Alloy material electric contact performance electrical test method based on arc characteristics

Abstract

The invention discloses an electric arc characteristic-based alloy material electric contact performance electrical test method, which comprises the following steps of: providing basic information for a high-voltage rotating arc diffusion arc and intermediate-frequency large-current breaking simulation test by acquiring contact data of a circuit breaker, and triggering a controllable rotating arc or diffusion arc between contacts by utilizing an alternating-current high-voltage small-current system, so that the contact performance of the high-voltage rotating arc and the intermediate-frequency large-current breaking simulation test is realized. An intermediate-frequency low-voltage large-current system is used for simulating the on-off working condition of an intermediate-frequency circuit breaker, electrical performance data and ablation damage information of a contact under the action of an intermediate-frequency arc are collected, weighted calculation is carried out on the arc temperature, the electrical performance and an ablation index, and a comprehensive electrical contact performance index is generated; the performance of the alloy contact under different working conditions is comprehensively evaluated, the electric contact performance test of the alloy material is realized, and the test accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of electrical testing technology, and in particular to an electrical testing method for the electrical contact performance of alloy materials based on arc characteristics. Background Technology

[0002] With the development of DC power distribution, electrified transportation and new power equipment, the arc response characteristics of the alloy materials used in circuit breaker contacts under high voltage and high current conditions have gradually become an important factor affecting the reliability of breaking. In order to evaluate the electrical contact performance of the contact materials under the action of arc, the laboratory usually needs to carry out a variety of tests to analyze the electrical contact performance of the contact materials under different working conditions.

[0003] In existing materials testing practices, arc tests on contact materials often rely on a single current source system, such as using high-voltage excitation to ignite the arc, or using a large-current system to simulate the breaking process.

[0004] However, in existing technologies, it is difficult to conduct controllable arc rotation or diffusion arc tests under high voltage and high current conditions. Under high voltage and low current conditions, the stability and controllability of the arc are insufficient, making it difficult to form a regular arc. Under high current conditions, there is a lack of precise magnetic arc control methods, making it impossible to stably control arc migration or diffusion. This makes it difficult to uniformly obtain and compare arc response data of contact materials. Therefore, existing technologies lack a unified arc testing mechanism that can simultaneously meet the requirements of controllable arc rotation or diffusion arc testing under high voltage conditions and breaking simulation measurement under medium frequency and high current conditions. This prevents researchers from fully understanding the response law of contact materials to arcs under different operating conditions, resulting in low accuracy of existing contact material testing. Summary of the Invention

[0005] Objective: This invention provides an electrical testing method for the electrical contact performance of alloy materials based on arc characteristics. This method acquires circuit breaker contact data, providing fundamental information for subsequent arc testing. A controllable rotating or spreading arc is induced between the contacts using an AC high-voltage, low-current system. Arc temperature parameters are collected using a schlieren system to obtain arc stability information. A medium-frequency, low-voltage, high-current system simulates the breaking conditions of a medium-frequency circuit breaker, collecting electrical performance data and ablation damage information of the contacts under the action of the medium-frequency arc. Weighted calculations are performed on arc temperature, electrical performance, and ablation indicators to obtain a comprehensive electrical contact performance index. This index is used to comprehensively evaluate the conductivity stability, ablation resistance, and degradation characteristics of alloy contacts under different operating conditions, thereby achieving rapid and comprehensive material performance evaluation and improving accuracy.

[0006] Technical solution: The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics provided by this invention includes the following steps: Acquire circuit breaker contact data containing a preset alloy material; Based on the circuit breaker contact data, the arc generating system is controlled to ignite between the circuit breaker contacts. The arc generating system includes: an AC high-voltage low-current system and a medium-frequency low-voltage high-current system. The system controls the generation of an electric arc between the contacts of a circuit breaker by controlling a high-voltage, low-current AC system. An external magnetic field is applied to the electric arc to induce a rotating or spreading arc. During the induction of the rotating or spreading arc, the temperature parameters of the electric arc are collected using a schlieren system. The system controls the flow of current between the contacts of a medium-frequency low-voltage high-current system to simulate the medium-frequency arc induced under the medium-frequency breaking condition of the medium-frequency circuit breaker. During the induction of the medium-frequency arc, electrical performance data and ablation data of the circuit breaker contacts are collected. Statistical analysis was performed on the temperature parameters of the electric arc to calculate the arc stability index. The deterioration index of the circuit breaker contacts was calculated based on the electrical performance data, and the ablation rate index of the circuit breaker contacts was calculated based on the ablation data. The arc stability index, degradation index, and ablation rate index are weighted and calculated to obtain the corresponding electrical contact performance index, which is used to evaluate the electrical contact performance of the preset alloy material used in the circuit breaker contacts under the action of an electric arc.

[0007] Furthermore, in the above method, when controlling the AC high-voltage low-current system to generate an electric arc between the circuit breaker contacts, and applying an external magnetic field to the arc to induce a rotating or spreading arc, the following steps are included: The control system for high-voltage, low-current AC circuit breakers outputs an AC excitation voltage greater than a preset voltage threshold while maintaining a preset contact gap, thereby generating an electric arc. The AC high-voltage low-current system outputs a first excitation current to form a first magnetic field perpendicular to the axial direction of the electric arc between the circuit breaker contacts; the AC high-voltage low-current system outputs a second excitation current to form a second magnetic field that pushes the electric arc to spread towards the edge of the circuit breaker contacts. The direction of the force on the electric arc is adjusted by superimposing the first and second magnetic fields, thus triggering a rotating arc or a spreading arc.

