Method and device for evaluating contact state of high-voltage switch cabinet wrench contact and terminal equipment

Abstract

The application is suitable for the electrical engineering technical field, and provides a high-voltage switch cabinet plum blossom contact contact state evaluation method, device and terminal equipment, the high-voltage switch cabinet plum blossom contact contact state evaluation method comprises the following steps: calculating the temperature rise limit value of the plum blossom contact under the current operating condition according to the equipment operating parameter of the high-voltage switch cabinet;Determine the minimum limit value of the contact pressure of the single contact finger of the plum blossom contact;Calculate the maximum limit value of the contact pressure of the single contact finger of the plum blossom contact;Based on the temperature rise limit value, the minimum limit value and the maximum limit value of the contact pressure of the plum blossom contact, the plum blossom contact contact state evaluation criterion is established.The application utilizes the contact state evaluation criterion, can effectively guide the equipment operation and maintenance personnel to carry out equipment operation and maintenance, and ensures the safe and good operation of the plum blossom contact.

Description

Technical Field

[0001] The present application belongs to the field of electrical engineering technology, and in particular relates to a method, device and terminal equipment for evaluating the contact status of plum blossom contacts of a high-voltage switch cabinet. Background Art

[0002] The plum blossom contact is a common contact type in high-voltage switchgear, often used in the connection between circuit breaker trolleys, isolating trolleys and static contacts. The contact area between the plum blossom contact and the static contact is one of the parts in high-voltage switchgear that is most prone to overheating. The reasons for overheating are: poor heat dissipation in the contact box; and excessive contact resistance at the contact area, which causes excessive Joule heat to be generated when current passes through. The plum blossom contact relies on an annular spring wrapped around its outer surface to provide contact pressure. After the plum blossom contact has been in operation for a long time, the annular spring may have insufficient elasticity, reducing the contact pressure provided to the plum blossom contact. The contact resistance at the contact area between the plum blossom contact and the static contact increases, causing overheating. On the other hand, excessive contact pressure will increase the friction during the contact engagement process, increase the operating force of the vehicle entering and exiting, and cause operational difficulties. It is also easy to cause wear on the contact surface, affecting the service life of the contact.

[0003] Therefore, the temperature and contact pressure of the plum blossom contact are important indicators for evaluating the contact state of the plum blossom contact. These temperatures and contact pressures must be maintained within a reasonable range to ensure safe and effective contact operation. However, currently, standards for evaluating plum blossom contact temperature and contact pressure have not been established. Operation and maintenance personnel often make judgments based on experience, which is easily influenced by subjective factors. This severely restricts the effectiveness of relevant detection technologies and affects the targeted operation and maintenance of equipment. Summary of the Invention

[0004] In order to overcome the problems existing in the relevant technology, the embodiments of the present application provide a method, device and terminal equipment for evaluating the contact status of the plum blossom contacts of a high-voltage switch cabinet, which can accurately and effectively evaluate the contact status of the plum blossom contacts under operating conditions, effectively guide operation and maintenance personnel to carry out equipment operation and maintenance, and ensure the safe and good operation of the high-voltage switch cabinet.

[0005] This application is achieved through the following technical solutions:

[0006] In the first aspect, an embodiment of the present application provides a method for evaluating the contact status of a plum blossom contact of a high-voltage switchgear, comprising: calculating the temperature rise limit of the plum blossom contact under the current operating conditions based on the equipment operating parameters of the high-voltage switchgear; determining the minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the minimum limit being the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirements under the current operating conditions and the electric stability and thermal stability requirements under the short-circuit conditions are met; calculating the maximum limit of the contact pressure of a single contact finger of the plum blossom contact; and establishing a contact status evaluation standard for the plum blossom contact based on the temperature rise limit, the minimum limit and the maximum limit.

[0007] In a possible implementation, the temperature rise limit of the plum blossom contact under the current operating conditions is calculated according to the equipment operating parameters of the high-voltage switch cabinet, including: Calculate the temperature rise limit; where τ max is the temperature rise limit, I n is the rated current, I is the working current of the plum blossom contact under the current operating conditions, and τ1 is converted to 1.1I under the current operating conditions n Temperature rise of the lower plum blossom contact.

