Determination method of second Touwson coefficient in electrode photoionization corona onset criterion and related device

Abstract

The invention discloses a method for determining a second coefficient of Thuesson in an electrode photoionization corona onset criterion and a related device, and belongs to the technical field of electrodes. The method comprises the following steps: determining an ionization region boundary during conductor corona onset through corona onset voltage, environmental parameters and a nominal electric field analytical formula; substituting a nominal electric field analytic formula into the photoionization corona inception criterion by utilizing a Morrow ionization coefficient and adhesion coefficient formula based on the obtained ionization region boundary during the corona inception of the lead to obtain an integral expression of the photoionization corona inception criterion; discretizing an integral interval in the integral expression of the photoionization corona inception criterion, assigning an initial value to the second coefficient of the Thuesson, substituting the initial value into the photoionization corona inception criterion for discretized integral calculation, and finally obtaining the second coefficient of the Thuesson. The method can be used for all alternating-current and direct-current wires needing the photoionization corona inception criterion, and can determine the Souxon second coefficient of the wire corona inception under the condition of changing the geometric dimension, the height to the ground, the humidity, the air pressure and the temperature of the wire.

Description

Technical Field

[0001] The invention belongs to the field of electrode technology and relates to a method for determining the Thomson second coefficient in the electrode photoionization corona criterion and a related device. Background Art

[0002] As a key indicator for evaluating the performance of electrical equipment, the photoionization corona criterion has a wide range of applicable scenarios, covering all kinds of wires and other electrical components from DC systems to AC systems. This criterion not only plays an important role in the design and maintenance of large-scale power facilities such as high-voltage transmission lines, transformers, and mutual inductors, but also penetrates into laboratory research, the development of power electronic equipment, and new energy technologies. Among them, the Thomson second coefficient, as a core parameter in the photoionization corona criterion, has a profound impact on the accuracy and reliability of the criterion. It is directly related to the generation and distribution of charge in the ionization process, which in turn affects the insulation performance and operating stability of electrical equipment.

[0003] Since the Thomson's second coefficient is difficult to calculate accurately through pure theoretical deduction, its value often depends on the accumulation and analysis of experimental data. What is more complicated is that there are significant differences in the physical mechanisms of positive and negative coronas in the photoionization process, which leads to different physical meanings and numerical expressions of the Thomson's second coefficient in the context of positive corona and negative corona. For example, Naidis tried to use the experimental data of Zheleznyak et al. to calculate the Thomson's second coefficient of positive corona, but the results were significantly different from the actual observed data, reflecting the complexity and uncertainty of this coefficient in practical applications. For negative corona, the situation is even more complicated. Since the photoionization process of negative corona is closely related to the characteristics of the surface material of the wire, there are significant differences in the electron escape characteristics of different material surfaces, which in turn affects the specific value of the Thomson's second coefficient. Therefore, it is difficult to give a universally applicable definite value for the Thomson's second coefficient of negative corona, which undoubtedly increases the difficulty of accurately evaluating the performance of electrical equipment.

[0004] Nowadays, scholars usually take the default value of Thomson's second coefficient, which is 3×10 -3 , the positive and negative corona are often taken the same. Although this approach simplifies the calculation process, it ignores the difference between positive and negative corona and the influence of the surface material of the conductor on the coefficient, which leads to certain errors in the calculation results. Summary of the invention

[0005] The purpose of the present invention is to provide a method and a related device for determining the Thomson second coefficient in the electrode photoionization corona onset criterion, so as to solve the technical problem that the value of the Thomson second coefficient in the prior art is inaccurate, which affects the accuracy of the photoionization corona onset criterion.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for determining the Thomson second coefficient in the electrode photoionization corona criterion, comprising the following steps:

[0008] The boundary of the ionization zone when the conductor is coronaing is determined by the coronaing voltage, environmental parameters and the analytical formula of the nominal electric field.

[0009] Based on the obtained ionization zone boundary c when the conductor is coronaing, using Morrow's ionization coefficient and adhesion coefficient formula, the nominal electric field analytical formula is substituted into the photoionization coronaing criterion to obtain the integral expression of the photoionization coronaing criterion.

