A circuit breaker contact residual electrical contact life prediction method

Abstract

The application discloses a circuit breaker contact residual electric contact life prediction method. The steps include determining a contact resistance degradation rate constant according to a cumulative total damage variable of a contact interface of a circuit breaker contact; establishing a contact resistance degradation model based on the contact resistance degradation rate constant; substituting a maximum contact resistance threshold value allowed by the circuit breaker contact into the contact resistance degradation model to obtain a contact life limit operation number; and finally, obtaining a contact residual electric contact number according to the contact life limit operation number and combining a current operation number of the contact. The application can break through the traditional life evaluation mode which depends on operation number or experience statistics, improve the scientificity and accuracy of prediction, and thus provide a reliable basis for condition-based maintenance and spare part management of the circuit breaker.

Description

Technical Field

[0001] This invention relates to the field of electrical equipment life prediction technology, and more specifically to a method for predicting the remaining electrical contact life of circuit breaker contacts. Background Technology

[0002] Currently, during long-term service, circuit breaker contacts are subjected to the combined effects of multiple damage factors, such as arc erosion, current-carrying friction wear, and thermo-electric coupling. This leads to cumulative damage at the contact interface, such as material migration, molten deposition, and structural degradation, resulting in increased contact resistance and decreased conductivity. In severe cases, it can even cause contact welding or malfunction, posing a direct threat to the safe operation of the circuit breaker.

[0003] However, the aforementioned damage evolution process is characterized by both gradual and sudden changes. Contact resistance changes slowly in the early stages of service, but deteriorates rapidly once a critical stage is reached. Traditional passive protection methods relying on real-time monitoring are insufficient to respond promptly to such abrupt risks. Therefore, if the remaining service life can be assessed in advance during the performance degradation process, and the failure threshold can be predicted, sufficient early warning time can be provided for maintenance personnel to rationally schedule maintenance windows, thereby effectively avoiding unplanned downtime and safety incidents.

[0004] However, current life assessment methods are mostly based on the number of operations or empirical statistical models, which are difficult to reflect the actual damage evolution process of contacts under complex working conditions. In particular, they lack a quantitative description of the interface cumulative damage mechanism under the multi-field coupling of electro-thermal-mechanical fields, resulting in insufficient accuracy of life prediction.

[0005] Therefore, there is an urgent need to develop a novel lifetime prediction method that can quantitatively describe the relationship between interface cumulative damage and performance degradation under multi-field coupling. Summary of the Invention

[0006] In view of the above problems, the present invention proposes a method for predicting the remaining electrical contact life of circuit breaker contacts, so as to overcome the above problems or at least partially solve the above problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, embodiments of the present invention provide a method for predicting the remaining electrical contact life of circuit breaker contacts, comprising the following steps: The contact resistance degradation rate constant is determined based on the cumulative total damage variable at the contact interface of the circuit breaker contacts. A contact resistance degradation model is established based on the aforementioned contact resistance degradation rate constant; Substituting the maximum allowable contact resistance threshold of the circuit breaker contacts into the contact resistance degradation model, the limit number of operation cycles for contact life is obtained; Based on the contact's lifespan limit number of operations and the current number of operations, the remaining number of electrical contacts of the contact is obtained.

[0009] Preferably, the contact resistance degradation rate constant is determined based on the cumulative total damage variable of the contact interface of the circuit breaker contacts, including determining the contact resistance degradation rate constant through a damage rate control function based on the rate of change of the cumulative total damage variable of the contact interface with respect to the number of cycles.

[0010] Preferably, the cumulative total damage variable at the contact interface includes material removal damage caused by mechanical friction, material melting and evaporation damage caused by arc ablation, and / or tissue degradation and thermal fatigue damage caused by temperature rise cycles.

[0011] Preferably, the material removal damage caused by mechanical friction is the ratio between the contact wear volume and the maximum allowable wear volume of the contact; the contact wear volume is expressed as:

[0012] In the formula, Indicates the contact wear volume. Indicates normal load, Indicates the sliding distance. This indicates the material hardness at temperature T. The value represents the wear coefficient, and N represents the current number of times the circuit breaker contacts have been operated.