[0008] In one possible implementation, determining the minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: calculating a first minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the first minimum limit being the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement is met under current operating conditions; calculating a second minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the second minimum limit being the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the electric stability requirement is met under short-circuit conditions; calculating a third minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the third minimum limit being the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the thermal stability requirement is met under short-circuit conditions; and determining the minimum limit based on the first minimum limit, the second minimum limit, and the third minimum limit.

[0009] In a possible implementation, the calculation of the first minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: Calculating the first minimum limit value. Calculating the second minimum limit value of the contact pressure of a single contact finger of the plum blossom contact includes: Calculating the second minimum limit value. Calculating the third minimum limit value of the contact pressure of a single contact finger of the plum blossom contact includes: The third minimum limit value is calculated.

[0010] Among them, K is the preset coefficient related to the contact surface condition and contact material, I nI is rated current, n1 is number of fingers, L is Lorentz constant, T e T is ambient temperature, T1 is temperature at temperature measurement point of the contact at 1.1 times rated current, τ is long-term operating temperature rise of the contact under current operating conditions, m is an index related to contact form, I m I is rated peak withstand current through a single finger, K b K is contact coefficient of the contact, I k I is rated short-time withstand current through a single finger, U kr U is contact resistance voltage drop at melting of the contact material.

[0011] In a possible implementation, the determining the minimum limit value based on the first minimum limit value, the second minimum limit value and the third minimum limit value comprises: determining the maximum value among the first minimum limit value, the second minimum limit value and the third minimum limit value as the minimum limit value.

[0012] In a possible implementation, the calculating the maximum limit value of the contact pressure of a single finger of the contact comprises: calculating the maximum limit value of the contact pressure of a single finger of the contact by F is the maximum limit value of the contact pressure of a single finger of the contact; wherein F max F is the maximum limit value of the contact pressure of a single finger of the contact, n1 is number of fingers, n2 is number of ring springs, K s K is design value of spring stiffness, D0 is design value of diameter of the ring spring in free state, D1 is design value of diameter of the ring spring in working state.

[0013] In a possible implementation, the evaluation criterion of the contact state of the contact comprises: when the contact state of the contact is normal, the following conditions should be met: τ is the temperature rise of the contact, F is the contact pressure of the single finger, τ max F is the limit value of the temperature rise, F min F is the minimum limit value, F max F is the maximum limit value.

[0014] In the second aspect, an embodiment of the present application provides a contact status evaluation device for a plum blossom contact of a high-voltage switchgear, including: a temperature rise limit calculation module, used to calculate the temperature rise limit of the plum blossom contact under the current operating conditions based on the equipment operating parameters of the high-voltage switchgear; a minimum limit determination module, used to determine the minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the minimum limit being the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirements under the current operating conditions and the electric stability and thermal stability requirements under the short-circuit conditions are met; a maximum limit calculation module, used to calculate the maximum limit of the contact pressure of a single contact finger of the plum blossom contact; and an evaluation standard establishment module, used to establish the evaluation standard for the contact status of the plum blossom contact based on the temperature rise limit, the minimum limit and the maximum limit.

[0015] In a third aspect, an embodiment of the present application provides a terminal device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the method described in any one of the first aspects.

[0016] In a fourth aspect, an embodiment of the present application 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, it implements the method as described in any one of the first aspects.

[0017] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the terminal device to execute any of the methods described in the first aspect above.

[0018] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0019] The embodiment of the present application comprehensively considers the dual indicators of temperature rise and contact pressure of the plum blossom contact based on the equipment operation data of the high-voltage switchgear and the existing technical standards, and derives the plum blossom contact state evaluation standard through theoretical formulas when the temperature rise under long-term working conditions and the electric stability and thermal stability requirements under short-circuit conditions are met. It takes into account both scientificity and practicality, can comprehensively and comprehensively evaluate the contact state of the plum blossom contact, effectively guide operation and maintenance personnel to carry out equipment operation and maintenance, and ensure the safe and good operation of the plum blossom contact.

[0020] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0022] Figure 1 is a flow chart of the high-voltage switch cabinet contact state evaluation method provided by an embodiment of the present application;

[0023] Figure 2 is a structural schematic diagram of the high-voltage switch cabinet contact state evaluation device provided by an embodiment of the present application;

[0024] Figure 3 is a structural schematic diagram of the high-voltage switch cabinet contact state evaluation terminal device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0025] In the following description, specific details are set forth in order to provide a thorough understanding of the embodiments of the present application. However, persons skilled in the art will understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary details.