[0010] The integral interval in the integral expression of the photoionization corona criterion is discretized, and the initial value of the Thomson second coefficient is assigned. The discretized integral calculation is performed in the photoionization corona criterion, and finally the Thomson second coefficient is obtained.

[0011] Furthermore, the step of determining the boundary of the ionization zone when the conductor corona is initiated by using the corona initiation voltage, environmental parameters and the nominal electric field analytical formula specifically includes:

[0012] The ionization zone boundary c of the conductor at the time of corona onset is calculated by the analytical formula of corona onset voltage, relative air density and nominal electric field; the specific calculation formula is:

[0013]

[0014]

[0015] In the formula, h is the height of the conductor center to the ground; a is the radius of the conductor; U is the voltage; b is a constant, r is the distance from the inspection point to the center of the conductor; δ is the relative air density; E is the nominal electric field;

[0016] For positive corona, the ionization zone boundary c is used directly;

[0017] For negative corona, the ionization boundary c is transformed into the effective ionization boundary m of the negative corona.

[0018] Furthermore, the step of converting the ionization boundary c into the effective ionization boundary m of the negative corona is specifically calculated by the following formula:

[0019] α'(r k )+α(r k )[α(r k )-η(r k )]=0 (4)

[0020]

[0021] Where α is the ionization coefficient; η is the electron adsorption coefficient; a is the wire radius.

[0022] Furthermore, the Morrow's ionization coefficient and adhesion coefficient formula are:

[0023]

[0024] In the formula, α is the ionization coefficient; η is the electron adsorption coefficient; N is the number density of gas molecules; and E is the electric field strength.

[0025] Furthermore, the expression of the photoionization corona criterion specifically includes:

[0026] The criterion for the photoionization corona onset of the positive conductor is:

[0027]

[0028] In the formula, A + Represents the photoionization corona criterion of the positive conductor; γ p+ is the Thomson second coefficient of the positive corona; μ is the photon absorption coefficient; a is the wire radius; r is the distance from the observation point to the center of the wire;

[0029] The photoionization corona criterion of the negative conductor is:

[0030]

[0031] In the formula, A - represents the photoionization corona criterion of the negative conductor; γ p- is the Thomson second coefficient of the negative corona.

[0032] Furthermore, the step of discretizing the integral interval in the integral expression of the photoionization corona onset criterion, assigning an initial value to the Thomson second coefficient, substituting it into the photoionization corona onset criterion for discretized integral calculation, and finally obtaining the Thomson second coefficient specifically includes:

[0033] The integral interval in the integral expression of the photoionization corona criterion is discretized to give the Thomson second coefficient γ p Assign the initial value to γ p0 , and set γ p min <γ p <γ p max ;

[0034] Judgment A + / - Whether the size of meets the set conditions, if not, change the Thomson second coefficient γ p The value of A + / - The size of meets the preset conditions and outputs the Thomson second coefficient γ p .

[0035] Furthermore, the judgment A+ / - Whether the size of meets the set conditions, if not, change the Thomson second coefficient γ p The value of A + / - The size of meets the preset conditions and outputs the Thomson second coefficient γ p The steps include:

[0036] Judgment A + / - Is it satisfied? + / - -1|<ε0, ε0 is the preset accuracy;

[0037] If not satisfied |A + / - -1|<ε0, then let γ pmin =γ p , using γ p =(γ pmin +γ pmax ) / 2Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output;

[0038] If |A + / - -1|<ε0, then let γ pmax =γ p , using γ p =(γ pmin +γ pmax ) / 2Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output.

