In one embodiment, the geometric structure analysis module includes a geometric model building module, a condition definition module and an oil flow circulation state analysis module, wherein:

[0041] A geometric model building module is used to collect the structural parameters of the converter transformer, build a two-dimensional geometric model of the converter transformer based on the structural parameters of the converter transformer, and design the oil channel of the converter transformer in the two-dimensional geometric model;

[0042] A condition definition module, used to define boundary conditions at the oil passage inlet and outlet of the converter transformer, and to set a preset pressure based on the boundary conditions at the oil passage inlet and outlet to adjust the flow rate at the oil passage inlet and outlet;

[0043] The oil flow circulation state analysis module is used to divide the two-dimensional geometric model of the converter transformer into a plurality of grid units, and analyze the oil flow circulation state of the oil channel of the converter transformer based on the two-dimensional geometric model after the grid is divided.

[0044] In one embodiment, the thermal decomposition analysis module includes an equilibrium constant formula definition module, a thermal decomposition equation group establishment module and a gas evolution law simulation module, wherein:

[0045] The equilibrium constant definition module is used to introduce predefined chemical equilibrium constants and molar constants, analyze the thermal decomposition process of alkane molecules, and derive the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the results of thermal decomposition analysis of alkane molecules;

[0046] Thermal decomposition equations building module, used to build carbon and hydrogen atom conservation equations, and to establish equilibrium constant expressions of alkane molecules at standard atmospheric pressure and atomic conservation equations in parallel, to form a thermal decomposition equations for alkane molecules with temperature as input and the molar fraction of gas produced during thermal decomposition as output;

[0047] The gas evolution simulation module is used to simulate and analyze the evolution of fault characteristic gases in the converter transformer oil as the temperature changes based on the alkane molecule thermal decomposition equations.

[0048] In one embodiment, the equilibrium constant formula definition module includes a thermal decomposition equation group initial definition module, a reaction product generation module and a mole number generation module, wherein:

[0049] The module for initially defining the thermal decomposition equations is used to establish the equilibrium constant expression between the gas phase partial pressure and the molar percentage based on the gas partial pressure definition formula, and to establish the initial expression of the thermal decomposition equations of the alkane molecules based on the equilibrium constant expression;

[0050] The reaction product generation module is used to analyze the thermal decomposition process of alkane molecules based on the initial expression, introduce the predefined initial molar number of alkane molecules and the competitive factor, and analyze the generation amount of reaction products of different reaction paths during the thermal decomposition of alkane molecules;

[0051] The mole number generation module is used to calculate the mole fraction of the reaction product in combination with the amount of the reaction product generated, and sum the mole fractions of the reaction products to obtain the total mole number of the alkane molecules in the thermal decomposition process.

[0052] In one embodiment, the equilibrium constant expression between the gas phase partial pressure and the molar percentage is:

[0053]

[0054] In the formula, represents the standard equilibrium constant under standard atmospheric pressure; p Θ represents standard atmospheric pressure; p represents the total pressure of the gas; x D 、x E and x F Respectively represent the molar percentage of reactant D, product E and product F; vB represents the stoichiometric coefficient.

[0055] In one embodiment, the initial expression of the alkane molecule thermal decomposition equation group is:

[0056]

[0057] In the formula, D represents the alkane molecule reactant, E and F represent the product, and v 1 、v 11 、v 12 They represent the stoichiometric coefficients of reactant D, product E, and product F respectively.

[0058] In one embodiment, the alkane molecule thermal decomposition equation set with temperature as input and the mole fraction of gas generated during the thermal decomposition process as output is:

[0059]

[0060] In the formula, α i represents the competitive factor, N represents the total number of moles of alkane molecules D during thermal decomposition, α i represents the competition factor, v ij represents the product, ξ represents the progress of the reaction, and x represents the number of moles when decomposition occurs.

[0061] According to a third aspect of an embodiment of the present invention, a computer device is provided.

[0062] In one embodiment, the computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0063] According to a fourth aspect of embodiments of the present invention, a computer-readable storage medium is provided.

[0064] In one embodiment, the computer-readable storage medium stores a computer program, and the computer program implements the steps of the above method when executed by a processor.

[0065] The technical solution provided by the embodiment of the present invention may include the following beneficial effects: By establishing a digital twin model and combining it with a dynamic deduction method, the present invention can monitor the operating status of the converter in real time, detect discharge faults and predict potential problems, thereby improving the reliability and stability of the power system, and further helping power engineers and operators to better manage power equipment, reduce downtime, and improve power transmission efficiency.