[0013] Preferably, the material melting and evaporation damage caused by arc ablation is expressed as:

[0014] In the formula, For the circuit breaker contacts to operate to the first This is followed by material melting and evaporation damage caused by arc ablation. This indicates the arc erosion rate of the contact material. Indicates the index of the number of break operations. Indicates the current number of times the circuit breaker contacts have been operated. and They represent the first The arc current waveform and arc voltage waveform at time t during the second interruption process. Indicates the first The duration of the electric arc during the secondary interruption process. This indicates the maximum permissible mass loss due to arc erosion at the contact.

[0015] Preferably, the tissue degradation and thermal fatigue damage caused by temperature rise cycles are expressed as follows:

[0016] In the formula, This indicates that the circuit breaker contacts have reached the [number]th [operation]. This is followed by tissue degeneration and thermal fatigue damage caused by temperature rise cycles. Indicates the index of the number of operations. Indicates the current number of times the circuit breaker contacts have been operated. Indicates the first The amplitude of plastic strain caused by the mismatch in temperature rise at the contact interface during this operation, subscript Indicates plastic strain, subscript Indicates the strain amplitude. This represents the fatigue ductility coefficient of the contact material. This indicates the fatigue ductility index of the contact material.

[0017] Preferably, in establishing a contact resistance degradation model based on the contact resistance degradation rate constant, the contact resistance degradation model is expressed as:

[0018] In the formula, Let N be the contact resistance of the circuit breaker contacts after N cycles. The initial contact resistance. is the contact resistance degradation rate constant.

[0019] Preferably, the maximum allowable contact resistance threshold of the circuit breaker contacts is:

[0020] In the formula, This represents the maximum permissible temperature rise of the circuit breaker contacts. The heat dissipation coefficient of the contact material. This is the rated operating current of the circuit breaker.

[0021] In a second aspect, embodiments of the present invention provide a device for predicting the remaining electrical contact life of a circuit breaker contact, used to implement the method for predicting the remaining electrical contact life of a circuit breaker contact as described in any of the preceding claims, including: The contact resistance degradation model construction module is used to calculate the cumulative total damage variable of the contact interface of the circuit breaker contact, determine the contact resistance degradation rate constant, and establish a contact resistance degradation model based on the contact resistance degradation rate constant. The remaining electrical contact life prediction module is used to obtain the maximum allowable contact resistance threshold of the circuit breaker contacts, input it into the contact resistance degradation model, obtain the contact life limit number of operation times, and obtain the remaining electrical contact times of the contacts based on the contact life limit number of operation times and the current number of operation times of the contacts.

[0022] Thirdly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method for predicting the remaining electrical contact life of circuit breaker contacts as described in any of the preceding claims.

[0023] This invention provides a method for predicting the remaining electrical contact life of circuit breaker contacts. Compared with existing technologies, this invention breaks through the traditional life assessment model that relies on the number of operations or empirical statistics. By constructing a multi-physics coupled model of the circuit breaker contacts (electricity, temperature rise, and contact pressure), it establishes the coupling relationship between current distribution, temperature rise, and contact pressure at the mechanistic level, achieving a quantitative description of the cumulative damage process at the contact interface. Simultaneously, it introduces the contact resistance degradation rate constant and rate of change as dynamic degradation characterization parameters and establishes a degradation model with correction factors. This enables the life prediction to sensitively reflect the real nonlinear degradation process of the contacts under complex operating conditions, significantly improving the scientific rigor and accuracy of the prediction, and ultimately providing a reliable basis for condition-based maintenance and spare parts management of circuit breakers. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the method for predicting the remaining electrical contact life of circuit breaker contacts provided in an embodiment of the present invention. Figure 2 Comparison of the comprehensive damage morphology of the contact interface of different contact materials after repeated breaking, as provided in the embodiments of the present invention; Figure 3 This is a schematic diagram of the contact resistance changing with the number of operations provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the remaining electrical contact lifetime prediction results provided in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] This invention discloses a method for predicting the remaining electrical contact life of circuit breaker contacts, which aims to predict the electrical contact life of circuit breaker contacts by quantitatively describing the relationship between interface cumulative damage and performance degradation under multi-field coupling.