[0039] In a second aspect, the present invention provides a system for determining the Thomson second coefficient in the electrode photoionization corona criterion, comprising:

[0040] The ionization zone boundary calculation module is used to determine the ionization zone boundary when the conductor corona is initiated by using the corona initiation voltage, environmental parameters and the nominal electric field analytical formula;

[0041] An integral expression determination module is used to substitute the nominal electric field analytical formula into the photoionization corona onset criterion based on the obtained ionization zone boundary c when the conductor is corona onset, using Morrow's ionization coefficient and adhesion coefficient formula, to obtain the integral expression of the photoionization corona onset criterion;

[0042] The assignment calculation module is used to discretize the integral interval in the integral expression of the photoionization corona criterion, assign an initial value to the Thomson second coefficient, substitute it into the photoionization corona criterion for discretized integral calculation, and finally obtain the Thomson second coefficient.

[0043] In a third aspect, the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0044] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention discloses a method for determining the Thomson second coefficient in the electrode photoionization corona criterion and a related device. First, the corona voltage and relative air density are obtained by experiment, and the nominal electric field analytical formula can be used to determine the boundary of the ionization zone when the conductor corona is onset. Then, the Morrow ionization coefficient and adhesion coefficient formula are used, and the nominal electric field analytical expression formula is substituted into the photoionization corona criterion. Finally, the integral interval in the criterion is discretized, and the initial value is assigned to the Thomson second coefficient, which is substituted into the photoionization criterion for discretized integral calculation to determine whether the criterion meets the conditions. If not, the Thomson second coefficient is changed until the criterion meets the conditions, and the Thomson second coefficient is obtained at this time. The present invention can be used for all AC and DC conductors that need to use the photoionization corona criterion, and can determine the Thomson second coefficient of the conductor corona when the conductor geometric size, height above the ground, humidity, air pressure, and temperature are changed. For positive corona, the Thomson second coefficient determined by the present method can be well used for the conductor type that has not been tested to predict the corona. For negative corona, the integral area in the criterion is improved to avoid the generation of truncation error, which can be well used for corona prediction of wires of the same material. The difference between the positive and negative corona Thomson second coefficient under the same external conditions can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0048] Figure 1 is a flow chart of the method of the present invention;

[0049] Figure 2 is a schematic diagram of the system of the present invention;

[0050] Figure 3 This is a schematic diagram of a conductor according to an embodiment of the present invention;

[0051] Figure 4 It is a flow chart for determining the Thomson second coefficient in the electrode photoionization corona criterion in an embodiment of the present invention;

[0052] Figure 5 It is a schematic diagram of the computer device structure of the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0056] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0057] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0058] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0060] See also Figure 1 The embodiment of the present invention discloses a method for determining the Thomson second coefficient in the electrode photoionization corona criterion, comprising the following steps:

[0061] S1, determine the ionization zone boundary when the conductor corona is initiated by using the corona initiation voltage, environmental parameters and the nominal electric field analytical formula;

[0062] The corona initiation voltage is obtained experimentally, and the relative air density and nominal electric field are obtained by monitoring. The ionization zone boundary c at the time of conductor corona initiation is calculated by the analytical formula; the specific calculation formula is:

[0063]

[0064] In the formula, h is the height of the conductor center to the ground; a is the radius of the conductor; U is the voltage; b is a constant, r is the distance from the inspection point to the center of the conductor; δ is the relative air density; E is the nominal electric field;

[0065] For positive corona, the ionization zone boundary c is used directly;

[0066] For negative corona, the ionization boundary c is transformed into the effective ionization boundary m of the negative corona. The specific calculation formula is as follows:

[0067] α'(r k )+α(r k )[α(r k )-η(r k )]=0 (4)

[0068]

[0069] Where α is the ionization coefficient; η is the electron adsorption coefficient; a is the wire radius.

[0070] S2, based on the obtained ionization zone boundary c when the conductor is coronaing, using Morrow's ionization coefficient and adhesion coefficient formula, the nominal electric field analytical formula is substituted into the photoionization coronaing criterion to obtain the integral expression of the photoionization coronaing criterion;

[0071] The Morrow's ionization coefficient and adhesion coefficient formula are:

[0072]

[0073] In the formula, α is the ionization coefficient; η is the electron adsorption coefficient; N is the number density of gas molecules; and E is the electric field strength.