[0066] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0068] Figure 1 is a flow chart of a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0069] Figure 2 is a principle block diagram of a converter transformer operating status monitoring system according to an exemplary embodiment;

[0070] Figure 3 is a structural schematic diagram of a computer device according to an exemplary embodiment;

[0071] Figure 4 is a schematic diagram showing a solution result of a propane thermal decomposition reaction equilibrium constant in a method for monitoring the operating state of a converter transformer according to an exemplary embodiment;

[0072] Figure 5 is a schematic diagram showing the solution results of the competitive factor in the propane thermal decomposition process in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0073] Figure 6 is a schematic diagram showing a calculation result of propane thermal decomposition gas content in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0074] Figure 7 is a schematic diagram showing a calculation result of the gas content produced by thermal decomposition of butane in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0075] Figure 8 is a schematic diagram showing the relationship between the amount of combustible gas generated and the temperature in a method for monitoring the operating state of a converter transformer according to an exemplary embodiment;

[0076] Fig. 9 is a schematic diagram showing a calculation result of the gas content produced by thermal decomposition of a mixture of propane and butane in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0077] Fig.10 is a schematic diagram of changes in gas concentration at three monitoring points in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0078] Fig.11 is a schematic diagram of changes in gas concentration at four top monitoring points in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0079] Fig.12 is a schematic diagram of changes in gas concentration at two lower monitoring points in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment;

[0080] Fig.13 The figure is a flow rate-balance time relationship diagram in a method for monitoring the operating status of a converter transformer according to an exemplary embodiment. DETAILED DESCRIPTION

[0081] The following description and accompanying drawings fully illustrate the specific embodiments of this article so that those skilled in the art can practice them. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of the embodiments of this article includes the entire scope of the claims, as well as all available equivalents of the claims. Herein, the terms "first", "second", etc. are only used to distinguish one element from another, without requiring or implying any actual relationship or order between these elements. In fact, the first element can also be called the second element, and vice versa. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the structure, device or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such structure, device or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the structure, device or equipment including the elements. Each embodiment is described in a progressive manner herein, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0082] The terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in this document indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this document and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of this document, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, it can also be the internal communication of two elements, it can be a direct connection, or it can be an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0083] As used herein, the term "plurality" means two or more than two, unless otherwise specified.

[0084] In this document, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B.

[0085] In this article, the term "and / or" is a description of the association relationship between objects, indicating that three relationships may exist. For example, A and / or B means: A or B, or, A and B.

[0086] Each module in the device or system of the present application can be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above modules.

[0087] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0088] Figure 1 An embodiment of the converter transformer operating status monitoring method of the present invention is shown.

[0089] In this optional embodiment, the converter transformer operating status monitoring method includes:

[0090] Step S101: construct a two-dimensional geometric model of the converter transformer based on pre-collected converter transformer structural parameters, and analyze the oil flow circulation state of the converter transformer oil channel according to the two-dimensional geometric model.

[0091] Step S103, establishing an alkane molecule thermal decomposition equation group, analyzing the evolution law of the fault characteristic gas in the converter transformer oil as the temperature changes, and predicting the gas production of the converter transformer based on the evolution law of the fault characteristic gas;

[0092] Step S105, when the oil flow circulation state is in a stable state, introducing dissolved gas into the oil channel of the converter transformer, and performing transient simulation on the process of dissolved gas diffusion to equilibrium in combination with the gas production of the converter transformer;

[0093] Step S107, analyzing the operating state of the converter transformer based on the transient simulation result of dissolved gas diffusion, identifying the discharge fault of the converter transformer based on the analysis result of the operating state of the converter transformer and formulating response measures.

[0094] In this optional embodiment, the two-dimensional geometric model of the converter transformer is constructed based on the pre-collected converter transformer structural parameters, and the oil flow circulation state of the converter transformer oil channel is analyzed according to the two-dimensional geometric model, including: collecting the converter transformer structural parameters, and constructing the two-dimensional geometric model of the converter transformer based on the converter transformer structural parameters, and designing the converter transformer oil channel in the two-dimensional geometric model; defining boundary conditions at the inlet and outlet of the converter transformer oil channel, and setting a preset pressure based on the boundary conditions of the oil channel inlet and outlet to adjust the flow rate of the oil channel inlet and outlet; dividing the two-dimensional geometric model of the converter transformer into a plurality of grid units, and analyzing the oil flow circulation state of the converter transformer oil channel based on the two-dimensional geometric model after grid division.