[0028] In one embodiment, Figure 1 This is a schematic diagram of the method for predicting the remaining electrical contact life of circuit breaker contacts according to the present invention. The diagram presents a complete evaluation closed loop from multiphysics modeling to macroscopic interface damage accumulation, and then to resistance degradation and remaining life prediction. The prediction steps include: The contact resistance degradation rate constant is determined based on the cumulative total damage variable at the contact interface of the circuit breaker contacts. A contact resistance degradation model is established based on the aforementioned contact resistance degradation rate constant; Substituting the maximum allowable contact resistance threshold of the circuit breaker contacts into the contact resistance degradation model, the limit number of operation cycles for contact life is obtained; Based on the contact's lifespan limit number of operations and the current number of operations, the remaining number of electrical contacts of the contact is obtained.

[0029] The following detailed description, with reference to the accompanying drawings, focuses on CuCr30 and CuCr30Gr contacts of a 30kV high-voltage circuit breaker. The method provided by this invention can be implemented based on online monitoring data or combined with offline test or simulation data for parameter calibration.

[0030] In one specific embodiment, during long-term operation, the circuit breaker contacts are simultaneously affected by multiple factors, including mechanical friction and wear, arc erosion, and thermal cycling shock, resulting in a gradual accumulation of interface degradation with each operation cycle. To quantitatively characterize the comprehensive degradation state of the contact interface, the total damage variable of the contact interface is defined as including material removal damage caused by mechanical friction, material melting and evaporation damage caused by arc erosion, and / or structural degradation and thermal fatigue damage caused by temperature rise cycles, expressed as:

[0031] in, This represents the cumulative total damage variable at the contact interface. To remove material damage caused by mechanical friction; Damage caused by material melting and evaporation due to arc ablation; This refers to tissue degradation and thermal fatigue damage caused by temperature rise cycles.

[0032] As a preferred approach, after obtaining each damage component, it is first normalized so that its value range is [0,1], and then the components are added together to determine the total cumulative damage variable of the contact interface.

[0033] In one alternative implementation, the material removal damage caused by mechanical friction is the ratio between the contact wear volume and the maximum allowable wear volume of the contact; that is...

[0034] In the formula, For the circuit breaker contacts to operate to the first This is caused by material removal damage due to mechanical friction. Indicates the maximum allowable wear volume of the contact. Let N represent the contact wear volume, and N represent the current number of times the circuit breaker contacts have been operated. Furthermore, in this implementation, based on the Archard wear model, the evolution relationship of the contact wear volume with the operating process is constructed:

[0035] In the formula, This represents the normal load, which varies with contact stress and thermal deformation. The sliding distance is determined by the contact opening and closing process. This indicates that the material hardness at temperature T decreases non-linearly with temperature. This represents the wear coefficient, which is related to material pairing and lubrication conditions.

[0036] In one optional implementation, the circuit breaker contacts generate a high-temperature electric arc during the breaking process. This arc causes melting, evaporation, and material migration on the contact surface, resulting in interfacial ablation damage. Since the arc current, arc voltage, and arc duration may differ in different breaking operations, this embodiment calculates the arc energy for each breaking process and then applies it to the preceding... The arc ablation damage caused by each interruption is accumulated to establish the following arc ablation damage model:

[0037] In the formula, For the circuit breaker contacts to operate to the first This is caused by material melting and evaporation damage due to arc ablation; This indicates the arc erosion rate of the contact material; Indicates the index of the number of open / close operations; Indicates the current number of times the circuit breaker contacts have been operated; and They represent the first The arc current waveform and arc voltage waveform at time t during the second interruption process; Indicates the first The duration of the electric arc during the secondary interruption process; This indicates the maximum permissible mass loss due to arc erosion at the contact.

[0038] In one alternative implementation, the contact interface region undergoes a periodic temperature rise and cooldown process under long-term current carrying and arc thermal shock. Due to the difference in thermal expansion between different regions of the contact interface, the periodic temperature changes cause cyclic thermal stress and plastic strain accumulation, leading to material degradation and thermal fatigue damage. This embodiment uses the Coffin-Manson relation to describe the relationship between plastic strain amplitude and thermal fatigue life:

[0039] In the formula, Indicates the first The amplitude of plastic strain caused by the mismatch in temperature rise at the contact interface during this operation, subscript Indicates plastic strain, subscript Indicates the strain amplitude. Indicates the index of the number of operations. Indicates the thermal fatigue life corresponding to the plastic strain amplitude, subscript This indicates fatigue failure. This represents the fatigue ductility coefficient of the contact material. This indicates the fatigue ductility index of the contact material.