[0008] Furthermore, the above method adjusts the force direction of the electric arc based on the superposition of the first and second magnetic fields to induce a rotating arc or a spreading arc, including: The amplitude ratio and phase difference of the first excitation current and the second excitation current are adjusted respectively to change the superposition direction of the first magnetic field and the second magnetic field; Based on the superposition direction to control the force direction of the electric arc, the electric arc migrates circumferentially along the circuit breaker contacts, triggering a rotating arc; Based on the superposition direction, the force direction of the electric arc is controlled, and the electric arc is pushed outward radially to induce a diffusion arc.

[0009] Furthermore, in the above method, during the initiation of a rotating arc or a spreading arc, the temperature parameters of the arc are collected using a schlieren system, including: During the induction of a rotating arc or a spreading arc, an image information of the arc is acquired using a schlieren system. Based on the image information, the change in the grayscale of the blade edge is measured to obtain light deflection information. The refractive index distribution within the arc channel is obtained by inverse transformation of the light deflection information, and the temperature parameters of the arc are calculated based on the inverse calculation of the refractive index distribution.

[0010] Furthermore, the medium-frequency low-voltage high-current system described in the above method includes an arc-starting circuit and a medium-frequency oscillation circuit, and the electrical performance data and ablation data of the circuit breaker contacts are collected using the following method: The arc-ignition circuit is controlled to apply a preset arc-ignition voltage to the circuit breaker contacts, thereby generating an arc-ignition current between the circuit breaker contacts. An arc-starting channel is established based on the arc-starting current generated by the arc-starting circuit, and the intermediate frequency oscillation circuit is controlled to output the intermediate frequency oscillation current. An intermediate frequency electric arc is formed in the arc-starting channel based on the intermediate frequency oscillation current. During the operation of the medium-frequency electric arc, the voltage, current and arc sustaining characteristics of the circuit breaker contacts are collected as electrical performance data. After the medium-frequency arc is extinguished, the surface of the circuit breaker contacts is measured to obtain the depth of the micro-pits, the area of ​​the erosion spots, and the amount of material spalling on the contact surface, which are used as ablation data.

[0011] Furthermore, the above method establishes an arc-starting channel based on the arc-starting current generated by the arc-starting circuit, controls the intermediate-frequency oscillation circuit to output an intermediate-frequency oscillation current, and forms an intermediate-frequency arc in the arc-starting channel based on the intermediate-frequency oscillation current, including: The intermediate frequency oscillation circuit is controlled to output an intermediate frequency oscillation current within a preset frequency range. The preset frequency range of the intermediate frequency oscillation current is used to simulate the current change characteristics of the intermediate frequency circuit breaker during the intermediate frequency breaking stage. The intermediate frequency oscillation circuit is controlled to adjust the peak amplitude of the intermediate frequency oscillation current, thereby forming an intermediate frequency electric arc in the arc ignition channel.

[0012] Furthermore, in the above method, during the operation of the medium-frequency arc, the voltage, current, and arc sustaining characteristics of the circuit breaker contacts are collected as electrical performance data, including: The intermediate frequency voltage and current of the intermediate frequency arc are sampled during the action period, and the arc power variation curve is constructed based on the intermediate frequency voltage and current. Based on the arc power variation curve, calculate the energy consumption of the medium-frequency arc and the contact power loss to form the first indicator; Based on the arc sustaining characteristic data, the sustaining time, extinction time, and voltage fluctuation data of the medium-frequency arc are calculated to form a second index. Electrical performance data are generated based on the first and second indicators of the mid-frequency electric arc.

[0013] Furthermore, in the above method, after the medium-frequency arc is extinguished, measurements are taken on the surface of the circuit breaker contacts to obtain the depth of micro-pits, the area of ​​erosion spots, and the amount of material spalling on the contact surface, as ablation data, including: After the medium-frequency arc is extinguished, the surface of the circuit breaker contacts is measured to obtain spatial distribution data of micro-pits and erosion spots; The spatial distribution data is processed to identify the depth of each micro-pit, calculate the depth of the micro-pit on the contact surface, identify the outline of each erosion spot, and calculate the area of ​​the erosion spot. Calculate the volume or mass of the detached material to obtain data on the amount of material detached. Data on the depth of micro-pits, area of ​​erosion spots, and amount of material spalling on the contact surface are processed to form ablation data.

[0014] Furthermore, the above method involves statistical analysis of the arc temperature parameters, calculation of the arc stability index, calculation of the circuit breaker contact degradation index based on electrical performance data, and calculation of the circuit breaker contact ablation rate index based on ablation data, including: Statistical analysis of the temperature parameters of the electric arc is performed to calculate the mean, maximum and fluctuation range of the electric arc temperature, thus forming an electric arc stability index. Based on electrical performance data, the contact resistance change rate, voltage fluctuation amplitude, and power loss are calculated to form the degradation index of the circuit breaker contacts. Based on the ablation data, the average depth, maximum depth, area of ​​erosion spots, and amount of material spalling on the surface of the circuit breaker contacts are statistically analyzed to calculate the ablation rate index.

[0015] Furthermore, in the above method, the arc stability index, degradation index, and ablation rate index are weighted and calculated to obtain the corresponding electrical contact performance indexes, including: The arc stability index, degradation index, and ablation rate index were normalized to obtain the arc stability factor, degradation factor, and ablation factor. The electric contact performance index is obtained by weighting the arc stability factor, degradation factor and ablation factor according to the preset weights.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. By combining AC high-voltage low-current system and medium-frequency low-voltage high-current system to test circuit breaker contacts, a comprehensive evaluation of the electrical contact performance of contacts under different current conditions can be achieved. Compared with the existing technology that only relies on a single current system for testing, more complete contact performance information can be obtained, and the reliability of material performance analysis can be improved.