[0095] In this optional embodiment, the establishment of a group of thermal decomposition equations for alkane molecules and the analysis of the evolution of fault characteristic gases in the oil of the converter transformer with temperature changes include: introducing predefined chemical equilibrium constants and molar constants, analyzing the thermal decomposition process of alkane molecules, and deriving the equilibrium constant expression of alkane molecules at standard atmospheric pressure based on the analysis results of the thermal decomposition of alkane molecules; establishing conservation equations for carbon atoms and hydrogen atoms, and parallelizing the equilibrium constant expression of alkane molecules at standard atmospheric pressure with the atomic conservation equation to form a group of thermal decomposition equations for alkane molecules with temperature as input and the molar fraction of gas generated during the thermal decomposition process as output; based on the group of thermal decomposition equations for alkane molecules, simulating and analyzing the evolution of fault characteristic gases in the oil of the converter transformer with temperature changes.

[0096] In this optional embodiment, the introduction of predefined chemical equilibrium constants and molar constants, the analysis of the thermal decomposition process of alkane molecules, and the derivation of the equilibrium constant expression of the alkane molecules at standard atmospheric pressure based on the analysis results of the thermal decomposition of the alkane molecules include: establishing an equilibrium constant expression between the gas phase partial pressure and the molar percentage based on the gas partial pressure definition formula, and establishing an initial expression of the thermal decomposition equation group of the alkane molecules according to the equilibrium constant expression; analyzing the thermal decomposition process of the alkane molecules based on the initial expression, and introducing predefined initial molar numbers and competition factors of the alkane molecules, and analyzing the amount of reaction products generated in different reaction paths during the thermal decomposition of the alkane molecules; calculating the molar fraction of the reaction product in combination with the amount of reaction product generated, and summing the molar fractions of the reaction products to obtain the total molar number of the alkane molecules during the thermal decomposition process.

[0097] Figure 2 An embodiment of the converter transformer operating status monitoring system of the present invention is shown.

[0098] In this optional embodiment, the converter transformer operating status monitoring system includes:

[0099] The geometric structure analysis module 201 is used to construct a two-dimensional geometric model of the converter transformer based on the pre-collected structural parameters of the converter transformer, and analyze the oil flow circulation state of the oil channel of the converter transformer according to the two-dimensional geometric model;

[0100] Thermal decomposition analysis module 203, used to establish a group of thermal decomposition equations of alkane molecules, analyze the evolution law of fault characteristic gas in converter transformer oil as temperature changes, and predict the gas production of converter transformer based on the evolution law of fault characteristic gas;

[0101] The gas diffusion simulation module 205 is used to introduce dissolved gas into the oil channel of the converter transformer when the oil flow circulation state is in a stable state, and perform transient simulation on the process of dissolved gas diffusion to equilibrium in combination with the gas production of the converter transformer;

[0102] The operating status analysis module 207 is used to analyze the operating status of the converter transformer based on the transient simulation results of dissolved gas diffusion, identify the discharge faults of the converter transformer based on the analysis results of the operating status of the converter transformer, and formulate response measures.

[0103] In this optional embodiment, the geometric structure analysis module 201 includes a geometric model building module (not shown in the figure), a condition definition module (not shown in the figure) and an oil flow circulation state analysis module (not shown in the figure), wherein:

[0104] A geometric model building module is used to collect the structural parameters of the converter transformer, build a two-dimensional geometric model of the converter transformer based on the structural parameters of the converter transformer, and design the oil channel of the converter transformer in the two-dimensional geometric model;

[0105] A condition definition module, used to define boundary conditions at the oil passage inlet and outlet of the converter transformer, and to set a preset pressure based on the boundary conditions at the oil passage inlet and outlet to adjust the flow rate at the oil passage inlet and outlet;

[0106] The oil flow circulation state analysis module is used to divide the two-dimensional geometric model of the converter transformer into a plurality of grid units, and analyze the oil flow circulation state of the oil channel of the converter transformer based on the two-dimensional geometric model after the grid is divided.