[0040] The first Thermal fatigue damage caused by a single temperature rise cycle is expressed as the ratio of the number of cycles to the corresponding thermal fatigue life, and is compared with the previous cycle. The damage caused by each operation is accumulated to obtain:

[0041] Thermal fatigue life determined by the Coffin-Manson relationship Substituting into the above cumulative damage formula, we get:

[0042] In the formula, This indicates that the circuit breaker contacts have reached the [number]th [operation]. This is followed by tissue degeneration and thermal fatigue damage caused by temperature rise cycles. Indicates the first The thermal fatigue life under the corresponding operating conditions for this operation. Indicates the first The amplitude of plastic strain caused by the mismatch in temperature rise at the contact interface during this operation. This represents the fatigue ductility coefficient of the contact material. This indicates the fatigue ductility index of the contact material. Indicates the index of the number of operations. This indicates the current number of times the circuit breaker contacts have been operated.

[0043] Figure 2The comprehensive damage morphology of the contact interface of different contact materials after repeated interruption is shown. During repeated interruption, the contacts are simultaneously subjected to mechanical friction, arc ablation, and cyclic temperature rise. In the initial stage of interruption, the arc heat causes localized melting and material migration on the contact surface; after cooling, the molten material forms a resolidified structure, and localized copper phase enrichment may occur. With increasing interruption cycles, the cyclic thermal stress generated by repeated temperature rise and cooling accumulates, forming stress concentrations in areas of inhomogeneous structure, promoting the initiation and gradual propagation of microcracks, eventually leading to... Figure 2 The crack pattern shown is illustrated. Meanwhile, mechanical friction further removes surface material and disrupts the resolidified layer, increasing the roughness and unevenness of the contact interface.

[0044] A comparison of the two contact materials reveals that the contact surface without added Gr exhibits more pronounced crack patterns and localized copper enrichment, indicating significant interfacial melting, material migration, and thermal stress concentration. The contact with added Gr shows a more uniform interfacial structure, a more dispersed precipitate distribution, and reduced localized copper enrichment and crack concentration. These morphological differences demonstrate that material composition affects the rate of damage accumulation at the contact interface, further influencing the degradation process of the actual conductive contact area and contact resistance.

[0045] In one specific embodiment, the contact resistance degradation rate constant is determined by a damage rate control function based on the rate of change of the cumulative total damage variable of the contact interface with respect to the number of cycles; the expression is:

[0046] In the formula, This represents the cumulative total damage variable at the contact interface, where N is the current number of times the circuit breaker contacts have been operated. This represents the damage rate regulation function. This represents the contact resistance degradation rate constant.

[0047] As an optional implementation, the damage rate control function is a linear function, and its expression is:

[0048] Therefore, the contact resistance degradation rate constant is expressed as:

[0049] In the formula, This represents the constant of the rate of degradation of the reference contact resistance. Indicates the damage rate regulation coefficient. and It can be determined by fitting test data on contact resistance and cumulative total damage at the contact interface.

[0050] Furthermore, with increasing operating cycles, wear, arc erosion, and thermal softening effects on the contact surface gradually intensify, leading to a reduction in the actual conductive contact area and consequently a continuous increase in contact resistance. Therefore, based on the evolution law of cumulative interface damage, this embodiment establishes the following contact resistance degradation model:

[0051] In the formula, Let N be the contact resistance of the circuit breaker contacts after N cycles. This represents the initial contact resistance.

[0052] In some implementations, the initial contact resistance is obtained through the following steps: Repeatedly open and close the contacts for testing, simultaneously collecting the voltage drop U at the electrical contact interface and the loop current I when the contacts are closed, and subtracting the inherent resistance of the line and structural components. Then, the precise initial contact resistance of the contact in the undegraded state was calculated. This is used as a benchmark parameter for subsequent life assessment. The initial contact resistance is expressed as:

[0053] In the formula, U represents the voltage drop at the electrical contact interface, and I represents the loop current. This indicates the inherent resistance of the circuit and structural components.