[0017] 2. By combining two current systems for testing, the arc behavior and ablation characteristics of the contact can be obtained simultaneously, achieving synchronous measurement of arc stability and material loss. Compared with existing technologies that cannot comprehensively obtain multi-dimensional performance indicators in the same experiment, this can improve the accuracy and comprehensiveness of contact performance evaluation.

[0018] 3. By comprehensively analyzing the test data of AC high-voltage low-current systems and medium-frequency low-voltage high-current systems, a unified evaluation of contact degradation trends and electrical contact performance can be achieved. Compared with the single-index evaluation method of existing technologies, this can provide a more comprehensive basis for alloy material selection and circuit breaker design. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall process of the present invention; Figure 2 This is a flowchart of the test process for the AC high-voltage low-current control system of the present invention; Figure 3 This is a flowchart of the test process for the control of the medium-frequency low-voltage high-current system of the present invention. Detailed Implementation

[0020] To ensure clarity and conciseness in the description of the following embodiments, a brief introduction to the related technologies is given first: In the existing technology, the electrical contact performance test of circuit breaker contact alloy materials usually relies on a single current source system. Such tests are usually divided into two types of operating conditions: high voltage and low current operating conditions and high current operating conditions.

[0021] Under high-voltage, low-current conditions, laboratories typically use a high-voltage power supply to apply an excitation voltage exceeding the air breakdown voltage to the contact gap of a circuit breaker, igniting an electric arc to measure the contact's conductivity stability and initial arc behavior. Under these conditions, the initial arc formation is highly dependent on the contact surface microstructure, gap uniformity, and environmental disturbances (such as airflow and temperature fluctuations). The arc is prone to random migration, flashover, or intermittent extinction, making it difficult to form a stable and repeatable swirling or spreading arc. This irregular arc behavior leads to significant differences in the measured data of temperature distribution, arc power, and local thermal damage, thus failing to accurately reflect the arc response characteristics of the material under high-voltage conditions.

[0022] Under high-current conditions, high-current power supplies are typically used to simulate the breaking process of medium-frequency circuit breakers in order to obtain information on the electrical performance and ablation damage of the contacts under the action of an electric arc. In this process, the formation of the electric arc depends on the transient characteristics of the contacts being energized, but without magnetic control or current regulation, it is impossible to control the radial diffusion or circumferential migration of the electric arc along the contact surface. Due to the instability of the electric arc, the distribution of the ablation area, melting depth, and spalling amount of the contact material has a large degree of randomness, which makes the data obtained from different tests of the same material significantly different, making it difficult to conduct consistency analysis and reliable comparison. In addition, the arc temperature and power fluctuations under high-current conditions are large, and existing single measurement methods cannot comprehensively collect these parameters.

[0023] Research has revealed that existing technologies rely on a single current source system, making it difficult to form a stable and controllable swirling or spreading arc under high voltage and low current conditions. Furthermore, the lack of effective magnetic control or current regulation methods under high current conditions leads to the inability to precisely control arc migration and diffusion. Consequently, the electrical properties, ablation damage, and arc temperature data of the contact material obtained under different test conditions in a single system vary significantly. Researchers find it difficult to comprehensively evaluate the electrical contact performance of the contact material under various operating conditions, which restricts the reliability and experimental efficiency of material performance testing and reduces the accuracy of material electrical contact performance testing.

[0024] To address the aforementioned problems, this application provides an electrical testing method for the electrical contact performance of alloy materials based on arc characteristics, such as... Figure 1 .

[0025] S101, acquire contact data containing preset alloy material.

[0026] Data on circuit breaker contacts containing preset alloy materials is acquired to construct a basic dataset for testing contact electrical contact performance. The contact data is organized according to structural, material, and geometric information to form a standardized dataset, providing basic input for subsequent arc initiation and performance testing. By collecting material information, geometric dimensions, surface condition, etc. of the contacts, a complete contact data archive is formed and preprocessed and standardized so that it can be directly called upon for subsequent electrical contact performance testing of AC high-voltage low-current systems and medium-frequency low-voltage high-current systems.

[0027] To ensure clarity and conciseness in the description of the following embodiments, a brief introduction to the relevant terms is given first: Preset alloy material: refers to the alloy composition used in the circuit breaker contacts, which may include silver-tungsten alloy, copper-tungsten alloy, magnesium-zinc alloy or other specific alloys optimized for electrical contact performance.

[0028] Circuit breaker contact data: A collection of data including the material composition, geometric dimensions, surface morphology, and machining status of circuit breaker contacts.

[0029] In some possible implementation methods, structured information, including contact length, thickness, contact surface shape, and preset alloy composition, is extracted from the circuit breaker contact design drawings, production records, and material testing reports. Simultaneously, surface conditions (such as pits, oxide layers, and roughness) are measured and collected, and missing or outlier data are supplemented or corrected. Through standardized and unified processing, data from contacts from different sources and batches are integrated into a complete dataset, providing input for subsequent testing.

[0030] For example, for magnesium-zinc alloy contacts, the following data are collected: contact dimensions (length, thickness, contact surface diameter), material composition (magnesium content, yttrium content, zinc content, and trace elements), grain size, surface roughness, and processing status. This data is recorded in a database according to a standardized format. Missing surface roughness or grain size information can be filled in by the average value of similar contacts, historical measurement data, or material standards. Abnormal processing status or damage data can be marked and used as a reference in subsequent tests. The resulting contact data set contains complete material information, geometric information, and microstructure information, providing a basic input for electrical contact performance analysis.

[0031] S102, based on the contact data, controls the AC high-voltage, low-current system for testing, such as... Figure 2 As shown.