[0026] It should be understood that when used in the specification and the appended claims of the present application, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0027] It should also be understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations thereof, and includes these combinations.

[0028] As used in the specification and the appended claims of the present application, the term "if" can be interpreted as "when" or "upon" or "in response to a determination" or "in response to detecting" depending on the context. Similarly, the phrase "if it is determined" or "if [a described condition or event] is detected" can be interpreted as meaning "upon determining" or "in response to determining" or "upon detecting [a described condition or event]" or "in response to detecting [a described condition or event]" depending on the context.

[0029] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0030] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figure 1 The details of the evaluation method for the contact status of the plum blossom contacts of the high-voltage switchgear are as follows:

[0033] In step 101, the temperature rise limit τ of the plum blossom contact under the current operating conditions is calculated according to the equipment operating parameters of the high-voltage switchgear. max .

[0034] For example, in step 101, Calculate the above temperature rise limit τ max , I n is the rated current, I is the working current of the plum blossom contact under the current operating conditions, and τ1 is converted to 1.1I under the current operating conditions n Temperature rise of the lower plum blossom contact.

[0035] Specifically, according to the heat balance equation I 2 R=K T From Sτ, we can know that in the case of resistance R and heat dissipation coefficient K T When the heat dissipation area S is constant, the temperature rise τ of the plum blossom contact is directly proportional to the square of the current. Considering that the higher the temperature rise, the higher the convection and radiation heat dissipation capacity of the object surface, it can be approximately considered that τ∝1.8I. The current power industry standard DL / T 593-2016 stipulates that the temperature rise limit of copper-plated silver contacts in air under temperature rise test conditions, that is, 1.1 times the rated current and the ambient air temperature does not exceed 40°C, is 65K. Therefore, the temperature rise of the plum blossom contact converted to 1.1 times the rated current can be calculated by the following formula (1):

[0036]

[0037] Wherein, τ is the long-term operating temperature rise of the plum blossom contact under the current operating conditions, and I is the long-term operating current of the plum blossom contact under the current operating conditions. τ and I can be obtained by viewing the online temperature monitoring data and current data; I n is the rated current; τ1 is converted to 1.1I under the current operating conditions n Temperature rise of the lower plum blossom contact.

[0038] Let τ1 take the maximum value of 65, and substitute it into formula (1) to obtain the temperature rise limit calculated by the following formula (2):

[0039]

[0040] In step 102 , the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact is determined.

[0041] Among them, the above minimum limit is the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirements under current operating conditions and the electric stability and thermal stability requirements under short-circuit conditions are met.

[0042] Exemplarily, step 102 may include: calculating a first minimum limit value for the contact pressure of a single contact finger of the plum blossom contact, calculating a second minimum limit value for the contact pressure of a single contact finger of the plum blossom contact, and calculating a third minimum limit value for the contact pressure of a single contact finger of the plum blossom contact, and determining the minimum limit values ​​based on the first, second, and third minimum limits. The first minimum limit value is the minimum limit value for the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under current operating conditions is met, the second minimum limit value is the minimum limit value for the contact pressure of a single contact finger of the plum blossom contact when the electric stability requirement under short-circuit conditions is met, and the third minimum limit value is the minimum limit value for the contact pressure of a single contact finger of the plum blossom contact when the thermal stability requirement under short-circuit conditions is met.

[0043] In some embodiments, the Calculate the first minimum limit F min1 .

[0044] Specifically, in engineering applications, the relationship between contact resistance and contact pressure is expressed by the following empirical formula (3):

[0045]

[0046] Among them, R jis the contact resistance of a single contact finger to the stationary contact; K is a coefficient related to the contact surface condition and the contact material, for a silver-plated copper contact finger, K is 80 (μΩ·N); m is an index related to the contact form, 0.5 for point contact, 0.7 for line contact, and 1 for surface contact, for a contact finger, m is 0.7; F is the contact pressure between a single contact finger and the stationary contact.

[0047] It should be noted that the above-mentioned coefficient K related to the contact surface condition and the contact material, for a silver-plated copper contact finger, K is 80 (μΩ·N), and the index m related to the contact form, 0.5 for point contact, 0.7 for line contact, and 1 for surface contact, for a contact finger, m is 0.7, are only exemplary and do not limit the present application, and those skilled in the art can adjust the related values according to actual needs.