[0074] The expression of the photoionization corona criterion specifically includes:

[0075] The criterion for the photoionization corona onset of the positive conductor is:

[0076]

[0077] In the formula, A + Represents the photoionization corona criterion of the positive conductor; γ p+ is the Thomson second coefficient of the positive corona; μ is the photon absorption coefficient; a is the wire radius; r is the distance from the observation point to the center of the wire;

[0078] The photoionization corona criterion of the negative conductor is:

[0079]

[0080] In the formula, A - represents the photoionization corona criterion of the negative conductor; γ p- is the Thomson second coefficient of the negative corona.

[0081] S3, discretize the integral interval in the integral expression of the photoionization corona criterion, assign an initial value to the Thomson second coefficient, substitute it into the photoionization corona criterion for discretized integral calculation, and finally obtain the Thomson second coefficient.

[0082] Judgment A + / - Is it satisfied? + / - -1|<ε0, ε0 is the preset accuracy;

[0083] If not satisfied |A + / - -1|<ε0, then let γ pmin =γ p , using γ p =(γ pmin +γ pmax ) / 2Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output;

[0084] If |A + / - -1|<ε0, then let γ pmax =γ p , using γ p =(γ pmin +γ pmax ) / 2Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output.

[0085] See also Figure 2 The embodiment of the present invention discloses a system for determining the Thomson second coefficient in the electrode photoionization corona criterion, including an ionization zone boundary calculation module, an integral expression determination module and an assignment calculation module.

[0086] It should be noted that the ionization zone boundary calculation module is used to determine the ionization zone boundary when the conductor corona is initiated by using the corona initiation voltage, environmental parameters and the nominal electric field analytical formula; for positive corona, the ionization zone boundary c is directly used; for negative corona, the ionization boundary c is converted into the effective ionization boundary m of the negative corona. The specific calculation formula is:

[0087]

[0088] An integral expression determination module is used to substitute the nominal electric field analytical formula into the photoionization corona onset criterion based on the obtained ionization zone boundary c when the conductor is corona onset, using Morrow's ionization coefficient and adhesion coefficient formula, to obtain the integral expression of the photoionization corona onset criterion;

[0089] The assignment calculation module is used to discretize the integral interval in the integral expression of the photoionization corona criterion, assign an initial value to the Thomson second coefficient, substitute it into the photoionization corona criterion for discretized integral calculation, and finally obtain the Thomson second coefficient. Specifically, the judgment process is: judge A + / - Is it satisfied? + / - -1|<ε0, ε0 is the preset accuracy;

[0090] If not satisfied |A + / - -1|<ε0, then let γ pmin =γ p , using γ p =(γ pmin +γ pmax ) / 2Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output;

[0091] If |A + / - -1|<ε0, then let γ pmax =γp , using γ p =(γ pmin +γ pmax ) / 2Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output.

[0092] Example:

[0093] This embodiment discloses a method for determining the Thomson second coefficient in the electrode photoionization corona criterion, which is as follows:

[0094] See also Figure 3 , the electric field strength directly below the center of the conductor has only the y component, the electric field strength on the surface of the conductor is the largest, and the corona occurs first. Taking the direction of the electric field strength as the positive direction of the y axis, for the nominal electric field E directly below the center of the negative conductor, there is an analytical formula (1). In formula (1), h is the height of the conductor center to the ground, a is the radius of the conductor, and U is the applied voltage. r is the distance from the observation point to the center of the conductor. From the center of the conductor to the negative direction of the y-axis, we can get formula (2). Where c is the boundary of the ionization zone, that is, the electron adsorption coefficient here is equal to the ionization coefficient, E0 is 20 degrees Celsius, and the nominal electric field strength at c under standard atmospheric pressure is a definite quantity. δ is the relative air density. The relationship between the corona initiation field strength and the ionization boundary is determined by formula (3). In this way, the ionization boundary c can be calculated using the corona initiation voltage obtained experimentally.