[0107] In this optional embodiment, the thermal decomposition analysis module 203 includes an equilibrium constant formula definition module (not shown in the figure), a thermal decomposition equation group establishment module (not shown in the figure) and a gas evolution law simulation module (not shown in the figure), wherein:

[0108] The equilibrium constant definition module is used to introduce predefined chemical equilibrium constants and molar constants, analyze the thermal decomposition process of alkane molecules, and derive the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the results of thermal decomposition analysis of alkane molecules;

[0109] Thermal decomposition equations building module, used to build carbon and hydrogen atom conservation equations, and to establish equilibrium constant expressions of alkane molecules at standard atmospheric pressure and atomic conservation equations in parallel, to form a thermal decomposition equations for alkane molecules with temperature as input and the molar fraction of gas produced during thermal decomposition as output;

[0110] The gas evolution simulation module is used to simulate and analyze the evolution of fault characteristic gases in the converter transformer oil as the temperature changes based on the alkane molecule thermal decomposition equations.

[0111] In this optional embodiment, the equilibrium constant formula definition module includes a thermal decomposition equation group initial definition module (not shown in the figure), a reaction product generation module (not shown in the figure) and a mole number generation module (not shown in the figure), wherein:

[0112] The module for initially defining the thermal decomposition equations is used to establish the equilibrium constant expression between the gas phase partial pressure and the molar percentage based on the gas partial pressure definition formula, and to establish the initial expression of the thermal decomposition equations of the alkane molecules based on the equilibrium constant expression;

[0113] The reaction product generation module is used to analyze the thermal decomposition process of alkane molecules based on the initial expression, introduce the predefined initial molar number of alkane molecules and the competitive factor, and analyze the generation amount of reaction products of different reaction paths during the thermal decomposition of alkane molecules;

[0114] The mole number generation module is used to calculate the mole fraction of the reaction product in combination with the amount of the reaction product generated, and sum the mole fractions of the reaction products to obtain the total mole number of the alkane molecules in the thermal decomposition process.

[0115] The converter transformer operating status monitoring method provided by the present invention is described in detail below in conjunction with specific implementation methods.

[0116] Based on any gas reaction:

[0117]

[0118] In the formula, v 1 , v 11 , v 12 They are the stoichiometric coefficients of reactant D and product E and F respectively. The ratio of the stoichiometric coefficients represents the ratio of the molar numbers of the substances undergoing the reaction.

[0119] From the above definition of gas partial pressure, we can deduce K expressed in gas phase partial pressure: p and K expressed as mole percent x The relationship between them is:

[0120]

[0121] In the formula, represents the standard equilibrium constant at standard atmospheric pressure (101.325 kPa); p Θ represents standard atmospheric pressure; p represents the total pressure of the gas; x D 、x E and x F Respectively represent the molar percentage of reactant D, product E and product F, v B The value of is determined by the stoichiometric coefficient of the substance, B represents a certain component, and Kx represents the mole percentage. The above equilibrium constant expression written by chemical reaction can be used as the basic formula for establishing the thermal decomposition equation group of alkane molecules, which links the chemical equilibrium constant with the change of the mole fraction of each substance in the reaction.

[0122] For any alkane molecule D, assuming that its thermal decomposition process consists of n thermal decomposition reactions, the thermal decomposition process is:

[0123]

[0124] Assume that the initial molar number of the alkane molecule D is 1 mol. When x∈(0,1) mol of the alkane molecule decomposes, the remaining molar number is 1-x. The reaction progress of the alkane molecule D is defined as ξ=|x / v1|. In the first reaction formula, D represents the alkane molecule reactant, E and F both represent the product, and v 1 , v 11 , v 12 They represent the stoichiometric coefficients of reactant D, product E, and product F respectively. The ratio of the stoichiometric coefficients represents the ratio of the molar numbers of the substances undergoing the reaction. In the thermal decomposition reaction that constitutes the reaction path of alkane molecule D, the generation of a characteristic gas generally involves the occurrence of multiple reactions. In order to describe the phenomenon of different reaction progress between reactions, the competition factor α is established i ∈[0,1), the competitive strength of the reaction is used to describe the amount of reaction products generated, and then quantify the different generation and consumption of the same characteristic gas by different thermal decomposition reactions at a certain temperature. i When (i=1, ..., n) is close to 1, it indicates that the reaction progress is high, the ability to obtain reaction enthalpy change values ​​in multiple reactions occurring simultaneously is strong, and the reaction competition is strong; otherwise, the reaction competition is weak.