[0048] The current density at the contact point of the contact finger and the stationary contact is the largest, and the temperature rise thereof is also higher than that of other parts of the contact finger, according to the potential-temperature theory and the Weir law, the following equation can be obtained:

[0049]

[0050] wherein, U j is the contact voltage drop, T m is the temperature at the contact point under 1.1 times the rated current, T1 is the temperature at the temperature measurement point of the contact finger under 1.1 times the rated current, τ m is the temperature rise of the contact point, L is the Lorentz constant, T e is the ambient temperature, and n1 is the number of contact fingers.

[0051] By combining equations (1), (3), and (4), the following equation can be obtained:

[0052]

[0053] As can be seen from equation (5), τ m is negatively correlated with F. Let τ m take the maximum value of 65, and substitute it into equation (5) to obtain the first minimum limit value F min1 of the contact pressure, which is as follows:

[0054]

[0055] It should be noted that the above-mentioned temperature rise τ m of the contact point takes 65, which is only exemplary and does not limit the present application, and those skilled in the art can adjust the threshold value according to actual needs.

[0056] In some embodiments, the second minimum limit value F min2 may be calculated by .

[0057] Specifically, the contact pressure F between each contact finger and the static contact must satisfy the following empirical formula:

[0058]

[0059] Among them, I m K is the rated peak withstand current flowing through a single contact finger. b is the coefficient, and for copper-copper plum blossom contacts, it is 5000. Therefore, the contact pressure F of a single contact finger of the plum blossom contact is min2 for:

[0060]

[0061] It should be noted that the above coefficient K b , taking 5000 for the copper-copper plum blossom contact is only for exemplary description and is not used to limit the invention. Those skilled in the art can also adjust the relevant values ​​according to actual needs.

[0062] In some embodiments, the Calculate the third minimum limit F min3 .

[0063] Specifically, when a large short-circuit current passes through the plum blossom contact, the contact material may soften or even melt. At this time, the contact resistance voltage drop should satisfy the following empirical formula:

[0064] U k =I k R j ≤U kr / (1.4~1.67) (9)

[0065] Among them, I k is the rated short-time withstand current flowing through a single contact finger, U kr The contact resistance voltage drop when the contact material melts can be obtained by referring to the product technical data. For copper contacts, it is 0.4V.

[0066] Combining equations (3) and (9) we can get:

[0067]

[0068] It should be noted that the contact resistance voltage drop U when the above contact material melts kr , taking 0.4V for the copper-copper plum blossom contact is only for exemplary explanation and is not used to limit the invention. Those skilled in the art can also adjust the relevant values ​​according to actual needs.

[0069] For example, the first minimum limit F min1 , the second minimum limit F min2and the third minimum limit F min3 The maximum value among is determined as the above minimum limit.

[0070] For example, the minimum contact pressure limit of a single finger of a plum blossom contact is the maximum contact pressure determined by equations (6), (8), and (10), that is:

[0071] F min =max(F min1 ,F min2 ,F min3 ) (11)

[0072] In step 103 , the maximum limit of the contact pressure of a single contact finger of the plum blossom contact is calculated.

[0073] For example, it can be achieved by Calculate the above maximum limit F max .

[0074] Specifically, the contact pressure of the plum blossom contact is related to the length and stiffness coefficient of the annular spring. After the contact has been running for a long time, the spring parameters change, making the contact pressure smaller. That is, the contact pressure of the plum blossom contact should be less than or equal to the factory value. If there is no factory value, the maximum contact pressure limit F can be calculated by the following formula: max :

[0075]

[0076] Among them, F max is the maximum limit of contact pressure of a single finger of the plum blossom contact, n1 is the number of fingers, n2 is the number of annular springs, K s is the design value of the spring stiffness coefficient, D0 is the design value of the diameter of the annular spring in the free state, and D1 is the design value of the diameter of the annular spring in the working state.

[0077] In step 104, based on the above-mentioned temperature rise limit, minimum limit and maximum limit, a criterion for judging the contact state of the plum blossom contact is established.