[0032] Based on the acquired circuit breaker contact data, while ensuring a preset contact gap is maintained, the AC high-voltage, low-current system is controlled to output an AC excitation voltage greater than a preset voltage threshold, causing an electric arc to form between the contacts. During the arc initiation process, the system simultaneously outputs a first excitation current, forming a first magnetic field perpendicular to the arc's axial direction to guide the arc's circumferential migration along the contacts, thus forming a rotating arc. A second excitation current is then output, forming a second magnetic field acting radially to propel the arc towards the contact edge. By adjusting the amplitude ratio and phase difference between the first and second excitation currents, the direction of the superposition of the two magnetic fields is changed, thereby controlling... The arc force direction enables the controllable generation of either a rotating or spreading arc. Switching between these two modes is possible as needed for testing. Throughout the arc initiation and migration process, a schlieren system continuously acquires arc image data. Based on image grayscale changes, the optical deflection information of the arc blade is measured. Then, an inverse optical transformation algorithm is used to obtain the refractive index distribution within the arc channel. Further inversion calculations yield the arc temperature parameters, forming a high-precision arc temperature data sequence. Furthermore, dynamic parameters such as the arc's diffusion path, rotation speed, and duration are recorded, providing a complete data foundation for subsequent calculations of arc stability, contact degradation, and ablation rates.

[0033] To ensure clarity and conciseness in the description of the following embodiments, a brief introduction to the relevant terms is given first: AC excitation voltage: refers to the AC voltage applied between the contacts of a circuit breaker by a high-voltage, low-current AC system, used to initiate an electric arc between the contacts.

[0034] First excitation current: refers to the first set of currents output between the contacts. The test device generates a magnetic field perpendicular to the arc axis, causing the arc to migrate circumferentially along the contacts, thus forming a rotating arc.

[0035] Second excitation current: refers to the second set of currents output between the contacts, used to form a magnetic field that drives the arc to spread radially, so that the arc is pushed outward radially to achieve a spreading arc.

[0036] First magnetic field and second magnetic field: The first magnetic field, generated by the first excitation current, is perpendicular to the arc axis and is used to guide the arc to migrate circumferentially. The second magnetic field, generated by the second excitation current, acts on the arc radially, causing the arc to spread towards the edge of the contact. The superposition direction of the two magnetic fields can be adjusted by the amplitude ratio and phase difference to control the direction of the force on the arc.

[0037] Rotating arc: refers to the electric arc formed between the contacts of a circuit breaker, which migrates around the contacts and moves in a circular motion. The electric arc can be continuously moved along a predetermined circumferential path by controlling a magnetic field perpendicular to the arc axis.

[0038] Diffusion arc: refers to the electric arc formed between the contacts of a circuit breaker, which extends radially toward the edge of the contacts. The diffusion of the electric arc toward the edge of the contact surface is achieved by controlling a radially acting magnetic field.

[0039] Schlieren system: An optical measurement system used to acquire images of electric arcs. It obtains light refraction information by measuring grayscale changes, and then inverts and calculates the refractive index distribution and temperature parameters within the arc channel, providing basic data for arc stability analysis.

[0040] S201 is used to test a high-voltage, low-current AC control system.

[0041] In some possible implementations, S202, an excitation current is output to induce an electric arc. The AC high-voltage, low-current system outputs a first excitation current, which, through the magnetic field coil of the testing device, forms a first magnetic field perpendicular to the arc axis between the contacts, causing the arc to migrate circumferentially along the contacts to form a rotating arc. Simultaneously, a second excitation current is output, generating a second magnetic field acting radially, pushing the arc towards the edge of the contact surface. During the formation of the rotating or spreading arc, the superposition direction and intensity distribution of the two magnetic fields are changed by adjusting the amplitude ratio and phase difference of the first and second excitation currents, thus controlling the direction of the arc force. Specifically, the current amplitude can be continuously adjusted within a preset range through programming, and the phase difference can be synchronously controlled. The magnetic field control includes two sets of orthogonally arranged excitation coils, driven by a first programmable current source and a second programmable current source, respectively. The first programmable current source outputs a first excitation current, used to generate a second magnetic field in a plane perpendicular to the contact axis. The second programmable current source outputs the second excitation current to generate a radial magnetic field. In step S203, the excitation current is controlled to induce a rotating arc and a spreading arc. The output amplitude and phase of the two programmable current sources are controlled to control the direction and intensity of the synthesized magnetic field, causing the arc to migrate or spread along a predetermined path, ensuring the stability and repeatability of the rotating or spreading arc. In step S204, a schlieren system is used to collect arc temperature parameters. During arc formation and migration, the schlieren system is used to collect high-frequency images of the arc, obtaining an image frame sequence of the arc channel. Based on the grayscale changes in each frame, optical deflection information is calculated, and the deflection data is inversely transformed to obtain the refractive index distribution within the arc channel. Then, combined with a thermo-optical inversion algorithm, the arc temperature field and distribution curve are calculated, yielding the arc temperature parameters. The acquisition frequency can be set according to the arc migration speed and experimental requirements, for example, once per millisecond or at a higher frequency to capture rapidly changing temperature characteristics.

[0042] S103, based on the contact data, controls the medium-frequency low-voltage high-current system for testing, such as... Figure 3 As shown.