[0095] The photoionization corona criterion for the positive and negative conductors is (8) and (9) respectively. For the positive corona, c can be used directly. For the negative corona, the ionization boundary c is transformed into the effective ionization boundary m of the negative corona from equations (4) and (5). Using Morrow's ionization coefficient and electron adsorption coefficient formula, i.e., equations (6) and (7), substituting equation (1) into equation (1), the integral expression of the entire criterion can be obtained. In this way, the Thomson second coefficient can be calculated through a simple program.

[0096] Discretize the width of the entire ionization zone from the wire surface to the ionization boundary, and take the number of discrete parts as C1. Calculation verification shows that the calculation result accuracy is generally good when C1 is greater than or equal to 5000. The program flow is as follows: Figure 4 As shown, the second coefficient of Thomson is γ p Assign the initial value to γ p0 , from γ p0 Start calculation (γ p Generally γ pmin -γ pmax Between. pmin With γ pmax You can change it yourself, as long as you ensure that they are substituted into the calculation respectively so that the criterion is less than 1 and greater than 1, which can generally be taken as 10 respectively. -4with 10 -1 ), judge whether the criterion meets the conditions (generally, the absolute value of the difference between the calculation results of equations (8) and (9) and 1 is less than ε0, ε0 is the accuracy and can be changed at will). If not, change γ p , until the criterion is met.

[0097] It should be noted that the method of the present invention can be applied to all electrode structures with an analytical formula for nominal electric field strength, including: wire plate electrodes (this embodiment), coaxial cylinders, parallel plate electrodes, etc. All of them can use this method.

[0098] The purpose of the present invention is to provide a method for determining the Thomson's second coefficient using the experimentally obtained corona initiation voltage of the wire plate electrode, wherein the photoionization corona initiation criterion is used, wherein the area factor of the wire plate electrode has an analytical formula. The nominal electric field analytical formula of the wire plate electrode and the Morrow's ionization coefficient and electron adsorption coefficient formula are used, and Morrow's formula is verified to be in good agreement with the experiment. Therefore, in the case of an analytical formula, the Thomson's second coefficient can be obtained using a simple program. The embodiment of the present invention can be used for all AC and DC conductors that need to use the photoionization corona initiation criterion, and can determine the Thomson's second coefficient of the conductor corona initiation under the conditions of changing the conductor geometric size, height above the ground, humidity, air pressure, and temperature. For positive corona, the Thomson's second coefficient determined by this method can be well used for the conductor type that has not been tested to predict the corona initiation. For negative corona, the integral area in the criterion is improved, the generation of truncation error is avoided, and it can be well used for the prediction of the corona initiation of the conductor of the same material. Being able to obtain the difference between the positive and negative corona Thomson second coefficient under the same external conditions helps to have a deeper understanding of the mechanism of gas discharge and has practical value in discharge control during the design, manufacture and operation of electrical equipment.

[0099] In one embodiment of the present invention, a computer device is provided, the computer device comprising a processor and a memory, the memory being used to store a computer program, the computer program comprising program instructions, and the processor being used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the method for determining the second coefficient of Thomson in the electrode photoionization corona criterion.

[0100] The present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the method for determining the second Thomson coefficient in the electrode photoionization corona criterion in the above embodiment.

[0101] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0102] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0103] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0104] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for determining the Thomson second coefficient in the electrode photoionization corona criterion, characterized in that: The following steps are involved: The boundary of the ionization zone when the conductor is coronaing is determined by the coronaing voltage, environmental parameters and the analytical formula of the nominal electric field. Based on the obtained ionization zone boundary when the conductor is coronaing, using Morrow's ionization coefficient and adhesion coefficient formula, the nominal electric field analytical formula is substituted into the photoionization coronaing criterion, and the integral expression of the photoionization coronaing criterion is obtained. The integral interval in the integral expression of the photoionization corona criterion is discretized, and the initial value of the Thomson second coefficient is assigned. The discretized integral calculation is performed in the photoionization corona criterion, and finally the Thomson second coefficient is obtained.