[0078] For example, the evaluation criteria for the contact state of the plum blossom contact can be determined by the plum blossom contact temperature rise τ and the contact pressure F of a single contact finger. When the plum blossom contact contact state is normal, it should meet the following conditions:

[0079]

[0080] In order to enhance the guiding role of the evaluation criteria for equipment operation and maintenance, the equipment's caution status criteria, abnormal status criteria, and severe status criteria can be specified with a certain margin. For example:

[0081] When τ max <τ≤105%τ max or 95% F min≤F <F min When 105%τ max <τ≤110%τ max or 90% F min ≤F<95%F min , the contact state of the plum blossom contact is considered to be abnormal, and it is necessary to immediately shut down the power supply or reduce the load; when τ>110%τ max or F<90%F min or F max <F min When the plum blossom contact state is considered to be serious, it is necessary to immediately cut off the power supply.

[0082] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0083] Exemplarily, the execution order of step 101, step 102 and step 103 is not specific, and step 101, step 102 and step 103 can be executed simultaneously, or step 101, step 102 and step 103 can be executed separately in sequence, which is not limited.

[0084] Corresponding to the method for evaluating the contact state of the plum blossom contacts of the high-voltage switchgear described in the above embodiment, Figure 2 A structural block diagram of a high-voltage switch cabinet plum contact contact state evaluation device provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0085] See also Figure 2 The high-voltage switch cabinet plum blossom contact contact state evaluation device in the embodiment of the present application may include a temperature rise limit calculation module 201, a minimum limit determination module 202, a maximum limit calculation module 203 and an evaluation standard establishment module 204.

[0086] Among them, the temperature rise limit calculation module 201 is used to calculate the temperature rise limit of the plum blossom contact under the current operating conditions based on the equipment operating parameters of the high-voltage switchgear. The minimum limit determination module 202 is used to determine the minimum limit of the contact pressure of a single contact finger of the target plum blossom contact, which is the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when meeting the temperature rise requirements under the current operating conditions and the electrical stability and thermal stability requirements under short-circuit conditions. The maximum limit calculation module 203 is used to calculate the maximum limit of the contact pressure of a single contact finger of the plum blossom contact. The evaluation standard establishment module 204 is used to establish the evaluation standard of the contact state of the plum blossom contact based on the temperature rise limit, the minimum limit, and the maximum limit.

[0087] Optionally, the minimum limit determination module 202 can be specifically used to: calculate the first minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the first minimum limit is the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under the current operating conditions is met; calculate the second minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the second minimum limit is the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under the current operating conditions is met; calculate the third minimum limit of the contact pressure of a single contact finger of the plum blossom contact, the third minimum limit is the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under the current operating conditions is met; determine the above minimum limits based on the first minimum limit, the second minimum limit and the third minimum limit.

[0088] Exemplarily, the calculation of the first minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: Calculate the first minimum limit. The above calculation of the second minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: Calculate the second minimum limit. The above calculation of the third minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: Calculate the third minimum limit.

[0089] Among them, K is the preset coefficient related to the contact surface condition and contact material, I n is the rated current, n1 is the number of contacts, L is the Lorentz constant, T e is the ambient temperature, T1 is the temperature at the plum blossom contact temperature measurement point at 1.1 times the rated current, τ is the long-term operating temperature rise of the plum blossom contact under the current operating conditions, m is an index related to the contact form, I m K is the rated peak withstand current flowing through a single contact finger. b is the plum blossom contact coefficient, I k is the rated short-time withstand current flowing through a single contact finger, U kr It is the contact resistance voltage drop when the contact material melts.

[0090] Exemplarily, determining the minimum limit value based on the first minimum limit value, the second minimum limit value, and the third minimum limit value includes: determining the maximum value among the first minimum limit value, the second minimum limit value, and the third minimum limit value as the minimum limit value.

[0091] Optionally, the temperature rise limit calculation module 201 is specifically used to: Calculate the temperature rise limit; where τ max is the temperature rise limit, I n is the rated current, I is the working current of the plum blossom contact under the current operating conditions, and τ1 is converted to 1.1I under the current operating conditions n Temperature rise of the lower plum blossom contact.

[0092] Optionally, the maximum limit calculation module 203 is specifically configured to: Calculate the above maximum limit; where F max is the maximum limit of contact pressure of a single finger of the plum blossom contact, n1 is the number of fingers, n2 is the number of annular springs, K s is the design value of the spring stiffness coefficient, D0 is the design value of the diameter of the annular spring in the free state, and D1 is the design value of the diameter of the annular spring in the working state.