[0043] Under the condition of maintaining a preset contact gap, a medium-frequency low-voltage high-current test is performed on the circuit breaker contacts. The medium-frequency low-voltage high-current system includes an arc-ignition circuit and a medium-frequency oscillation circuit, which is used to simulate the medium-frequency arc characteristics under the medium-frequency breaking condition of the medium-frequency circuit breaker. During the test, the arc-ignition circuit is controlled to apply a preset arc-ignition voltage to the contacts, forming an arc-ignition current between the contacts, thereby establishing an initial arc-ignition channel and providing a guiding path for the generation of the medium-frequency arc. After the arc-ignition channel is established, the medium-frequency oscillation circuit is controlled to output a medium-frequency oscillation current within a preset frequency range, and the peak amplitude is adjusted according to the test requirements so that the medium-frequency oscillation current forms a medium-frequency arc in the arc-ignition channel to simulate the current change during the medium-frequency breaking stage of the medium-frequency circuit breaker. During the formation and maintenance of the medium-frequency arc, the testing system collects data on voltage, current, and arc maintenance characteristics between the contacts. By sampling, an arc power change curve is constructed. Based on the power curve, parameters such as energy consumption of the medium-frequency arc, contact power loss, maintenance time, arc extinguishing time, and voltage fluctuation are calculated, thereby forming electrical performance data. This provides accurate data for contact degradation analysis. After the medium-frequency arc is extinguished, the contact surface is measured to obtain the depth of micro-pits, the area of ​​erosion spots, and the amount of material spalling. At the same time, the spatial distribution information of micro-pits and erosion spots is collected. Image recognition and measurement algorithms are used to identify the depth of each micro-pit and the contour of each erosion spot, and the volume or mass of the spalled material is calculated to form contact ablation data.

[0044] To ensure clarity and conciseness in the description of the following embodiments, a brief introduction to the relevant terms is given first: Arc ignition circuit: refers to a circuit module in a medium-frequency low-voltage high-current system used to apply a preset voltage between the contacts of a circuit breaker to establish an initial arc. By controlling the voltage output between the contacts, an arc ignition current is generated between the contacts, forming an initial channel that can guide a medium-frequency arc.

[0045] Medium-frequency oscillation circuit: refers to a circuit module used in medium-frequency low-voltage high-current systems to output medium-frequency oscillation current in the arc-starting channel. It can generate a stable medium-frequency current within a preset frequency range to simulate the current change characteristics of the medium-frequency circuit breaker during the medium-frequency breaking stage, thereby initiating and maintaining a medium-frequency arc.

[0046] Preset arc ignition voltage: refers to the voltage value output by the arc ignition circuit, which is greater than the breakdown voltage threshold between the contacts. It is used to generate the initial arc ignition current between the contacts and establish an arc ignition channel, providing a path for the generation of a medium-frequency arc by the medium-frequency oscillation current.

[0047] Arc ignition current: refers to the current generated between the contacts by the arc ignition circuit, which is used to establish the arc ignition channel. This current is maintained with sufficient intensity to ensure channel stability. At the same time, controlling the current amplitude can affect the generation conditions and initial characteristics of the medium frequency arc.

[0048] Arc ignition path: refers to the conductive path established between the contacts through the arc ignition current, providing a channel for the flow of intermediate frequency oscillation current. This path determines the starting position and shape of the intermediate frequency arc and is a necessary basic structure for simulating intermediate frequency interruption conditions.

[0049] Medium-frequency oscillation current: refers to the alternating current output by the medium-frequency oscillation circuit. Its frequency and amplitude are adjustable within a preset range. It flows through the arc-starting channel to form a medium-frequency arc, simulating the current fluctuation characteristics of the medium-frequency circuit breaker during the medium-frequency breaking stage, and is used for contact electrical performance testing.

[0050] Medium-frequency arc: refers to the arc generated by medium-frequency oscillating current in the arc-ignition channel. Its characteristics include duration, energy consumption and power fluctuation. It is used to evaluate the electrical performance and ablation behavior of contacts under medium-frequency switching conditions. The collection of voltage, current and surface ablation data forms the basis for integrity performance evaluation.

[0051] S301 is used to test a medium-frequency, low-voltage, high-current system.

[0052] In some possible implementations, S302, the intermediate frequency oscillation circuit is controlled to output an intermediate frequency oscillation current to form an intermediate frequency arc. The arc-ignition circuit is controlled to apply a preset arc-ignition voltage greater than the inter-contact breakdown voltage to the contacts. Under the action of this voltage, a stable arc-ignition current is formed between the contacts. This current establishes an initial arc-ignition channel between the contacts, providing a conductive path for the intermediate frequency arc. The amplitude and duration of the arc-ignition current are adjusted by a programmable power supply. During this process, a current sensor is used for detection to ensure that the arc-ignition process is implemented according to test requirements. This step ensures that the subsequent intermediate frequency oscillation current can smoothly form an intermediate frequency arc in the arc-ignition channel and provide a stable current path, avoiding arc extinction or instability caused by excessive current fluctuations. After establishment, the intermediate frequency oscillation circuit outputs an adjustable amplitude and frequency intermediate frequency oscillation current, forming a stable intermediate frequency arc in the arc ignition channel. The intermediate frequency arc simulates the current change characteristics of the intermediate frequency circuit breaker during the intermediate frequency breaking stage. The output of the intermediate frequency oscillation circuit can be realized through closed-loop control, that is, based on current and voltage sampling, the circuit output is adjusted to ensure that the arc is maintained stably throughout the entire action cycle. The frequency of the output current is adjusted within a preset range to simulate the current fluctuation during the breaking process. By adjusting the current amplitude, the power input and heat load of the arc are controlled to ensure that the contacts are heated uniformly and repeatedly. This process fully considers the influence of the arc on the local heating of the contact surface and the melting of the material, providing an accurate experimental basis for subsequent ablation data analysis.