[0125] The mole fraction of each substance is:

[0126]

[0127] In the formula, the sum of r(B) represents the competitive factor α of the reaction in all chemical reactions involving substance B. i and the stoichiometric coefficient of substance B (reactant v i , the product v ij), reaction progress ξ, so as to ensure the accuracy of the order of the reaction path without causing leapfrogging reactions. N represents the total number of moles of alkane molecules D during thermal decomposition. The calculation formula for the total number of moles N of alkane molecules D during thermal decomposition is:

[0128]

[0129] At this point, the equilibrium constant expression of the ith reaction under standard atmospheric pressure can be derived. In addition to establishing equations from the perspective of chemical equilibrium, it is also necessary to supplement the C and H atomic conservation equations from the perspective of material balance. By combining the equilibrium constant expressions of all thermal decomposition reactions with the atomic conservation equations, we can obtain the set of thermal decomposition equations for alkane molecules with temperature T as input and the mole fraction of various gases produced during the thermal decomposition process as output:

[0130]

[0131] C 3 H 8 As a calculation example, the equilibrium constant, competitive factor and molecular content of each product can be obtained when the molecule is decomposed. (1) In the conservation equation of C and H atoms, α i represents the competitive factor; (2) In the ith thermal decomposition reaction equation, N represents the total number of moles of alkane molecules D during the thermal decomposition process, α i represents the competition factor, v ij represents the product, ξ represents the reaction progress, x represents the number of moles when decomposition occurs, x∈(0,1)mol; when the initial reactant is an alkane molecule, the sum of r(B) represents the competitive factor α of the reaction in all chemical reactions involving substance B. i and the stoichiometric coefficient of substance B (reactant v i , the product v ij ), reaction progress ξ; when the initial reactant is not an alkane molecule, K i Indicates mole percentage, and the other letters have the same meaning as above. Figure 4-Figure 7 As shown in the table below; the gas generation based on temperature in the United States Department of the Interior (DOI) is used as the calculation standard, as shown in the table below: Figure 8 shown.

[0132] In order to simulate the growth law and amplitude of fault gas in transformer oil in actual conditions as much as possible, the fault characteristic gas (CH 4 , C 2 H 6 , C 2 H 4 , C2 H 2 , H 2 ) content and composition as the equivalent principle, C 3 H 8 and C 4 H 10 The calculation was carried out by mixing the two alkane molecules in a certain ratio. Assuming that the total initial molar number of the two alkane molecules is 1 mol, the propane ratio is 0.1-0.9 with a step length of 0.05. Changing the propane mixing ratio will cause the characteristic gas molecules (CH 4 , C 2 H 6 , C 2 H 4 , C 2 H 2 , C 3 H 6 , H 2 ) The content changes proportionally during the evolution process and does not affect the starting temperature of the reaction. When the set temperature range is 100℃-1227℃, Fig. 9 The gas content calculation method shown is for 0.45 molC 3 H 8 With 0.55molC 4 H 10 The fault characteristic gas evolution law is obtained by solving the mixed system, where Hydrogen (H2) represents hydrogen; Methane (CH4) represents methane; Ethane (C2H6) represents ethane; Ehylene (C2H4) represents ethylene; Acetylene (C2H2) represents acetylene; and Temperature represents temperature.

[0133] It can be seen that CH 4 , C 2 H 2 The gas formation starting temperature has an error of 50°C from the actual gas generation law given by DOI, and H 2 , C 2 H 6 , C 2 H 4 The starting temperature of gas formation has errors of 137℃, 114℃ and 234℃ compared with the actual situation. The corresponding temperature of each gas at the highest gas content point and the changing trend of each gas with temperature are well consistent with the actual situation.

[0134] Table 1: Comparison of combustible gas generation and mixed gas content

[0135]

[0136] Table 1 is a comparison table of the characteristic gas evolution law calculated for the propane and butane mixture system and the actual combustible gas generation. It can be seen that H 2 , CH 4 , C 2 H 6 , C 2 H 4 At 287℃, 116℃, 136℃, and 116℃, a small amount of CH 4 , C 2 H 6 , C 2 H 4 The amount of C generated decreases with increasing temperature. 2 H 2 , the molar fraction at 744℃ is 0.011, after which its generation rate increases. 4 , C 2 H 2 The gas formation starting temperature has an error of 50°C from the actual gas generation law given by DOI, and H 2 , C 2 H 6 , C 2 H 4 The starting temperature of gas formation has errors of 137℃, 114℃ and 234℃ compared with the actual situation. The corresponding temperature of each gas at the highest gas content point and the changing trend of each gas with temperature are well consistent with the actual situation.