[0093] Optionally, the above-mentioned plum blossom contact contact state evaluation criteria include: when the plum blossom contact contact state is normal, it meets: Among them, τ is the temperature rise of the plum blossom contact, F is the contact pressure of a single contact finger, τ max is the temperature rise limit, F min is the minimum limit, F max is the maximum limit.

[0094] The present application also provides a terminal device. Figure 3 The terminal device 300 may include: at least one processor 310 and a memory 320. The memory 320 stores a computer program that can be run on the at least one processor 310. When the processor 310 executes the computer program, the steps in any of the above method embodiments are implemented, such as Figure 1 Steps 101 to 104 in the embodiment shown. Alternatively, when the processor 310 executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are realized, for example Figure 2 Functions of modules 201 to 204 are shown.

[0095] For example, the computer program may be divided into one or more modules / units, one or more modules / units being stored in the memory 320 and executed by the processor 310 to complete the present application. The one or more modules / units may be a series of computer program segments capable of completing specific functions, and the program segments are used to describe the execution process of the computer program in the terminal device 300.

[0096] Those skilled in the art will understand that Figure 3 These are merely examples of terminal devices and do not constitute a limitation on the terminal devices. The terminal devices may include more or fewer components than shown in the figure, or a combination of certain components, or different components, such as input and output devices, network access devices, buses, etc.

[0097] The processor 310 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0098] The memory 320 can be an internal storage unit of the terminal device or an external storage device of the terminal device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. The memory 320 is used to store the computer program and other programs and data required by the terminal device. The memory 320 can also be used to temporarily store data that has been output or is about to be output.

[0099] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0100] The method for evaluating the contact status of plum blossom contacts of a high-voltage switchgear provided in the embodiment of the present application can be applied to terminal devices such as computers, tablet computers, laptops, netbooks, and personal digital assistants (PDAs). The embodiment of the present application does not impose any restrictions on the specific type of terminal device.

[0101] An embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps in each embodiment of the above-mentioned method for evaluating the contact state of plum blossom contacts of a high-voltage switch cabinet can be implemented.

[0102] An embodiment of the present application provides a computer program product. When the computer program product is run on a mobile terminal, the mobile terminal implements the steps of each embodiment of the above-mentioned method for evaluating the contact state of plum blossom contacts of a high-voltage switch cabinet.

[0103] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process of the above-mentioned method embodiment by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can at least include: any entity or device capable of carrying computer program code to the camera / terminal device, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal, and software distribution medium. For example, a USB flash drive, mobile hard drive, magnetic disk, or optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals or telecommunication signals.

[0104] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0105] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0106] In the embodiments provided in this application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0107] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0108] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for evaluating the contact status of plum blossom contacts of a high-voltage switchgear, characterized in that: include: Calculate the temperature rise limit of the plum blossom contact under the current operating conditions based on the equipment operating parameters of the high-voltage switchgear; Determine a minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, wherein the minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under the current operating conditions and the electric stability and thermal stability requirements under the short-circuit condition are met; Calculate the maximum limit of contact pressure of a single contact finger of a plum blossom contact; Establishing a contact state evaluation standard for the plum blossom contacts based on the temperature rise limit, the minimum limit, and the maximum limit; Wherein, the determination of the minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: Calculating a first minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, where the first minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under current operating conditions is met; Calculating a second minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, where the second minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when the electric stability requirement under a short-circuit condition is met; Calculating a third minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, where the third minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when thermal stability requirements under a short-circuit condition are met; determining the minimum limit value based on the first minimum limit value, the second minimum limit value, and the third minimum limit value; The calculation of the first minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass calculating the first minimum limit; The calculation of the second minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass calculating the second minimum limit; The calculation of the third minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass Calculating the third minimum limit; Among them, K is the preset coefficient related to the contact surface condition and contact material, I n is the rated current, n1 is the number of contacts, L is the Lorentz constant, T e is the ambient temperature, T1 is the temperature at the plum blossom contact temperature measurement point at 1.1 times the rated current, τ is the long-term operating temperature rise of the plum blossom contact under the current operating conditions, m is an index related to the contact form, I m K is the rated peak withstand current flowing through a single contact finger. b is the plum blossom contact coefficient, I k is the rated short-time withstand current flowing through a single contact finger, U kr The contact resistance voltage drop when the contact material melts; The determining the minimum limit value based on the first minimum limit value, the second minimum limit value, and the third minimum limit value includes: The maximum value among the first minimum limit value, the second minimum limit value and the third minimum limit value is determined as the minimum limit value.