[0053] The S303 collects contact electrical performance data during the operation of a medium-frequency electric arc. During the operation, it continuously collects voltage, current, and arc sustaining characteristic data between the contacts, including arc sustaining time, arc extinction time, and voltage fluctuations. The acquisition frequency can be set to per millisecond or higher based on the rapid changes in the arc to ensure the capture of transient arc characteristics. Data processing includes two main directions: First, the collected voltage and current data are matched and processed to calculate the instantaneous power change of the arc during the operating cycle. By continuously detecting the power change trend over time, the energy input of the arc at different time points and the transient load characteristics of the contacts under the arc's action can be directly observed. The arc power change curve reflects the arc's intensity fluctuations, sustaining stability, and the impact on the contact material's thermal load. Using the arc power change curve, the total energy consumption of the medium-frequency arc throughout the entire operating cycle, as well as the contact... The analysis of power loss under electric arc action quantifies the arc heat load and transient power impact borne by the contact, forming the first indicator, which reflects the contact's energy bearing capacity and power loss level under medium-frequency arc conditions. Secondly, based on the collected arc duration, extinction time, and voltage fluctuation data, the stability and disappearance process of the arc throughout the entire operating cycle are analyzed. Arc duration and extinction time reveal the contact material's continuous arc bearing capacity under medium-frequency interruption conditions, while voltage fluctuation parameters reflect the contact's response to current fluctuations and the transient stability of the arc. These characteristic parameters are combined to form the second indicator, used to evaluate the contact's electrical stability under rapid current changes. Combining the first and second indicators, and through weighted or unified evaluation logic, comprehensive electrical performance data is calculated. This comprehensive performance data reflects the contact's heat load bearing capacity, electrical stability, and deterioration trend under arc action under medium-frequency interruption conditions.

[0054] S304: After the intermediate frequency arc is extinguished, contact ablation data is collected. Following arc extinguishing, a three-dimensional laser scanning device or optical measurement device is used to scan the contact surface. This scanning device can accurately acquire minute surface structural changes, collecting spatial distribution information of each micro-pit and ablation spot, including changes in location, shape, and depth. High-resolution acquisition ensures the capture of micron-level surface damage features. Image processing and spatial data analysis are performed on the collected contact surface data to identify surface depressions as micro-pits. The depth of each micro-pit is measured to obtain individual micro-pit depth information. Finally, statistical processing is performed on all micro-pit data. The average micro-pit depth or depth distribution characteristics are calculated. Using 3D scanning or optical images, the contours of the erosion spots on the contact surface are identified, and the area of ​​each erosion spot is calculated. By statistically processing all erosion spot areas, the average erosion area and the total erosion area can be obtained. The change in erosion spot area is closely related to the arc power, duration, and contact material properties. The volume or mass of the material peeled off the contact surface is measured. By comparing the changes in surface morphology before and after scanning, the 3D volume of the peeled part can be calculated, or the mass data can be obtained by density conversion. The collected data on micro-pit depth, erosion spot area, and material peeling amount are integrated and processed to form complete ablation data.

[0055] S104 processes the test data to obtain performance indicators.

[0056] After completing the above AC high-voltage low-current test and medium-frequency low-voltage high-current test, the collected arc temperature parameters, electrical performance data and ablation data are comprehensively processed to generate the performance indicators of the circuit breaker contacts.

[0057] In some possible implementation methods, the arc temperature data is preprocessed, including noise reduction, filtering, and outlier removal, to ensure the continuity and reliability of the temperature curve. The temperature data is sampled and statistically analyzed in chronological order. The average arc temperature is calculated, which is the arithmetic mean of the temperatures at all sampling points throughout the entire operating cycle, reflecting the overall thermal level of the arc. The maximum arc temperature is calculated, which is the peak value in the sampling sequence, used to measure the local transient high-temperature load of the arc. The temperature fluctuation range is calculated, which is the difference between the maximum and minimum values ​​in the temperature sequence, or the standard deviation or variance index is used to reflect the stability of the arc temperature. By normalizing the temperature mean, maximum temperature, and fluctuation range, and weighting and fusing them according to their importance in the arc stability evaluation, an arc stability index is formed. This index can simultaneously reflect the overall thermal intensity, transient peak control capability, and fluctuation stability of the arc, thus providing a comprehensive, quantitative, and reliable basis for judging the thermal stability of the contact arc bearing characteristics.

[0058] Based on the electrical performance data during the mid-frequency arcing period, the electrical performance of the contacts was analyzed. Voltage and current data were time-aligned and synchronized. The contact resistance change rate was calculated by dividing the voltage data by the current data, and the resistance change rate was statistically analyzed over the entire test cycle to obtain the resistance change trend, reflecting the degree of degradation of the contact material caused by the arcing. The voltage fluctuation amplitude was assessed by calculating the range or standard deviation of the voltage data to evaluate the contact's response stability under arcing. Power loss was calculated by multiplying the instantaneous voltage and instantaneous current to obtain the instantaneous power, and then integrating the results over the entire testing cycle. The total energy and transient load absorbed by the contact can be quantified by either division or accumulation. In order to form a unified degradation evaluation system, the three types of indicators can be normalized to give them consistent dimensions and evaluation scales. Preset weights can be assigned according to their contribution to the contact degradation mechanism. For example, the key role of the rate of change of resistance in the degradation of conductivity should be highlighted, while taking into account the impact of voltage fluctuations on stability and the correlation between power loss and thermal degradation. By weighting and fusing the three normalized parameters, a contact degradation index can be formed, which can intuitively reflect the overall degradation level of the electrical performance of the contact under medium-frequency arc conditions.

[0059] The ablation data of the contact surface is analyzed. Based on the statistically processed micro-pit data in the ablation data, the average and maximum depths of the micro-pits are calculated to reflect the local wear of the contact surface. The total and average erosion areas are obtained by statistically analyzing the areas of all erosion spots, which are used to assess the range of surface material loss. For the spalled material, the three-dimensional volume is calculated by comparing the surface morphology before and after scanning, or the mass is obtained by converting it with the material density, thus quantifying the amount of material spalling. The micro-pit depth, erosion spot area, and material spalling amount are normalized or standardized. According to the material failure mechanism and the contribution relationship of the three types of ablation features in the actual contact life decay, the micro-pit depth, erosion spot area, and material spalling amount are assigned preset weights. The depth, reflecting the local damage risk, the area, reflecting the damage coverage, and the spalling amount, reflecting the actual material loss, can all participate in the final index according to a predetermined ratio. The three normalized feature values ​​are weighted and summed to form the ablation rate index, which is used to quantify the overall ablation level of the contact under arc conditions.