[0054] Figure 3 This is a schematic diagram of the contact resistance versus the number of operations, reflecting the degradation of the macroscopic conductivity of the contact interface. In the early stages of service, interface damage is minimal, and the contact resistance remains relatively stable. With increasing number of operations, the destruction of the surface microstructure and the intensification of material remelting and deposition lead to a reduction in actual conductive spots, causing the curve slope to gradually increase and exhibiting an overall non-linear, phased growth trend. By extracting discrete experimental data and fitting them, a degradation mapping relationship between contact resistance and the number of operations is constructed. For example, for CuCr30Gr contacts, the mapping relationship is as follows: For CuCr30 contacts, the mapping relationship is as follows: Based on this continuous mapping model, the rate of change of contact resistance can be further calculated to characterize the degradation rate at the current stage of the lifespan. Figure 4 This is a schematic diagram showing the predicted results of the remaining electrical contact life.

[0055] In one specific embodiment, as wear, arc erosion, and thermal degradation accumulate at the contact interface, the actual conductive contact area of ​​the contact gradually decreases, leading to a continuous increase in contact resistance. When the contact resistance reaches the upper limit of the allowable value, the conductivity of the contact significantly decreases, accompanied by abnormal temperature rise and deterioration of contact stability. Therefore, reaching the critical value of the contact resistance is used as the criterion for termination of the contact's lifespan.

[0056] in, This is the maximum allowable contact resistance threshold for the circuit breaker contacts.

[0057] In this embodiment, the maximum allowable contact resistance threshold of the circuit breaker contacts is the maximum allowable contact resistance of the contacts under rated operating conditions, which is determined based on the contact temperature rise limit condition. As the contact resistance increases, the heat generated at the contact interface continues to increase, leading to a rise in interface temperature. When the contact temperature rise exceeds the material's allowable temperature rise limit, it will cause material softening, a decrease in contact pressure, and deterioration of conductivity. Therefore, the contact resistance under the corresponding condition is defined as the maximum allowable contact resistance threshold of the circuit breaker contacts. The calculation formula is:

[0058] In the formula, The maximum permissible temperature rise of the circuit breaker contacts can be determined according to the temperature rise limits in GB / T 11022 "Common Technical Requirements for High Voltage Switchgear and Controlgear Standards". The heat dissipation coefficient of the contact material is determined by the alloy material selected for the contact. This is the rated operating current of the circuit breaker.

[0059] Furthermore, the maximum allowable contact resistance threshold for the circuit breaker contacts is set. Substituting this into the contact resistance degradation model, that is, letting This allows us to obtain the lifespan limit corresponding to when the contact reaches a failure state. Then, based on the current number of runs Ncurrent, we calculate the remaining electrical contact life of the contact:

[0060] In the formula, This represents the remaining number of electrical contacts of the contacts. This refers to the maximum number of operation cycles required for the contact's lifespan. This represents the current number of times the contact has been run.

[0061] Based on the same inventive concept, embodiments of the present invention further provide a device for predicting the remaining electrical contact life of circuit breaker contacts, the device comprising: The contact resistance degradation model construction module is used to calculate the cumulative total damage variable of the contact interface of the circuit breaker contact, determine the contact resistance degradation rate constant, and establish a contact resistance degradation model based on the contact resistance degradation rate constant. The remaining electrical contact life prediction module is used to obtain the maximum allowable contact resistance threshold of the circuit breaker contacts, input it into the contact resistance degradation model, obtain the contact life limit number of operation times, and obtain the remaining electrical contact times of the contacts based on the contact life limit number of operation times and the current number of operation times of the contacts.

[0062] The circuit breaker contact residual contact life prediction device provided in this embodiment of the invention produces the same technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the corresponding content in the aforementioned method embodiment, and will not be repeated here.

[0063] Furthermore, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method for predicting the remaining electrical contact life of circuit breaker contacts as described in any of the preceding claims.

[0064] The embodiments of the present invention have been described in detail above, and the principles and implementation methods of the present invention have been explained. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, computer software program products, or electronic devices, etc. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] Any content or technical means not mentioned in the embodiments of this invention can be obtained by referring to the prior art. This disclosure does not limit the scope of the invention and therefore will not be elaborated further.