[0137] Table 2: Modified IEC ratio method diagnosis

[0138]

[0139] Table 2 shows the results of encoding and calculating the mixed gas content using the improved IEC ratio method. From Table 2, it can be seen that as the temperature of the calculation condition increases, the faults associated with the calculation results change from low-temperature overheating, medium-temperature overheating, to high-temperature overheating, and the boundary temperature of the thermal fault is close to the calculation condition. When the temperature is greater than 927°C, the associated fault type is high-energy discharge. Therefore, it is believed that the fault diagnosis obtained by the improved IEC ratio method is consistent with the calculation conditions, which verifies that the proposed gas content calculation method is effective. It can be considered that the gas production results calculated when the propane and butane are mixed in this ratio can provide a reference for estimating the gas production in transformer oil.

[0140] In this embodiment, a two-dimensional geometric model is constructed for the scaled transformer model, and a circulating oil channel is constructed to circulate the oil flow in the box. By defining the fan boundary, the flow rate of the pressure regulating oil channel outlet is set between 0.1m / s-0.2m / s, and the geometric structure is meshed on this basis.

[0141] It should be noted that when constructing the transformer model, the nonlinear coupling relationship of electrical materials is taken into account, the multi-physical field coupling modeling method of commutation transformer electrical, magnetic and thermal is studied, and the commutation transformer digital biological architecture design integrating CAE multi-field simulation module is adopted to implement the model.

[0142] The internal flow field of the transformer in a steady state is calculated by simulation software (the simulation software may be Ansys Fluent, i.e., the fluid dynamics CFD tool in Ansys software). After the oil flow is stabilized, an initial dissolved gas is set in the oil channel, and a transient simulation of the dissolved gas diffusion to equilibrium is performed.

[0143] Depend on Figure 10-12 It can be seen that in the main oil channel of the transformer, since the diffusion speed of the dissolved gas is much lower than the oil flow speed, the dissolved gas will be affected by the transformer oil flow field and dispersed into several relatively high-concentration gas centers. The high-concentration centers of the dissolved gas in the oil channel will circulate several times with the oil flow until they are completely diffused. During the circulation process, they will pass through each gas concentration detection point in the main oil channel in turn. Therefore, the concentration of the monitoring point will show several peaks and troughs in the early stage of gas diffusion. After the diffusion is complete, the dissolved gas concentration values ​​of each monitoring point are basically the same, reaching the equilibrium state of gas diffusion. For the fluid area near the upper and lower boundaries of the core, the flow rate is one order of magnitude or more than that of the main oil channel. The gas will diffuse to this place after several cycles, and the volatility of the gas concentration in this area is not obvious.

[0144] like Fig.13 It can be seen that by adjusting the pressure parameters of the fan boundary, controlling the oil flow rate between 0.1m / s-0.2m / s, and calculating the dissolved gas diffusion process, the time required for the dissolved gas to diffuse to equilibrium at different flow rates can be obtained.

[0145] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 3As shown. The computer device includes a processor, a memory and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store static information and dynamic information data. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the steps in the above method embodiment are implemented.

[0146] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0147] In addition, the present invention also provides a computer device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiment when executing the computer program.

[0148] In addition, the present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the above method embodiment are implemented.

[0149] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0150] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for monitoring the operating status of a converter transformer, characterized in that: The method includes: Based on the pre-collected converter transformer structural parameters, a two-dimensional geometric model of the converter transformer is constructed, and the oil flow circulation state of the converter transformer oil channel is analyzed according to the two-dimensional geometric model; Establish the alkane molecule thermal decomposition equations, analyze the evolution law of fault characteristic gas in converter transformer oil with temperature change, and predict the gas production of converter transformer based on the evolution law of fault characteristic gas; When the oil circulation state is stable, the dissolved gas is introduced into the oil channel of the converter transformer, and the transient simulation of the dissolved gas diffusion to equilibrium process is carried out in combination with the gas production of the converter transformer; Based on the transient simulation results of dissolved gas diffusion, the operating status of the converter transformer is analyzed. Based on the analysis results of the operating status of the converter transformer, the discharge faults of the converter transformer are identified and response measures are formulated.