2. The method for determining the Thomson second coefficient in the electrode photoionization corona criterion according to claim 1, characterized in that: The step of determining the ionization zone boundary when the conductor corona is initiated by using the corona initiation voltage, environmental parameters and the nominal electric field analytical formula specifically includes: The ionization zone boundary c of the conductor at the time of corona onset is calculated by the analytical formula of corona onset voltage, relative air density and nominal electric field; the specific calculation formula is: In the formula, h is the height of the conductor center from the ground; a is the radius of the conductor; U is the voltage; b is a constant. r is the distance from the inspection point to the center of the conductor; δ is the relative air density; E is the nominal electric field; For positive corona, the ionization zone boundary c is used directly; For negative corona, the ionization boundary c is transformed into the effective ionization boundary m of the negative corona.

3. The method for determining the Thomson second coefficient in the electrode photoionization corona criterion according to claim 2, characterized in that: The step of converting the ionization boundary c into the effective ionization boundary m of the negative corona is specifically calculated as follows: a'(r k )+α(r k )[α(r k )-η(r k )]=0 (4) Where α is the ionization coefficient; η is the electron adsorption coefficient; a is the wire radius.

4. The method for determining the Thomson second coefficient in the electrode photoionization corona criterion according to claim 1, characterized in that: The Morrow's ionization coefficient and adhesion coefficient formula are: Where α is the ionization coefficient; η is the electron adsorption coefficient; N is the number density of gas molecules; and E is the electric field strength.

5. The method for determining the Thomson second coefficient in the electrode photoionization corona criterion according to claim 1, characterized in that: The expression of the photoionization corona criterion specifically includes: The criterion for the photoionization corona onset of the positive conductor is: In the formula, A + Represents the photoionization corona criterion of the positive conductor; γ p+ is the Thomson second coefficient of the positive corona; μ is the photon absorption coefficient; a is the wire radius; r is the distance from the observation point to the center of the wire; The photoionization corona criterion of the negative conductor is: In the formula, A - represents the photoionization corona criterion of the negative conductor; γ p- is the Thomson second coefficient of the negative corona.

6. The method for determining the second Thomson coefficient in the electrode photoionization corona criterion according to claim 1, characterized in that: The step of discretizing the integral interval in the integral expression of the photoionization corona onset criterion, assigning an initial value to the Thomson second coefficient, substituting it into the photoionization corona onset criterion for discretized integral calculation, and finally obtaining the Thomson second coefficient specifically includes: The integral interval in the integral expression of the photoionization corona criterion is discretized to give the Thomson second coefficient Assign the initial value to And set Judgment A + / - Whether the size meets the set conditions, if not, change the Thomson second coefficient The value of A + / - The size of meets the preset conditions and outputs the Thomson second coefficient 7. The method for determining the Thomson second coefficient in the electrode photoionization corona criterion according to claim 6, characterized in that: The judgment A + / - Whether the size meets the set conditions, if not, change the Thomson second coefficient The value of A + / - The size of meets the preset conditions and outputs the Thomson second coefficient The steps include: Judgment A + / - Is it satisfied? + / - -1|<ε0, ε0 is the preset accuracy; If not satisfied |A + / - -1|<ε0, then let use Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output; If |A + / - -1|<ε0, then let use Re-judge A + / - Whether the size meets the set conditions, multiple iterations are performed until A + / - Meet the preset criteria and output.

8. A system for determining the second Thomson coefficient in the electrode photoionization corona criterion, characterized in that: include: The ionization zone boundary calculation module is used to determine the ionization zone boundary when the conductor corona is initiated by using the corona initiation voltage, environmental parameters and the nominal electric field analytical formula; An integral expression determination module is used to substitute the nominal electric field analytical formula into the photoionization corona onset criterion based on the obtained ionization zone boundary c when the conductor is corona onset, using Morrow's ionization coefficient and adhesion coefficient formula, to obtain the integral expression of the photoionization corona onset criterion; The assignment calculation module is used to discretize the integral interval in the integral expression of the photoionization corona criterion, assign an initial value to the Thomson second coefficient, substitute it into the photoionization corona criterion for discretized integral calculation, and finally obtain the Thomson second coefficient.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, 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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