[0066] It should be noted that the word "comprising" does not exclude the presence of components or steps not listed in the claims. The words "a" or "an" preceding a component do not exclude the presence of a plurality of such components. This invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for predicting the remaining electrical contact life of circuit breaker contacts, characterized in that, include: The contact resistance degradation rate constant is determined based on the cumulative total damage variable at the contact interface of the circuit breaker contacts. A contact resistance degradation model is established based on the aforementioned contact resistance degradation rate constant; Substituting the maximum allowable contact resistance threshold of the circuit breaker contacts into the contact resistance degradation model, the limit number of operation cycles for contact life is obtained; Based on the contact's lifespan limit number of operations and the current number of operations, the remaining number of electrical contacts of the contact is obtained.

2. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 1, characterized in that, The contact resistance degradation rate constant is determined based on the cumulative total damage variable of the contact interface of the circuit breaker contacts, including determining the contact resistance degradation rate constant through a damage rate control function based on the rate of change of the cumulative total damage variable of the contact interface with respect to the number of cycles.

3. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 1 or 2, characterized in that, The cumulative total damage variable at the contact interface includes material removal damage caused by mechanical friction, material melting and evaporation damage caused by arc ablation, and / or tissue degradation and thermal fatigue damage caused by temperature rise cycles.

4. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 3, characterized in that, The material removal damage caused by mechanical friction is the ratio between the contact wear volume and the maximum allowable wear volume of the contact; the contact wear volume is expressed as: In the formula, Indicates the contact wear volume. Indicates normal load, Indicates the sliding distance. This indicates the material hardness at temperature T. The value represents the wear coefficient, and N represents the current number of times the circuit breaker contacts have been operated.

5. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 3, characterized in that, The material melting and evaporation damage caused by arc ablation is represented as follows: In the formula, For the circuit breaker contacts to operate to the first This is followed by material melting and evaporation damage caused by arc ablation. This indicates the arc erosion rate of the contact material. Indicates the index of the number of break operations. Indicates the current number of times the circuit breaker contacts have been operated. and They represent the first The arc current waveform and arc voltage waveform at time t during the second interruption process. Indicates the first The duration of the electric arc during the secondary interruption process. This indicates the maximum permissible mass loss due to arc erosion at the contact.

6. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 3, characterized in that, The tissue degradation and thermal fatigue damage caused by temperature rise cycles are represented as follows: In the formula, This indicates that the circuit breaker contacts have reached the [number]th [operation]. This is followed by tissue degeneration and thermal fatigue damage caused by temperature rise cycles. Indicates the index of the number of operations. Indicates the current number of times the circuit breaker contacts have been operated. Indicates the first The amplitude of plastic strain caused by the mismatch in temperature rise at the contact interface during this operation, subscript Indicates plastic strain, subscript Indicates the strain amplitude. This represents the fatigue ductility coefficient of the contact material. This indicates the fatigue ductility index of the contact material.

7. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 1, characterized in that, In the contact resistance degradation model established based on the aforementioned contact resistance degradation rate constant, the contact resistance degradation model is expressed as follows: In the formula, Let N be the contact resistance of the circuit breaker contacts after N cycles. The initial contact resistance. is the contact resistance degradation rate constant.

8. The method for predicting the remaining electrical contact life of circuit breaker contacts as described in claim 1, characterized in that, The maximum allowable contact resistance threshold for the circuit breaker contacts is: In the formula, This represents the maximum permissible temperature rise of the circuit breaker contacts. The heat dissipation coefficient of the contact material. This is the rated operating current of the circuit breaker.

9. A device for predicting the remaining electrical contact life of circuit breaker contacts, characterized in that, A method for predicting the remaining electrical contact life of circuit breaker contacts as described in any one of claims 1 to 8, comprising: The contact resistance degradation model construction module is used to calculate the cumulative total damage variable of the contact interface of the circuit breaker contact, determine the contact resistance degradation rate constant, and establish a contact resistance degradation model based on the contact resistance degradation rate constant. The remaining electrical contact life prediction module is used to obtain the maximum allowable contact resistance threshold of the circuit breaker contacts, input it into the contact resistance degradation model, obtain the contact life limit number of operation times, and obtain the remaining electrical contact times of the contacts based on the contact life limit number of operation times and the current number of operation times of the contacts.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for predicting the remaining electrical contact life of circuit breaker contacts as described in any one of claims 1 to 8.

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