2. The method for monitoring the operating status of a converter transformer according to claim 1, characterized in that: The method of constructing a two-dimensional geometric model of the converter transformer based on the pre-collected converter transformer structural parameters and analyzing the oil flow circulation state of the converter transformer oil channel according to the two-dimensional geometric model includes: Collecting converter transformer structural parameters, building a two-dimensional geometric model of the converter transformer based on the converter transformer structural parameters, and designing the converter transformer oil channel in the two-dimensional geometric model; Defining boundary conditions at the inlet and outlet of the oil passage of the converter transformer, and setting a preset pressure based on the boundary conditions of the inlet and outlet of the oil passage to adjust the flow rate of the inlet and outlet of the oil passage; The two-dimensional geometric model of the converter transformer is divided into a number of grid units, and the oil flow circulation state of the oil channel of the converter transformer is analyzed based on the two-dimensional geometric model after the grid is divided.

3. The method for monitoring the operating status of a converter transformer according to claim 2, characterized in that: The method of establishing the alkane molecule thermal decomposition equation group and analyzing the evolution law of the fault characteristic gas in the converter transformer oil as the temperature changes includes: Introduce predefined chemical equilibrium constants and molar constants to analyze the thermal decomposition process of alkane molecules, and derive the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the results of thermal decomposition analysis of alkane molecules; The conservation equations of carbon and hydrogen atoms are established, and the equilibrium constant expression of alkane molecules under standard atmospheric pressure and the atomic conservation equation are paralleled to form a set of thermal decomposition equations of alkane molecules with temperature as input and the mole fraction of gas produced during thermal decomposition as output; Based on the alkane molecular thermal decomposition equations, the evolution law of fault characteristic gas in converter transformer oil as temperature changes is simulated and analyzed.

4. The method for monitoring the operating status of a converter transformer according to claim 3, characterized in that: The introduction of the predefined chemical equilibrium constant and molar constant to analyze the thermal decomposition process of alkane molecules and the derivation of the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the thermal decomposition analysis results of alkane molecules include: Based on the definition of gas partial pressure, the equilibrium constant expression between gas phase partial pressure and molar percentage is established, and based on the equilibrium constant expression, the initial expression of the alkane molecule thermal decomposition equation group is established; The thermal decomposition process of alkane molecules is analyzed based on the initial expression, and the predefined initial molar number and competition factor of the alkane molecules are introduced to analyze the production amount of reaction products in different reaction paths during the thermal decomposition of alkane molecules; The mole fraction of the reaction product is calculated based on the amount of reaction product generated, and the mole fractions of the reaction products are summed to obtain the total mole number of alkane molecules in the thermal decomposition process.

5. The method for monitoring the operating status of a converter transformer according to claim 4, characterized in that: The equilibrium constant expression between the gas phase partial pressure and the molar percentage is: In the formula, represents the standard equilibrium constant under standard atmospheric pressure; p Θ represents standard atmospheric pressure; p represents the total pressure of the gas; x D 、x E and x F Respectively represent the molar percentage of reactant D, product E and product F; v B represents the stoichiometric coefficient.

6. The method for monitoring the operating status of a converter transformer according to claim 5, characterized in that: The initial expression of the alkane molecule thermal decomposition equation group is: In the formula, D represents the alkane molecule reactant, E and F represent the product, v1, v 11 、v 12 They represent the stoichiometric coefficients of reactant D, product E, and product F respectively.

7. The method for monitoring the operating status of a converter transformer according to claim 6, characterized in that: The alkane molecule thermal decomposition equation group with temperature as input and the mole fraction of gas generated during the thermal decomposition process as output is: In the formula, α i represents the competitive factor, N represents the total number of moles of alkane molecules D during thermal decomposition, α i represents the competition factor, v ij represents the product, ξ represents the progress of the reaction, and x represents the number of moles when decomposition occurs.

8. A converter transformer operating status monitoring system, characterized in that: The system includes: A geometric structure analysis module is used to construct a two-dimensional geometric model of the converter transformer based on pre-collected converter transformer structural parameters, and analyze the oil flow circulation state of the converter transformer oil channel according to the two-dimensional geometric model; Thermal decomposition analysis module, used to establish the thermal decomposition equations of alkane molecules, analyze the evolution law of fault characteristic gas in converter transformer oil as temperature changes, and predict the gas production of converter transformer based on the evolution law of fault characteristic gas; The gas diffusion simulation module is used to introduce dissolved gas into the oil channel of the converter transformer when the oil flow circulation state is stable, and to perform transient simulation of the dissolved gas diffusion to equilibrium process in combination with the gas production of the converter transformer; The operating status analysis module is used to analyze the operating status of the converter transformer based on the transient simulation results of dissolved gas diffusion, identify the discharge faults of the converter transformer based on the analysis results of the operating status of the converter transformer and formulate response measures.