[0060] S105, the performance indicators are integrated to obtain the comprehensive electrical contact performance indicators of the preset alloy material.

[0061] After calculating the arc stability index, contact deterioration index, and ablation rate index, the above three types of performance indexes are uniformly dimensionalized and integrated to obtain the comprehensive electrical contact performance index of the preset alloy material.

[0062] In some possible implementations, to integrate the arc stability index, contact degradation index, and ablation rate index within the same evaluation system, a normalization method based on interval mapping can be used for the three types of indices. First, the typical range of each type of index in the historical sample database is determined, including the estimated minimum and maximum performance values. This is used as the normalization mapping interval. The original index corresponding to the alloy material to be evaluated is linearly mapped within this interval, converting the original index into a dimension-consistent factor within a fixed numerical range. For example, a larger arc stability index indicates a more stable arc, so its normalized value is in the high range. The contact degradation index and ablation rate index can be mapped positively or negatively according to the degree of degradation and the degree of material loss, so that the normalized outputs maintain a consistent evaluation logic. Through this interval mapping method, it can be ensured that the indices obtained from different batches of materials on different testing platforms still have a uniform scale, making the three types of indices completely comparable in dimensions and avoiding evaluation deviations caused by differences in measuring equipment or testing conditions.

[0063] After normalization, in order to further develop the comprehensive electrical contact performance index of the preset alloy material, a weighted calculation method oriented towards multi-factor fusion can be adopted to reflect the contribution of different performance factors to the final electrical contact performance.

[0064] In some possible implementations, a weighting table can be established to assign corresponding weights to the arc stability factor, degradation factor, and ablation factor. The weighting configuration can be set based on the material application scenario, engineering requirements, failure mechanism analysis results, and domain experience. For example, the weight of the arc stability factor can be increased in high breaking capacity circuit breakers, the weight of the ablation factor can be increased in life-priority products, and the weight of the degradation factor can be increased in low impedance conductivity scenarios. By using a weighted summation method based on cumulative contribution, the three types of factors can be fused according to preset weights, so that the output of each factor can make a quantifiable contribution to the comprehensive performance index when weighted. The weighting calculation logic follows the principle that the higher the weight, the greater the impact on the comprehensive performance index, so that the final comprehensive electrical contact performance index can truly reflect the overall performance of the alloy material in the three performance dimensions, and achieve a unified evaluation of the material's quality.

[0065] The “AC high-voltage low-current system” and “medium-frequency low-voltage high-current system” mentioned in this application belong to system types with a clear technical context in the field of circuit breaker arc testing and electrical contact performance testing.

[0066] This application standardizes and processes the material composition, geometry, and microstructure of circuit breaker contacts. It combines a high-voltage, low-current AC system with a low-voltage, high-current medium-frequency system to achieve controllable arc rotation and radial diffusion. Using a schlieren system and 3D scanning technology, it acquires high-precision data on the arc temperature field, path, and contact surface micro-pits, erosion spots, and spalling material. Through normalized weighted fusion of arc stability, contact degradation, and ablation rate indices, a comprehensive electrical contact performance evaluation index is formed. This enables a quantitative assessment of the performance of a pre-defined alloy material under multi-dimensional arc conditions. Compared to existing technologies, this improves the accuracy and repeatability of contact performance testing and comprehensively reflects the material's thermal load bearing capacity, electrical stability, and ablation loss level under complex arc conditions. It provides a reliable basis for alloy material selection, optimization, and circuit breaker design, enhancing the engineering applicability of the testing method.

Claims

1. An electrical testing method for the electrical contact performance of alloy materials based on arc characteristics, characterized in that, Includes the following steps: Acquire circuit breaker contact data containing a preset alloy material; Based on the circuit breaker contact data, the arc generating system is controlled to ignite between the circuit breaker contacts. The arc generating system includes: an AC high-voltage low-current system and a medium-frequency low-voltage high-current system. The system controls the generation of an electric arc between the contacts of a circuit breaker by controlling a high-voltage, low-current AC system. An external magnetic field is applied to the electric arc to induce a rotating or spreading arc. During the induction of the rotating or spreading arc, the temperature parameters of the electric arc are collected using a schlieren system. The system controls the flow of current between the contacts of a medium-frequency low-voltage high-current system to simulate the medium-frequency arc induced under the medium-frequency breaking condition of the medium-frequency circuit breaker. During the induction of the medium-frequency arc, electrical performance data and ablation data of the circuit breaker contacts are collected. Statistical analysis was performed on the temperature parameters of the electric arc to calculate the arc stability index. The deterioration index of the circuit breaker contacts was calculated based on the electrical performance data, and the ablation rate index of the circuit breaker contacts was calculated based on the ablation data. The arc stability index, degradation index, and ablation rate index are weighted and calculated to obtain the corresponding electrical contact performance index, which is used to evaluate the electrical contact performance of the preset alloy material used in the circuit breaker contacts under the action of an electric arc.

2. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 1, characterized in that, When controlling an AC high-voltage, low-current system to generate an electric arc between circuit breaker contacts, and applying an external magnetic field to the arc to induce a rotating or spreading arc, the following applies: The control system for high-voltage, low-current AC circuit breakers outputs an AC excitation voltage greater than a preset voltage threshold while maintaining a preset contact gap, thereby generating an electric arc. The AC high-voltage low-current system outputs a first excitation current to form a first magnetic field perpendicular to the axial direction of the electric arc between the circuit breaker contacts; the AC high-voltage low-current system outputs a second excitation current to form a second magnetic field that pushes the electric arc to spread towards the edge of the circuit breaker contacts. The direction of the force on the electric arc is adjusted by superimposing the first and second magnetic fields, thus triggering a rotating arc or a spreading arc.

3. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 2, characterized in that, Adjusting the force direction of the electric arc based on the superposition of the first and second magnetic fields can induce a rotating or spreading arc, including: The amplitude ratio and phase difference of the first excitation current and the second excitation current are adjusted respectively to change the superposition direction of the first magnetic field and the second magnetic field; Based on the superposition direction to control the force direction of the electric arc, the electric arc migrates circumferentially along the circuit breaker contacts to induce a rotating arc; Based on the superposition direction, the force direction of the electric arc is controlled, and the electric arc is pushed outward radially to induce a diffusion arc.

4. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 1, characterized in that, During the initiation of a rotating or spreading arc, the temperature parameters of the arc are collected using a schlieren system, including: During the induction of a rotating arc or a spreading arc, an image information of the arc is acquired using a schlieren system. Based on the image information, the change in the grayscale of the blade edge is measured to obtain light deflection information. The refractive index distribution within the arc channel is obtained by inverse transformation of the light deflection information, and the temperature parameters of the arc are calculated based on the inverse calculation of the refractive index distribution.

5. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 1, characterized in that, The medium-frequency low-voltage high-current system includes an arc-starting circuit and a medium-frequency oscillation circuit, and the electrical performance data and ablation data of the circuit breaker contacts are collected using the following methods: The arc-ignition circuit is controlled to apply a preset arc-ignition voltage to the circuit breaker contacts, thereby generating an arc-ignition current between the circuit breaker contacts. An arc-starting channel is established based on the arc-starting current generated by the arc-starting circuit, and the intermediate frequency oscillation circuit is controlled to output the intermediate frequency oscillation current. An intermediate frequency electric arc is formed in the arc-starting channel based on the intermediate frequency oscillation current. During the operation of the medium-frequency electric arc, the voltage, current and arc sustaining characteristics of the circuit breaker contacts are collected as electrical performance data. After the medium-frequency arc is extinguished, the surface of the circuit breaker contacts is measured to obtain the depth of the micro-pits, the area of ​​the erosion spots, and the amount of material spalling on the contact surface, which are used as ablation data.

6. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 5, characterized in that, An arc-starting channel is established based on the arc-starting current generated by the arc-starting circuit. The intermediate-frequency oscillation circuit is controlled to output an intermediate-frequency oscillation current. An intermediate-frequency arc is formed in the arc-starting channel based on the intermediate-frequency oscillation current, including: The intermediate frequency oscillation circuit is controlled to output an intermediate frequency oscillation current within a preset frequency range. The preset frequency range of the intermediate frequency oscillation current is used to simulate the current change characteristics of the intermediate frequency circuit breaker during the intermediate frequency breaking stage. The intermediate frequency oscillation circuit is controlled to adjust the peak amplitude of the intermediate frequency oscillation current, thereby forming an intermediate frequency electric arc in the arc ignition channel.

7. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 5, characterized in that, During the operation of a medium-frequency electric arc, data on the voltage, current, and arc sustaining characteristics of the circuit breaker contacts are collected as electrical performance data, including: The intermediate frequency voltage and current of the intermediate frequency arc are sampled during the action period, and the arc power variation curve is constructed based on the intermediate frequency voltage and current. Based on the arc power variation curve, calculate the energy consumption of the medium-frequency arc and the contact power loss to form the first indicator; Based on the arc sustaining characteristic data, the sustaining time, extinction time, and voltage fluctuation data of the medium-frequency arc are calculated to form a second index. Electrical performance data are generated based on the first and second indicators of the mid-frequency electric arc.

8. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 5, characterized in that, After the medium-frequency arc is extinguished, measurements are taken on the surface of the circuit breaker contacts to obtain the depth of micro-pits, the area of ​​erosion spots, and the amount of material spalling, which are used as ablation data, including: After the medium-frequency arc is extinguished, the surface of the circuit breaker contacts is measured to obtain spatial distribution data of micro-pits and erosion spots; The spatial distribution data is processed to identify the depth of each micro-pit, calculate the depth of the micro-pit on the contact surface, identify the outline of each erosion spot, and calculate the area of ​​the erosion spot. Calculate the volume or mass of the detached material to obtain data on the amount of material detached. Data on the depth of micro-pits, area of ​​erosion spots, and amount of material spalling on the contact surface are processed to form ablation data.

9. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 1, characterized in that, Statistical analysis is performed on the temperature parameters of the electric arc to calculate the arc stability index. Based on electrical performance data, the degradation index of the circuit breaker contacts is calculated. Based on erosion data, the ablation rate index of the circuit breaker contacts is calculated, including: Statistical analysis of the temperature parameters of the electric arc is performed to calculate the mean, maximum and fluctuation range of the electric arc temperature, thus forming an electric arc stability index. Based on electrical performance data, the contact resistance change rate, voltage fluctuation amplitude, and power loss are calculated to form the degradation index of the circuit breaker contacts. Based on the ablation data, the average depth, maximum depth, area of ​​erosion spots, and amount of material spalling on the surface of the circuit breaker contacts are statistically analyzed to calculate the ablation rate index.

10. The electrical testing method for the electrical contact performance of alloy materials based on arc characteristics according to claim 1, characterized in that, The arc stability index, degradation index, and ablation rate index are weighted and calculated separately to obtain the corresponding electrical contact performance indexes, including: The arc stability index, degradation index, and ablation rate index were normalized to obtain the arc stability factor, degradation factor, and ablation factor. The electric contact performance index is obtained by weighting the arc stability factor, degradation factor and ablation factor according to the preset weights.

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