2. The method for evaluating the contact state of the plum blossom contacts of a high-voltage switch cabinet according to claim 1, characterized in that: Calculating the temperature rise limit of the plum blossom contact under the current operating conditions based on the equipment operating parameters of the high-voltage switchgear includes: pass Calculating the temperature rise limit; Among them, τ max is the temperature rise limit, I n is the rated current, I is the working current of the plum blossom contact under the current operating conditions, and τ1 is converted to 1.1I under the current operating conditions n Temperature rise of the lower plum blossom contact.

3. The method for evaluating the contact status of plum blossom contacts of a high-voltage switch cabinet according to claim 1, characterized in that: The calculation of the maximum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass calculating said maximum limit; Among them, F max is the maximum limit of contact pressure of a single finger of the plum blossom contact, n1 is the number of fingers, n2 is the number of annular springs, K s is the design value of the spring stiffness coefficient, D0 is the design value of the diameter of the annular spring in the free state, and D1 is the design value of the diameter of the annular spring in the working state.

4. The method for evaluating the contact state of plum blossom contacts of a high-voltage switch cabinet according to claim 1, characterized in that: The criteria for judging the contact state of the plum blossom contacts include: When the contact state of the plum blossom contact is normal, the following conditions are met: Wherein, τ is the temperature rise of the plum blossom contact, F is the contact pressure of the single contact finger, τ max is the temperature rise limit, F min is the minimum limit, F max is the maximum limit.

5. A device for evaluating the contact status of plum blossom contacts of a high-voltage switch cabinet, characterized in that: include: The temperature rise limit calculation module is used to calculate the temperature rise limit of the plum blossom contact under the current operating conditions according to the equipment operating parameters of the high-voltage switchgear; A minimum limit determination module is used to determine the minimum limit of the contact pressure of a single contact finger of the plum blossom contact, wherein the minimum limit is the minimum limit of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under the current operating conditions and the electric stability and thermal stability requirements under the short-circuit conditions are met; A maximum limit calculation module is used to calculate the maximum limit of the contact pressure of a single contact finger of the plum blossom contact; A judging standard establishing module, configured to establish a judging standard for the contact state of the plum blossom contact based on the temperature rise limit, the minimum limit, and the maximum limit; Wherein, the minimum limit determination module is used to: Calculating a first minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, where the first minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when the temperature rise requirement under current operating conditions is met; Calculating a second minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, where the second minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when the electric stability requirement under a short-circuit condition is met; Calculating a third minimum limit value of the contact pressure of a single contact finger of the plum blossom contact, where the third minimum limit value is the minimum limit value of the contact pressure of a single contact finger of the plum blossom contact when thermal stability requirements under a short-circuit condition are met; determining the minimum limit value based on the first minimum limit value, the second minimum limit value, and the third minimum limit value; The calculation of the first minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass calculating the first minimum limit; The calculation of the second minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass calculating the second minimum limit; The calculation of the third minimum limit of the contact pressure of a single contact finger of the plum blossom contact includes: pass Calculating the third minimum limit; Among them, K is the preset coefficient related to the contact surface condition and contact material, I n is the rated current, n1 is the number of contacts, L is the Lorentz constant, T e is the ambient temperature, T1 is the temperature at the plum blossom contact temperature measurement point at 1.1 times the rated current, τ is the long-term operating temperature rise of the plum blossom contact under the current operating conditions, m is an index related to the contact form, I m K is the rated peak withstand current flowing through a single contact finger. b is the plum blossom contact coefficient, I k is the rated short-time withstand current flowing through a single contact finger, U kr The contact resistance voltage drop when the contact material melts; The determining the minimum limit value based on the first minimum limit value, the second minimum limit value, and the third minimum limit value includes: The maximum value among the first minimum limit value, the second minimum limit value and the third minimum limit value is determined as the minimum limit value.

6. A terminal device comprising a memory and a processor, characterized in that: The memory stores a computer program that can be run on the processor, and the processor implements the method according to any one of claims 1 to 4 when executing the computer program.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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