9. The converter transformer operating status monitoring system according to claim 8, characterized in that: The geometric structure analysis module includes a geometric model building module, a condition definition module and an oil flow circulation state analysis module, wherein: A geometric model building module is used to collect the structural parameters of the converter transformer, build a two-dimensional geometric model of the converter transformer based on the structural parameters of the converter transformer, and design the oil channel of the converter transformer in the two-dimensional geometric model; A condition definition module, used to define boundary conditions at the oil passage inlet and outlet of the converter transformer, and to set a preset pressure based on the boundary conditions at the oil passage inlet and outlet to adjust the flow rate at the oil passage inlet and outlet; The oil flow circulation state analysis module is used to divide the two-dimensional geometric model of the converter transformer into a plurality of grid units, and analyze the oil flow circulation state of the oil channel of the converter transformer based on the two-dimensional geometric model after the grid is divided.

10. The converter transformer operating status monitoring system according to claim 9, characterized in that: The thermal decomposition analysis module includes a module for defining equilibrium constants, a module for establishing thermal decomposition equations, and a module for simulating gas evolution laws, wherein: The equilibrium constant definition module is used to introduce predefined chemical equilibrium constants and molar constants, analyze the thermal decomposition process of alkane molecules, and derive the equilibrium constant expression of alkane molecules under standard atmospheric pressure based on the results of thermal decomposition analysis of alkane molecules; Thermal decomposition equations building module, used to build carbon and hydrogen atom conservation equations, and to establish equilibrium constant expressions of alkane molecules at standard atmospheric pressure and atomic conservation equations in parallel, to form a thermal decomposition equations for alkane molecules with temperature as input and the molar fraction of gas produced during thermal decomposition as output; The gas evolution simulation module is used to simulate and analyze the evolution of fault characteristic gases in the converter transformer oil as the temperature changes based on the alkane molecule thermal decomposition equations.

11. The converter transformer operating status monitoring system according to claim 10, characterized in that: The equilibrium constant formula definition module includes a thermal decomposition equation group initial definition module, a reaction product generation module and a mole number generation module, wherein: The module for initially defining the thermal decomposition equations is used to establish the equilibrium constant expression between the gas phase partial pressure and the molar percentage based on the gas partial pressure definition formula, and to establish the initial expression of the thermal decomposition equations of the alkane molecules based on the equilibrium constant expression; The reaction product generation module is used to analyze the thermal decomposition process of alkane molecules based on the initial expression, introduce the predefined initial molar number of alkane molecules and the competitive factor, and analyze the generation amount of reaction products of different reaction paths during the thermal decomposition of alkane molecules; The mole number generation module is used to calculate the mole fraction of the reaction product in combination with the amount of the reaction product generated, and sum the mole fractions of the reaction products to obtain the total mole number of the alkane molecules in the thermal decomposition process.

12. The converter transformer operating status monitoring system according to claim 11, characterized in that: The equilibrium constant expression between the gas phase partial pressure and the molar percentage is: In the formula, represents the standard equilibrium constant under standard atmospheric pressure; p Θ represents standard atmospheric pressure; p represents the total pressure of the gas; x D 、x E and x F Respectively represent the molar percentage of reactant D, product E and product F; v B represents the stoichiometric coefficient.

13. The converter transformer operating status monitoring system according to claim 12, characterized in that: The initial expression of the alkane molecule thermal decomposition equation group is: In the formula, D represents the alkane molecule reactant, E and F represent the product, v1, v 11 、v 12 They represent the stoichiometric coefficients of reactant D, product E, and product F respectively.

14. The converter transformer operating status monitoring system according to claim 13, characterized in that: The alkane molecule thermal decomposition equation group with temperature as input and the mole fraction of gas generated during the thermal decomposition process as output is: In the formula, α i represents the competitive factor, N represents the total number of moles of alkane molecules D during thermal decomposition, α i represents the competition factor, v ij represents the product, ξ represents the progress of the reaction, and x represents the number of moles when decomposition occurs.

15. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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